KSC-08pd2382

NASA Image and Video Library

2008-08-12

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, technicians begin lifting the cover of the Wide Field Camera 3, or WFC3, shipping container. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. WFC3 is part of the payload on the fifth and final Hubble servicing mission, STS-125, targeted for launch Oct. 8. Photo credit: NASA/Jack Pfaller

KSC-08pd2379

NASA Image and Video Library

2008-08-12

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, technicians unlatch the cover of the Wide Field Camera 3, or WFC3,shipping container before removing it. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. WFC3 is part of the payload on the fifth and final Hubble servicing mission, STS-125, targeted for launch Oct. 8. Photo credit: NASA/Jack Pfaller

VizieR Online Data Catalog: >20yrs of HST obs. of Cepheids in SNIa host gal. (Hoffmann+, 2016)

NASA Astrophysics Data System (ADS)

Hoffmann, S. L.; Macri, L. M.; Riess, A. G.; Yuan, W.; Casertano, S.; Foley, R. J.; Filippenko, A. V.; Tucker, B. E.; Chornock, R.; Silverman, J. M.; Welch, D. L.; Goobar, A.; Amanullah, R.

2017-01-01

HST observations of Cepheid variables (both archival or newly obtained) span more than two decades (1994-2016; see table 1). The earliest Cepheid observations we analyzed were obtained with the Wide Field and Planetary Camera 2 (WFPC2) as part of the initial efforts to measure H0 with HST (Freedman+ 2001ApJ...553...47F; Sandage+ 2006ApJ...653..843S) and were later used by Freedman+ (2012ApJ...758...24F) to reach beyond the LMC for the Carnegie Hubble Project. We also re-analyzed observations obtained in previous phases of our project (Riess+ 2009, J/ApJS/183/109; 2011, J/ApJ/730/119) with the Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) and/or the Wide Field Camera 3 (WFC3) Ultraviolet and Visible Channel (UVIS). Finally, we obtained new observations of nine SN Ia hosts using WFC3. We obtained the majority of our optical images with these modern cameras, 113 and 132 unique epochs with ACS and WFC3, respectively, while WFPC2 contributes a smaller fraction with 67 epochs. (6 data files).

KSC-08pd2459

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, technicians check the placement of an overhead crane to the Wide Field Camera 3, or WFC3, that will transfer the WFC3 to the Super Lightweight Interchangeable Carrier. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2469

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, an overhead crane moves the Wide Field Camera 3, or WFC3, from its stand. The WFC3 will be transferred to the Super Lightweight Interchangeable Carrier. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2451

NASA Image and Video Library

2008-08-16

CAPE CANAVERAL, Fla. – Technicians in the Payload Hazardous Servicing Facility complete removal of the protective cover from the Wide Field Camera 3, or WFC3. The WFC3 is part of the payload on space shuttle Atlantis for the fifth and final Hubble servicing mission, STS-125. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Jack Pfaller

KSC-08pd2453

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, technicians check the Wide Field Camera 3, or WFC3, after removal of its protective cover. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2454

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, technicians check the Wide Field Camera 3, or WFC3, after removal of its protective cover. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2474

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, the Wide Field Camera 3, or WFC3, is lowered onto the Super Lightweight Interchangeable Carrier. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2472

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, the Wide Field Camera 3, or WFC3, is moved toward the Super Lightweight Interchangeable Carrier. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2473

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, the Wide Field Camera 3, or WFC3, is lowered toward the Super Lightweight Interchangeable Carrier. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2471

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, an overhead crane lifts the Wide Field Camera 3, or WFC3, above the stand holding the Super Lightweight Interchangeable Carrier. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2458

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, the Wide Field Camera 3, or WFC3, is ready to be transferred to the Super Lightweight Interchangeable Carrier. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2448

NASA Image and Video Library

2008-08-16

CAPE CANAVERAL, Fla. – The Wide Field Camera 3, or WFC3, rests on a work stand in the Payload Hazardous Servicing Facility since its arrival Aug. 12. WFC3 is part of the payload on space shuttle Atlantis for the fifth and final Hubble servicing mission, STS-125. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Jack Pfaller

KSC-08pd2452

NASA Image and Video Library

2008-08-16

CAPE CANAVERAL, Fla. – Technicians in the Payload Hazardous Servicing Facility complete removal of the protective cover from the Wide Field Camera 3, or WFC3. The WFC3 is part of the payload on space shuttle Atlantis for the fifth and final Hubble servicing mission, STS-125. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Jack Pfaller

KSC-08pd2456

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, a technicians clean the radiator on the Wide Field Camera 3, or WFC3,that will be installed on NASA's Hubble Space Telescope. The radiator is the "outside" of WFC3 that will be exposed to space. It will expel heat out of Hubble and into space through black body radiation. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2460

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, the Wide Field Camera 3, or WFC3, waits to be transferred to the Super Lightweight Interchangeable Carrier. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. The part shown here is the radiator, the "outside" of WFC3 that will be exposed to space and will expel heat out of Hubble and into space through black body radiation. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2465

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, technicians observe as the Wide Field Camera 3, or WFC3, is rotated. The WFC3 will be transferred to the Super Lightweight Interchangeable Carrier. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. The curved edge shown at the back is the radiator, the "outside" of WFC3 that will be exposed to space and will expel heat out of Hubble and into space through black body radiation. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2466

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, technicians observe as the Wide Field Camera 3, or WFC3, is rotated to vertical. The WFC3 will be transferred to the Super Lightweight Interchangeable Carrier. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. The curved edge shown at top is the radiator, the "outside" of WFC3 that will be exposed to space and will expel heat out of Hubble and into space through black body radiation. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2467

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – After rotation of the Wide Field Camera 3 (background left), or WFC3, in the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, technicians check the data. The WFC3 will be transferred to the Super Lightweight Interchangeable Carrier. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. The curved edge shown at top is the radiator, the "outside" of WFC3 that will be exposed to space and will expel heat out of Hubble and into space through black body radiation. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2464

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, the Wide Field Camera 3, or WFC3, has been rotated. The WFC3 will be transferred to the Super Lightweight Interchangeable Carrier. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. The curved edge shown at top is the radiator, the "outside" of WFC3 that will be exposed to space and will expel heat out of Hubble and into space through black body radiation. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2461

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, technicians wait for the rotation of the Wide Field Camera 3, or WFC3, in order to attach a crane. The WFC3 will be transferred to the Super Lightweight Interchangeable Carrier. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. The part shown here is the radiator, the "outside" of WFC3 that will be exposed to space and will expel heat out of Hubble and into space through black body radiation. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2462

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, technicians wait for the rotation of the Wide Field Camera 3, or WFC3, in order to attach a crane. The WFC3 will be transferred to the Super Lightweight Interchangeable Carrier. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. The curved edge shown at left is the radiator, the "outside" of WFC3 that will be exposed to space and will expel heat out of Hubble and into space through black body radiation. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2463

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, technicians stand by as the Wide Field Camera 3, or WFC3, is rotated. The WFC3 will be transferred to the Super Lightweight Interchangeable Carrier. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. The curved edge shown at left is the radiator, the "outside" of WFC3 that will be exposed to space and will expel heat out of Hubble and into space through black body radiation. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2468

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, a technician guides a crane for attachment to the radiator on the Wide Field Camera 3, or WFC3. The WFC3 will be transferred to the Super Lightweight Interchangeable Carrier. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. The radiator is the "outside" of WFC3 that will be exposed to space and will expel heat out of Hubble and into space through black body radiation. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2470

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, an overhead crane lifts the Wide Field Camera 3, or WFC3, high above the floor for transfer to the Super Lightweight Interchangeable Carrier. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

KSC-08pd2457

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, a technician checks the pick-off mirror on the Wide Field Camera 3, or WFC3, that will be installed on NASA's Hubble Space Telescope. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to Hubble. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

Twelve Years of the HST Advanced Camera for Surveys : Calibration Update

NASA Astrophysics Data System (ADS)

Grogin, Norman A.

2014-06-01

The Advanced Camera for Surveys (ACS) has been a workhorse HST imager for over twelve years, subsequent to its Servicing Mission 3B installation. The once defunct ACS Wide Field Channel (WFC) has now been operating longer since its Servicing Mission 4 repair than it had originally operated prior to its 2007 failure. Despite the accumulating radiation damage to the WFC CCDs during their long stay in low Earth orbit, ACS continues to be heavily exploited by the HST community as both a prime and a parallel detector. Conspicuous examples include the recently completed HST Multi-cycle Treasury programs, and the ongoing HST Frontier Fields (HFF) program.We review recent developments in ACS calibration that enable the continued high performance of this instrument, with particular attention the to the Wide Field Channel. Highlights include: 1) the refinement of the WFC geometric distortion solution and its time dependency; 2) the efficacy of both pixel-based and catalog-based corrections for the worsening WFC charge-transfer efficiency (CTE); 3) the extension of pixel-based CTE correction to the WFC 2K subarray mode; and 4) a novel "self-calibration" technique appropriate for large-number stacks of deep WFC exposures (such as the HFF targets) that provides superior reductions compared to the standard CALACS reduction pipeline.

KSC-08pd2455

NASA Image and Video Library

2008-08-18

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, a technician cleans the edge of the radiator on the Wide Field Camera 3, or WFC3,that will be installed on NASA's Hubble Space Telescope. The radiator is the "outside" of WFC3 that will be exposed to space. It will expel heat out of Hubble and into space through black body radiation. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to NASA's Hubble Space Telescope. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller

VizieR Online Data Catalog: Hubble Tarantula Treasury Project (HTTP). III. (Sabbi+, 2016)

NASA Astrophysics Data System (ADS)

Sabbi, E.; Lennon, D. J.; Anderson, J.; Cignoni, M.; van der Marel, R. P.; Zaritsky, D.; de Marchi, G.; Panagia, N.; Gouliermis, D. A.; Grebel, E. K.; Gallagher, J. S., III; Smith, L. J.; Sana, H.; Aloisi, A.; Tosi, M.; Evans, C. J.; Arab, H.; Boyer, M.; de Mink, S. E.; Gordon, K.; Koekemoer, A. M.; Larsen, S. S.; Ryon, J. E.; Zeidler, P.

2016-02-01

Hubble Tarantula Treasury Project (HTTP; HST 12939, PI Elena Sabbi + HST 12499, PI Danny Lennon) was awarded 60 orbits of HST time in cycle 20 to survey the entire Tarantula Nebula (30 Doradus), using both the UVIS and the IR channels of the Wide Field Camera 3 (WFC3), and, in parallel, the Wide Field Channel (WFC) of the Advanced Camera for Surveys (ACS). See log of the observations (from 2011 Oct 03 to 2013 Sep 17) in table 1. (2 data files).

A New Method for Wide-field Near-IR Imaging with the Hubble Space Telescope

NASA Astrophysics Data System (ADS)

Momcheva, Ivelina G.; van Dokkum, Pieter G.; van der Wel, Arjen; Brammer, Gabriel B.; MacKenty, John; Nelson, Erica J.; Leja, Joel; Muzzin, Adam; Franx, Marijn

2017-01-01

We present a new technique for wide and shallow observations using the near-infrared channel of Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). Wide-field near-IR surveys with HST are generally inefficient, as guide star acquisitions make it impractical to observe more than one pointing per orbit. This limitation can be circumvented by guiding with gyros alone, which is possible as long as the telescope has three functional gyros. The method presented here allows us to observe mosaics of eight independent WFC3-IR pointings in a single orbit by utilizing the fact that HST drifts by only a very small amount in the 25 s between non-destructive reads of unguided exposures. By shifting the reads and treating them as independent exposures the full resolution of WFC3 can be restored. We use this “drift and shift” (DASH) method in the Cycle 23 COSMOS-DASH program, which will obtain 456 WFC3 H 160 pointings in 57 orbits, covering an area of 0.6 degree in the COSMOS field down to H 160 = 25. When completed, the program will more than triple the area of extra-galactic survey fields covered by near-IR imaging at HST resolution. We demonstrate the viability of the method with the first four orbits (32 pointings) of this program. We show that the resolution of the WFC3 camera is preserved, and that structural parameters of galaxies are consistent with those measured in guided observations.

Re-visiting the Amplifier Gains of the HST/ACS Wide Field Channel CCDs

NASA Astrophysics Data System (ADS)

Desjardins, Tyler D.; Grogin, Norman A.; ACS Team

2018-06-01

For the first time since HST Servicing Mission 4 (SM4) in May 2009, we present an analysis of the amplifier gains of the Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) CCDs. Using a series of in-flight flat-field exposures taken in November 2017 with a tungsten calibration lamp, we utilize the photon transfer method to estimate the gains of the WFC1 and WFC2 CCD amplifiers. We find evidence that the gains of the four readout amplifiers have changed by a small, but statistically significant, 1–2% since SM4. We further present a study of historical ACS/WFC observations of the globular cluster NGC 104 (47 Tuc) in an attempt to estimate the time dependence of the gains.

Status and performance of HST/Wide Field Camera 3

NASA Astrophysics Data System (ADS)

Kimble, Randy A.; MacKenty, John W.; O'Connell, Robert W.

2006-06-01

Wide Field Camera 3 (WFC3) is a powerful UV/visible/near-infrared camera currently in development for installation into the Hubble Space Telescope. WFC3 provides two imaging channels. The UVIS channel features a 4096 x 4096 pixel CCD focal plane covering 200 to 1000 nm wavelengths with a 160 x 160 arcsec field of view. The UVIS channel provides unprecedented sensitivity and field of view in the near ultraviolet for HST. It is particularly well suited for studies of the star formation history of local galaxies and clusters, searches for Lyman alpha dropouts at moderate redshift, and searches for low surface brightness structures against the dark UV sky background. The IR channel features a 1024 x 1024 pixel HgCdTe focal plane covering 800 to 1700 nm with a 139 x 123 arcsec field of view, providing a major advance in IR survey efficiency for HST. IR channel science goals include studies of dark energy, galaxy formation at high redshift, and star formation. The instrument is being prepared for launch as part of HST Servicing Mission 4, tentatively scheduled for late 2007, contingent upon formal approval of shuttle-based servicing after successful shuttle return-to-flight. We report here on the status and performance of WFC3.

New CALIPSO Data Products

Atmospheric Science Data Center

2013-07-10

... Imaging Radiometer (IIR) Level 1 and Level 2, and Wide Field-of-View Camera (WFC) Level 1 data products are now available to support near real-time weather forecasting operations and measurement field campaigns. ...

WFC3 Anomalies Flagged by the Quicklook Team

NASA Astrophysics Data System (ADS)

Gosmeyer, C. M.

2017-09-01

Like all detectors, the UVIS and IR detectors of the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope are subject to detector and optical anomalies. Many of them can be corrected for or avoided with careful planning. We summarize, with examples, the various WFC3 anomalies, which when found are flagged by the WFC3 "Quicklook" team of daily image inspectors and stored in an internal database. We also give examples of known detector features and defects, and some non-standard observing modes. The aim of this report is (1) to educate users of WFC3 to more easily assess the quality of science images and (2) to serve as a reference for the WFC3 Quicklook team members in their daily visual inspections. This report was produced by C.M. Gosmeyer and The Quicklook Team.

WFC3: SMOV and Cycle 17 Calibration Programs

NASA Astrophysics Data System (ADS)

Deustua, Susana E.; MacKenty, J.; Kimble, R.; Martel, A. R.; Baggett, S.; Barker, E.; Borders, T.; Bushouse, H.; Brown, T. M.; Dressel, L.; Dulude, M.; Hartig, G.; Hilbert, B.; Kalirai, J.; Quijano, J. Kim; Kozhurina-Platais, V.; McLean, B.; McCullough, P.; Pavlovsky, C.; Petro, L.; Pirzkal, N.; Rajan, A.; Riess, A.; Sabbi, E.; Viana, A.; Wheeler, T.; Wong, M. H.; Kuemmel, M.; Kuntschner, H.; Walsh, J.; WFC3 Team

2010-01-01

The Servicing Mission Observatory Verification (SMOV4) commissioning activities were carried out over 3 months following the installation of Wide Field Camera 3 (WFC3) into HST during Servicing Mission 4. Following SMOV4, once WFC3 was enabled for routine science observations, the WFC3 Cycle 17 Calibration program began. Both SMOV4 and Cycle 17 calibration programs characterize the UVIS and IR channels, monitor their behavior with time, and provide the reference files used in the data reduction pipeline. Comprising 43 SMOV4 and 35 Cycle 17 programs, the commissioning and calibration of WFC3 require approximately 400 orbits during its first 15 months on-orbit. This paper discusses the contents, rationale, and initial results of WFC3 SMOV4 and Cycle 17 Calibration Programs. We also highlight some issues that may affect GO programs.

WFC3: In-Flight Performance Highlights

NASA Astrophysics Data System (ADS)

Kimble, Randy A.; MacKenty, J. W.; O'Connell, R. W.; Townsend, J. A.; WFC3 Team

2010-01-01

Wide Field Camera 3 (WFC3), a powerful new imager for the Hubble Space Telescope (HST), was successfully installed in the telescope in May 2009 during the first dramatic spacewalk of space shuttle flight STS-125, also known as HST Servicing Mission 4. This new camera offers unique observing capabilities in two channels spanning a broad wavelength range from the near ultraviolet to the near infrared (200-1000nm in the UV/Visible [UVIS] channel; 850-1700nm in the IR channel). After an initial outgassing period, WFC3 was cooled to its observing configuration in June. In the following months, a highly successful Servicing Mission Observatory Verification (SMOV4) program was executed, which has confirmed the exciting scientific potential of the instrument. Detailed performance results from the SMOV4 program are presented in a number of papers in this session. In this paper, we highlight some top-level performance assessments (throughput, limiting magnitudes, survey speeds) for WFC3, which is now actively engaged in the execution of forefront astronomical observing programs.

Visible-infrared achromatic imaging by wavefront coding with wide-angle automobile camera

NASA Astrophysics Data System (ADS)

Ohta, Mitsuhiko; Sakita, Koichi; Shimano, Takeshi; Sugiyama, Takashi; Shibasaki, Susumu

2016-09-01

We perform an experiment of achromatic imaging with wavefront coding (WFC) using a wide-angle automobile lens. Our original annular phase mask for WFC was inserted to the lens, for which the difference between the focal positions at 400 nm and at 950 nm is 0.10 mm. We acquired images of objects using a WFC camera with this lens under the conditions of visible and infrared light. As a result, the effect of the removal of the chromatic aberration of the WFC system was successfully determined. Moreover, we fabricated a demonstration set assuming the use of a night vision camera in an automobile and showed the effect of the WFC system.

Fifteen Years of the Hubble Space Telescope's Advanced Camera for Surveys: Calibration Update

NASA Astrophysics Data System (ADS)

Grogin, Norman A.; Advanced CameraSurveys Instrument Team

2017-06-01

The Advanced Camera for Surveys (ACS) has been a workhorse HST imager for over fifteen years, subsequent to its Servicing Mission 3B installation in 2002. The once defunct ACS Wide Field Channel (WFC) has now been operating almost twice as long (>8yrs) since its Servicing Mission 4 (SM4) repair than it had originally operated prior to its 2007 failure. Despite the accumulating radiation damage to the WFC CCDs during their long stay in low Earth orbit, ACS continues to be heavily exploited by the HST community as both a prime and a parallel detector.The past year has seen several advancements in ACS data acquisition and calibration capabilities: the mostwidespread changes since shortly after SM4. We review these recent developments that enable the continued high performance of this instrument, including both the WFC and the Solar Blind Channel (SBC). Highlightsinclude: 1) implementaton of new WFC subarray modes to allow for more consistent high-fidelity calibration; 2) a thorough modernization of the original pixel-based correction of WFC charge-transfer efficiency decline; 3)"save the pixels" initiatives resulting in much less WFC bad-pixel flagging via hot-pixel stability analyses and readout-dark modeling; and 4) a new initiative to provide improved PSF estimates via empirical fitting to the full ACS archive of nearly 200,000 images.

Pixel Stability in the Hubble Space Telescope WFC3/UVIS Detector

NASA Astrophysics Data System (ADS)

Bourque, Matthew; Baggett, Sylvia M.; Borncamp, David; Desjardins, Tyler D.; Grogin, Norman A.; Wide Field Camera 3 Team

2018-06-01

The Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) Ultraviolet-Visible (UVIS) detector has acquired roughly 12,000 dark images since the installation of WFC3 in 2009, as part of a daily monitoring program to measure the instrinsic dark current of the detector. These images have been reconfigured into 'pixel history' images in which detector columns are extracted from each dark and placed into a new time-ordered array, allowing for efficient analysis of a given pixel's behavior over time. We discuss how we measure each pixel's stability, as well as plans for a new Data Quality (DQ) flag to be introduced in a future release of the WFC3 calibration pipeline (CALWF3) for flagging pixels that are deemed unstable.

Updated MDRIZTAB Parameters for ACS/WFC

NASA Astrophysics Data System (ADS)

Hoffman, S. L.; Avila, R. J.

2017-03-01

The Mikulski Archive for Space Telescopes (MAST) pipeline performs geometric distortion corrections, associated image combinations, and cosmic ray rejections with AstroDrizzle. The MDRIZTAB reference table contains a list of relevant parameters that controls this program. This document details our photometric analysis of Advanced Camera for Surveys Wide Field Channel (ACS/WFC) data processed by AstroDrizzle. Based on this analysis, we update the MDRIZTAB table to improve the quality of the drizzled products delivered by MAST.

VizieR Online Data Catalog: HST BVI catalogue of star clusters in 5 HCGs (Fedotov+, 2015)

NASA Astrophysics Data System (ADS)

Fedotov, K.; Gallagher, S. C.; Durrell, P. R.; Bastian, N.; Konstantopoulos, I. S.; Charlton, J.; Johnson, K. E.; Chandar, R.

2015-11-01

The data for this project were obtained with the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFC3). These observations are part of two programmes: ID 10787 (PI J. Charlton) and ID 11502 (PI K. Noll). The observations were carried out in the F435W (F438W for WFC3), F606W, and F814W filters, which are similar to the Johnson BVI bands. Hereafter, we refer to the HST filters as B435, B438, V606, and I814, although we did not make transformations to the Johnson-Cousins system. (2 data files).

WFC3: Precision Infrared Spectrophotometry with Spatial Scans of HD 189733b and Vega

NASA Astrophysics Data System (ADS)

McCullough, Peter R.; Crouzet, N.; Deming, D.; Madhusudhan, N.; Deustua, S. E.; WFC3

2014-01-01

The Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) now routinely provides near-infrared spectroscopy of transiting extrasolar planet atmospheres with better than ~50 ppm precision per 0.05-micron resolution bin per transit, for sufficiently bright host stars. Two improvements of WFC3 (the detector) and HST (the spatial scanning technique) have made transiting planet spectra more sensitive and more repeatable than was feasible with NICMOS. In addition, the data analysis is much simpler with WFC3 than with NICMOS. We present time-series spectra of HD 189733b from 1.1 to 1.7 microns in transit and eclipse with fidelity similar to that of the WFC3 transit spectrum of HD 209458b (Deming et al. 2013). In a separate program, we obtained scanned infrared spectra of the bright star, Vega, thereby extending the dynamic range of WFC3 to ~26 magnitudes! Analysis of these data will affect the absolute spectrophotometric calibration of the WFC3, placing it on an SI traceable scale.

Here Be Dragons: Characterization of ACS/WFC Scattered Light Anomalies

NASA Astrophysics Data System (ADS)

Porterfield, B.; Coe, D.; Gonzaga, S.; Anderson, J.; Grogin, N.

2016-11-01

We present a study characterizing scattered light anomalies that occur near the edges of Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) images. We inspected all 8,573 full-frame ACS/WFC raw images with exposure times longer than 350 seconds obtained in the F606W and F814W filters from 2002 to October 2013. We visually identified two particular scattered light artifacts known as "dragon's breath" and edge glow. Using the 2MASS point source catalog and Hubble Guide Star Catalog (GSC II), we identified the stars that caused these artifacts. The stars are all located in narrow bands ( 3" across) just outside the ACS/WFC field of view (2" - 16" away). We provide a map of these risky areas around the ACS/WFC detectors - users should avoid positioning bright stars in these regions when designing ACS/WFC imaging observations. We also provide interactive webpages which display all the image artifacts we identified, allowing users to see examples of the severity of artifacts they might expect for a given stellar magnitude at a given position relative to the ACS/WFC field of view. On average, 10th (18th) magnitude stars produce artifacts about 1,000 (100) pixels long. But the severity of these artifacts can vary strongly with small positional shifts (∼ 1"). The results are similar for both filters (F606W and F814W) when expressed in total fluence, or flux multiplied by exposure time.

Identification of Active Galactic Nuclei through HST optical variability in the GOODS South field

NASA Astrophysics Data System (ADS)

Pouliasis, Ektoras; Georgantopoulos; Bonanos, A.; HCV Team

2016-08-01

This work aims to identify AGN in the GOODS South deep field through optical variability. This method can easily identify low-luminosity AGN. In particular, we use images in the z-band obtained from the Hubble Space Telescope with the ACS/WFC camera over 5 epochs separated by ~45 days. Aperture photometry has been performed using SExtractor to extract the lightcurves. Several variability indices, such as the median absolute deviation, excess variance, and sigma were applied to automatically identify the variable sources. After removing artifacts, stars and supernovae from the variable selected sample and keeping only those sources with known photometric or spectroscopic redshift, the optical variability was compared to variability in other wavelengths (X-rays, mid-IR, radio). This multi-wavelength study provides important constraints on the structure and the properties of the AGN and their relation to their hosts. This work is a part of the validation of the Hubble Catalog of Variables (HCV) project, which has been launched at the National Observatory of Athens by ESA, and aims to identify all sources (pointlike and extended) showing variability, based on the Hubble Source Catalog (HSC, Whitmore et al. 2015). The HSC version 1 was released in February 2015 and includes 80 million sources imaged with the WFPC2, ACS/WFC, WFC3/UVIS and WFC3/IR cameras.

Sixteen Years of the Hubble Space Telescope's Advanced Camera for Surveys: Calibration Update

NASA Astrophysics Data System (ADS)

Grogin, Norman A.; ACS Instrument Team

2018-06-01

The Advanced Camera for Surveys (ACS) has been a workhorse HST imager for over sixteen years, subsequent to its Servicing Mission 3B installation in 2002. The once defunct ACS Wide Field Channel (WFC) has now been operating nearly twice as long (>9yrs) since its Servicing Mission 4 (SM4) repair than it had originally operated prior to its 2007 failure. Despite the accumulating radiation damage to the WFC CCDs during their long stay in low Earth orbit, ACS continues to be heavily exploited by the HST community as both a prime and a parallel detector.During past year, there have been two new releases of the CALACS image reduction pipeline that have incorporated several recent advancements in ACS calibration capabilities. We review these updates, along with the enhanced calibration reference files (superbiases, superdarks, etc.) associated with these CALACS releases. We also present results from long-term monitoring of WFC dark current and readout noise, and from new studies of detector performance from both WFC and the ACS Solar Blind Channel (SBC). Highlights include: 1) improved characterization of WFC post-flash LED illumination, including a low-level annual modulation of LED intensity; 2) comprehensive assessment of SBC dark current as a function of detector operating temperature, and of SBC operating temperature versus duration of use; and 3) an update to the WFC bad-pixel table resulting from a minor particulate-contamination event in May 2017.

VizieR Online Data Catalog: HST observations of star clusters in NGC 3256 (Mulia+, 2016)

NASA Astrophysics Data System (ADS)

Mulia, A. J.; Chandar, R.; Whitmore, B. C.

2016-09-01

Our observations come from the ACS on Hubble Space Telescope (HST). NGC 3256 was observed using the filters F555W (~V in the Johnson-Cousins system; exposed for 2552s), FR656N (Hα; 2552s), and F330W (~U; 11358s) as part of the program GO-9735 (PI: Whitmore). The V and U band images were taken in 2003 November using the Wide Field Camera (WFC) and High Resolution Camera (HRC), respectively. The Hα observations were taken in 2004 March. WFC observations using F435W (~B) and F814W (~I) filters were taken in 2005 November as part of program GO-10592 (PI: Evans) for 1320 and 760s, respectively. (1 data file).

Accounting for Dark Current Accumulated during Readout of Hubble's ACS/WFC Detectors

NASA Astrophysics Data System (ADS)

Ryon, Jenna E.; Grogin, Norman A.; Coe, Dan A.; ACS Team

2018-06-01

We investigate the properties of excess dark current accumulated during the 100-second full-frame readout of the Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) detectors. This excess dark current, called "readout dark", gives rise to ambient background gradients and hot columns in each ACS/WFC image. While readout dark signal is removed from science images during the bias correction step in CALACS, the additional noise from the readout dark is currently not taken into account. We develop a method to estimate the readout dark noise properties in ACS/WFC observations. We update the error (ERR) extensions of superbias images to include the appropriate noise from the ambient readout dark gradient and stable hot columns. In recent data, this amounts to about 5 e-/pixel added variance in the rows farthest from the WFC serial registers, and about 7 to 30 e-/pixel added variance along the stable hot columns. We also flag unstable hot columns in the superbias data quality (DQ) extensions. The new reference file pipeline for ACS/WFC implements these updates to our superbias creation process.

HST/WFC3: Understanding and Mitigating Radiation Damage Effects in the CCD Detectors

NASA Astrophysics Data System (ADS)

Baggett, S.; Anderson, J.; Sosey, M.; MacKenty, J.; Gosmeyer, C.; Noeske, K.; Gunning, H.; Bourque, M.

2015-09-01

At the heart of the Hubble Space Telescope Wide Field Camera 3 (HST/WFC3) UVIS channel resides a 4096x4096 pixel e2v CCD array. While these detectors are performing extremely well after more than 5 years in low-earth orbit, the cumulative effects of radiation damage cause a continual growth in the hot pixel population and a progressive loss in charge transfer efficiency (CTE) over time. The decline in CTE has two effects: (1) it reduces the detected source flux as the defects trap charge during readout and (2) it systematically shifts source centroids as the trapped charge is later released. The flux losses can be significant, particularly for faint sources in low background images. Several mitigation options exist, including target placement within the field of view, empirical stellar photometric corrections, post-flash mode and an empirical pixel-based CTE correction. The application of a post-flash has been remarkably effective in WFC3 at reducing CTE losses in low background images for a relatively small noise penalty. Currently all WFC3 observers are encouraged to post-flash images with low backgrounds. Another powerful option in mitigating CTE losses is the pixel-based CTE correction. Analagous to the CTE correction software currently in use in the HST Advanced Camera for Surveys (ACS) pipeline, the algorithm employs an empirical observationally-constrained model of how much charge is captured and released in order to reconstruct the image. Applied to images (with or without post-flash) after they are acquired, the software is currently available as a standalone routine. The correction will be incorporated into the standard WFC3 calibration pipeline.

Images and Spectral Performance of WFC3 Interference Filters

NASA Technical Reports Server (NTRS)

Quijada, Manuel A.; Boucarut, R.; Telfer, R.; Baggett, S.; Quijano, J. Kim; Allen, George; Arsenovic, Peter

2006-01-01

The Wide Field Camera 3 (WFC3) is a panchromatic imager that will be deployed in the Hubble Space Telescope (HST). The mission of the WFC3 is to enhance HST1s imaging capability in the ultraviolet, visible and near-infrared spectral regions. Together with a wavelength coverage spanning 2000A to 1.7 micron, the WFC3 high sensitivity, high spatial resolution, and large field-of-view provide the astronomer with an unprecedented set of tools for exploring all types of exciting astrophysical terrain and for addressing many key questions in astronomy today. The filter compliment, which includes broad, medium, and narrow band filters, naturally reflects the diversity of astronomical programs to be targeted with WFC3. The WFC3 holds 61 UVIS filters elements, 14 IR filters, and 3 dispersive elements. During ground testing, the majority of the UVIS filters were found to exhibit excellent performance consistent with or exceeding expectations; however, a subset of filters showed considerable ghost images; some with relative intensity as high as 10-15%. Replacement filters with band-defining coatings that substantially reduce these ghost images were designed and procured. A state-of-the-art characterization setup was developed to measured the intensity of ghost images, focal shift, wedge direction , transmitted uniformity and surface feature of filters that could effect uniform flat field images. We will report on this new filter characterization methods, as well as the spectral performance measurements of the in-band transmittance and blocking.

HST/WFC3: understanding and mitigating radiation damage effects in the CCD detectors

NASA Astrophysics Data System (ADS)

Baggett, S. M.; Anderson, J.; Sosey, M.; Gosmeyer, C.; Bourque, M.; Bajaj, V.; Khandrika, H.; Martlin, C.

2016-07-01

At the heart of the Hubble Space Telescope Wide Field Camera 3 (HST/WFC3) UVIS channel is a 4096x4096 pixel e2v CCD array. While these detectors continue to perform extremely well after more than 7 years in low-earth orbit, the cumulative effects of radiation damage are becoming increasingly evident. The result is a continual increase of the hotpixel population and the progressive loss in charge-transfer efficiency (CTE) over time. The decline in CTE has two effects: (1) it reduces the detected source flux as the defects trap charge during readout and (2) it systematically shifts source centroids as the trapped charge is later released. The flux losses can be significant, particularly for faint sources in low background images. In this report, we summarize the radiation damage effects seen in WFC3/UVIS and the evolution of the CTE losses as a function of time, source brightness, and image-background level. In addition, we discuss the available mitigation options, including target placement within the field of view, empirical stellar photometric corrections, post-flash mode and an empirical pixel-based CTE correction. The application of a post-flash has been remarkably effective in WFC3 at reducing CTE losses in low-background images for a relatively small noise penalty. Currently, all WFC3 observers are encouraged to consider post-flash for images with low backgrounds. Finally, a pixel-based CTE correction is available for use after the images have been acquired. Similar to the software in use in the HST Advanced Camera for Surveys (ACS) pipeline, the algorithm employs an observationally-defined model of how much charge is captured and released in order to reconstruct the image. As of Feb 2016, the pixel-based CTE correction is part of the automated WFC3 calibration pipeline. Observers with pre-existing data may request their images from MAST (Mikulski Archive for Space Telescopes) to obtain the improved products.

The Hubble Space Telescope extragalactic distance scale key project. 2: Photometry of WFC images of M81

NASA Technical Reports Server (NTRS)

Hughes, Shaun M. G.; Stetson, Peter B.; Turner, Anne; Kennicutt, Robert C., Jr.; Hill, Robert; Lee, Myung Gyoon; Freedman, Wendy L.; Mould, Jeremy R.; Madore, Barry F.; Ferrarese, Laura

1994-01-01

The Extragalactic Distance Scale (H(sub o)) Key Project for Hubble Space Telescope (HST) aims to employ the Cepheid period-luminosity (P-L) relation to measure galaxy distances out as far as the Virgo Cluster. The vital steps in this program are (1) to obtain precise photometry of stellar images from the Wide Field Camera (WFC) exposures of selected galaxies, and (2) to calibrate this photometry to obtain reliable distances to these galaxies from the Cepheid P-L relation. We have used the DAOPHOT II and ALLFRAME programs to determine 28 instrumental magnitudes -- 22 of F555W (of about V) and six of F785LP (of about I) -- of all stars brighter than V of about 25 in each of two 2.56 arcmin x 2.56 arcmin WFC fields of M81. The reductions use a varying point-spread function to account for the field effects in the WFC optics and yield instrumental magnitudes with single epoch precision ranging from 0.09 to 0.24 mag, at V of about 21.8 to 23.8 -- the magnitude range of the 30 Cepheids that we have now identified in M81. For brighter stars (V of about 22), single epoch magnitudes are precise to 0.09 mag. The photometric calibration onto the Johnson V and Kron-Cousins I systems was determined from independent ground-based CCD observing at the Canada-France-Hawaii Telescope (CFHT) 3.6 m (confirmed by the Kitt Peak National Observatory (KPNO) 4.0 m) and from the Palomar 5.0 m (using the wide-field COSMIC camera) and 1.5 m telescopes. Secondary standards, taken from the COSMIC and CFHT frames, were established in each of the WFC fields in V and I, allowing a direct transformation from ALLFRAME magnitudes to calibrated V and I magnitudes, giving mean V of about 23 magnitudes accurate to of about +/- 0.1 mag. The stellar populations in M81 have been analyzed in terms of the luminosity functions and color magnitude diagrams (CMD) derived from these data, from which we identify numerous supergiants, and a CMD morphology similar to M33.

HST/WFC3 Characteristics: gain, post-flash stability, UVIS low-sensitivity pixels, persistence, IR flats and bad pixel table

NASA Astrophysics Data System (ADS)

Gunning, Heather C.; Baggett, Sylvia; Gosmeyer, Catherine M.; Long, Knox S.; Ryan, Russell E.; MacKenty, John W.; Durbin, Meredith

2015-08-01

The Wide Field Camera 3 (WFC3) is a fourth-generation imaging instrument on the Hubble Space Telescope (HST). Installed in May 2009, WFC3 is comprised of two observational channels covering wavelengths from UV/Visible (UVIS) to infrared (IR); both have been performing well on-orbit. We discuss the gain stability of both WFC3 channel detectors from ground testing through present day. For UVIS, we detail a low-sensitivity pixel population that evolves during the time between anneals, but is largely reset by the annealing procedure. We characterize the post-flash LED lamp stability, used and recommended to mitigate CTE effects for observations with less than 12e-/pixel backgrounds. We present mitigation options for IR persistence during and after observations. Finally, we give an overview on the construction of the IR flats and provide updates on the bad pixel table.

Charge transfer efficiency in HST WFC3/UVIS: monitoring and mitigation

NASA Astrophysics Data System (ADS)

Baggett, Sylvia M.; Anderson, Jay; Sosey, Megan L.; Bourque, Matthew; Martlin, Catherine; Kurtz, Heather; Shanahan, Clare; Kozhurina-Platais, Vera; Sabbi, Elena; WFC3 Team

2017-01-01

The UVIS channel of the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) contains a 4096x4096 pixel e2v CCD array. The detectors have been performing well on-orbit but as expected, are exhibiting the cumulative effects of radiation damage. The result is a growing hot pixel population and declining charge transfer efficiency. We summarize the progression of the CTE losses, their effects on science data, and discuss two of the primary mitigation options: post-flash and a pixel-based CTE correction. The latter is now part of the automated WFC3 calibration pipeline in the Mikulski Archive for Space Telescopes (MAST), providing observers with both standard and CTE-corrected data products.

Go Long! Identifying Distant Brown Dwarfs in HST/WFC3 Parallel Field

NASA Astrophysics Data System (ADS)

Aganze, Christian; Burgasser, Adam J.; Malkan, Matthew Arnold; Masters, Daniel C.; Mercado, Gretel; Suarez, Adrian; Tamiya, Tomoki

2016-01-01

The spatial distribution of brown dwarfs beyond the local Solar Neighborhood is crucial for understanding their Galactic formation, dynamical and evolutionary history. Wide-field red optical and infrared surveys (e.g., 2MASS, SDSS, WISE) have enabled measures of the local density of brown dwarfs, but probe a relatively shallow (˜100 parsecs) volume; few constraints exist for the scale height or radial distributions of these low mass and low luminosity objects. We have searched ~1400 square arcminutes of WFC3 Infrared Spectroscopic Parallel Survey (WISPS) data to identify distant brown dwarfs (d > 300 pc) with near-infrared grism spectra from the the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3). Using spectral indices to identify candidates, measure spectral types and estimate distances, and comparing the WFC3 spectra to spectral templates in the SpeX Prism Library, we report our first results from this work, the discovery of ~50 late-M, L and T dwarfs with distances of 30 - 1000+ pc. We compare the distance and spectral type distribution to population simulations, and discuss current selection biases.The material presented here is based on work supported by the National Aeronautics and Space Administration under Grant No. NNX15AI75G

Practical Cleanroom Operations Constraints

NASA Technical Reports Server (NTRS)

Hughes, David; Ginyard, Amani

2007-01-01

This viewgraph presentation reviews the GSFC Cleanroom Facility i.e., Spacecraft Systems Development and Integration Facility (SSDIF) with particular interest in its use during the development of the Wide Field Camera 3 (WFC3). The SSDIF is described and a diagram of the SSDIF is shown. A Constraint Table was created for consistency within Contamination Control Team. This table is shown. Another table that shows the activities that were allowed during the integration under given WFC3 condition and activity location is presented. Three decision trees are shown for different phases of the work: (1) Hardware Relocation, Hardware Work, and Contamination Control Operations.

Swimming in Sculptor

NASA Image and Video Library

2016-03-07

Peering deep into the early Universe, this picturesque parallel field observation from the NASA/ESA Hubble Space Telescope reveals thousands of colourful galaxies swimming in the inky blackness of space. A few foreground stars from our own galaxy, the Milky Way, are also visible. In October 2013 Hubble’s Wide Field Camera 3 (WFC3) and Advanced Camera for Surveys (ACS) began observing this portion of sky as part of the Frontier Fields programme. This spectacular skyscape was captured during the study of the giant galaxy cluster Abell 2744, otherwise known as Pandora’s Box. While one of Hubble’s cameras concentrated on Abell 2744, the other camera viewed this adjacent patch of sky near to the cluster. Containing countless galaxies of various ages, shapes and sizes, this parallel field observation is nearly as deep as the Hubble Ultra-Deep Field. In addition to showcasing the stunning beauty of the deep Universe in incredible detail, this parallel field — when compared to other deep fields — will help astronomers understand how similar the Universe looks in different directions

Implementation of PSF engineering in high-resolution 3D microscopy imaging with a LCoS (reflective) SLM

NASA Astrophysics Data System (ADS)

King, Sharon V.; Doblas, Ana; Patwary, Nurmohammed; Saavedra, Genaro; Martínez-Corral, Manuel; Preza, Chrysanthe

2014-03-01

Wavefront coding techniques are currently used to engineer unique point spread functions (PSFs) that enhance existing microscope modalities or create new ones. Previous work in this field demonstrated that simulated intensity PSFs encoded with a generalized cubic phase mask (GCPM) are invariant to spherical aberration or misfocus; dependent on parameter selection. Additional work demonstrated that simulated PSFs encoded with a squared cubic phase mask (SQUBIC) produce a depth invariant focal spot for application in confocal scanning microscopy. Implementation of PSF engineering theory with a liquid crystal on silicon (LCoS) spatial light modulator (SLM) enables validation of WFC phase mask designs and parameters by manipulating optical wavefront properties with a programmable diffractive element. To validate and investigate parameters of the GCPM and SQUBIC WFC masks, we implemented PSF engineering in an upright microscope modified with a dual camera port and a LCoS SLM. We present measured WFC PSFs and compare them to simulated PSFs through analysis of their effect on the microscope imaging system properties. Experimentally acquired PSFs show the same intensity distribution as simulation for the GCPM phase mask, the SQUBIC-mask and the well-known and characterized cubic-phase mask (CPM), first applied to high NA microscopy by Arnison et al.10, for extending depth of field. These measurements provide experimental validation of new WFC masks and demonstrate the use of the LCoS SLM as a WFC design tool. Although efficiency improvements are needed, this application of LCoS technology renders the microscope capable of switching among multiple WFC modes.

Analysis of Dragon's Breath and Scattered Light Detector Anomalies on WFC3/UVIS

NASA Astrophysics Data System (ADS)

Fowler, Julia; Markwardt, Larissa; Bourque, Matthew; Anderson, Jay

2017-02-01

We summarize the examination of the light anomalies known as Dragon's Breath and Scattered Light for the UVIS channel of Wide Field Camera 3 (WFC3) of the Hubble Space Telescope (HST). We present three methods for WFC3 users to help avoid these effects during observation planning. We analyzed all of the full-frame wide and long pass filters with exposure times ≥ 300 seconds, comprising ∼13% of WFC3/UVIS on-orbit data (∼20% of all full-frame data, and ∼35% of all full-frame ≥300 second exposures.) We find that stars producing Dragon's Breath peak at specific orientations to the detector and V-band magnitudes. The bulk of these stars fall along the vertical and horizontal edges, within ∼490 pixels of the image frame. The corners of the detector show significantly fewer instances of Dragon's Breath and Scattered Light, though still a few occurrences. Furthermore, matching stars outside the field of the image to V-band magnitude data from the Hubble Guide Star Catalog II (GSC-II) shows that stars causing the anomaly consistently peak around a V-band magnitude of 11.9 or 14.6, whereas the general trend of objects lying outside the field instead peaks around a magnitude of 16.5 within our exposure time and filter selection.

Theoretical colours and isochrones for some Hubble Space Telescope colour systems

NASA Technical Reports Server (NTRS)

Edvardsson, B.; Bell, R. A.

1989-01-01

Synthetic spectra for effective temperatures of 4000-7250 K, logarithmic surface gravities typical of dwarfs and subgiants, and metallicities from solar values to 0.001 of the solar metallicity were used to derive a grid of synthetic surface brightness magnitudes for 21 of the Hubble Space Telescope Wide Field Camera (WFC) band passes. The absolute magnitudes of these 21 band passes are also obtained for a set of globular cluster isochrones with different helium abundances, metallicities, oxygen abundances, and ages. The usefulness and efficiency of different sets of broad and intermediate bandwidth WFC colors for determining ages and metallicities for globular clusters are evaluated.

Hubble Space Telescope Discovery of a Probable Caustic-Crossing Event in the MACS1149 Galaxy Cluster Field

NASA Astrophysics Data System (ADS)

Kelly, Patrick L.; Rodney, Steven; Diego, Jose Maria; Zitrin, Adi; Broadhurst, Tom; Selsing, Jonatan; Balestra, Italo; Benito, Alberto Molino; Bradac, Marusa; Bradley, Larry; Brammer, Gabriel; Cenko, Brad; Christensen, Lise; Coe, Dan; Filippenko, Alexei V.; Foley, Ryan; Frye, Brenda; Graham, Melissa; Graur, Or; Grillo, Claudio; Hjorth, Jens; Howell, Andy; Jauzac, Mathilde; Jha, Saurabh; Kaiser, Nick; Kawamata, Ryota; Kneib, Jean-Paul; Lotz, Jennifer; Matheson, Thomas; McCully, Curtis; Merten, Julian; Nonino, Mario; Oguri, Masamune; Richard, Johan; Riess, Adam; Rosati, Piero; Schmidt, Kasper Borello; Sharon, Keren; Smith, Nathan; Strolger, Lou; Treu, Tommaso; Wang, Xin; Weiner, Ben; Williams, Liliya; Zheng, Weikang

2016-05-01

While monitoring the MACS1149 (z = 0.54) galaxy cluster as part of the RefsdalRedux program (PID 14199; PI Kelly) with the Hubble Space Telescope (HST) WFC3 IR camera, we have detected a rising transient that appears to be coincident ( Target-of-opportunity optical follow-up imaging in several ACS and WFC3 bands with the FrontierSN program (PID 14208; PI Rodney) has revealed that its rest-frame ultraviolet through optical spectrum may be reasonably well fit with that of a B star at z=1.49 exhibiting a strong Balmer break.

Improving Image Drizzling in the HST Archive: Advanced Camera for Surveys

NASA Astrophysics Data System (ADS)

Hoffmann, Samantha L.; Avila, Roberto J.

2017-06-01

The Mikulski Archive for Space Telescopes (MAST) pipeline performs geometric distortion corrections, associated image combinations, and cosmic ray rejections with AstroDrizzle on Hubble Space Telescope (HST) data. The MDRIZTAB reference table contains a list of relevant parameters that controls this program. This document details our photometric analysis of Advanced Camera for Surveys Wide Field Channel (ACS/WFC) data processed by AstroDrizzle. Based on this analysis, we update the MDRIZTAB table to improve the quality of the drizzled products delivered by MAST.

VizieR Online Data Catalog: Young stellar objects in NGC 6823 (Riaz+, 2012)

NASA Astrophysics Data System (ADS)

Riaz, B.; Martin, E. L.; Tata, R.; Monin, J.-L.; Phan-Bao, N.; Bouy, H.

2016-10-01

The optical V-, R- and I-band images were obtained using the Prime Focus camera [William Herschel Telescope (WHT)/Wide Field Camera (WFC) detector] mounted on 4-m WHT in La Palma, Canary Islands, Spain. Observations were performed in 2005 May, The NIR J-, H-, Ks-band images were obtained using the Infrared Side Port Imager (ISPI) mounted on Cerro Tololo Inter-American Observatory (CTIO) 4-m Blanco Telescope in Cerro Tololo, Chile. Observations were performed in 2007 March. (3 data files).

Wayne—A Simulator for HST   WFC3 IR Grism Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varley, R.; Tsiaras, A.; Karpouzas, K., E-mail: r.varley@ucl.ac.uk

Wayne is an algorithm that simulates Hubble Space Telescope Wide Field Camera 3 (WFC3) grism spectroscopic frames, including sources of noise and systematics. It can simulate both staring and spatial scan modes, and observations such as the transit and the eclipse of an exoplanet. Unlike many other instrument simulators, the focus of Wayne is on creating frames with realistic systematics in order to test the effectiveness of different data analysis methods in a variety of different scenarios. This approach is critical for method validation and optimizing observing strategies. In this paper we describe the implementation of Wayne for WFC3 inmore » the near-infrared channel with the G102 and G141 grisms. We compare the simulations to real data obtained for the exoplanet HD 209458b, to verify the accuracy of the simulation. The software is now available as open source at https://github.com/ucl-exoplanets/wayne.« less

ON THE BINARY FREQUENCY OF THE LOWEST MASS MEMBERS OF THE PLEIADES WITH HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia, E. V.; Dupuy, Trent J.; Allers, Katelyn N.

2015-05-01

We present the results of a Hubble Space Telescope Wide Field Camera 3 (WFC3) imaging survey of 11 of the lowest mass brown dwarfs in the Pleiades known (25–40 M{sub Jup}). These objects represent the predecessors to T dwarfs in the field. Using a semi-empirical binary point-spread function (PSF)-fitting technique, we are able to probe to 0.″ 03 (0.75 pixel), better than 2x the WFC3/UVIS diffraction limit. We did not find any companions to our targets. From extensive testing of our PSF-fitting method on simulated binaries, we compute detection limits which rule out companions to our targets with mass ratiosmore » of ≳0.7 and separations ≳4 AU. Thus, our survey is the first to attain the high angular resolution needed to resolve brown dwarf binaries in the Pleiades at separations that are most common in the field population. We constrain the binary frequency over this range of separation and mass ratio of 25–40 M{sub Jup} Pleiades brown dwarfs to be <11% for 1σ (<26% at 2σ). This binary frequency is consistent with both younger and older brown dwarfs in this mass range.« less

Advanced Camera for Surveys Instrument Handbook for Cycle 25 v. 16.0

NASA Astrophysics Data System (ADS)

Avila, R. J.

2017-01-01

The Advanced Camera for Surveys (ACS), a third-generation instrument, was installed in the Hubble Space Telescope during Servicing Mission 3B, on March 7, 2002. Its primary purpose was to increase HST imaging discovery efficiency by about a factor of 10, with a combination of detector area and quantum efficiency that surpasses previous instruments. ACS has three independent cameras that have provided wide-field, high resolution, and ultraviolet imaging capabilities respectively, using a broad assortment of filters designed to address a large range of scientific goals. In addition, coronagraphic, polarimetric, and grism capabilities have made the ACS a versatile and powerful instrument. The ACS Instrument Handbook, which is maintained by the ACS Team at STScI, descr ibes the instrument properties, performance, operations, and calibration. It is the basic technical reference manual for the instrument, and should be used with other documents (listed in Table 1.1) for writing Phase I proposals, detailed Phase II programs, and for data analysis. (See Figure 1.1). In May 2009, Servicing Mission 4 (SM4) successfully restored the ACS Wide Field Camera (WFC) to regular service after its failure in January 2007. Unfortunately, the ACS High Resolution Camera (HRC) was not restored to operation during SM4, so it cannot be proposed for new observations. Nevertheless, this handbook retains description of the HRC to support analysis of archived observations. The ACS Solar Blind Channel (SBC) was unaffected by the January 2007 failure of WFC and HRC. The SBC has remained in steady operation, and was not serviced during SM4. It remains available for new observations.

OP09O-OP404-9 Wide Field Camera 3 CCD Quantum Efficiency Hysteresis

NASA Technical Reports Server (NTRS)

Collins, Nick

2009-01-01

The HST/Wide Field Camera (WFC) 3 UV/visible channel CCD detectors have exhibited an unanticipated quantum efficiency hysteresis (QEH) behavior. At the nominal operating temperature of -83C, the QEH feature contrast was typically 0.1-0.2% or less. The behavior was replicated using flight spare detectors. A visible light flat-field (540nm) with a several times full-well signal level can pin the detectors at both optical (600nm) and near-UV (230nm) wavelengths, suppressing the QEH behavior. We are characterizing the timescale for the detectors to become unpinned and developing a protocol for flashing the WFC3 CCDs with the instrument's internal calibration system in flight. The HST/Wide Field Camera 3 UV/visible channel CCD detectors have exhibited an unanticipated quantum efficiency hysteresis (QEH) behavior. The first observed manifestation of QEH was the presence in a small percentage of flat-field images of a bowtie-shaped contrast that spanned the width of each chip. At the nominal operating temperature of -83C, the contrast observed for this feature was typically 0.1-0.2% or less, though at warmer temperatures contrasts up to 5% (at -50C) have been observed. The bowtie morphology was replicated using flight spare detectors in tests at the GSFC Detector Characterization Laboratory by power cycling the detector while cold. Continued investigation revealed that a clearly-related global QE suppression at the approximately 5% level can be produced by cooling the detector in the dark; subsequent flat-field exposures at a constant illumination show asymptotically increasing response. This QE "pinning" can be achieved with a single high signal flat-field or a series of lower signal flats; a visible light (500-580nm) flat-field with a signal level of several hundred thousand electrons per pixel is sufficient for QE pinning at both optical (600nm) and near-UV (230nm) wavelengths. We are characterizing the timescale for the detectors to become unpinned and developing a protocol for flashing the WFC3 CCDs with the instrument's internal calibration system in flight. A preliminary estimate of the decay timescale for one detector is that a drop of 0.1-0.2% occurs over a ten day period, indicating that relatively infrequent cal lamp exposures can mitigate the behavior to extremely low levels.

VizieR Online Data Catalog: HST FGS-1r parallaxes for 8 metal-poor stars (Chaboyer+, 2017)

NASA Astrophysics Data System (ADS)

Chaboyer, B.; McArthur, B. E.; O'Malley, E.; Benedict, G. F.; Feiden, G. A.; Harrison, T. E.; McWilliam, A.; Nelan, E. P.; Patterson, R. J.; Sarajedini, A.

2017-08-01

Each program star was observed with the HST Advanced Camera for Surveys-Wide Field Camera (ACS/WFC) in the F606W and F814W filters. The CTE-corrected ACS/WFC images for the program stars were retrieved from MAST. These instrumental magnitudes were corrected for exposure time, matched to form colors, and calibrated to the VEGAMag and ground-based VI systems using the Sirianni+ (2005PASP..117.1049S) photometric transformations. Ground based photometry for all of our program stars were obtained using the New Mexico State University (NMSU) 1m telescope, the MDM 1.3m telescope, and the SMARTS 0.9m telescope. See appendix A1 for further details. We used HST FGS-1r, a two-axis interferometer, to make the astrometric observations. Eighty-nine orbits of HST astrometric observations were made between 2008 December and 2013 June. Every orbit contained several observations of the target and surrounding reference stars. (4 data files).

The Grism Lens-Amplified Survey from Space (GLASS). I. Survey Overview and First Data Release

NASA Astrophysics Data System (ADS)

Treu, T.; Schmidt, K. B.; Brammer, G. B.; Vulcani, B.; Wang, X.; Bradač, M.; Dijkstra, M.; Dressler, A.; Fontana, A.; Gavazzi, R.; Henry, A. L.; Hoag, A.; Huang, K.-H.; Jones, T. A.; Kelly, P. L.; Malkan, M. A.; Mason, C.; Pentericci, L.; Poggianti, B.; Stiavelli, M.; Trenti, M.; von der Linden, A.

2015-10-01

We give an overview of the Grism Lens Amplified Survey from Space (GLASS), a large Hubble Space Telescope program aimed at obtaining grism spectroscopy of the fields of 10 massive clusters of galaxies at redshift z = 0.308-0.686, including the Hubble Frontier Fields (HFF). The Wide Field Camera 3 (WFC3) yields near-infrared spectra of the cluster cores covering the wavelength range 0.81-1.69 μm through grisms G102 and G141, while the Advanced Camera for Surveys in parallel mode provides G800L spectra of the infall regions of the clusters. The WFC3 spectra are taken at two almost orthogonal position angles in order to minimize the effects of confusion. After summarizing the scientific drivers of GLASS, we describe the sample selection as well as the observing strategy and data processing pipeline. We then utilize MACS J0717.5+3745, a HFF cluster and the first one observed by GLASS, to illustrate the data quality and the high-level data products. Each spectrum brighter than {H}{{AB}}=23 is visually inspected by at least two co-authors and a redshift is measured when sufficient information is present in the spectra. Furthermore, we conducted a thorough search for emission lines through all of the GLASS WFC3 spectra with the aim of measuring redshifts for sources with continuum fainter than {H}{{AB}}=23. We provide a catalog of 139 emission-line-based spectroscopic redshifts for extragalactic sources, including three new redshifts of multiple image systems (one probable, two tentative). In addition to the data itself, we also release software tools that are helpful to navigate the data.

HST WFC3 Early Release Science: Emission-Line Galaxies from IR Grism Observations

NASA Technical Reports Server (NTRS)

Straughn, A. N.; Kuntschner, H.; Kuemmel, M.; Walsh, J. R.; Cohen, S. H.; Gardner, J. P.; Windhorst, R. A.; O'Connell, R. W.; Pirzkal, N.; Meurer, G.;

The HST Frontier Fields

NASA Astrophysics Data System (ADS)

Lotz, Jennifer; Mountain, M.; Grogin, N. A.; Koekemoer, A. M.; Capak, P. L.; Mack, J.; Coe, D. A.; Barker, E. A.; Adler, D. S.; Avila, R. J.; Anderson, J.; Casertano, S.; Christian, C. A.; Gonzaga, S.; Ferguson, H. C.; Fruchter, A. S.; Jenkner, H.; Jordan, I. J.; Hammer, D.; Hilbert, B.; Lawton, B. L.; Lee, J. C.; Lucas, R. A.; MacKenty, J. W.; Mutchler, M. J.; Ogaz, S.; Reid, I. N.; Royle, P.; Robberto, M.; Sembach, K.; Smith, L. J.; Sokol, J.; Surace, J. A.; Taylor, D.; Tumlinson, J.; Viana, A.; Williams, R. E.; Workman, W.

2014-01-01

Using Director's Discretionary observing time, HST is undertaking a revolutionary deep field observing program to peer deeper into the Universe than ever before. The Frontier Fields will combine the power of HST with the natural gravitational telescopes of high-magnification clusters of galaxies to produce the deepest observations of clusters and their lensed galaxies and the second-deepest observations of blank fields ever obtained. Up to six strong-lensing clusters (Abell 2744, MACSJ0416.1-2403, MACSJ0717.5+3745, MACSJ1149.5+2223, AbellS1063, and Abell 370) will be targeted with coordinated parallels of adjacent blank fields with ACS/WFC and WFC3/IR cameras to ~29th ABmag depths in seven bandpasses over the next three years. These observations will reveal distant galaxy populations ~10-100 times fainter than any previously observed, and improve our statistical understanding of galaxies during the epoch of reionization. Here we present Hubble Space Telescope observations of the first set of the Frontier Fields, Abell 2744, and describe the HST Frontier Fields observing strategy and schedule. All data for this observing program is nonproprietary and available immediately upon entry into the Mikulski Archive for Space Telescopes.

WFC3 UVIS Detector Performance

NASA Astrophysics Data System (ADS)

Gunning, Heather C.; Baggett, Sylvia M.; Gosmeyer, Catherine; Bourque, Matthew; MacKenty, John W.; Anderson, Jay; WFC3 Team

2015-01-01

The Wide Field Camera 3 (WFC3) is a fourth-generation imaging instrument installed on the Hubble Space Telescope (HST) during Servicing Mission 4 (SM4) in May 2000. WFC3 has two observational channels, UV/visible (UVIS) and infrared (IR); both have been performing well on-orbit. Since installation, the WFC3 team has been diligent in monitoring the performance of both detectors. The UVIS channel consists of two e2v, backside illuminated, 2Kx4K CCDs arranged in a 2x1 mosaic. We present results from some of the monitoring programs used to check various aspects of the UVIS detector. We discuss the growth trend of hot pixels and the efficacy of regular anneals in controlling the hot pixel population. We detail a pixel population with lowered-sensitivity that evolves during the time between anneals, and is largely reset by each anneal procedure. We discuss the stability of the post-flash LED lamp, used and recommended for CTE mitigation in observations with less than 12 e-/pixel backgrounds. Finally, we summarize long-term photometric trends of the UVIS detector, as well as the absolute gain measurement, used as a proxy for the on-orbit evolution of the UVIS channel.

A Calibration of NICMOS Camera 2 for Low Count Rates

NASA Astrophysics Data System (ADS)

Rubin, D.; Aldering, G.; Amanullah, R.; Barbary, K.; Dawson, K. S.; Deustua, S.; Faccioli, L.; Fadeyev, V.; Fakhouri, H. K.; Fruchter, A. S.; Gladders, M. D.; de Jong, R. S.; Koekemoer, A.; Krechmer, E.; Lidman, C.; Meyers, J.; Nordin, J.; Perlmutter, S.; Ripoche, P.; Schlegel, D. J.; Spadafora, A.; Suzuki, N.

2015-05-01

NICMOS 2 observations are crucial for constraining distances to most of the existing sample of z\\gt 1 SNe Ia. Unlike conventional calibration programs, these observations involve long exposure times and low count rates. Reciprocity failure is known to exist in HgCdTe devices and a correction for this effect has already been implemented for high and medium count rates. However, observations at faint count rates rely on extrapolations. Here instead, we provide a new zero-point calibration directly applicable to faint sources. This is obtained via inter-calibration of NIC2 F110W/F160W with the Wide Field Camera 3 (WFC3) in the low count-rate regime using z∼ 1 elliptical galaxies as tertiary calibrators. These objects have relatively simple near-IR spectral energy distributions, uniform colors, and their extended nature gives a superior signal-to-noise ratio at the same count rate than would stars. The use of extended objects also allows greater tolerances on point-spread function profiles. We find space telescope magnitude zero points (after the installation of the NICMOS cooling system, NCS) of 25.296\\+/- 0.022 for F110W and 25.803\\+/- 0.023 for F160W, both in agreement with the calibration extrapolated from count rates ≳1000 times larger (25.262 and 25.799). Before the installation of the NCS, we find 24.843\\+/- 0.025 for F110W and 25.498\\+/- 0.021 for F160W, also in agreement with the high-count-rate calibration (24.815 and 25.470). We also check the standard bandpasses of WFC3 and NICMOS 2 using a range of stars and galaxies at different colors and find mild tension for WFC3, limiting the accuracy of the zero points. To avoid human bias, our cross-calibration was “blinded” in that the fitted zero-point differences were hidden until the analysis was finalized. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555, under programs SM2/NIC-7049, SM2/NIC-7152, CAL/NIC-7607, CAL/NIC-7691, CAL/NIC-7693, GO-7887, CAL/NIC-7902, CAL/NIC-7904, GO/DD-7941, SM3/NIC-8983, SM3/NIC-8986, GTO/ACS-9290, ENG/NIC-9324, CAL/NIC-9325, GO-9352, GO-9375, SNAP-9485, CAL/NIC-9639, GO-9717, GO-9834, GO-9856, CAL/NIC-9995, CAL/NIC-9997, GO-10189, GO-10258, CAL/NIC-10381, CAL/NIC-10454, GO-10496, CAL/NIC-10725, CAL/NIC-10726, GO-10886, CAL/NIC-11060, CAL/NIC-11061, GO-11135, GO-11143, GO-11202, CAL/NIC-11319, GO/DD-11359, SM4/WFC3-11439, SM4/WFC3-11451, GO-11557, GO-11591, GO-11600, GO/DD-11799, CAL/WFC3-11921, CAL/WFC3-11926, GO/DD-12051, GO-12061, GO-12062, GO-12177, CAL/WFC3-12333, CAL/WFC3-12334, CAL/WFC3-12341, GO-12443, GO-12444, GO-12445, CAL/WFC3-12698, CAL/WFC3-12699, GO-12874, CAL/WFC3-13088, and CAL/WFC3-13089.

Ultra-High Resolution Orbit Determination of (486958) 2014 MU69: Predicting an Occultation with 1% of an Orbit

NASA Astrophysics Data System (ADS)

Porter, Simon Bernard; Buie, Marc W.; Spencer, John R.; Folkner, William; Parker, Alex; Zangari, Amanda Marie; Verbiscer, Anne J.; Benecchi, Susan; Stern, S. Alan; Terrell, Dirk; Soto, Alejandro; Tamblyn, Peter; Wasserman, Lawrence H.; Young, Eliot F.; New Horizons MU69 Occultation Team

2017-10-01

In November 2015, the NASA New Horizons spacecraft burned its thrusters to intercept the cold classical Kuiper Belt Object (486958) 2014 MU69. Then, on July 17, 2017, five small telescopes in Chubut Province, Argentina recorded a solid body occultation of MU69. Both these events required an orbital solution of unprecedented accuracy, as will the January 1, 2019 flyby of MU69 by New Horizons. This was especially difficult because there were no precoveries of MU69 prior to July 2014, it is in an extremely crowded field near the galactic core, and it is faint enough to only be reliably detected by Hubble Space Telescope’s Wide Field Camera 3 (WFC3). To accomplish this, we performed an extremely detailed analysis of 237 WFC3 images, down to the subpixel distortion level, in order to produce individual probability distribution functions (PDFs) for the position of MU69 in each WFC3 image. We registered each WFC3 image against a pre-release version of the Gaia DR2 catalog, which produced even smaller residuals than the now-released DR1. We then combined these WFC3+Gaia PDFs with a high-precision few-body numerical integrator and a Monte Carlo Markov Chain (MCMC) sampler to produce a state vector PDF for MU69 at defined epoch. Propagating those state vectors from the epoch produces an instantaneous positional cloud for MU69 at any given time. This positional cloud was then directly translated into a shadow path uncertainty cloud in order to plan the MU69 occultation campaign. We will describe this process of fully propagating errors from WFC3 images to telescope sites on the ground, and also describe refinements for future guiding of New Horizons to its encounter with MU69. We thank NASA, Hubble, Gaia, CONAE, the city of Comodoro Rivadavia, and the government of Argentina for their assistance and support of the MU69 occultation campaign.

VizieR Online Data Catalog: Strong lensing mass modeling of 4 HFF clusters (Kawamata+, 2016)

NASA Astrophysics Data System (ADS)

Kawamata, R.; Oguri, M.; Ishigaki, M.; Shimasaku, K.; Ouchi, M.

2018-02-01

We use the public HFF data (http://www.stsci.edu/hst/campaigns/frontier-fields/) for our analysis. The HFF targets six massive clusters, Abell 2744 (z=0.308), MACS J0416.1-2403 (z=0.397), MACS J0717.5+3745 (z=0.545), MACS J1149.6+2223 (z=0.541), Abell S1063 (z=0.348), and Abell 370 (z=0.375), which have been chosen according to their lensing strength and also their accessibility from major ground-based telescopes. The cluster core and parallel field region of each cluster are observed deeply with the IR channel of Wide Field Camera 3 (WFC3/IR) and the Advanced Camera for Surveys (ACS). As of 2015 October, HST observations for the first four clusters, Abell 2744, MACS J0416.1-2403, MACS J0717.5+3745, and MACS J1149.6+2223, are completed. In this study, we use the Version 1.0 data products of drizzled images with a pixel scale of 0.03"/pixel provided by the Space Telescope Science Institute (STScI). The images for each cluster consist of F435W (B435), F606W (V606), and F814W (i814) images from ACS, and F105W (Y105), F125W (J125), F140W (JH140), and F160W (H160) images from WFC3/IR. (7 data files).

DUST EXTINCTION FROM BALMER DECREMENTS OF STAR-FORMING GALAXIES AT 0.75 {<=} z {<=} 1.5 WITH HUBBLE SPACE TELESCOPE/WIDE-FIELD-CAMERA 3 SPECTROSCOPY FROM THE WFC3 INFRARED SPECTROSCOPIC PARALLEL SURVEY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dominguez, A.; Siana, B.; Masters, D.

Spectroscopic observations of H{alpha} and H{beta} emission lines of 128 star-forming galaxies in the redshift range 0.75 {<=} z {<=} 1.5 are presented. These data were taken with slitless spectroscopy using the G102 and G141 grisms of the Wide-Field-Camera 3 (WFC3) on board the Hubble Space Telescope as part of the WFC3 Infrared Spectroscopic Parallel survey. Interstellar dust extinction is measured from stacked spectra that cover the Balmer decrement (H{alpha}/H{beta}). We present dust extinction as a function of H{alpha} luminosity (down to 3 Multiplication-Sign 10{sup 41} erg s{sup -1}), galaxy stellar mass (reaching 4 Multiplication-Sign 10{sup 8} M {sub Sunmore » }), and rest-frame H{alpha} equivalent width. The faintest galaxies are two times fainter in H{alpha} luminosity than galaxies previously studied at z {approx} 1.5. An evolution is observed where galaxies of the same H{alpha} luminosity have lower extinction at higher redshifts, whereas no evolution is found within our error bars with stellar mass. The lower H{alpha} luminosity galaxies in our sample are found to be consistent with no dust extinction. We find an anti-correlation of the [O III] {lambda}5007/H{alpha} flux ratio as a function of luminosity where galaxies with L {sub H{alpha}} < 5 Multiplication-Sign 10{sup 41} erg s{sup -1} are brighter in [O III] {lambda}5007 than H{alpha}. This trend is evident even after extinction correction, suggesting that the increased [O III] {lambda}5007/H{alpha} ratio in low-luminosity galaxies is likely due to lower metallicity and/or higher ionization parameters.« less

A Physical Model-based Correction for Charge Traps in the Hubble Space Telescope ’s Wide Field Camera 3 Near-IR Detector and Its Applications to Transiting Exoplanets and Brown Dwarfs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Yifan; Apai, Dániel; Schneider, Glenn

The Hubble Space Telescope Wide Field Camera 3 (WFC3) near-IR channel is extensively used in time-resolved observations, especially for transiting exoplanet spectroscopy as well as brown dwarf and directly imaged exoplanet rotational phase mapping. The ramp effect is the dominant source of systematics in the WFC3 for time-resolved observations, which limits its photometric precision. Current mitigation strategies are based on empirical fits and require additional orbits to help the telescope reach a thermal equilibrium . We show that the ramp-effect profiles can be explained and corrected with high fidelity using charge trapping theories. We also present a model for this processmore » that can be used to predict and to correct charge trap systematics. Our model is based on a very small number of parameters that are intrinsic to the detector. We find that these parameters are very stable between the different data sets, and we provide best-fit values. Our model is tested with more than 120 orbits (∼40 visits) of WFC3 observations and is proved to be able to provide near photon noise limited corrections for observations made with both staring and scanning modes of transiting exoplanets as well as for starting-mode observations of brown dwarfs. After our model correction, the light curve of the first orbit in each visit has the same photometric precision as subsequent orbits, so data from the first orbit no longer need to be discarded. Near-IR arrays with the same physical characteristics (e.g., JWST/NIRCam ) may also benefit from the extension of this model if similar systematic profiles are observed.« less

A Physical Model-based Correction for Charge Traps in the Hubble Space Telescope’s Wide Field Camera 3 Near-IR Detector and Its Applications to Transiting Exoplanets and Brown Dwarfs

NASA Astrophysics Data System (ADS)

Zhou, Yifan; Apai, Dániel; Lew, Ben W. P.; Schneider, Glenn

2017-06-01

The Hubble Space Telescope Wide Field Camera 3 (WFC3) near-IR channel is extensively used in time-resolved observations, especially for transiting exoplanet spectroscopy as well as brown dwarf and directly imaged exoplanet rotational phase mapping. The ramp effect is the dominant source of systematics in the WFC3 for time-resolved observations, which limits its photometric precision. Current mitigation strategies are based on empirical fits and require additional orbits to help the telescope reach a thermal equilibrium. We show that the ramp-effect profiles can be explained and corrected with high fidelity using charge trapping theories. We also present a model for this process that can be used to predict and to correct charge trap systematics. Our model is based on a very small number of parameters that are intrinsic to the detector. We find that these parameters are very stable between the different data sets, and we provide best-fit values. Our model is tested with more than 120 orbits (∼40 visits) of WFC3 observations and is proved to be able to provide near photon noise limited corrections for observations made with both staring and scanning modes of transiting exoplanets as well as for starting-mode observations of brown dwarfs. After our model correction, the light curve of the first orbit in each visit has the same photometric precision as subsequent orbits, so data from the first orbit no longer need to be discarded. Near-IR arrays with the same physical characteristics (e.g., JWST/NIRCam) may also benefit from the extension of this model if similar systematic profiles are observed.

VizieR Online Data Catalog: Velocities and BR photometry of Abell 1995 (Boschin+, 2012)

NASA Astrophysics Data System (ADS)

Boschin, W.; Girardi, M.; Barrena, R.

2013-01-01

We performed spectroscopic observations of A1995 in May 2009. We used the instrument DOLORES at TNG1 in MOS mode with the LR-B grism, which covers the wavelength range 3000-8430Å. We performed photometric observations of A1995 in January 2008 by using the Wide Field Camera (WFC3) mounted on the 2.5m INT Telescope. (1 data file).

Lessons Learned from the Wide Field Camera 3 TV1 and TV2 Thermal Vacuum Test Campaigns

NASA Technical Reports Server (NTRS)

Peabody, Hume; Stavely, Richard; Bast, William

2008-01-01

The Wide Field Camera 3 (WFC3) instrument has undergone two complete thermal vacuum tests (TV1 and TV2), during which valuable lessons were learned regarding test configuration, test execution, model capabilities, and modeling practices. The very complex thermal design of WFC3 produced a number of challenging aspects to ground testing with numerous ThermoElectric Coolers and heat pipes, not all of which were functional. Lessons learned during TV1 resulted in significant upgrades to the model capabilities and a change in the test environment approach for TV2. These upgrades proved invaluable during TV2 when pretest modeling assumptions proved to be false. Each of the lessons learned relate to one of two following broad statements: 1. Ensure the design can be tested and that the effect of non-flight like conditions is well understood, particularly with respect to non passive devices (TECs, Heat Pipes, etc) 2. Ensure that the model is sufficiently detailed and is capable of predicting off-nominal behavior and the power dissipation of any thermal devices, especially TECs This paper outlines a number of the lessons learned over these two test campaigns with respect to the thermal design, model, and test configuration and presents recommendations for future tests.

Lessons Learned from the Wide Field Camera 3 Flight Correlation

NASA Technical Reports Server (NTRS)

Peabody, Hume L.; Stavely, Richard A.; Townsend, Jackie; Abel, Josh; Mandi, Joe; Bast, William

2010-01-01

The Wide Field Camera 3 (WFC3) instrument was installed into the Hubble Space Telescope (HST) as part of the activities for STS (Space Transportation System)-125 (HST Servicing Mission 4). Initial model predictions for power and radiator temperature were not in good agreement with flight data during a relatively hot, stable period, with the flight power and temperatures being significantly higher than predictions. Significant efforts were undertaken to identify the causes of the discrepancies and to resolve the flight model correlation problems as the thermal vacuum test correlation indicated good agreement. The WFC3 thermal design performance has proven difficult to accurately predict, since the power dissipation on the radiator typically increases as the radiator temperature increases, due to a Thermo Electric Cooler (TEC) attached to the this radiator. This self beating continues until the radiative emissive capability is met for a given temperature, and only then does the system find a quasi-steady regime. Various other factors may also contribute to the radiator temperature, such as backloadlng from the observatory itself and the planet, local high-absorptivity regions near fasteners/holes, and temperature varying parasitic heat leaks from the instrument itself to the radiator. Each of these effects in turn may increase the radiator temperature, and furthermore the demand on the TEC.

VizieR Online Data Catalog: The Carnegie-Chicago Hubble Program. II. IC 1613 (Hatt+, 2017)

NASA Astrophysics Data System (ADS)

Hatt, D.; Beaton, R. L.; Freedman, W. L.; Madore, B. F.; Jang, I.-S.; Hoyt, T. J.; Lee, M. G.; Monson, A. J.; Rich, J. A.; Scowcroft, V.; Seibert, M.

2018-04-01

Observations of IC 1613 were obtained on 2015 June 12 using the Inamori-Magellan Areal Camera and Spectrograph (IMACS) on the 6.5m Magellan-Baade telescope at Las Campanas Observatory. We obtain a 15.46'x15.46' field of view with resolution of 0.2"/pixel and observed in the BVI filters. See section 2.1.1. We have made use of archival imaging of IC 1613 taken from the Local Cosmology from Isolated Dwarfs program (PID:GO10505, PI: Gallart; Gallart 2005, LCID). A single field was imaged over 24 orbits between 2006 August 28 and 30 approximately 5' west of the center of IC 1613 using the HST ACS/WFC instrument, which provides a 202"x202" field of view with 0.05"/pixel resolution. Each orbit was divided between two ~1200s exposures in the F475W and F814W passbands, resulting in 48 epochs per filter. See section 2.1.2. We obtained near-infrared imaging over 24 orbits between 2014 December 17 and 18 using the HST WFC3/IR instrument (PID:GO13691, PI: Freedman; Freedman W. 2014 HST Proposal). The orbits were divided between two overlapping 136"x123" WFC3/IR pointings with a native resolution of 0.135"/pixel. See section 2.1.3. In parallel with the observations described in the previous section were 24 orbits with the HST ACS/WFC instrument (PID:GO13691, PI: Freedman; Freedman 2014 W. HST Proposal). Each exposure in F606W and F814W spanned ~500s. See section 2.1.4. (2 data files).

Photometric Repeatability of Scanned Imagery: UVIS

NASA Astrophysics Data System (ADS)

Shanahan, Clare E.; McCullough, Peter; Baggett, Sylvia

2017-08-01

We provide the preliminary results of a study on the photometric repeatability of spatial scans of bright, isolated white dwarf stars with the UVIS channel of the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). We analyze straight-line scans from the first pair of identical orbits of HST program 14878 to assess if sub 0.1% repeatability can be attained with WFC3/UVIS. This study is motivated by the desire to achieve better signal-to-noise in the UVIS contamination and stability monitor, in which observations of standard stars in staring mode have been taken from the installation of WFC3 in 2009 to the present to assess temporal photometric stability. Higher signal to noise in this program would greatly benefit the sensitivity to detect contamination, and to better characterize the observed small throughput drifts over time. We find excellent repeatability between identical visits of program 14878, with sub 0.1% repeatability achieved in most filters. These! results support the initiative to transition the staring mode UVIS contamination and photometric stability monitor from staring mode images to spatial scans.

High-precision Orbit Fitting and Uncertainty Analysis of (486958) 2014 MU69

NASA Astrophysics Data System (ADS)

Porter, Simon B.; Buie, Marc W.; Parker, Alex H.; Spencer, John R.; Benecchi, Susan; Tanga, Paolo; Verbiscer, Anne; Kavelaars, J. J.; Gwyn, Stephen D. J.; Young, Eliot F.; Weaver, H. A.; Olkin, Catherine B.; Parker, Joel W.; Stern, S. Alan

2018-07-01

NASA’s New Horizons spacecraft will conduct a close flyby of the cold-classical Kuiper Belt Object (KBO) designated (486958) 2014 MU69 on 2019 January 1. At a heliocentric distance of 44 au, “MU69” will be the most distant object ever visited by a spacecraft. To enable this flyby, we have developed an extremely high-precision orbit fitting and uncertainty processing pipeline, making maximal use of the Hubble Space Telescope’s Wide Field Camera 3 (WFC3) and pre-release versions of the ESA Gaia Data Release 2 (DR2) catalog. This pipeline also enabled successful predictions of a stellar occultation by MU69 in 2017 July. We describe how we process the WFC3 images to match the Gaia DR2 catalog, extract positional uncertainties for this extremely faint target (typically 140 photons per WFC3 exposure), and translate those uncertainties into probability distribution functions for MU69 at any given time. We also describe how we use these uncertainties to guide New Horizons, plan stellar occultions of MU69, and derive MU69's orbital evolution and long-term stability.

The Hubble Space Telescope Wide Field Camera 3 Early Release Science Data: Panchromatic Faint Object Counts From 0.2-2 Micron To Ab=26-27 Mag

NASA Astrophysics Data System (ADS)

Windhorst, Rogier A.; McCarthy, P.; Cohen, S.; Ryan, R.; Driver, S.; Hathi, N.; Koekemoer, A.; Mechtley, M.; O'Connell, R.; Rutkowski, M.; Yan, H.; SOC, WFC3

2010-01-01

We describe the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) Early Release Science (ERS) observations in the GOODS-South field. The new WFC3 ERS data provide calibrated, drizzled mosaics with FHWM=0.07--0.15" in the near-UV (filters F225W, F275W, and F336W) and near-IR (F098W, F125W, and F160W) in typically 2 orbits per filter. Together with the existing HST/ACS GOODS-S mosaics in the BVi'z' filters, the 10-band ERS data cover 40-50 sq. arcmin to AB=26-27.0 mag (10-sigma for point sources). In this poster, we describe the: (1) scientific rationale, data taking and reduction procedures of the WFC3 ERS mosaics; (2) object cataloging and star-galaxy separation techniques used in these 10 different filters; (3) reliability and completeness of the 10-band object catalogs from the ERS mosaics; (4) object counts in 10 different filters from 0.2-1.7 microns to AB=26.0-27.0 mag; and (5) the full-color 10-band ERS images. We discuss the panchromatic structure for a variety of interesting ERS objects at intermediate redshifts (z=0.5-3), including examples of galaxies with nuclear star-forming rings, bars, or weak AGN activity, UV-dropout galaxies at redshifts z=2-3, and objects of other interesting appearance. The 10-band panchromatic ERS data base is very rich in morphological structure at all restframe wavelengths where young or older stars shine during the peak epoch in the cosmic star-formation rate (at z=1-2). This work is based on ERS observations made by the WFC3 Scientific Oversight Committee. We are grateful to the Space Telescope Science Institute Director for awarding Director's Discretionary time for this program. Support for HST program 11359 was provided by NASA through grants GO-11359.0*.A from STScI, which is operated by AURA under NASA contract NAS 5-26555. We dedicate this paper to the memory of the STS-107 Columbia Shuttle astronauts, and of Dr. Rodger Doxsey.

INT WFC pre-discovery detection of the nova M31N 2017-11a (AT2017hvi, PTSS-17zap, TCP J00425419+4130425)

NASA Astrophysics Data System (ADS)

Mantero-Castaneda, E. A.; Hernandez-Sanchez, M.; Arce-Tord, C.; Esteban-Gutierrez, A.; Garcia-Broock, E.; Garcia-Rivas, M.; Gonzalez-Cuesta, L.; Hermosa-Munoz, L.; Jimenez-Gallardo, A.; Lopez-Navas, E.; Otero-Santos, J.; Prendin, M. G.; Rodriguez-Sanchez, M.; Perez-Fournon, I.

2017-12-01

We report the pre-discovery detection of the nova M31N 2017-11a (AT2017hvi, PTSS-17zap, TCP J00425419+4130425) with the Isaac Newton Telescope* Wide Field Camera on the night of 29 October 2017, 4.845 days before the discovery observations on 2017/11/04.695 by the PMO-Tsinghua Supernova Survey (PTSS).

STOP Analysis and Optimization of a Very-Low-Distortion Space Instrument: HST WFC3 Case Study

NASA Technical Reports Server (NTRS)

Kunt, Cengiz; Broduer, Steve (Technical Monitor)

2001-01-01

New generation optical instruments with very demanding stability requirements are being proposed and developed for space applications. STOP (Structural-Thermal-Optical Performance) analysis and optimization is crucial in meeting the very tight distortion budgets of these instruments. This presentation outlines STOP analysis and optimization approach in the context of WFC3 (Wide-Field Camera 3), which is a radial instrument designed to replace the Wide-Field Planetary Camera 2 (WFPC2) of the Hubble Space Telescope (HST). WFC3 houses two separate channels, UVIS and IR, and will have greater throughput and sensitivity than WFPC2. WFC3 line-of-sight alignment budget for the UVIS and IR channels are as small as 10 and 20 milli-arcsec, respectively. Its optical bench is the most critical subsystem effecting the optical stability of WFC3 hence our effort concentrates on the design and analysis of the bench and its interfaces. Structural analysis has accompanied the mechanical design of the bench since the initial concept study. A high fidelity structural Finite Element Model (FEM) of the bench has been developed and used for minimizing its thermally induced distortions as well as sizing it to meet the stiffness and strength requirements of a Shuttle launch. The bench is a composite honeycomb panel box structure with a very low planar Coefficient of Thermal Expansion (CTE) of approximately 0.1 ppm/C. Optic components are mounted to super-INVAR inserts bonded into the panels. The bench is kinematically supported on three HST latches via interface struts, which are tailored to exhibit negative CTE to cancel out the thermal motions of the latches. The interface struts also incorporate flexure elements to minimize the mechanical distortions coming into the bench from its enclosure. Bench FEM is coupled with the enclosure FEM to quantify these effects. Short term or on-orbit STOP analysis includes distortion due to the temperature variations of the bench, the struts, and the enclosure. Long term or ground-to-orbit STOP analysis includes distortional effects of gravity release, desorption, and assembly in addition to the ground-to-orbit temperature variations. A rigorous testing program has been implemented for verifying the material properties and the analysis predictions. STOP analysis results demonstrate that both the short-term and the long-term alignment budgets will be met. Presentation will cover design and analysis details that are critical to a successful implementation of the STOP analysis and optimization process.

THE PANCHROMATIC HUBBLE ANDROMEDA TREASURY. X. ULTRAVIOLET TO INFRARED PHOTOMETRY OF 117 MILLION EQUIDISTANT STARS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, Benjamin F.; Dalcanton, Julianne J.; Weisz, Daniel R.

We have measured stellar photometry with the Hubble Space Telescope Wide Field Camera 3 (WFC3) and Advanced Camera for Surveys in near ultraviolet (F275W, F336W), optical (F475W, F814W), and near infrared (F110W, F160W) bands for 117 million resolved stars in M31. As part of the Panchromatic Hubble Andromeda Treasury survey, we measured photometry with simultaneous point-spread function (PSF) fitting across all bands and at all source positions after precise astrometric image alignment (<5-10 mas accuracy). In the outer disk, the photometry reaches a completeness-limited depth of F475W ∼ 28, while in the crowded, high surface brightness bulge, the photometry reachesmore » F475W ∼ 25. We find that simultaneous photometry and optimized measurement parameters significantly increase the detection limit of the lowest-resolution filters (WFC3/IR) providing color-magnitude diagrams (CMDs) that are up to 2.5 mag deeper when compared with CMDs from WFC3/IR photometry alone. We present extensive analysis of the data quality including comparisons of luminosity functions and repeat measurements, and we use artificial star tests to quantify photometric completeness, uncertainties and biases. We find that the largest sources of systematic error in the photometry are due to spatial variations in the PSF models and charge transfer efficiency corrections. This stellar catalog is the largest ever produced for equidistant sources, and is publicly available for download by the community.« less

Early Observations with the ACS Ramp Filters

NASA Astrophysics Data System (ADS)

Tsvetanov, Z.; Hartig, G.; Bohlin, R.; Tran, H. D.; Martel, A.; Sirianni, M.; Clampin, M.

2002-05-01

The Advanced Camera for Surveys (ACS) on-board the Hubble Space Telescope (HST) is equipped with a set of ramp filters which provide imaging capability at 2% and 9% bandwidth in the range 3700-10700 Å. Each ramp filter consist of three segments where the middle segment can be used with both the Wide Field Channel (WFC) and High Resolution Channel (HRC), while the inner and outer segments can be used only with WFC. The monochromatic field of view is approximately 40'' by 80''. We will present observations of the planetary nebula (PN) NGC6543 (the Cat's Eye) taken with the ACS ramp filetrs in several key emission lines - [O II] 3727, [O III] 5007, H-alpha+[N II], and [S II] 6725. These four emission lines fall onto three separate middle ramp segments - FR388N, FR505N, and FR656N - and will allow inter-comparison between the ACS ramp filters and fixed bandpass narrow-band filters F502N and F658N for both the WFC and HRC detectors. These observations were taken as part of the HST Servicing Mission Orbital Verification program and were designed to test ramp filters performance. We will demostrate our ability to obtain monochromatic (i.e., emission line) images at arbitrary wavelength and recover the surface brightness distribution. This work was supported by a NASA contract and a NASA grant.

VizieR Online Data Catalog: Velocities of galaxies in Abell 520 (Girardi+, 2008)

NASA Astrophysics Data System (ADS)

Girardi, M.; Barrena, R.; Boschin, W.; Ellingson, E.

2009-01-01

Multi-object spectroscopic observations of A520 were carried out at the TNG telescope in December 2006. We used DOLORES/MOS with the LR-B Grism 1. As far as photometry is concerned, our observations were carried out with the Wide Field Camera (WFC), mounted at the prime focus of the 2.5m INT telescope (located at Roque de los Muchachos observatory, La Palma, Spain). We observed A520 in January 2008. (1 data file).

Stellar Populations of Lyman Break Galaxies at z approx. to 1-3 in the HST/WFC3 Early Release Science Observations

NASA Technical Reports Server (NTRS)

Hathi, N. P.; Cohen, S. H.; Ryan, R. E., Jr.; Finkelstein, S. L.; McCarthy, P. J.; Windhorst, R. A.; Yan, H.; Koekemoer, A. M.; Rutkowski, M. J.; OConnell, R. W.;

THE HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3 EARLY RELEASE SCIENCE DATA: PANCHROMATIC FAINT OBJECT COUNTS FOR 0.2-2 {mu}m WAVELENGTH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Windhorst, Rogier A.; Cohen, Seth H.; Mechtley, Matt

2011-04-01

We describe the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) Early Release Science (ERS) observations in the Great Observatories Origins Deep Survey (GOODS) South field. The new WFC3 ERS data provide calibrated, drizzled mosaics in the UV filters F225W, F275W, and F336W, as well as in the near-IR filters F098M (Y{sub s} ), F125W (J), and F160W (H) with 1-2 HST orbits per filter. Together with the existing HST Advanced Camera for Surveys (ACS) GOODS-South mosaics in the BViz filters, these panchromatic 10-band ERS data cover 40-50 arcmin{sup 2} at 0.2-1.7 {mu}m in wavelength at 0.''07-0.''15 FWHM resolutionmore » and 0.''090 Multidrizzled pixels to depths of AB {approx_equal} 26.0-27.0 mag (5{sigma}) for point sources, and AB {approx_equal} 25.5-26.5 mag for compact galaxies. In this paper, we describe (1) the scientific rationale, and the data taking plus reduction procedures of the panchromatic 10-band ERS mosaics, (2) the procedure of generating object catalogs across the 10 different ERS filters, and the specific star-galaxy separation techniques used, and (3) the reliability and completeness of the object catalogs from the WFC3 ERS mosaics. The excellent 0.''07-0.''15 FWHM resolution of HST/WFC3 and ACS makes star-galaxy separation straightforward over a factor of 10 in wavelength to AB {approx_equal} 25-26 mag from the UV to the near-IR, respectively. Our main results are: (1) proper motion of faint ERS stars is detected over 6 years at 3.06 {+-} 0.66 mas year{sup -1} (4.6{sigma}), consistent with Galactic structure models; (2) both the Galactic star counts and the galaxy counts show mild but significant trends of decreasing count slopes from the mid-UV to the near-IR over a factor of 10 in wavelength; (3) combining the 10-band ERS counts with the panchromatic Galaxy and Mass Assembly survey counts at the bright end (10 mag {approx}< AB {approx}< 20 mag) and the Hubble Ultra Deep Field counts in the BVizY{sub s}JH filters at the faint end (24 mag {approx}< AB {approx}< 30 mag) yields galaxy counts that are well measured over the entire flux range 10 mag {approx}< AB {approx}< 30 mag for 0.2-2 {mu}m in wavelength; (4) simple luminosity+density evolution models can fit the galaxy counts over this entire flux range. However, no single model can explain the counts over this entire flux range in all 10 filters simultaneously. More sophisticated models of galaxy assembly are needed to reproduce the overall constraints provided by the current panchromatic galaxy counts for 10 mag {approx}< AB {approx}< 30 mag over a factor of 10 in wavelength.« less

Hubble Sees a Legion of Galaxies

NASA Image and Video Library

2017-12-08

Peering deep into the early universe, this picturesque parallel field observation from the NASA/ESA Hubble Space Telescope reveals thousands of colorful galaxies swimming in the inky blackness of space. A few foreground stars from our own galaxy, the Milky Way, are also visible. In October 2013 Hubble’s Wide Field Camera 3 (WFC3) and Advanced Camera for Surveys (ACS) began observing this portion of sky as part of the Frontier Fields program. This spectacular skyscape was captured during the study of the giant galaxy cluster Abell 2744, otherwise known as Pandora’s Box. While one of Hubble’s cameras concentrated on Abell 2744, the other camera viewed this adjacent patch of sky near to the cluster. Containing countless galaxies of various ages, shapes and sizes, this parallel field observation is nearly as deep as the Hubble Ultra-Deep Field. In addition to showcasing the stunning beauty of the deep universe in incredible detail, this parallel field — when compared to other deep fields — will help astronomers understand how similar the universe looks in different directions. Image credit: NASA, ESA and the HST Frontier Fields team (STScI), NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

HST/WFC3: Evolution of the UVIS Channel's Charge Transfer Efficiency

NASA Astrophysics Data System (ADS)

Gosmeyer, Catherine; Baggett, Sylvia M.; Anderson, Jay; WFC3 Team

2016-06-01

The Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) contains both an IR and a UVIS channel. After more than six years on orbit, the UVIS channel performance remains stable; however, on-orbit radiation damage has caused the charge transfer efficiency (CTE) of UVIS's two CCDs to degrade. This degradation is seen as vertical charge 'bleeding' from sources during readout and its effect evolves as the CCDs age. The WFC3 team has developed software to perform corrections that push the charge back to the sources, although it cannot recover faint sources that have been bled out entirely. Observers can mitigate this effect in various ways such as by placing sources near the amplifiers, observing bright targets, and by increasing the total background to at least 12 electrons, either by using a broader filter, lengthening exposure time, or post-flashing. We present results from six years of calibration data to re-evaluate the best level of total background for mitigating CTE loss and to re-verify that the pixel-based CTE correction software is performing optimally over various background levels. In addition, we alert observers that CTE-corrected products are now available for retrieval from MAST as part of the CALWF3 v3.3 pipeline upgrade.

VizieR Online Data Catalog: Astro-photometric catalog of the core of NGC 5139 (Bellini+, 2017)

NASA Astrophysics Data System (ADS)

Bellini, A.; Anderson, J.; Bedin, L. R.; King, I. R.; van der Marel, R. P.; Piotto, G.; Cool, A.

2018-01-01

The core of ω Cen (NGC 5139) has been observed through many of the WFC3 filters since 2009 for calibration purposes, and new observations continue to be scheduled. Table 1 summarizes the massive archive of data, organized in a camera/filter fashion. We downloaded from the archive a total of 655 exposures (~205Ks) taken through 26 HST different bands: 18 for WFC3/UVIS (385 exposures) and 8 for WFC3/IR (270 exposures); spanning 2009 July to 2013 March. This data set can be accessed at MAST via this link: http://archive.stsci.edu/doi/resolve/resolve.html?doi=10.17909/T9WG6S (5 data files).

Updates to Post-Flash Calibration for the Advanced Camera for Surveys Wide Field Channel

NASA Astrophysics Data System (ADS)

Miles, Nathan

2018-03-01

This report presents a new technique for generating the post-flash calibration reference file for the Advanced Camera for Surveys (ACS) Wide Field Channel (WFC). The new method substantially reduces, if not, eliminates all together the presence of dark current artifacts arising from improper dark subtraction, while simultaneously preserving flat-field artifacts. The stability of the post-flash calibration reference file over time is measured using data taken yearly since 2012 and no statistically significant deviations are found. An analysis of all short-flashed darks taken every two days since January 2015 reveals a periodic modulation of the LED intensity on timescales of about one year. This effect is most readily explained by changes to the local temperature in the area surrounding the LED. However, a slight offset between the periods of the temperature and LED modulations lends to the possibility that the effect is a chance observation of the two sinusoids at an unfortunate point in their beat cycle.

Disappearance of the Supergiant Progenitor of SN 2011dh in M51

NASA Astrophysics Data System (ADS)

Van Dyk, Schuyler D.; Filippenko, Alexei V.; Fox, Ori; Kelly, Patrick; Smith, Nathan

2013-03-01

We report that in Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) observations at F555W and F814W with the UVIS channel, conducted on 2013 March 2 UT as part of our Cycle 20 Snapshot program GO-13029 (PI: A. Filippenko), we have discovered that the yellow supergiant star, identified by Van Dyk et al. (2011, ApJ, 741, L28) and Maund et al. (2011, MNRAS, 739, L37) at the position of the Type IIb SN 2011dh in M51, has vanished.

Free-form reflective optics for mid-infrared camera and spectrometer on board SPICA

NASA Astrophysics Data System (ADS)

Fujishiro, Naofumi; Kataza, Hirokazu; Wada, Takehiko; Ikeda, Yuji; Sakon, Itsuki; Oyabu, Shinki

2017-11-01

SPICA (Space Infrared Telescope for Cosmology and Astrophysics) is an astronomical mission optimized for mid-and far-infrared astronomy with a cryogenically cooled 3-m class telescope, envisioned for launch in early 2020s. Mid-infrared Camera and Spectrometer (MCS) is a focal plane instrument for SPICA with imaging and spectroscopic observing capabilities in the mid-infrared wavelength range of 5-38μm. MCS consists of two relay optical modules and following four scientific optical modules of WFC (Wide Field Camera; 5'x 5' field of view, f/11.7 and f/4.2 cameras), LRS (Low Resolution Spectrometer; 2'.5 long slits, prism dispersers, f/5.0 and f/1.7 cameras, spectral resolving power R ∼ 50-100), MRS (Mid Resolution Spectrometer; echelles, integral field units by image slicer, f/3.3 and f/1.9 cameras, R ∼ 1100-3000) and HRS (High Resolution Spectrometer; immersed echelles, f/6.0 and f/3.6 cameras, R ∼ 20000-30000). Here, we present optical design and expected optical performance of MCS. Most parts of MCS optics adopt off-axis reflective system for covering the wide wavelength range of 5-38μm without chromatic aberration and minimizing problems due to changes in shapes and refractive indices of materials from room temperature to cryogenic temperature. In order to achieve the high specification requirements of wide field of view, small F-number and large spectral resolving power with compact size, we employed the paraxial and aberration analysis of off-axial optical systems (Araki 2005 [1]) which is a design method using free-form surfaces for compact reflective optics such as head mount displays. As a result, we have successfully designed compact reflective optics for MCS with as-built performance of diffraction-limited image resolution.

Hubble Space Telescope  Wide Field Camera 3 Observations of Escaping Lyman Continuum Radiation from Galaxies and Weak AGN at Redshifts z ∼ 2.3–4.1

NASA Astrophysics Data System (ADS)

Smith, Brent M.; Windhorst, Rogier A.; Jansen, Rolf A.; Cohen, Seth H.; Jiang, Linhua; Dijkstra, Mark; Koekemoer, Anton M.; Bielby, Richard; Inoue, Akio K.; MacKenty, John W.; O’Connell, Robert W.; Silk, Joseph I.

2018-02-01

We present observations of escaping Lyman Continuum (LyC) radiation from 34 massive star-forming galaxies (SFGs) and 12 weak AGN with reliably measured spectroscopic redshifts at z≃ 2.3{--}4.1. We analyzed Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) mosaics of the Early Release Science (ERS) field in three UVIS filters to sample the rest-frame LyC over this redshift range. With our best current assessment of the WFC3 systematics, we provide 1σ upper limits for the average LyC emission of galaxies at < z> = 2.35, 2.75, and 3.60 to ∼28.5, 28.1, and 30.7 mag in image stacks of 11–15 galaxies in the WFC3/UVIS F225W, F275W, and F336W, respectively. The LyC flux of weak AGN at < z> = 2.62 and 3.32 are detected at 28.3 and 27.4 mag with S/Ns of ∼2.7 and 2.5 in F275W and F336W for stacks of 7 and 3 AGN, respectively, while AGN at < z> = 2.37 are constrained to ≳27.9 mag at 1σ in a stack of 2 AGN. The stacked AGN LyC light profiles are flatter than their corresponding non-ionizing UV continuum profiles out to radii of r≲ 0\\buildrel{\\prime\\prime}\\over{.} 9, which may indicate a radial dependence of porosity in the ISM. With synthetic stellar SEDs fit to UV continuum measurements longward of {{Ly}}α and IGM transmission models, we constrain the absolute LyC escape fractions to {f}{esc}{abs}≃ {22}-22+44% at < z> = 2.35 and ≲55% at < z> = 2.75 and 3.60, respectively. All available data for galaxies, including published work, suggests a more sudden increase of {f}{esc} with redshift at z≃ 2. Dust accumulating in (massive) galaxies over cosmic time correlates with increased H I column density, which may lead to reducing {f}{esc} more suddenly at z≲ 2. This may suggest that SFGs collectively contributed to maintaining cosmic reionization at redshifts z≳ 2{--}4, while AGN likely dominated reionization at z≲ 2.

Stellar Populations of Lyα Emitters at z ~ 6-7: Constraints on the Escape Fraction of Ionizing Photons from Galaxy Building Blocks

NASA Astrophysics Data System (ADS)

Ono, Yoshiaki; Ouchi, Masami; Shimasaku, Kazuhiro; Dunlop, James; Farrah, Duncan; McLure, Ross; Okamura, Sadanori

2010-12-01

We investigate the stellar populations of Lyα emitters (LAEs) at z = 5.7 and 6.6 in a 0.65 deg2 sky of the Subaru/XMM-Newton Deep Survey (SXDS) Field, using deep images taken with the Subaru/Suprime-Cam, United Kingdom Infrared Telescope/Wide Field Infrared Camera, and Spitzer/Infrared Array Camera (IRAC). We produce stacked multiband images at each redshift from 165 (z = 5.7) and 91 (z = 6.6) IRAC-undetected objects to derive typical spectral energy distributions (SEDs) of z ~ 6-7 LAEs for the first time. The stacked LAEs have as blue UV continua as the Hubble Space Telescope (HST)/Wide Field Camera 3 (WFC3) z-dropout galaxies of similar M UV, with a spectral slope β ~ -3, but at the same time they have red UV-to-optical colors with detection in the 3.6 μm band. Using SED fitting we find that the stacked LAEs have low stellar masses of ~(3-10) × 107 M sun, very young ages of ~1-3 Myr, negligible dust extinction, and strong nebular emission from the ionized interstellar medium, although the z = 6.6 object is fitted similarly well with high-mass models without nebular emission; inclusion of nebular emission reproduces the red UV-to-optical colors while keeping the UV colors sufficiently blue. We infer that typical LAEs at z ~ 6-7 are building blocks of galaxies seen at lower redshifts. We find a tentative decrease in the Lyα escape fraction from z = 5.7 to 6.6, which may imply an increase in the intergalactic medium neutral fraction. From the minimum contribution of nebular emission required to fit the observed SEDs, we place an upper limit on the escape fraction of ionizing photons of f ion esc ~ 0.6 at z = 5.7 and ~0.9 at z = 6.6. We also compare the stellar populations of our LAEs with those of stacked HST/WFC3 z-dropout galaxies. Based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

M Dwarfs from Hubble Space Telescope Star Counts. IV.

NASA Astrophysics Data System (ADS)

Zheng, Zheng; Flynn, Chris; Gould, Andrew; Bahcall, John N.; Salim, Samir

2001-07-01

We study a sample of about 1400 disk M dwarfs that are found in 148 fields observed with the Wide Field Camera 2 (WFC2) on the Hubble Space Telescope and 162 fields observed with pre-repair Planetary Camera 1 (PC1), of which 95 of the WFC2 fields are newly analyzed. The method of maximum likelihood is applied to derive the luminosity function and the Galactic disk parameters. At first, we use a local color-magnitude relation and a locally determined mass-luminosity relation in our analysis. The results are consistent with those of previous work but with considerably reduced statistical errors. These small statistical errors motivate us to investigate the systematic uncertainties. Considering the metallicity gradient above the Galactic plane, we introduce a modified color-magnitude relation that is a function of Galactic height. The resultant M dwarf luminosity function has a shape similar to that derived using the local color-magnitude relation but with a higher peak value. The peak occurs at MV~12, and the luminosity function drops sharply toward MV~14. We then apply a height-dependent mass-luminosity function interpolated from theoretical models with different metallicities to calculate the mass function. Unlike the mass function obtained using local relations, which has a power-law index α=0.47, the one derived from the height-dependent relations tends to be flat (α=-0.10). The resultant local surface density of disk M dwarfs (12.2+/-1.6 Msolar pc-2) is somewhat smaller than the one obtained using local relations (14.3+/-1.3 Msolar pc-2). Our measurement favors a short disk scale length, H=2.75+/-0.16 (statistical)+/-0.25 (systematic) kpc. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Calibration of HST wide field camera for quantitative analysis of faint galaxy images

NASA Technical Reports Server (NTRS)

Ratnatunga, Kavan U.; Griffiths, Richard E.; Casertano, Stefano; Neuschaefer, Lyman W.; Wyckoff, Eric W.

1994-01-01

We present the methods adopted to optimize the calibration of images obtained with the Hubble Space Telescope (HST) Wide Field Camera (WFC) (1991-1993). Our main goal is to improve quantitative measurement of faint images, with special emphasis on the faint (I approximately 20-24 mag) stars and galaxies observed as a part of the Medium-Deep Survey. Several modifications to the standard calibration procedures have been introduced, including improved bias and dark images, and a new supersky flatfield obtained by combining a large number of relatively object-free Medium-Deep Survey exposures of random fields. The supersky flat has a pixel-to-pixel rms error of about 2.0% in F555W and of 2.4% in F785LP; large-scale variations are smaller than 1% rms. Overall, our modifications improve the quality of faint images with respect to the standard calibration by about a factor of five in photometric accuracy and about 0.3 mag in sensitivity, corresponding to about a factor of two in observing time. The relevant calibration images have been made available to the scientific community.

The Frontier Fields: Survey Design and Initial Results

NASA Astrophysics Data System (ADS)

Lotz, J. M.; Koekemoer, A.; Coe, D.; Grogin, N.; Capak, P.; Mack, J.; Anderson, J.; Avila, R.; Barker, E. A.; Borncamp, D.; Brammer, G.; Durbin, M.; Gunning, H.; Hilbert, B.; Jenkner, H.; Khandrika, H.; Levay, Z.; Lucas, R. A.; MacKenty, J.; Ogaz, S.; Porterfield, B.; Reid, N.; Robberto, M.; Royle, P.; Smith, L. J.; Storrie-Lombardi, L. J.; Sunnquist, B.; Surace, J.; Taylor, D. C.; Williams, R.; Bullock, J.; Dickinson, M.; Finkelstein, S.; Natarajan, P.; Richard, J.; Robertson, B.; Tumlinson, J.; Zitrin, A.; Flanagan, K.; Sembach, K.; Soifer, B. T.; Mountain, M.

2017-03-01

What are the faintest distant galaxies we can see with the Hubble Space Telescope (HST) now, before the launch of the James Webb Space Telescope? This is the challenge taken up by the Frontier Fields, a Director’s discretionary time campaign with HST and the Spitzer Space Telescope to see deeper into the universe than ever before. The Frontier Fields combines the power of HST and Spitzer with the natural gravitational telescopes of massive high-magnification clusters of galaxies to produce the deepest observations of clusters and their lensed galaxies ever obtained. Six clusters—Abell 2744, MACSJ0416.1-2403, MACSJ0717.5+3745, MACSJ1149.5+2223, Abell S1063, and Abell 370—have been targeted by the HST ACS/WFC and WFC3/IR cameras with coordinated parallel fields for over 840 HST orbits. The parallel fields are the second-deepest observations thus far by HST with 5σ point-source depths of ˜29th ABmag. Galaxies behind the clusters experience typical magnification factors of a few, with small regions magnified by factors of 10-100. Therefore, the Frontier Field cluster HST images achieve intrinsic depths of ˜30-33 mag over very small volumes. Spitzer has obtained over 1000 hr of Director’s discretionary imaging of the Frontier Field cluster and parallels in IRAC 3.6 and 4.5 μm bands to 5σ point-source depths of ˜26.5, 26.0 ABmag. We demonstrate the exceptional sensitivity of the HST Frontier Field images to faint high-redshift galaxies, and review the initial results related to the primary science goals.

AGN Unification at z ~ 1: u - R Colors and Gradients in X-Ray AGN Hosts

NASA Astrophysics Data System (ADS)

Ammons, S. Mark; Rosario, David J. V.; Koo, David C.; Dutton, Aaron A.; Melbourne, Jason; Max, Claire E.; Mozena, Mark; Kocevski, Dale D.; McGrath, Elizabeth J.; Bouwens, Rychard J.; Magee, Daniel K.

2011-10-01

We present uncontaminated rest-frame u - R colors of 78 X-ray-selected active galactic nucleus (AGN) hosts at 0.5 < z < 1.5 in the Chandra Deep Fields measured with Hubble Space Telescope (HST)/Advanced Camera for Surveys/NICMOS and Very Large Telescope/ISAAC imaging. We also present spatially resolved NUV - R color gradients for a subsample of AGN hosts imaged by HST/Wide Field Camera 3 (WFC3). Integrated, uncorrected photometry is not reliable for comparing the mean properties of soft and hard AGN host galaxies at z ~ 1 due to color contamination from point-source AGN emission. We use a cloning simulation to develop a calibration between concentration and this color contamination and use this to correct host galaxy colors. The mean u - R color of the unobscured/soft hosts beyond ~6 kpc is statistically equivalent to that of the obscured/hard hosts (the soft sources are 0.09 ± 0.16 mag bluer). Furthermore, the rest-frame V - J colors of the obscured and unobscured hosts beyond ~6 kpc are statistically equivalent, suggesting that the two populations have similar distributions of dust extinction. For the WFC3/infrared sample, the mean NUV - R color gradients of unobscured and obscured sources differ by less than ~0.5 mag for r > 1.1 kpc. These three observations imply that AGN obscuration is uncorrelated with the star formation rate beyond ~1 kpc. These observations favor a unification scenario for intermediate-luminosity AGNs in which obscuration is determined geometrically. Scenarios in which the majority of intermediate-luminosity AGNs at z ~ 1 are undergoing rapid, galaxy-wide quenching due to AGN-driven feedback processes are disfavored.

THE HUBBLE WIDE FIELD CAMERA 3 TEST OF SURFACES IN THE OUTER SOLAR SYSTEM: SPECTRAL VARIATION ON KUIPER BELT OBJECTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fraser, Wesley C.; Brown, Michael E.; Glass, Florian, E-mail: wesley.fraser@nrc.ca

2015-05-01

Here, we present additional photometry of targets observed as part of the Hubble Wide Field Camera 3 (WFC3) Test of Surfaces in the Outer Solar System. Twelve targets were re-observed with the WFC3 in the optical and NIR wavebands designed to complement those used during the first visit. Additionally, all of the observations originally presented by Fraser and Brown were reanalyzed through the same updated photometry pipeline. A re-analysis of the optical and NIR color distribution reveals a bifurcated optical color distribution and only two identifiable spectral classes, each of which occupies a broad range of colors and has correlatedmore » optical and NIR colors, in agreement with our previous findings. We report the detection of significant spectral variations on five targets which cannot be attributed to photometry errors, cosmic rays, point-spread function or sensitivity variations, or other image artifacts capable of explaining the magnitude of the variation. The spectrally variable objects are found to have a broad range of dynamical classes and absolute magnitudes, exhibit a broad range of apparent magnitude variations, and are found in both compositional classes. The spectrally variable objects with sufficiently accurate colors for spectral classification maintain their membership, belonging to the same class at both epochs. 2005 TV189 exhibits a sufficiently broad difference in color at the two epochs that span the full range of colors of the neutral class. This strongly argues that the neutral class is one single class with a broad range of colors, rather than the combination of multiple overlapping classes.« less

AGN UNIFICATION AT z {approx} 1: u - R COLORS AND GRADIENTS IN X-RAY AGN HOSTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mark Ammons, S.; Rosario, David J. V.; Koo, David C., E-mail: ammons@as.arizona.edu, E-mail: rosario@ucolick.org, E-mail: koo@ucolick.org

2011-10-10

We present uncontaminated rest-frame u - R colors of 78 X-ray-selected active galactic nucleus (AGN) hosts at 0.5 < z < 1.5 in the Chandra Deep Fields measured with Hubble Space Telescope (HST)/Advanced Camera for Surveys/NICMOS and Very Large Telescope/ISAAC imaging. We also present spatially resolved NUV - R color gradients for a subsample of AGN hosts imaged by HST/Wide Field Camera 3 (WFC3). Integrated, uncorrected photometry is not reliable for comparing the mean properties of soft and hard AGN host galaxies at z {approx} 1 due to color contamination from point-source AGN emission. We use a cloning simulation tomore » develop a calibration between concentration and this color contamination and use this to correct host galaxy colors. The mean u - R color of the unobscured/soft hosts beyond {approx}6 kpc is statistically equivalent to that of the obscured/hard hosts (the soft sources are 0.09 {+-} 0.16 mag bluer). Furthermore, the rest-frame V - J colors of the obscured and unobscured hosts beyond {approx}6 kpc are statistically equivalent, suggesting that the two populations have similar distributions of dust extinction. For the WFC3/infrared sample, the mean NUV - R color gradients of unobscured and obscured sources differ by less than {approx}0.5 mag for r > 1.1 kpc. These three observations imply that AGN obscuration is uncorrelated with the star formation rate beyond {approx}1 kpc. These observations favor a unification scenario for intermediate-luminosity AGNs in which obscuration is determined geometrically. Scenarios in which the majority of intermediate-luminosity AGNs at z {approx} 1 are undergoing rapid, galaxy-wide quenching due to AGN-driven feedback processes are disfavored.« less

VizieR Online Data Catalog: 47 Tuc sub-giant branch chemical abundances (Marino+, 2016)

NASA Astrophysics Data System (ADS)

Marino, A. F.; Milone, A. P.; Casagrande, L.; Collet, R.; Dotter, A.; Johnson, C. I.; Lind, K.; Bedin, L. R.; Jerjen, H.; Aparicio, A.; Sbordone, L.

2017-06-01

The photometric data set used in our study of 47 Tuc consists of HST photometry for the innermost ~3x3arcmin and ground-based photometry for the outer cluster region. Specifically, we have used the catalogues published by Milone et al. (2012ApJ...744...58M) that include photometry in the F336W (30s+1160s images from GO 11729, PI. Holtzmann), F395N bands (90s+2x1120s images from GO 11729, PI. Holtzmann) from the Ultraviolet and Visual Channel of the Advanced Camera for Surveys 3 (UVIS/WFC3) and in the F435W (9x105 s images from GO 9281, PI. Grindlay), F606W (3s+4x50s images from GO 10775, PI. Sarajedini), and F814W (3s+4x50s images from GO 10775, PI. Sarajedini) band from the Wide Field Channel of the Advanced Camera for Surveys (WFC/ACS) on board of HST. Moreover, we have used ground-based photometry in the U, B, V, and I filters from the archive maintained by Peter Stetson. The photometric catalogue has been obtained by Stetson (2000PASP..112..925S) from 856 CCD images, including 480 images taken with the Wide-Field Imager of the ESO/MPI 2.2 m telescope, and 200 with the 1.5 m telescope at Cerro Tololo Inter-American Observatory. The remaining 176 images come from various other telescopes. All the images were reduced using the method described by Stetson (2005PASP..117..563S) and are calibrated on the Landolt (1992AJ....104..340L, Cat. II/183) photometric system. (2 data files).

VizieR Online Data Catalog: Radial velocities of galaxies in A523 field (Girardi+, 2016)

NASA Astrophysics Data System (ADS)

Girardi, M.; Boschin, W.; Gastaldello, F.; Giovannini, G.; Govoni, F.; Murgia, M.; Barrena, R.; Ettori, S.; Trasatti, M.; Vacca, V.

2016-09-01

Multi-object spectroscopic observations of A523 were carried out at the TNG in 2012 December and 2014 January. We used the instrument DOLORES in MOS mode with the LR-B Grism. In summary, we observed six MOS masks for a total of 210 slits. The total exposure time was 3600s for three masks, 5400s for two masks and 7200s for the last one. Our photometric observations were carried out with the Wide Field Camera (WFC), mounted at the prime focus of the 2.5-m INT telescope. We observed A523 in g, r and i Sloan-Gunn filters in photometric conditions and a seeing of ~1.4arcsec. (1 data file).

A High-precision Trigonometric Parallax to an Ancient Metal-poor Globular Cluster

NASA Astrophysics Data System (ADS)

Brown, T. M.; Casertano, S.; Strader, J.; Riess, A.; VandenBerg, D. A.; Soderblom, D. R.; Kalirai, J.; Salinas, R.

2018-03-01

Using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST), we have obtained a direct trigonometric parallax for the nearest metal-poor globular cluster, NGC 6397. Although trigonometric parallaxes have been previously measured for many nearby open clusters, this is the first parallax for an ancient metal-poor population—one that is used as a fundamental template in many stellar population studies. This high-precision measurement was enabled by the HST/WFC3 spatial-scanning mode, providing hundreds of astrometric measurements for dozens of stars in the cluster and also for Galactic field stars along the same sightline. We find a parallax of 0.418 ± 0.013 ± 0.018 mas (statistical, systematic), corresponding to a true distance modulus of 11.89 ± 0.07 ± 0.09 mag (2.39 ± 0.07 ± 0.10 kpc). The V luminosity at the stellar main-sequence turnoff implies an absolute cluster age of 13.4 ± 0.7 ± 1.2 Gyr. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs GO-13817, GO-14336, and GO-14773.

The Hubble Space Telescope UV Legacy Survey of Galactic globular clusters - XIII. ACS/WFC parallel-field catalogues

NASA Astrophysics Data System (ADS)

Simioni, M.; Bedin, L. R.; Aparicio, A.; Piotto, G.; Milone, A. P.; Nardiello, D.; Anderson, J.; Bellini, A.; Brown, T. M.; Cassisi, S.; Cunial, A.; Granata, V.; Ortolani, S.; van der Marel, R. P.; Vesperini, E.

2018-05-01

As part of the Hubble Space Telescope UV Legacy Survey of Galactic globular clusters, 110 parallel fields were observed with the Wide Field Channel of the Advanced Camera for Surveys, in the outskirts of 48 globular clusters, plus the open cluster NGC 6791. Totalling about 0.3 deg2 of observed sky, this is the largest homogeneous Hubble Space Telescope photometric survey of Galalctic globular clusters outskirts to date. In particular, two distinct pointings have been obtained for each target on average, all centred at about 6.5 arcmin from the cluster centre, thus covering a mean area of about 23 arcmin2 for each globular cluster. For each field, at least one exposure in both F475W and F814W filters was collected. In this work, we publicly release the astrometric and photometric catalogues and the astrometrized atlases for each of these fields.

Exoplanet Transit Spectroscopy Using WFC3: WASP-12 b, WASP-17 b, and WASP-19 b

NASA Technical Reports Server (NTRS)

Mandell, Avram Max; Haynes, Korey N.; Sinukoff, Evan; Madhusudhan, Nikku; Burrows, Adam; Deming, Drake

2013-01-01

We report an analysis of transit spectroscopy of the extrasolar planets WASP-12 b, WASP-17 b, and WASP-19 b using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). We analyze the data for a single transit for each planet using a strategy similar, in certain aspects, to the techniques used by Berta et al., but we extend their methodology to allow us to correct for channel- or wavelength-dependent instrumental effects by utilizing the band-integrated time series and measurements of the drift of the spectrum on the detector over time. We achieve almost photon-limited results for individual spectral bins, but the uncertainties in the transit depth for the band-integrated data are exacerbated by the uneven sampling of the light curve imposed by the orbital phasing of HST's observations. Our final transit spectra for all three objects are consistent with the presence of a broad absorption feature at 1.4 nano meter most likely due to water. However, the amplitude of the absorption is less than that expected based on previous observations with Spitzer, possibly due to hazes absorbing in the NIR or non-solar compositions. The degeneracy of models with different compositions and temperature structures combined with the low amplitude of any features in the data preclude our ability to place unambiguous constraints on the atmospheric composition without additional observations with WFC3 to improve the signal-to-noise ratio and/or a comprehensive multi-wavelength analysis.

Radial Distributions of Sub-Populations in the Globular Cluster M15: A More Centrally Concentrated Primordial Population

NASA Astrophysics Data System (ADS)

Larsen, Søren S.; Baumgardt, Holger; Bastian, Nate; Brodie, Jean P.; Grundahl, Frank; Strader, Jay

2015-05-01

We examine the radial distributions of stellar populations in the globular cluster (GC) M15, using Hubble Space Telescope/Wide Field Camera 3 (WFC3) photometry of red giants in the nitrogen-sensitive F343N-F555W color. Surprisingly, we find that giants with “primordial” composition (i.e., N abundances similar to those in field stars) are the most centrally concentrated within the WFC3 field. We then combine our WFC3 data with Sloan Digital Sky Survey u,g photometry and find that the trend reverses for radii ≳ 1\\prime (3 pc) where the ratio of primordial to N-enhanced giants increases outward, as already found by Lardo et al. The ratio of primordial to enriched stars thus has a U-shaped dependency on radius with a minimum near the half-light radius. N-body simulations show that mass segregation might produce a trend resembling the observed one, but only if the N-enhanced giants are ˜ 0.25 {{M}⊙ } less massive than the primordial giants, which requires extreme He enhancement (Y≳ 0.40). However, such a large difference in Y is incompatible with the negligible optical color differences between primordial and enriched giants, which suggest {Δ }Y≲ 0.03 and thus a difference in turn-off mass of {Δ }M≲ 0.04 {{M}⊙ } between the different populations. The radial trends in M15 are thus unlikely to be of dynamical origin and presumably reflect initial conditions, a result that challenges all current GC formation scenarios. We note that population gradients in the central regions of GCs remain poorly investigated and may show a more diverse behavior than hitherto thought. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program #13295.

The Frontier Fields: Survey Design and Initial Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lotz, J. M.; Koekemoer, A.; Grogin, N.

What are the faintest distant galaxies we can see with the Hubble Space Telescope ( HST ) now, before the launch of the James Webb Space Telescope ? This is the challenge taken up by the Frontier Fields, a Director’s discretionary time campaign with HST and the Spitzer Space Telescope to see deeper into the universe than ever before. The Frontier Fields combines the power of HST and Spitzer with the natural gravitational telescopes of massive high-magnification clusters of galaxies to produce the deepest observations of clusters and their lensed galaxies ever obtained. Six clusters—Abell 2744, MACSJ0416.1-2403, MACSJ0717.5+3745, MACSJ1149.5+2223, Abellmore » S1063, and Abell 370—have been targeted by the HST ACS/WFC and WFC3/IR cameras with coordinated parallel fields for over 840 HST orbits. The parallel fields are the second-deepest observations thus far by HST with 5 σ point-source depths of ∼29th ABmag. Galaxies behind the clusters experience typical magnification factors of a few, with small regions magnified by factors of 10–100. Therefore, the Frontier Field cluster HST images achieve intrinsic depths of ∼30–33 mag over very small volumes. Spitzer has obtained over 1000 hr of Director’s discretionary imaging of the Frontier Field cluster and parallels in IRAC 3.6 and 4.5 μ m bands to 5 σ point-source depths of ∼26.5, 26.0 ABmag. We demonstrate the exceptional sensitivity of the HST Frontier Field images to faint high-redshift galaxies, and review the initial results related to the primary science goals.« less

Comparing the ACS/WFC and WFC3/UVIS Calibration and Photometry

NASA Astrophysics Data System (ADS)

Deustua, S. E.; Mack, J.

2018-03-01

A study was undertaken using synthetic photometry of CALSPEC stars to compare the ACS Wide Field Channel (WFC) photometry to the WFC3 UVIS imaging channel in eight similarly named passbands corresponding to the broadband filters F435W (ACS/WFC) F438W (WFC3/UVIS) and F475W, F555W, F606W, F625W, F775W, F814W and F850LP (both ACS/WFC and WFC3/UVIS). The uncertainty of the photometric calibration of ACS/WFC and WFC3/UVIS with respect to the white dwarf standard stars is within ± 0.5% for F814W, F775W, F606W and F475W, and within ±1% for F625W and F850LP. For F555W the apparent difference in the calibration is 2% for F555W and 6% for UVIS/F438W and ACS/F435W due to inherent differences in the filter passbands. Comparing the ACS/WFC to WFC3/UVIS mean flux for stars having a range of spectral types shows a color dependence. The WFC to UVIS F814W color dependence is ± 0.02 mags for F814W, F775W, F475W and F606W. For the other filters the range is -0.06 to +0.02 mags. Aperture photometry of the 47 Tucanae cluster confirm the results from using synthetic photometry of CALSPEC stars.

WFPC2 Filters after 16 Years on Orbit

NASA Astrophysics Data System (ADS)

Lian Lim, Pey; Quijada, M.; Baggett, S.; Biretta, J.; MacKenty, J.; Boucarut, R.; Rice, S.; del Hoyo, J.

2011-01-01

Wide Field Planetary Camera 2 (WFPC2) was installed on Hubble Space Telescope (HST) in December 1993 during Servicing Mission 1 by the crew of Shuttle Mission STS-61. WFPC2 replaced Wide Field Planetary Camera 1 (WFPC1), providing improved UV performance, more advanced detectors, better contamination control, and its own corrective optics. After 16 years of exceptional service, WFPC2 was retired in May 2009 during Servicing Mission 4, when it was removed from HST in order to allow for the installation of Wide Field Camera 3 (WFC3). WFPC2 was carried back to Earth in the shuttle bay by the crew of Shuttle Mission STS-125. In a joint investigation by Goddard Space Flight Center (GSFC) and Space Telescope Science Institute (STScI), the Selectable Optical Filter Assembly (SOFA) of WFPC2 was extracted and the filter wheels removed and examined for any on-orbit changes. The filters were inspected, photographed and scanned with a spectrophotometer at GSFC. The data have been analyzed at STScI with a view towards understanding how prolonged exposure to the HST space environment affected the filters and what the resultant impacts are to WFPC2 calibrations. We will summarize our results from these post-SM4 laboratory studies, including a comparison of pre- to post-mission filter throughput measurements, evaluations of the UV filter red leaks, and assessment of the condition of the filter coatings.

Close-up of M27, the Dumbbell Nebula

NASA Image and Video Library

2003-02-11

An aging star last hurrah creates a flurry of glowing knots of gas that appear to be streaking through space. This closeup image of the Dumbbell Nebula was taken by the JPL-built and designed WFC3 camera, onboard NASA's Hubble Space Telescope. http://photojournal.jpl.nasa.gov/catalog/PIA04249

High-redshift galaxies and low-mass stars

NASA Astrophysics Data System (ADS)

Wilkins, Stephen M.; Stanway, Elizabeth R.; Bremer, Malcolm N.

2014-03-01

The sensitivity available to near-infrared surveys has recently allowed us to probe the galaxy population at z ≈ 7 and beyond. The existing Hubble Wide Field Camera 3 (WFC3) and Visible and Infrared Survey Telescope for Astronomy (VISTA) Infrared Camera (VIRCam) instruments allow deep surveys to be undertaken well beyond 1 μm - a capability that will be further extended with the launch and commissioning of the James Webb Space Telescope (JWST). As new regions of parameter space in both colour and depth are probed, new challenges for distant galaxy surveys are identified. In this paper, we present an analysis of the colours of L- and T-dwarf stars in widely used photometric systems. We also consider the implications of the newly identified Y-dwarf population - stars that are still cooler and less massive than T-dwarfs for both the photometric selection and spectroscopic follow-up of faint and distant galaxies. We highlight the dangers of working in the low-signal-to-noise regime, and the potential contamination of existing and future samples. We find that Hubble/WFC3 and VISTA/VIRCam Y-drop selections targeting galaxies at z ˜ 7.5 are vulnerable to contamination from T- and Y-class stars. Future observations using JWST, targeting the z ˜ 7 galaxy population, are also likely to prove difficult without deep medium-band observations. We demonstrate that single emission line detections in typical low-signal-to-noise spectroscopic observations may also be suspect, due to the unusual spectral characteristics of the cool dwarf star population.

The panchromatic Hubble Andromeda treasury. VII. The steep mid-ultraviolet to near-infrared extinction curve in the central 200 pc of the M31 Bulge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dong, Hui; Lauer, Tod R.; Olsen, Knut

We measure the extinction curve in the central 200 pc of M31 at mid-ultraviolet to near-infrared wavelengths (from 1928 Å to 1.5 μm), using Swift/UVOT and Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3)/Advanced Camera for Surveys (ACS) observations in 13 bands. Taking advantage of the high angular resolution of the HST/WFC3 and ACS detectors, we develop a method to simultaneously determine the relative extinction and the fraction of obscured starlight for five dusty complexes located in the circumnuclear region. The extinction curves of these clumps (R{sub V} = 2.4-2.5) are steeper than the average Galactic one (R{sub V}more » = 3.1), but are similar to optical and near-infrared curves recently measured toward the Galactic bulge (R{sub V} ∼ 2.5). This similarity suggests that steep extinction curves may be common in the inner bulge of galaxies. In the ultraviolet, the extinction curves of these clumps are also unusual. We find that one dusty clump (size < 2 pc) exhibits a strong UV bump (extinction at 2175 Å), more than three standard deviation higher than that predicted by common models. Although the high stellar metallicity of the M31 bulge indicates that there are sufficient carbon and silicon to produce large dust grains, the grains may have been destroyed by supernova explosions or past activity of the central supermassive black hole, resulting in the observed steepened extinction curve.« less

Exoplanet Transit Spectroscopy Using WFC3: WASP-12b, WASP-17b, and WASP-19b

NASA Technical Reports Server (NTRS)

Mandell, Avi M.; Haynes, Korey; Sinukoff, Evan; Madhusudhan, Nikku; Burrows, Adam; Deming, Drake

2013-01-01

We report an analysis of transit spectroscopy of the extrasolar planets WASP-12 b, WASP-17 b, and WASP-19 b using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). We analyze the data for a single transit for each planet using a strategy similar, in certain aspects, to the techniques used by Berta et al., but we extend their methodology to allow us to correct for channel- or wavelength-dependent instrumental effects by utilizing the band-integrated time series and measurements of the drift of the spectrum on the detector over time. We achieve almost photon-limited results for individual spectral bins, but the uncertainties in the transit depth for the band-integrated data are exacerbated by the uneven sampling of the light curve imposed by the orbital phasing of HST's observations. Our final transit spectra for all three objects are consistent with the presence of a broad absorption feature at 1.4 microns most likely due to water. However, the amplitude of the absorption is less than that expected based on previous observations with Spitzer, possibly due to hazes absorbing in the NIR or non-solar compositions. The degeneracy of models with different compositions and temperature structures combined with the low amplitude of any features in the data preclude our ability to place unambiguous constraints on the atmospheric composition without additional observations with WFC3 to improve the signal-to-noise ratio and/or a comprehensive multi-wavelength analysis. Key words: planetary systems - techniques: photometric - techniques: spectroscopic

Onboard Processing on PWE OFA/WFC (Onboard Frequency Analyzer/Waveform Capture) aboard the ERG (ARASE) Satellite

NASA Astrophysics Data System (ADS)

Matsuda, S.; Kasahara, Y.; Kojima, H.; Kasaba, Y.; Yagitani, S.; Ozaki, M.; Imachi, T.; Ishisaka, K.; Kurita, S.; Ota, M.; Kumamoto, A.; Tsuchiya, F.; Yoshizumi, M.; Matsuoka, A.; Teramoto, M.; Shinohara, I.

2017-12-01

Exploration of energization and Radiation in Geospace (ERG) is a mission for understanding particle acceleration, loss mechanisms, and the dynamic evolution of space storms in the context of cross-energy and cross-regional coupling [Miyoshi et al., 2012]. The ERG (ARASE) satellite was launched on December 20, 2016, and successfully inserted into an orbit. The Plasma Wave Experiment (PWE) is one of the science instruments on board the ERG satellite to measure electric field and magnetic field in the inner magnetosphere. PWE consists of three sub-components, EFD (Electric Field Detector), OFA/WFC (Onboard Frequency Analyzer and Waveform Capture), and HFA (High Frequency Analyzer). Especially, OFA/WFC measures electric and magnetic field spectrum and waveform from a few Hz to 20 kHz. OFA/WFC processes signals detected by a couple of dipole wire-probe antenna (WPT) and tri-axis magnetic search coils (MSC) installed onboard the satellite. The PWE-OFA subsystem calculates and produces three kind of data; OFA-SPEC (power spectrum), OFA-MATRIX (spectrum matrix), and OFA-COMPLEX (complex spectrum). They are continuously processed 24 hours per day and all data are sent to the ground. OFA-MATRIX and OFA-COMPLEX are used for polarization analyses and direction finding of the plasma waves. The PWE-WFC subsystem measures raw (64 kHz sampled) and down-sampled (1 kHz sampled) burst waveform detected by the WPT and the MSC sensors. It activates by a command, automatic triggering, and scheduling. The initial check-out process of the PWE successfully completed, and initial data has been obtained. In this presentation, we introduce onboard processing technique on PWE OFA/WFC and its initial results.

Atmospheric characterization of five hot Jupiters with the wide field Camera 3 on the Hubble space telescope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ranjan, Sukrit; Charbonneau, David; Désert, Jean-Michel

We probe the structure and composition of the atmospheres of five hot Jupiter exoplanets using the Hubble Space Telescope Wide Field Camera 3 (WFC3) instrument. We use the G141 grism (1.1-1.7 μm) to study TrES-2b, TrES-4b, and CoRoT-1b in transit; TrES-3b in secondary eclipse; and WASP-4b in both. This wavelength region includes a predicted absorption feature from water at 1.4 μm, which we expect to be nondegenerate with the other molecules that are likely to be abundant for hydrocarbon-poor (e.g., solar composition) hot Jupiter atmospheres. We divide our wavelength regions into 10 bins. For each bin we produce a spectrophotometricmore » light curve spanning the time of transit or eclipse. We correct these light curves for instrumental systematics without reference to an instrument model. For our transmission spectra, our mean 1σ precision per bin corresponds to variations of 2.1, 2.8, and 3.0 atmospheric scale heights for TrES-2b, TrES-4b, and CoRoT-1b, respectively. We find featureless spectra for these three planets. We are unable to extract a robust transmission spectrum for WASP-4b. For our dayside emission spectra, our mean 1σ precision per bin corresponds to a planet-to-star flux ratio of 1.5 × 10{sup –4} and 2.1 × 10{sup –4} for WASP-4b and TrES-3b, respectively. We combine these estimates with previous broadband measurements and conclude that for both planets isothermal atmospheres are disfavored. We find no signs of features due to water. We confirm that WFC3 is suitable for studies of transiting exoplanets, but in staring mode multivisit campaigns are necessary to place strong constraints on water abundance.« less

Atmospheric Characterization of Five Hot Jupiters with the Wide Field Camera 3 on the Hubble Space Telescope

NASA Technical Reports Server (NTRS)

Ranjan, Sukrit; Charbonneau, David; Desert, Jean-Michel; Madhusudhan, Nikku; Deming, Drake; Wilkins, Ashlee; Mandell, Avi M.

2014-01-01

We probe the structure and composition of the atmospheres of five hot Jupiter exoplanets using the Hubble Space Telescope Wide Field Camera 3 (WFC3) instrument. We use the G141 grism (1.1-1.7 micrometers) to study TrES-2b, TrES-4b, and CoRoT-1b in transit; TrES-3b in secondary eclipse; and WASP-4b in both. This wavelength region includes a predicted absorption feature from water at 1.4 micrometers, which we expect to be nondegenerate with the other molecules that are likely to be abundant for hydrocarbon-poor (e.g., solar composition) hot Jupiter atmospheres. We divide our wavelength regions into 10 bins. For each bin we produce a spectrophotometric light curve spanning the time of transit or eclipse. We correct these light curves for instrumental systematics without reference to an instrument model. For our transmission spectra, our mean 1s precision per bin corresponds to variations of 2.1, 2.8, and 3.0 atmospheric scale heights for TrES-2b, TrES-4b, and CoRoT-1b, respectively. We find featureless spectra for these three planets. We are unable to extract a robust transmission spectrum for WASP-4b. For our dayside emission spectra, our mean 1 sigma precision per bin corresponds to a planet-to-star flux ratio of 1.5 x 10(exp -4) and 2.1 x 10(exp -4) for WASP-4b and TrES-3b, respectively. We combine these estimates with previous broadband measurements and conclude that for both planets isothermal atmospheres are disfavored. We find no signs of features due to water. We confirm that WFC3 is suitable for studies of transiting exoplanets, but in staring mode multivisit campaigns are necessary to place strong constraints on water abundance.

Monster Clusters in the Young Universe? Weak-lensing Masses of SPT-CL J0205-5829 and MOO1014+0038 with HST Observations

NASA Astrophysics Data System (ADS)

Feilx Kim, Seojin; Jee, Myungkook James

2018-01-01

Measuring High-z clusters’ masses is very important as the cluster abundance is extremely sensitive to the cosmological parameters. However, deriving their masses from the intracluster medium properties (i.e., Sunyaev-Zel’dovich or X-ray observations) is not the best method because of their departure from the hydrostatic equilibrium. Fortunately, the “See Change” Hubble Space Telescope program offers a rare opportunity to measure them using weak gravitational lensing. We study SPT-CL J0205-5829 (z=1.322) and MOO1014+0038 (z=1.24) discovered in the SPT-SZ and MaDCoW Surveys, respectively. Previous non-lensing based approaches suggest that both targets might be extremely massive clusters. After carefully addressing various possible systematics from the Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFC3) images, we successfully detect clear weak lensing signals. We present their 2-dimensional mass maps and compare our weak-lensing masses with previous ICM-based results.

WFPC2 Filters after 16 Years on Orbit

NASA Astrophysics Data System (ADS)

Lim, P. L.; Quijada, M.; Baggett, S. M.; Biretta, J.; MacKenty, J.; Boucarut, R.; Rice, S.; Del Hoyo, J.

2010-07-01

Wide Field Planetary Camera 2 (WFPC2) was installed on Hubble Space Telescope (HST) in December 1993 during Servicing Mission 1 by the crew of Shuttle Mission STS-61. WFPC2 replaced Wide Field Planetary Camera 1 (WFPC1), providing improved UV performance, more advanced detectors, better contamination control, and its own corrective optics. After 16 years of exceptional service, WFPC2 was retired in May 2009 during Servicing Mission 4 (SM4), when it was removed from HST in order to allow for the installation of Wide Field Camera 3 (WFC3). WFPC2 was carried back to Earth in the shuttle bay by the crew of Shuttle Mission STS-125. In a joint investigation by Goddard Space Flight Center (GSFC) and Space Telescope Science Institute (STScI), the Selectable Optical Filter Assembly (SOFA) of WFPC2 was extracted and the filter wheels removed and examined for any on-orbit changes. The filters were inspected, photographed and scanned with a spectrophotometer at GSFC. The data have been analyzed at STScI with a view towards understanding how prolonged exposure to the HST space environment affected the filters and what the resultant impacts are to WFPC2 calibrations. In this paper, we present our early results from these post-SM4 laboratory studies, including comparisons of pre- to post-mission filter transmission measurements for F343N, F160AW, F160BW, F450W, and F170W.

Telescope Multi-Field Wavefront Control with a Kalman Filter

NASA Technical Reports Server (NTRS)

Lou, John Z.; Redding, David; Sigrist, Norbert; Basinger, Scott

2008-01-01

An effective multi-field wavefront control (WFC) approach is demonstrated for an actuated, segmented space telescope using wavefront measurements at the exit pupil, and the optical and computational implications of this approach are discussed. The integration of a Kalman Filter as an optical state estimator into the wavefront control process to further improve the robustness of the optical alignment of the telescope will also be discussed. Through a comparison of WFC performances between on-orbit and ground-test optical system configurations, the connection (and a possible disconnection) between WFC and optical system alignment under these circumstances are analyzed. Our MACOS-based computer simulation results will be presented and discussed.

Hubble Space Telescope Medium Deep Survey. 2: Deconvolution of Wide Field Camera field galaxy images in the 13 hour + 43 deg field

NASA Technical Reports Server (NTRS)

Windhorst, R. A.; Schmidtke, P. C.; Pascarelle, S. M.; Gordon, J. M.; Griffiths, R. E.; Ratnatunga, K. U.; Neuschaefer, L. W.; Ellis, R. S.; Gilmore, G.; Glazebrook, K.

1994-01-01

We present isophotal profiles of six faint field galaxies from some of the first deep images taken for the Hubble Space Telescope (HST) Medium Deep Survey (MDS). These have redshifts in the range z = 0.126 to 0.402. The images were taken with the Wide Field Camera (WFC) in `parallel mode' and deconvolved with the Lucy method using as the point-spread function nearby stars in the image stack. The WFC deconvolutions have a dynamic range of 16 to 20 dB (4 to 5 mag) and an effective resolution approximately less than 0.2 sec (FWHM). The multiorbit HST images allow us to trace the morphology, light profiles, and color gradients of faint field galaxies down to V approximately equal to 22 to 23 mag at sub-kpc resolution, since the redshift range covered is z = 0.1 to 0.4. The goals of the MDS are to study the sub-kpc scale morphology, light profiles, and color gradients for a large samole of faint field galaxies down to V approximately equal to 23 mag, and to trace the fraction of early to late-type galaxies as function of cosmic time. In this paper we study the brighter MDS galaxies in the 13 hour + 43 deg MDS field in detail, and investigate to what extent model fits with pure exponential disks or a(exp 1/4) bulges are justified at V approximately less than 22 mag. Four of the six field galaxies have light profiles that indicate (small) inner bulges following r(exp 1/4) laws down to 0.2 sec resolution, plus a dominant surrounding exponential disk with little or no color gradients. Two occur in a group at z = 0.401, two are barred spiral galaxies at z = 0.179 and z = 0.302, and two are rather subluminous (and edge-on) disk galaxies at z = 0.126 and z = 0.179. Our deep MDS images can detect galaxies down to V, I approximately less than 25 to 26 mag, and demonstrate the impressive potential of HST--even with its pre-refurbished optics--to resolve morphological details in galaxies at cosmologically significant distances (v approximately less than 23 mag). Since the median redshift of these galaxies is approximately less than 0.4, the HST resolution allows us to study sub kpc size scales at the galaxy, which cannot be done with stable images over wide fields from the best ground-based sites.

On-Orbit Multi-Field Wavefront Control with a Kalman Filter

NASA Technical Reports Server (NTRS)

Lou, John; Sigrist, Norbert; Basinger, Scott; Redding, David

2008-01-01

A document describes a multi-field wavefront control (WFC) procedure for the James Webb Space Telescope (JWST) on-orbit optical telescope element (OTE) fine-phasing using wavefront measurements at the NIRCam pupil. The control is applied to JWST primary mirror (PM) segments and secondary mirror (SM) simultaneously with a carefully selected ordering. Through computer simulations, the multi-field WFC procedure shows that it can reduce the initial system wavefront error (WFE), as caused by random initial system misalignments within the JWST fine-phasing error budget, from a few dozen micrometers to below 50 nm across the entire NIRCam Field of View, and the WFC procedure is also computationally stable as the Monte-Carlo simulations indicate. With the incorporation of a Kalman Filter (KF) as an optical state estimator into the WFC process, the robustness of the JWST OTE alignment process can be further improved. In the presence of some large optical misalignments, the Kalman state estimator can provide a reasonable estimate of the optical state, especially for those degrees of freedom that have a significant impact on the system WFE. The state estimate allows for a few corrections to the optical state to push the system towards its nominal state, and the result is that a large part of the WFE can be eliminated in this step. When the multi-field WFC procedure is applied after Kalman state estimate and correction, the stability of fine-phasing control is much more certain. Kalman Filter has been successfully applied to diverse applications as a robust and optimal state estimator. In the context of space-based optical system alignment based on wavefront measurements, a KF state estimator can combine all available wavefront measurements, past and present, as well as measurement and actuation error statistics to generate a Maximum-Likelihood optimal state estimator. The strength and flexibility of the KF algorithm make it attractive for use in real-time optical system alignment when WFC alone cannot effectively align the system.

3D-HST WFC3-selected Photometric Catalogs in the Five CANDELS/3D-HST Fields: Photometry, Photometric Redshifts, and Stellar Masses

NASA Astrophysics Data System (ADS)

Skelton, Rosalind E.; Whitaker, Katherine E.; Momcheva, Ivelina G.; Brammer, Gabriel B.; van Dokkum, Pieter G.; Labbé, Ivo; Franx, Marijn; van der Wel, Arjen; Bezanson, Rachel; Da Cunha, Elisabete; Fumagalli, Mattia; Förster Schreiber, Natascha; Kriek, Mariska; Leja, Joel; Lundgren, Britt F.; Magee, Daniel; Marchesini, Danilo; Maseda, Michael V.; Nelson, Erica J.; Oesch, Pascal; Pacifici, Camilla; Patel, Shannon G.; Price, Sedona; Rix, Hans-Walter; Tal, Tomer; Wake, David A.; Wuyts, Stijn

2014-10-01

The 3D-HST and CANDELS programs have provided WFC3 and ACS spectroscopy and photometry over ≈900 arcmin2 in five fields: AEGIS, COSMOS, GOODS-North, GOODS-South, and the UKIDSS UDS field. All these fields have a wealth of publicly available imaging data sets in addition to the Hubble Space Telescope (HST) data, which makes it possible to construct the spectral energy distributions (SEDs) of objects over a wide wavelength range. In this paper we describe a photometric analysis of the CANDELS and 3D-HST HST imaging and the ancillary imaging data at wavelengths 0.3-8 μm. Objects were selected in the WFC3 near-IR bands, and their SEDs were determined by carefully taking the effects of the point-spread function in each observation into account. A total of 147 distinct imaging data sets were used in the analysis. The photometry is made available in the form of six catalogs: one for each field, as well as a master catalog containing all objects in the entire survey. We also provide derived data products: photometric redshifts, determined with the EAZY code, and stellar population parameters determined with the FAST code. We make all the imaging data that were used in the analysis available, including our reductions of the WFC3 imaging in all five fields. 3D-HST is a spectroscopic survey with the WFC3 and ACS grisms, and the photometric catalogs presented here constitute a necessary first step in the analysis of these grism data. All the data presented in this paper are available through the 3D-HST Web site (http://3dhst.research.yale.edu).

3D-HST WFC3-SELECTED PHOTOMETRIC CATALOGS IN THE FIVE CANDELS/3D-HST FIELDS: PHOTOMETRY, PHOTOMETRIC REDSHIFTS, AND STELLAR MASSES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skelton, Rosalind E.; Whitaker, Katherine E.; Momcheva, Ivelina G.

The 3D-HST and CANDELS programs have provided WFC3 and ACS spectroscopy and photometry over ≈900 arcmin{sup 2} in five fields: AEGIS, COSMOS, GOODS-North, GOODS-South, and the UKIDSS UDS field. All these fields have a wealth of publicly available imaging data sets in addition to the Hubble Space Telescope (HST) data, which makes it possible to construct the spectral energy distributions (SEDs) of objects over a wide wavelength range. In this paper we describe a photometric analysis of the CANDELS and 3D-HST HST imaging and the ancillary imaging data at wavelengths 0.3-8 μm. Objects were selected in the WFC3 near-IR bands,more » and their SEDs were determined by carefully taking the effects of the point-spread function in each observation into account. A total of 147 distinct imaging data sets were used in the analysis. The photometry is made available in the form of six catalogs: one for each field, as well as a master catalog containing all objects in the entire survey. We also provide derived data products: photometric redshifts, determined with the EAZY code, and stellar population parameters determined with the FAST code. We make all the imaging data that were used in the analysis available, including our reductions of the WFC3 imaging in all five fields. 3D-HST is a spectroscopic survey with the WFC3 and ACS grisms, and the photometric catalogs presented here constitute a necessary first step in the analysis of these grism data. All the data presented in this paper are available through the 3D-HST Web site (http://3dhst.research.yale.edu)« less

Wide Field Collimator 2 (WFC2) for GOES Imager and Sounder

NASA Technical Reports Server (NTRS)

Etemad, Shahriar; Bremer, James C.; Zukowski, Barbara J.; Pasquale, Bert A.; zukowski, Tmitri J.; Prince, Robert E.; O'Neill, Patrick A.; Ross, Robert W.

2004-01-01

Two of the GOES instruments, the Imager and the Sounder, perform scans of the Earth to provide a full disc picture of the Earth. To verify the entire scan process, an image of a target that covers an 18 deg. circular field-of-view is collimated and projected into the field of regard of each instrument. The Wide Field Collimator 2 (WFC2) has many advantages over its predecessor, WFC1, including lower thermal dissipation higher fir field MTF, smaller package, and a more intuitive (faster) focusing process. The illumination source is an LED array that emits in a narrow spectral band centered at 689 nm, within the visible spectral bands of the Imager and Sounder. The illumination level can be continuously adjusted electronically. Lower thermal dissipation eliminates the need for forced convection cooling and minimizes time to reach thermal stability. The lens system has been optimized for the illumination source spectral output and athernalized to remain in focus during bulk temperature changes within the laboratory environment. The MTF of the lens is higher than that of the WFC1 at the edge of FOV. The target is focused in three orthogonal motions, controlled by an ergonomic system that saves substantial time and produces a sharper focus. Key words: Collimator, GOES, Imager, Sounder, Projector

Separation in 5 Msun Binaries

NASA Astrophysics Data System (ADS)

Evans, Nancy R.; Bond, H. E.; Schaefer, G.; Mason, B. D.; Karovska, M.; Tingle, E.

2013-01-01

Cepheids (5 Msun stars) provide an excellent sample for determining the binary properties of fairly massive stars. International Ultraviolet Explorer (IUE) observations of Cepheids brighter than 8th magnitude resulted in a list of ALL companions more massive than 2.0 Msun uniformly sensitive to all separations. Hubble Space Telescope Wide Field Camera 3 (WFC3) has resolved three of these binaries (Eta Aql, S Nor, and V659 Cen). Combining these separations with orbital data in the literature, we derive an unbiased distribution of binary separations for a sample of 18 Cepheids, and also a distribution of mass ratios. The distribution of orbital periods shows that the 5 Msun binaries prefer shorter periods than 1 Msun stars, reflecting differences in star formation processes.

Aperture shape dependencies in extended depth of focus for imaging camera by wavefront coding

NASA Astrophysics Data System (ADS)

Sakita, Koichi; Ohta, Mitsuhiko; Shimano, Takeshi; Sakemoto, Akito

2015-02-01

Optical transfer functions (OTFs) on various directional spatial frequency axes for cubic phase mask (CPM) with circular and square apertures are investigated. Although OTF has no zero points, it has a very close value to zero for a circular aperture at low frequencies on diagonal axis, which results in degradation of restored images. The reason for close-to-zero value in OTF is also analyzed in connection with point spread function profiles using Fourier slice theorem. To avoid close-to-zero condition, square aperture with CPM is indispensable in WFC. We optimized cubic coefficient α of CPM and coefficients of digital filter, and succeeded to get excellent de-blurred images at large depth of field.

New Subarray Readout Patterns for the ACS Wide Field Channel

NASA Astrophysics Data System (ADS)

Golimowski, D.; Anderson, J.; Arslanian, S.; Chiaberge, M.; Grogin, N.; Lim, Pey Lian; Lupie, O.; McMaster, M.; Reinhart, M.; Schiffer, F.; Serrano, B.; Van Marshall, M.; Welty, A.

2017-04-01

At the start of Cycle 24, the original CCD-readout timing patterns used to generate ACS Wide Field Channel (WFC) subarray images were replaced with new patterns adapted from the four-quadrant readout pattern used to generate full-frame WFC images. The primary motivation for this replacement was a substantial reduction of observatory and staff resources needed to support WFC subarray bias calibration, which became a new and challenging obligation after the installation of the ACS CCD Electronics Box Replacement during Servicing Mission 4. The new readout patterns also improve the overall efficiency of observing with WFC subarrays and enable the processing of subarray images through stages of the ACS data calibration pipeline (calacs) that were previously restricted to full-frame WFC images. The new readout patterns replace the original 512×512, 1024×1024, and 2048×2046-pixel subarrays with subarrays having 2048 columns and 512, 1024, and 2048 rows, respectively. Whereas the original square subarrays were limited to certain WFC quadrants, the new rectangular subarrays are available in all four quadrants. The underlying bias structure of the new subarrays now conforms with those of the corresponding regions of the full-frame image, which allows raw frames in all image formats to be calibrated using one contemporaneous full-frame "superbias" reference image. The original subarrays remain available for scientific use, but calibration of these image formats is no longer supported by STScI.

WFC3/UVIS External CTE Monitor: Single-Chip CTE Measurements

NASA Astrophysics Data System (ADS)

Gosmeyer, C. M.; Baggett, S.

2016-12-01

We present the first results of single-chip measurements of charge transfer efficiency (CTE) in the UVIS channel of the Hubble Space Telescope Wide Field Camera 3 (HST/WFC3). This test was performed in Cycle 20 in two visits. In the first visit a field in the star cluster NGC 6583 was observed. In a second visit, the telescope returned to the field, but rotated by 180 degrees and with a shift in pointing that allowed the same stars to be imaged, near and far from the amplifiers, on the same chip of the two-chip UVIS field of-view. This dataset enables a measurement of CTE loss on each separate chip. The current CTE monitor measures CTE loss as an average of the two chips because it dithers by a chip-height to obtain observations of the same sources near and far from the amplifiers, instead of the more difficult to-schedule 180-degree rotation. We find that CTE loss is worse on Chip 1 than on Chip 2 across all cases for which we had data: short and long exposures and w! ith and without the pixel-based CTE correction. In the best case, for long exposures with the CTE correction applied, the max difference between the two chip's flux losses is 3%/2048 pixels. This case should apply for most science observations where the background is 12 e-/pixel. In the worst case of low-background short exposures, e.g. those without post-flash, the max difference between the two chips is 17% flux loss/2048 pixels. Uncertainties are <0.01% flux loss/2048 pixels. Because of the two chips' different CTE loss rates, we will consider adding this test as part of the routine yearly monitor and creating a chip-specific CTE correction software.

Water vapor in the spectrum of the extrasolar planet HD 189733b. I. The transit

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCullough, P. R.; Crouzet, N.; Deming, D.

2014-08-10

We report near-infrared spectroscopy of the gas giant planet HD 189733b in transit. We used the Hubble Space Telescope Wide Field Camera 3 (HST WFC3) with its G141 grism covering 1.1 μm to 1.7 μm and spatially scanned the image across the detector at 2'' s{sup –1}. When smoothed to 75 nm bins, the local maxima of the transit depths in the 1.15 μm and 1.4 μm water vapor features are, respectively, 83 ± 53 ppm and 200 ± 47 ppm greater than the local minimum at 1.3 μm. We compare the WFC3 spectrum with the composite transit spectrum ofmore » HD 189733b assembled by Pont et al., extending from 0.3 μm to 24 μm. Although the water vapor features in the WFC3 spectrum are compatible with the model of non-absorbing, Rayleigh-scattering dust in the planetary atmosphere, we also re-interpret the available data with a clear planetary atmosphere. In the latter interpretation, the slope of increasing transit depth with shorter wavelengths from the near infrared, through the visible, and into the ultraviolet is caused by unocculted star spots, with a smaller contribution of Rayleigh scattering by molecular hydrogen in the planet's atmosphere. At relevant pressures along the terminator, our model planetary atmosphere's temperature is ∼700 K, which is below the condensation temperatures of sodium- and potassium-bearing molecules, causing the broad wings of the spectral lines of Na I and K I at 0.589 μm and 0.769 μm to be weak.« less

Marginalizing Instrument Systematics in HST WFC3 Transit Light Curves

NASA Astrophysics Data System (ADS)

Wakeford, H. R.; Sing, D. K.; Evans, T.; Deming, D.; Mandell, A.

2016-03-01

Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) infrared observations at 1.1-1.7 μm probe primarily the H2O absorption band at 1.4 μm, and have provided low-resolution transmission spectra for a wide range of exoplanets. We present the application of marginalization based on Gibson to analyze exoplanet transit light curves obtained from HST WFC3 to better determine important transit parameters such as Rp/R*, which are important for accurate detections of H2O. We approximate the evidence, often referred to as the marginal likelihood, for a grid of systematic models using the Akaike Information Criterion. We then calculate the evidence-based weight assigned to each systematic model and use the information from all tested models to calculate the final marginalized transit parameters for both the band-integrated and spectroscopic light curves to construct the transmission spectrum. We find that a majority of the highest weight models contain a correction for a linear trend in time as well as corrections related to HST orbital phase. We additionally test the dependence on the shift in spectral wavelength position over the course of the observations and find that spectroscopic wavelength shifts {δ }λ (λ ) best describe the associated systematic in the spectroscopic light curves for most targets while fast scan rate observations of bright targets require an additional level of processing to produce a robust transmission spectrum. The use of marginalization allows for transparent interpretation and understanding of the instrument and the impact of each systematic evaluated statistically for each data set, expanding the ability to make true and comprehensive comparisons between exoplanet atmospheres.

Marginalizing Instrument Systematics in HST WFC3 Transit Light Curves

NASA Technical Reports Server (NTRS)

Wakeford, H. R.; Sing, D.K.; Deming, D.; Mandell, A.

2016-01-01

Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) infrared observations at 1.1-1.7 microns probe primarily the H2O absorption band at 1.4 microns, and have provided low-resolution transmission spectra for a wide range of exoplanets. We present the application of marginalization based on Gibson to analyze exoplanet transit light curves obtained from HST WFC3 to better determine important transit parameters such as "ramp" probability (R (sub p)) divided by "ramp" total (R (sub asterisk)), which are important for accurate detections of H2O. We approximate the evidence, often referred to as the marginal likelihood, for a grid of systematic models using the Akaike Information Criterion. We then calculate the evidence-based weight assigned to each systematic model and use the information from all tested models to calculate the final marginalized transit parameters for both the band-integrated and spectroscopic light curves to construct the transmission spectrum. We find that a majority of the highest weight models contain a correction for a linear trend in time as well as corrections related to HST orbital phase. We additionally test the dependence on the shift in spectral wavelength position over the course of the observations and find that spectroscopic wavelength shifts delta (sub lambda) times lambda) best describe the associated systematic in the spectroscopic light curves for most targets while fast scan rate observations of bright targets require an additional level of processing to produce a robust transmission spectrum. The use of marginalization allows for transparent interpretation and understanding of the instrument and the impact of each systematic evaluated statistically for each data set, expanding the ability to make true and comprehensive comparisons between exoplanet atmospheres.

A TYPE Ia SUPERNOVA AT REDSHIFT 1.55 IN HUBBLE SPACE TELESCOPE INFRARED OBSERVATIONS FROM CANDELS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodney, Steven A.; Riess, Adam G.; Jones, David O.

2012-02-10

We report the discovery of a Type Ia supernova (SN Ia) at redshift z = 1.55 with the infrared detector of the Wide Field Camera 3 (WFC3-IR) on the Hubble Space Telescope (HST). This object was discovered in CANDELS imaging data of the Hubble Ultra Deep Field and followed as part of the CANDELS+CLASH Supernova project, comprising the SN search components from those two HST multi-cycle treasury programs. This is the highest redshift SN Ia with direct spectroscopic evidence for classification. It is also the first SN Ia at z > 1 found and followed in the infrared, providing amore » full light curve in rest-frame optical bands. The classification and redshift are securely defined from a combination of multi-band and multi-epoch photometry of the SN, ground-based spectroscopy of the host galaxy, and WFC3-IR grism spectroscopy of both the SN and host. This object is the first of a projected sample at z > 1.5 that will be discovered by the CANDELS and CLASH programs. The full CANDELS+CLASH SN Ia sample will enable unique tests for evolutionary effects that could arise due to differences in SN Ia progenitor systems as a function of redshift. This high-z sample will also allow measurement of the SN Ia rate out to z Almost-Equal-To 2, providing a complementary constraint on SN Ia progenitor models.« less

Cloud Atlas: Rotational Modulations in the L/T Transition Brown Dwarf Companion HN Peg B

NASA Technical Reports Server (NTRS)

Zhou, Yifan; Apai, Daniel; Metchev, Stanimir; Lew, Ben W. P.; Schneider, Glenn; Marley, Mark S.; Karalidi, Theodora; Manjavacas, Elena; Bedin, Luigi R.; Cowan, Nicolas B.;

WFC3/UVIS Dark Calibration: Monitoring Results and Improvements to Dark Reference Files

NASA Astrophysics Data System (ADS)

Bourque, M.; Baggett, S.

2016-04-01

The Wide Field Camera 3 (WFC3) UVIS detector possesses an intrinsic signal during exposures, even in the absence of light, known as dark current. A daily monitor program is employed every HST cycle to characterize and measure this current as well as to create calibration files which serve to subtract the dark current from science data. We summarize the results of the daily monitor program for all on-orbit data. We also introduce a new algorithm for generating the dark reference files that provides several improvements to their overall quality. Key features to the new algorithm include correcting the dark frames for Charge Transfer Efficiency (CTE) losses, using an anneal-cycle average value to measure the dark current, and generating reference files on a daily basis. This new algorithm is part of the release of the CALWF3 v3.3 calibration pipeline on February 23, 2016 (also known as "UVIS 2.0"). Improved dark reference files have been regenerated and re-delivered to the Calibration Reference Data System (CRDS) for all on-orbit data. Observers with science data taken prior to the release of CALWF3 v3.3 may request their data through the Mikulski Archive for Space Telescopes (MAST) to obtain the improved products.

Resolved Companions of Cepheids as Seen by HST and XMM

NASA Astrophysics Data System (ADS)

Evans, Nancy Remage; Bond, Howard E.; Schaefer, Gail; Mason, Brian D.; Tingle, Evan; Karovska, Margarita; Pillitteri, Ignazio; Wolk, Scott J.; Guinan, Edward F.; Engle, Scott G.

2016-01-01

We have conducted a survey of 70 classical Cepheids with the Hubble Wide Field Camera3 (WFC3) to identify possible resolved companions. Data cover the range of 0.3" to 20" which typically corresponds to 200 AU to 0.1 pc. At present only possible companions greater than 5" from the Cepheid are discussed, since closer companions require a sophisticated point spread correction for the light of the much brighter Cepheid. We have followed up a subset of the possible resolved companions with XMM observations to determine whether they are young (X-ray active) enough to be physical companions of the Cepheids. We estimate that 4% of the Cepheids have a physical resolved companion, with the widest having a separation of 4000 AU. The one wider young star is in the field of S Nor, but since it is a cluster member, the companion is not assumed to be gravitationally bound to the Cepheid.

New Hubble Space Telescope Multi-Wavelength Imaging of the Eagle Nebula

NASA Astrophysics Data System (ADS)

Levay, Zoltan G.; Christian, Carol A.; Mack, Jennifer; Frattare, Lisa M.; Livio, Mario; Meyett, Michele L.; Mutchler, Maximilian J.; Noll, Keith S.; Hubble Heritage

2015-01-01

One of the most iconic images from the Hubble Space Telescope has been the 1995 WFPC2 image of the Eagle Nebula (M16, sometimes known as the "Pillars of Creation"). Nineteen years after those original observations, new images have been obtained with HST's current instrumentation: a small mosaic in visible-light, narrow-band filters with WFC3/UVIS, infrared, broad-band filters with WFC3/IR, and parallel Hα imaging with ACS/WFC. The wider field of view, higher resolution, and broader wavelength coverage of the new images highlight the improved capabilities of HST over its long-lasting operation, made possible by the upgraded instrumentation installed during Space Shuttle servicing missions. Csite images from these datasets are presented to commemorate the 25th anniversary of HST's launch. Carefully combined, aligned and calibrated datasets from the primary WFC3 fields are available as High-Level Science Products in MAST (http://archive.stsci.edu/prepds/heritage/). Color composite images from these datasets are presented to commemorate the 25th anniversary of HST's launch.

Work-family conflict and health in Swedish working women and men: a 2-year prospective analysis (the SLOSH study).

PubMed

Leineweber, Constanze; Baltzer, Maria; Magnusson Hanson, Linda L; Westerlund, Hugo

2013-08-01

Research has suggested that gender is related to perceptions of work-family conflict (WFC) and an underlying assumption is that interference of paid work with family life will burden women more than men. There is, however, mixed evidence as to whether men and women report different levels of WFC. Even less studies investigate gender differences in health outcomes of WFC. Also the number of longitudinal studies in this field is low. Based on the Swedish Longitudinal Occupational Survey of Health, we prospectively examined the effects of WFC on three different health measures representing a wide spectrum off ill health (i.e. self-rated health, emotional exhaustion and problem drinking). Logistic regression analyses were used to analyse multivariate associations between WFC in 2008 and health 2 years later. The results show that WFC was associated with an increased risk of emotional exhaustion among both men and women. Gender differences are suggested as WFC was related to an increased risk for poor self-rated health among women and problem drinking among men. Interaction analyses revealed that the risk of poor self-rated health was substantially more influenced by WFC among women than among men. We conclude that, despite the fact that women experience conflict between work and family life slightly more often than men, both men's and women's health is negatively affected by this phenomenon.

The Relationship between Ultraviolet Line Emission and Magnetic Field Strength in Magnetic Cataclysmic Variables

NASA Astrophysics Data System (ADS)

Howell, Steve B.; Cash, Jennifer; Mason, Keith O.; Herzog, Adrienne E.

1999-02-01

We present the first UV spectral observations of six magnetic cataclysmic variables discovered by the ROSAT Wide Field Camera (WFC). Using the^ International Ultraviolet Explorer (IUE), 1200-3400 Å spectra were obtained of the AM Herculis stars RE 0531-46, RE 1149+28, RE 1844-74, QS Tel (RE 1938-46), and HU Aqr (RE 2107-05) and the DQ Herculis star PQ Gem (RE 0751+14). The high-state UV spectra are dominated by strong emission lines. Continuum flux distributions for these stars (from 100 to 5500 Å) reveal that over this entire range, none of the spectral energy distributions can be fitted by a single-valued blackbody. Our new UV observations and additional archival IUE spectra were used to discover a correlation between the strength of the high-state UV emission lines and the strength of the white dwarf magnetic field. Model spectral results are used to confirm the production of the UV emission lines by photoionization from X-ray and EUV photons.

VizieR Online Data Catalog: Redshifts of galaxies in Abell 1351 field (Barrena+, 2014)

NASA Astrophysics Data System (ADS)

Barrena, R.; Girardi, M.; Boschin, W.; de Grandi, S.; Rossetti, M.

2015-03-01

Multi-object spectroscopic (MOS) observations of A1351 were carried out at the TNG on 2010 March 10. We used DOLORES/MOS with the LR-B Grism 1, yielding a dispersion of 187Å/mm. We used the 2048x2048 pixel E2V CCD, with a pixel size of 13.5um. In total, we observed four MOS masks including 143 slits. For each mask, the exposure time was 3x1800s. We had already observed A1351 field with the Wide Field Camera (WFC), mounted at the prime focus of the 2.5m INT telescope. We took exposures of 9x600s and 9x300s in B and R Harris filters in photometric conditions and 1.2-arcsec seeing. However, we used SDSS-DR7 data because a greater number of photometric bands are available, which allows an accurate colour analysis. INT and SDSS-DR7 photometric data are very similar. The completeness magnitude is r'=20.8. (1 data file).

A Magnified View of the Kinematics and Morphology of RCSGA 032727-132609: Zooming in on a Merger at z = 1.7

NASA Technical Reports Server (NTRS)

Wuyts, Eva; Rigby, Jane R.; Gladders, Michael D.; Sharon, Keren

2014-01-01

We present a detailed analysis of multi-wavelength Hubble Space Telescope/Wide Field Camera 3 (WFC3) imaging and Keck/OSIRIS near-infrared adaptive optics-assisted integral field spectroscopy for a highly magnified lensed galaxy at z = 1.70. This young starburst is representative of ultraviolet-selected star-forming galaxies (SFGs) at z approx. 2 and contains multiple individual star-forming regions. Due to the lensing magnification, we can resolve spatial scales down to 100 pc in the source plane of the galaxy. The velocity field shows disturbed kinematics suggestive of an ongoing interaction and there is a clear signature of a tidal tail. We constrain the age, reddening, star formation rate, and stellar mass of the star-forming clumps from spectral energy distribution (SED) modeling of the WFC3 photometry and measure their H(alpha) luminosity, metallicity, and outflow properties from the OSIRIS data.With strong star-formation-driven outflows in four clumps, RCSGA0327 is the first high-redshift SFG at stellar mass <10(exp 10) Stellar Mass with spatially resolved stellar winds. We compare the H(alpha) luminosities, sizes, and dispersions of the star-forming regions with other high-z clumps as well as local giant H(II) regions and find no evidence for increased clump star formation surface densities in interacting systems, unlike in the local universe. Spatially resolved SED modeling unveils an established stellar population at the location of the largest clump and a second mass concentration near the edge of the system that is not detected in H(alpha) emission. This suggests a picture of an equal-mass mixed major merger, which has not triggered a new burst of star formation or caused a tidal tail in the gas-poor component.

Searching for Low-mass Companions of Cepheids, Part II

NASA Astrophysics Data System (ADS)

Remage Evans, Nancy; Tingle, E.; Bond, H. E.; Schaefer, G. H.; Mason, B.; Karovska, M.; Wolk, S.; Pillitteri, I.; DePasquale, J.; Guinan, E.; Engle, S.

2012-01-01

The formation of a binary/multiple system is an effective way to manipulate angular momentum during the star-formation process. The properties of binary systems (separations and mass ratios) are thus the ``fingerprints" of the process. Low mass companions are the most difficult to identify particularly for massive stars. We are conducting a snapshot survey of the nearest Cepheids (5 Msun stars) using the Hubble Space Telescope Wide Field Camera 3 (WFC3) to discover possible resolved low mass companions. The color-magnitude combination is the first approach to identifying probable physical companions. The distributions of mass and separation for these stars will be discussed. Financial suppoet was provided by Hubble grant GO-12215.01-A and the Chandra X-ray Center NASA contract NAS8-03060.

VizieR Online Data Catalog: Abundances & RVs for stars near (or in) NGC6273 (Johnson+, 2017)

NASA Astrophysics Data System (ADS)

Johnson, C. I.; Caldwell, N.; Rich, R. M.; Mateo, M.; Bailey, J. I., III; Clarkson, W. I.; Olszewski, E. W.; Walker, M. G.

2017-09-01

In order to efficiently obtain a large number of high-resolution spectra, we employed the Michigan/Magellan Fiber System (M2FS) and MSpec multi-object spectrograph mounted on the Magellan-Clay 6.5m telescope (R~27000). We supplemented the M2FS CaT data set with additional observations of 300 RGB stars taken with the VLT FLAMES-GIRAFFE instrument. The data were downloaded from the European Southern Observatory (ESO) Science Archive Facility (R~18000 from 8482 to 9000Å). In support of our spectroscopic observations, we have obtained new HST Wide Field Camera 3 UVIS channel (WFC3/UVIS) data centered on NGC 6273 that includes the F336W, F438W, F555W, and F814W filters. (7 data files).

Isochrone Fitting of Hubble Photometry in UV-Vis Bands

NASA Astrophysics Data System (ADS)

Barker, Hallie; Paust, Nathaniel

2017-01-01

We present the results of isochrone fitting of color-magnitude diagrams from Hubble Space Telescope Wide Field Camera 3 (WFC3) and Advanced Camera for Surveys (ACS) photometry of the globular clusters M13 and M80 in five bands from the ultraviolet to near infrared. Fits from both the Dartmouth Stellar Evolution Program (DSEP) and the PAdova and TRieste Stellar Evolution Code (PARSEC) are examined. Ages, extinctions, and distances are found from the isochrone fitting, and metallicities are confirmed. We conduct careful qualitative analysis on the inconsistencies of the fits across all of the color combinations possible with the five observed bands, and find that the (F606W-F814W) color generally produces very good fits, but that there are large discrepancies when the data is fit using colors including UV bands for both models. Finally, we directly compare the two models by performing isochrone-isochrone fitting, and find that the age in PARSEC is on average 1.5 Gyr younger than DSEP for similar-appearing models at the same metallicity, and that the two models become less discrepant at lower metallicities.

Work–family conflict and health in Swedish working women and men: a 2-year prospective analysis (the SLOSH study)

PubMed Central

Baltzer, Maria; Magnusson Hanson, Linda L.; Westerlund, Hugo

2013-01-01

Background: Research has suggested that gender is related to perceptions of work–family conflict (WFC) and an underlying assumption is that interference of paid work with family life will burden women more than men. There is, however, mixed evidence as to whether men and women report different levels of WFC. Even less studies investigate gender differences in health outcomes of WFC. Also the number of longitudinal studies in this field is low. Methods: Based on the Swedish Longitudinal Occupational Survey of Health, we prospectively examined the effects of WFC on three different health measures representing a wide spectrum off ill health (i.e. self-rated health, emotional exhaustion and problem drinking). Logistic regression analyses were used to analyse multivariate associations between WFC in 2008 and health 2 years later. Results: The results show that WFC was associated with an increased risk of emotional exhaustion among both men and women. Gender differences are suggested as WFC was related to an increased risk for poor self-rated health among women and problem drinking among men. Interaction analyses revealed that the risk of poor self-rated health was substantially more influenced by WFC among women than among men. Conclusions: We conclude that, despite the fact that women experience conflict between work and family life slightly more often than men, both men’s and women’s health is negatively affected by this phenomenon. PMID:22683777

ACS/WFC Sky Flats from Frontier Fields Imaging

NASA Astrophysics Data System (ADS)

Mack, J.; Lucas, R. A.; Grogin, N. A.; Bohlin, R. C.; Koekemoer, A. M.

2018-04-01

Parallel imaging data from the HST Frontier Fields campaign (Lotz et al. 2017) have been used to compute sky flats for the ACS/WFC detector in order to verify the accuracy of the current set of flat field reference files. By masking sources and then co-adding many deep frames, the F606W and F814W filters have enough combined background signal that from Poisson statistics are <1% per pixel. In these two filters, the sky flats show spatial residuals 1% or less. These residuals are similar in shape to the WFC flat field 'donut' pattern, in which the detector quantum efficiency tracks the thickness of the two WFC chips. Observations of blue and red calibration standards measured at various positions on the detector (Bohlin et al. 2017) confirm the fidelity of the F814W flat, with aperture photometry consistent to 1% across the FOV, regardless of spectral type. At bluer wavelengths, the total sky background is substantially lower, and the F435W sky flat shows a combination of both flat errors and detector artifacts. Aperture photometry of the red standard star shows a maximum deviation of 1.4% across the array in this filter. Larger residuals up to 2.5% are found for the blue standard, suggesting that the spatial sensitivity in F435W depends on spectral type.

Dust Science with SPICA/MCS

NASA Astrophysics Data System (ADS)

Sakon, I.; Onaka, T.; Kataza, H.; Wada, T.; Sarugaku, Y.; Matsuhara, H.; Nakagawa, T.; Kobayashi, N.; Kemper, C.; Ohyama, Y.; Matsumoto, T.; Seok, J. Y.

Mid-Infrared Camera and Spectrometers (MCS) is one of the Focal-Plane Instruments proposed for the SPICA mission in the pre-project phase. SPICA MCS is equipped with two spectrometers with different spectral resolution powers (R=λ /δ λ ); medium-resolution spectrometer (MRS) which covers 12-38µ m with R≃1100-3000, and high-resolution spectrometer (HRS) which covers either 12-18µ m with R≃30000. MCS is also equipped with Wide Field Camera (WFC), which is capable of performing multi-objects grism spectroscopy in addition to the imaging observation. A small slit aperture for low-resolution slit spectroscopy is planned to be placed just next to the field of view (FOV) aperture for imaging and slit-less spectroscopic observation. MCS covers an important part of the core spectral range of SPICA and, complementary with SAFARI (SpicA FAR-infrared Instrument), can do crucial observations for a number of key science cases to revolutionize our understanding of the lifecycle of dust in the universe. In this article, the latest design specification and the expected performance of the SPICA/MCS are introduced. Key science cases that should be targetted by SPICA/MCS have been discussed by the MCS science working group. Among such science cases, some of those related to dust science are briefly introduced.

Conceptual Design of the TPF-O SC Buses

NASA Technical Reports Server (NTRS)

Purves, Lloyd R.

2007-01-01

The Terrestrial Planet Finder - Occulter (TPF-O) mission has two Spacecraft (SC) buses, one for a space telescope and the other for a formation-flying occulter. SC buses typically supply the utilities (support structures, propulsion, attitude control, power, communications, etc) required by the payloads. Unique requirements for the occulter SC bus are to provide the large delta V required for the slewing maneuvers of the occulter, and comunications for formation flying. The TPF-O telescope SC bus shares some key features of the one for the Hubble Space Telescope (HST): both support space telescopes designed to observe in the visible to near infrared range of wavelengths with comparable primary mirror apertures (2.4 m for HST, 2.4 - 4.0 m for TPF-O). However, TPF-O is expected to have a Wide Field Camera (WFC) with a Field of View (FOV) much larger than that of HST. Ths WFC is also expected to provide fine guidance. TPF-O is designed to operate in an orbit around the Sun-Earth Lagrange 2 (SEL2) point. The longer communications range to SEL2 and the large science FOV require higher performance communications than HST. Maintaining a SEL2 orbit requires TPF-O, unlike HST, to have a propulsion system. The velocity required for reachng SEL2 and the limited capabilities of affordable launch vehicles require both TPF-O elements to have compact, low-mass designs. Finally, it is possible that TPF-O may utilize a modular design derived fiom that of HST to allow servicing in the SEL2 orbit.

Progress with the Prime Focus Spectrograph for the Subaru Telescope: a massively multiplexed optical and near-infrared fiber spectrograph

NASA Astrophysics Data System (ADS)

Sugai, Hajime; Tamura, Naoyuki; Karoji, Hiroshi; Shimono, Atsushi; Takato, Naruhisa; Kimura, Masahiko; Ohyama, Youichi; Ueda, Akitoshi; Aghazarian, Hrand; de Arruda, Marcio V.; Barkhouser, Robert H.; Bennett, Charles L.; Bickerton, Steve; Bozier, Alexandre; Braun, David F.; Bui, Khanh; Capocasale, Christopher M.; Carr, Michael A.; Castilho, Bruno; Chang, Yin-Chang; Chen, Hsin-Yo; Chou, Richard C. Y.; Dawson, Olivia R.; Dekany, Richard G.; Ek, Eric M.; Ellis, Richard S.; English, Robin J.; Ferrand, Didier; Ferreira, Décio; Fisher, Charles D.; Golebiowski, Mirek; Gunn, James E.; Hart, Murdock; Heckman, Timothy M.; Ho, Paul T. P.; Hope, Stephen; Hovland, Larry E.; Hsu, Shu-Fu; Hu, Yen-Sang; Huang, Pin Jie; Jaquet, Marc; Karr, Jennifer E.; Kempenaar, Jason G.; King, Matthew E.; Le Fèvre, Olivier; Le Mignant, David; Ling, Hung-Hsu; Loomis, Craig; Lupton, Robert H.; Madec, Fabrice; Mao, Peter; Marrara, Lucas S.; Ménard, Brice; Morantz, Chaz; Murayama, Hitoshi; Murray, Graham J.; de Oliveira, Antonio Cesar; de Oliveira, Claudia M.; de Oliveira, Ligia S.; Orndorff, Joe D.; de Paiva Vilaça, Rodrigo; Partos, Eamon J.; Pascal, Sandrine; Pegot-Ogier, Thomas; Reiley, Daniel J.; Riddle, Reed; Santos, Leandro; dos Santos, Jesulino B.; Schwochert, Mark A.; Seiffert, Michael D.; Smee, Stephen A.; Smith, Roger M.; Steinkraus, Ronald E.; Sodré, Laerte; Spergel, David N.; Surace, Christian; Tresse, Laurence; Vidal, Clément; Vives, Sebastien; Wang, Shiang-Yu; Wen, Chih-Yi; Wu, Amy C.; Wyse, Rosie; Yan, Chi-Hung

2014-07-01

The Prime Focus Spectrograph (PFS) is an optical/near-infrared multi-fiber spectrograph with 2394 science fibers, which are distributed in 1.3 degree diameter field of view at Subaru 8.2-meter telescope. The simultaneous wide wavelength coverage from 0.38 μm to 1.26 μm, with the resolving power of 3000, strengthens its ability to target three main survey programs: cosmology, Galactic archaeology, and galaxy/AGN evolution. A medium resolution mode with resolving power of 5000 for 0.71 μm to 0.89 μm also will be available by simply exchanging dispersers. PFS takes the role for the spectroscopic part of the Subaru Measurement of Images and Redshifts (SuMIRe) project, while Hyper Suprime-Cam (HSC) works on the imaging part. HSC's excellent image qualities have proven the high quality of the Wide Field Corrector (WFC), which PFS shares with HSC. The PFS collaboration has succeeded in the project Preliminary Design Review and is now in a phase of subsystem Critical Design Reviews and construction. To transform the telescope plus WFC focal ratio, a 3-mm thick broad-band coated microlens is glued to each fiber tip. The microlenses are molded glass, providing uniform lens dimensions and a variety of refractive-index selection. After successful production of mechanical and optical samples, mass production is now complete. Following careful investigations including Focal Ratio Degradation (FRD) measurements, a higher transmission fiber is selected for the longest part of cable system, while one with a better FRD performance is selected for the fiber-positioner and fiber-slit components, given the more frequent fiber movements and tightly curved structure. Each Fiber positioner consists of two stages of piezo-electric rotary motors. Its engineering model has been produced and tested. After evaluating the statistics of positioning accuracies, collision avoidance software, and interferences (if any) within/between electronics boards, mass production will commence. Fiber positioning will be performed iteratively by taking an image of artificially back-illuminated fibers with the Metrology camera located in the Cassegrain container. The camera is carefully designed so that fiber position measurements are unaffected by small amounts of high special-frequency inaccuracies in WFC lens surface shapes. Target light carried through the fiber system reaches one of four identical fast-Schmidt spectrograph modules, each with three arms. All optical glass blanks are now being polished. Prototype VPH gratings have been optically tested. CCD production is complete, with standard fully-depleted CCDs for red arms and more-challenging thinner fully-depleted CCDs with blue-optimized coating for blue arms. The active damping system against cooler vibration has been proven to work as predicted, and spectrographs have been designed to avoid small possible residual resonances.

The CETUS Probe Mission Concept 1.5m Optical Telescope Assembly: A high A-Omega approach for ultraviolet astrophysics

NASA Astrophysics Data System (ADS)

Hull, Anthony; Heap, Sara; Woodruff, Robert; Mehle, Greg; Tomic, Matt; Dodson, Kelly; Burge, Jim; Lewis, Ben; Valente, Martin; Kendrick, Stephen E.; Purves, Lloyd; Danchi, William

2018-01-01

We describe the 1.5-m Cosmic Evolution Through Ultraviolet Spectroscopy (CETUS) Optical Telescope Assembly (OTA), a Three Mirror Anastigmat (TMA), providing a large usable focus, which permits non-shared locations for several Ultraviolet (UV) instruments. NASA has selected CETUS as a Probe Mission Concept for consideration by The Decadal Survey ASTRO2020. CETUS will fly in a L2 halo orbit and typically be pointing between 85 degrees and 135 degrees from the sun, and looking at galaxies at redshifts between z=1 and z=2. However, the CETUS payload also will be able to rapidly slew to sun angles between 85 degrees and 180 degrees to reach objects of opportunity, an example of which is a neutron star merger event. CETUS thermal stability starts with lightweighted ZERODUR® mirrors, that are an excellent thermal match to a metering structure of carbon fiber reinforced polymer (CFRP) M55J. This basic passive athermalization approach will be supplemented with controlled heaters, especially at metallic mounts, composite terminations and mechanisms. After launch, solid body metering errors will be optimized by an actuated hexapod in the secondary mirror assembly (SMA). Thus the CETUS telescope can respond to any pointing induced change in solar view factors. Contamination is managed by commissioning heaters radiating to each mirror surface, and a capping shutter over the telescope aperture. The instruments include a wide-field-of-view (WFoV) multi-object spectrometer (MOS), and a complimentary WFoV camera, as well as high-resolution point source Echelle spectrometers (R~40,000). They do not require that the OTA deliver diffraction limited performance over the extent of the instrument wavelength range (115nm to 400nm). The camera and spectrometer each cover a field of view of ~ 1000 arcsec by ~ 1000 arcsec compared to ~ 150 arcsec by ~ 150 arcsec for WFC3 on the Hubble Space Telescope (HST). Thus, the AW (etendue) factor for CETUS is ~700 m^2-arcmin^2, compared to the AW factor for WFC3 on HST which is ~ 25 meter^2-arcmin^2. Thus, CETUS provides a factor of ~30 higher etendue than HST.

VizieR Online Data Catalog: Antennae galaxies (NGC 4038/4039) revisited (Whitmore+, 2010)

NASA Astrophysics Data System (ADS)

Whitmore, B. C.; Chandar, R.; Schweizer, F.; Rothberg, B.; Leitherer, C.; Rieke, M.; Rieke, G.; Blair, W. P.; Mengel, S.; Alonso-Herrero, A.

2012-06-01

Observations of the main bodies of NGC 4038/39 were made with the Hubble Space Telescope (HST), using the ACS, as part of Program GO-10188. Multi-band photometry was obtained in the following optical broadband filters: F435W (~B), F550M (~V), and F814W (~I). Archival F336W photometry of the Antennae (Program GO-5962) was used to supplement our optical ACS/WFC observations. Infrared observations were made using the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) camera on HST as part of Program GO-10188. Observations were made using the NIC2 camera with the F160W, F187N, and F237M filters, and the NIC3 camera with the F110W, F160W, F164W, F187N, and F222M filters. (10 data files).

Extreme Emission Line Galaxies in CANDELS: Broad-Band Selected, Star-Bursting Dwarf Galaxies at Z greater than 1

NASA Technical Reports Server (NTRS)

VanDerWel, A.; Straughn, A. N.; Rix, H.-W.; Finkelstein, S. L.; Koekemoer, A. M.; Weiner, B. J.; Wuyts, S.; Bell, E. F.; Faber, S. M.; Trump, J. R.;

Extreme Emission Line Galaxies in CANDELS: Broad-Band Selected, Star-Bursting Dwarf Galaxies at Z greater than 1

NASA Technical Reports Server (NTRS)

vanderWel, A.; Straughn, A. N.; Rix, H.-W.; Finkelstein, S. L.; Koekemoer, A. M.; Weiner, B. J.; Wuyts, S.; Bell, E. F.; Faber, S. M.; Trump, J. R.;

Searching For Low-mass Companions Of Cepheids

NASA Astrophysics Data System (ADS)

Remage Evans, Nancy; Bond, H.; Schaefer, G.; Karovska, M.; Mason, B.; DePasquale, J.; Pillitteri, I.; Guinan, E.; Engle, S.

2011-05-01

The role played by binary and multiple stars in star formation is receiving a great deal of attention, both theoretically and observationally. Two questions under discussion are how wide physical companions can be and how frequently massive stars have low mass companions. An important new observational tool is the development of high resolution imaging, both from space and from the ground (Adaptive Optics and interferometry). We are conducting a snapshot survey of the nearest Cepheids using the Hubble Space Telescope Wide Field Camera 3 (WFC3). The aim is to discover possible resolved low mass companions. Results from this survey will be discussed, including images of Eta Aql. X-ray luminosity can confirm or refute that putative low mass companions are young enough to be physical companions. This project tests the reality of both wide and low mass companions of these intermediate-mass stars.

HST images of very compact blue galaxies at z approximately 0.2

NASA Technical Reports Server (NTRS)

Koo, David C.; Bershady, Matthew A.; Wirth, Gregory D.; Stanford, S. Adam; Majewski, Steven R.

1994-01-01

We present the results of Hubble Space Telescope (HST) Wide-Field Camera (WFC) imaging of seven very compact, very blue galaxies with B less than or equal to 21 and redshifts z approximately 0.1 to 0.35. Based on deconvolved images, we estimate typical half-light diameters of approximately 0.65 sec, corresponding to approximately 1.4 h(exp -1) kpc at redshifts z approximately 0.2. The average rest frame surface brightness within this diameter is mu(sub v) approximately 20.5 mag arcsec(exp -2), approximately 1 mag brighter than that of typical late-type blue galaxies. Ground-based spectra show strong, narrow emission lines indicating high ionization; their very blue colors suggest recent bursts of star-formation; their typical luminosities are approximately 4 times fainter than that of field galaxies. These characteristics suggest H II galaxies as likely local counterparts of our sample, though our most luminous targets appear to be unusually compact for their luminosities.

Hubble Space Telescope Snapshot Survey for Resolved Companions of Galactic Cepheids

NASA Astrophysics Data System (ADS)

Evans, Nancy Remage; Bond, Howard E.; Schaefer, Gail H.; Mason, Brian D.; Tingle, Evan; Karovska, Margarita; Pillitteri, Ignazio

2016-05-01

We have conducted an imaging survey with the Hubble Space Telescope Wide Field Camera 3 (WFC3) of 70 Galactic Cepheids, typically within 1 kpc, with the aim of finding resolved physical companions. The WFC3 field typically covers the 0.1 pc area where companions are expected. In this paper, we identify 39 Cepheids having candidate companions, based on their positions in color-magnitude diagrams, and having separations ⩾ 5'' from the Cepheids. We use follow-up observations of 14 of these candidates with XMM-Newton, and of one of them with ROSAT, to separate X-ray-active young stars (probable physical companions) from field stars (chance alignments). Our preliminary estimate, based on the optical and X-ray observations, is that only 3% of the Cepheids in the sample have wide companions. Our survey easily detects resolved main-sequence companions as faint as spectral type K. Thus the fact that the two most probable companions (those of FF Aql and RV Sco) are earlier than type K is not simply a function of the detection limit. We find no physical companions having separations larger than 4000 au in the X-ray survey. Two Cepheids are exceptions in that they do have young companions at significantly larger separations (δ Cep and S Nor), but both belong to a cluster or a loose association, so our working model is that they are not gravitationally bound binary members, but rather cluster/association members. All of these properties provide constraints on both star formation and subsequent dynamical evolution. The low frequency of true physical companions at separations > 5'' is confirmed by examination of the subset of the nearest Cepheids and also the density of the fields. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Metallicities of Emission-Line Galaxies from HST ACS PEARS and HST WFC3 ERS Grism Spectroscopy at 0.6 is less than z is less than 2.4

NASA Technical Reports Server (NTRS)

Xia, Lifang; Malhotra, Sangetta; Rhoads, James; Pirzkal, Nor; Straughn, Amber; Finkelstein, Steven; Cohen, Seth; Kuntschner, Harald; Walsh, Jeremy; Windhorst, Rogier A.;

The MASSIVE Survey. IX. Photometric Analysis of 35 High-mass Early-type Galaxies with HST WFC3/IR

NASA Astrophysics Data System (ADS)

Goullaud, Charles F.; Jensen, Joseph B.; Blakeslee, John P.; Ma, Chung-Pei; Greene, Jenny E.; Thomas, Jens

2018-03-01

We present near-infrared observations of 35 of the most massive early-type galaxies in the local universe. The observations were made using the infrared channel of the Hubble Space Telescope Wide Field Camera 3 (WFC3) in the F110W (1.1 μm) filter. We measured surface brightness profiles and elliptical isophotal fit parameters from the nuclear regions out to a radius of ∼10 kpc in most cases. We find that 37% (13) of the galaxies in our sample have isophotal position-angle rotations greater than 20° over the radial range imaged by WFC3/IR, which is often due to the presence of neighbors or multiple nuclei. Most galaxies in our sample are significantly rounder near the center than in the outer regions. This sample contains 6 fast rotators and 28 slow rotators. We find that all fast rotators are either disky or show no measurable deviation from purely elliptical isophotes. Among slow rotators, significantly disky and boxy galaxies occur with nearly equal frequency. The galaxies in our sample often exhibit changing isophotal shapes, sometimes showing both significantly disky and boxy isophotes at different radii. The fact that parameters vary widely between galaxies and within individual galaxies is evidence that these massive galaxies have complicated formation histories, and some of them have experienced recent mergers and have not fully relaxed. These data demonstrate the value of IR imaging of galaxies at high spatial resolution and provide measurements necessary for determining stellar masses, dynamics, and black hole masses in high-mass galaxies. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with Program GO-14219.

Unveiling the nature of bright z ≃ 7 galaxies with the Hubble Space Telescope

NASA Astrophysics Data System (ADS)

Bowler, R. A. A.; Dunlop, J. S.; McLure, R. J.; McLeod, D. J.

2017-04-01

We present new Hubble Space Telescope/Wide Field Camera 3 (HST/WFC3) imaging of 25 extremely luminous (-23.2 ≤ MUV ≲ -21.2) Lyman-break galaxies (LBGs) at z ≃ 7. The sample was initially selected from 1.65 deg2 of ground-based imaging in the UltraVISTA/COSMOS and UDS/SXDS fields, and includes the extreme Lyman α emitters, 'Himiko' and 'CR7'. A deconfusion analysis of the deep Spitzer photometry available suggests that these galaxies exhibit strong rest-frame optical nebular emission lines (EW0(Hβ + [O III]) > 600 Å). We find that irregular, multiple-component morphologies suggestive of clumpy or merging systems are common (fmulti > 0.4) in bright z ≃ 7 galaxies, and ubiquitous at the very bright end (MUV < -22.5). The galaxies have half-light radii in the range r1/2 ˜ 0.5-3 kpc. The size measurements provide the first determination of the size-luminosity relation at z ≃ 7 that extends to MUV ˜ -23. We find the relation to be steep with r1/2 ∝ L1/2. Excluding clumpy, multicomponent galaxies however, we find a shallower relation that implies an increased star formation rate surface density in bright LBGs. Using the new, independent, HST/WFC3 data we confirm that the rest-frame UV luminosity function at z ≃ 7 favours a power-law decline at the bright end, compared to an exponential Schechter function drop-off. Finally, these results have important implications for the Euclid mission, which we predict will detect >1000 similarly bright galaxies at z ≃ 7. Our new HST imaging suggests that the vast majority of these galaxies will be spatially resolved by Euclid, mitigating concerns over dwarf star contamination.

VizieR Online Data Catalog: A deep Chandra ACIS survey of M83 (Long+, 2014)

NASA Astrophysics Data System (ADS)

Long, K. S.; Kuntz, K. D.; Blair, W. P.; Godfrey, L.; Plucinsky, P. P.; Soria, R.; Stockdale, C.; Winkler, P. F.

2014-07-01

X-ray observations of M83 were all carried out with Chandra/ACIS-S in the "very faint" mode and spaced over a period of one year from 2010 December to 2011 December. We included in our analysis earlier Chandra observations of M83 in 2000 and 2001 totaling 61ks obtained by G. Rieke (Prop ID. 1600489; ObsID 73) and by A. Prestwich (Prop ID. 267005758; ObsID 2064). To support and extend our X-ray study of M83, we have been carrying out a number of other studies of M83, including optical broadband and narrowband imaging with the IMACS camera on Magellan (Blair et al. 2012, Cat. J/ApJS/203/8), optical imaging with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST; W. P. Blair PI, Prop. ID. 12513, Blair et al. 2014ApJ...788...55B), and radio imaging with the Jansky Very Large Array (JVLA; C. Stockdale PI, Prog. ID. 12A-335). Here we describe new 6 and 3cm radio imaging we have obtained from ATCA (Australia Telescope Compact Array) on 2011 April 28, 29, and 30 (table 2). (4 data files).

Do Lyman-alpha photons escape from star-forming galaxies through dust holes?

NASA Astrophysics Data System (ADS)

France, Kevin; Wofford, A.; Leitherer, C.; Fleming, B.; McCandliss, S. R.; Nell, N.

2014-01-01

H I Lyman-alpha (LyA) is commonly used as a signpost for the entire galaxy at redshifts z>2, and yet spatially and kinematically resolved views of the local conditions within galaxies that determine the integrated properties of this line are scarce. We obtained Hubble Space Telescope (HST) images in continuum-subtracted LyA, H-alpha, H-beta, and far-UV continuum of three low-inclination spiral star-forming galaxies located at redshifts z=0.02, 0.03, and 0.05. This was accomplished using the UVIS and SBC channels of the Wide Field Camera 3 (WFC3) and the Advanced Camera for Surveys (ACS), respectively. Previous HST spectroscopy obtained by our team with the Cosmic Origins Spectrograph (COS) showed that the galaxies display different integrated LyA profiles within their central few kiloparsecs, i.e., pure absorption, single emission, and double emission, which are representative of what is observed between redshifts 0-3. This data is useful for establishing the relative importance of starburst phase, dust content, and gas kinematics in determining the LyA escape. We present preliminary results that combine our spectroscopic and imaging observations.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Po-Feng; Tully, R. Brent; Jacobs, Bradley A.

In this paper, we extend the use of the tip of the red giant branch (TRGB) method to near-infrared wavelengths from the previously used I-band, using the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3). Upon calibration of a color dependency of the TRGB magnitude, the IR TRGB yields a random uncertainty of ∼5% in relative distance. The IR TRGB methodology has an advantage over the previously used Advance Camera for Surveys F606W and F814W filter set for galaxies that suffer from severe extinction. Using the IR TRGB methodology, we obtain distances toward three principal galaxies in the Maffei/ICmore » 342 complex, which are located at low Galactic latitudes. New distance estimates using the TRGB method are 3.45{sub −0.13}{sup +0.13} Mpc for IC 342, 3.37{sub −0.23}{sup +0.32} Mpc for Maffei 1, and 3.52{sub −0.30}{sup +0.32} Mpc for Maffei 2. The uncertainties are dominated by uncertain extinction, especially for Maffei 1 and Maffei 2. Our IR calibration demonstrates the viability of the TRGB methodology for observations with the James Webb Space Telescope.« less

The M 4 Core Project with HST - V. Characterizing the PSFs of WFC3/UVIS by focus★

NASA Astrophysics Data System (ADS)

Anderson, J.; Bedin, L. R.

2017-09-01

As part of the astrometric Hubble Space Telescope (HST) large program GO-12911, we conduct an in-depth study to characterize the point spread function (PSF) of the Uv-VISual channel of the Wide Field Camera 3 (WFC3), as a necessary step to achieve the astrometric goals of the program. We extracted a PSF from each of the 589 deep exposures taken through the F467M filter over the course of a year and find that the vast majority of the PSFs lie along a 1-D locus that stretches continuously from one side of focus, through optimal focus, to the other side of focus. We constructed a focus-diverse set of PSFs and find that with only five medium-bright stars in an exposure it is possible to pin down the focus level of that exposure. We show that the focus-optimized PSF does a considerably better job fitting stars than the average 'library' PSF, especially when the PSF is out of focus. The fluxes and positions are significantly improved over the 'library' PSF treatment. These results are beneficial for a much broader range of scientific applications than simply the program at hand, but the immediate use of these PSFs will enable us to search for astrometric wobble in the bright stars in the core of the globular cluster M 4, which would indicate a dark, high-mass companion, such as a white dwarf, neutron star or black hole.

RXTE and BeppoSAX Observations of the Transient X-ray Pulsar XTE J 18591+083

NASA Technical Reports Server (NTRS)

Corbet, R. H. D.; intZand, J. J. M.; Levine, A. M.; Marshall, F. E.

2008-01-01

We present observations of the 9.8 s X-ray pulsar XTE J159+083 made with the All-Sky Monitor (ASM) and Proportional Counter Array (PCA) on board the Rossi X-ray Timing Explorer (RXTE), and the Wide Field Cameras (WFC) on board BeppoSAX. The ASM data cover a 12 year time interval and show that an extended outburst occurred between approximately MJD50, 250, and 50, 460 (1996 June 16 to 1997 January 12). The ASM data excluding this outburst interval suggest a possible 61 day modulation. Eighteen sets of PCA observations were obtained over an approx. one month interval in 1999. The flux variability measured with the PCA appears consistent with the possible period found with the ASM. The PCA measurements of the pulse period showed it to decrease non-monotonically and then to increase significantly. Doppler shifts due to orbital motion rather than accretion torques appear to be better able to explain the pulse period changes. Observations with the WFC during the extended outburst give an error box which is consistent with a previously determined PCA error box but is significantly smaller. The transient nature of XTE J1859+083 and the length of its pulse period are consistent with it being a Be/neutral star binary. The possible 61 day orbital period would be of the expected length for a Be star system with a 9.8 s pulse period.

Multiwavelength Observations of the Candidate Disintegrating Sub-Mercury KIC 12557548b

NASA Astrophysics Data System (ADS)

Croll, Bryce; Rappaport, Saul; DeVore, John; Gilliland, Ronald L.; Crepp, Justin R.; Howard, Andrew W.; Star, Kimberly M.; Chiang, Eugene; Levine, Alan M.; Jenkins, Jon M.; Albert, Loic; Bonomo, Aldo S.; Fortney, Jonathan J.; Isaacson, Howard

2014-05-01

We present multiwavelength photometry, high angular resolution imaging, and radial velocities of the unique and confounding disintegrating low-mass planet candidate KIC 12557548b. Our high angular resolution imaging, which includes space-based Hubble Space Telescope Wide Field Camera 3 (HST/WFC3) observations in the optical (~0.53 μm and ~0.77 μm), and ground-based Keck/NIRC2 observations in K' band (~2.12 μm), allow us to rule out background and foreground candidates at angular separations greater than 0.''2 that are bright enough to be responsible for the transits we associate with KIC 12557548. Our radial velocity limit from Keck/HIRES allows us to rule out bound, low-mass stellar companions (~0.2 M ⊙) to KIC 12557548 on orbits less than 10 yr, as well as placing an upper limit on the mass of the candidate planet of 1.2 Jupiter masses; therefore, the combination of our radial velocities, high angular resolution imaging, and photometry are able to rule out most false positive interpretations of the transits. Our precise multiwavelength photometry includes two simultaneous detections of the transit of KIC 12557548b using Canada-France-Hawaii Telescope/Wide-field InfraRed Camera (CFHT/WIRCam) at 2.15 μm and the Kepler space telescope at 0.6 μm, as well as simultaneous null-detections of the transit by Kepler and HST/WFC3 at 1.4 μm. Our simultaneous HST/WFC3 and Kepler null-detections provide no evidence for radically different transit depths at these wavelengths. Our simultaneous CFHT/WIRCam detections in the near-infrared and with Kepler in the optical reveal very similar transit depths (the average ratio of the transit depths at ~2.15 μm compared with ~0.6 μm is: 1.02 ± 0.20). This suggests that if the transits we observe are due to scattering from single-size particles streaming from the planet in a comet-like tail, then the particles must be ~0.5 μm in radius or larger, which would favor that KIC 12557548b is a sub-Mercury rather than super-Mercury mass planet. Based on observations obtained with WIRCam, a joint project of CFHT, Taiwan, Korea, Canada, and France, at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institute National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The observatory was made possible by the generous financial support of the W.M. Keck Foundation.

Linear: A Novel Algorithm for Reconstructing Slitless Spectroscopy from HST/WFC3

NASA Astrophysics Data System (ADS)

Ryan, R. E., Jr.; Casertano, S.; Pirzkal, N.

2018-03-01

We present a grism extraction package (LINEAR) designed to reconstruct 1D spectra from a collection of slitless spectroscopic images, ideally taken at a variety of orientations, dispersion directions, and/or dither positions. Our approach is to enumerate every transformation between all direct image positions (i.e., a potential source) and the collection of grism images at all relevant wavelengths. This leads to solving a large, sparse system of linear equations, which we invert using the standard LSQR algorithm. We implement a number of color and geometric corrections (such as flat field, pixel-area map, source morphology, and spectral bandwidth), but assume many effects have been calibrated out (such as basic reductions, background subtraction, and astrometric refinement). We demonstrate the power of our approach with several Monte Carlo simulations and the analysis of archival data. The simulations include astrometric and photometric uncertainties, sky-background estimation, and signal-to-noise calculations. The data are G141 observations obtained with the Wide-Field Camera 3 of the Hubble Ultra-Deep Field, and show the power of our formalism by improving the spectral resolution without sacrificing the signal-to-noise (a tradeoff that is often made by current approaches). Additionally, our approach naturally accounts for source contamination, which is only handled heuristically by present softwares. We conclude with a discussion of various observations where our approach will provide much improved spectral 1D spectra, such as crowded fields (star or galaxy clusters), spatially resolved spectroscopy, or surveys with strict completeness requirements. At present our software is heavily geared for Wide-Field Camera 3 IR, however we plan extend the codebase for additional instruments.

The 3D-HST Survey: Hubble Space Telescope WFC3/G141 Grism Spectra, Redshifts, and Emission Line Measurements for ~ 100,000 Galaxies

NASA Astrophysics Data System (ADS)

Momcheva, Ivelina G.; Brammer, Gabriel B.; van Dokkum, Pieter G.; Skelton, Rosalind E.; Whitaker, Katherine E.; Nelson, Erica J.; Fumagalli, Mattia; Maseda, Michael V.; Leja, Joel; Franx, Marijn; Rix, Hans-Walter; Bezanson, Rachel; Da Cunha, Elisabete; Dickey, Claire; Förster Schreiber, Natascha M.; Illingworth, Garth; Kriek, Mariska; Labbé, Ivo; Ulf Lange, Johannes; Lundgren, Britt F.; Magee, Daniel; Marchesini, Danilo; Oesch, Pascal; Pacifici, Camilla; Patel, Shannon G.; Price, Sedona; Tal, Tomer; Wake, David A.; van der Wel, Arjen; Wuyts, Stijn

2016-08-01

We present reduced data and data products from the 3D-HST survey, a 248-orbit HST Treasury program. The survey obtained WFC3 G141 grism spectroscopy in four of the five CANDELS fields: AEGIS, COSMOS, GOODS-S, and UDS, along with WFC3 H 140 imaging, parallel ACS G800L spectroscopy, and parallel I 814 imaging. In a previous paper, we presented photometric catalogs in these four fields and in GOODS-N, the fifth CANDELS field. Here we describe and present the WFC3 G141 spectroscopic data, again augmented with data from GO-1600 in GOODS-N (PI: B. Weiner). We developed software to automatically and optimally extract interlaced two-dimensional (2D) and one-dimensional (1D) spectra for all objects in the Skelton et al. (2014) photometric catalogs. The 2D spectra and the multi-band photometry were fit simultaneously to determine redshifts and emission line strengths, taking the morphology of the galaxies explicitly into account. The resulting catalog has redshifts and line strengths (where available) for 22,548 unique objects down to {{JH}}{IR}≤slant 24 (79,609 unique objects down to {{JH}}{IR}≤slant 26). Of these, 5459 galaxies are at z\\gt 1.5 and 9621 are at 0.7\\lt z\\lt 1.5, where Hα falls in the G141 wavelength coverage. The typical redshift error for {{JH}}{IR}≤slant 24 galaxies is {σ }z≈ 0.003× (1+z), I.e., one native WFC3 pixel. The 3σ limit for emission line fluxes of point sources is 2.1× {10}-17 erg s-1 cm-2. All 2D and 1D spectra, as well as redshifts, line fluxes, and other derived parameters, are publicly available.18

VizieR Online Data Catalog: z>~5 AGN in Chandra Deep Field-South (Weigel+, 2015)

NASA Astrophysics Data System (ADS)

Weigel, A. K.; Schawinski, K.; Treister, E.; Urry, C. M.; Koss, M.; Trakhtenbrot, B.

2015-09-01

The Chandra 4-Ms source catalogue by Xue et al. (2011, Cat. J/ApJS/195/10) is the starting point of this work. It contains 740 sources and provides counts and observed frame fluxes in the soft (0.5-2keV), hard (2-8keV) and full (0.5-8keV) band. All object IDs used in this work refer to the source numbers listed in the Xue et al. (2011, Cat. J/ApJS/195/10) Chandra 4-Ms catalogue. We make use of Hubble Space Telescope (HST)/Advanced Camera for Surveys (ACS) data from the Great Observatories Origins Deep Survey South (GOODS-south) in the optical wavelength range. We use catalogues and images for filters F435W (B), F606W (V), F775W (i) and 850LP (z) from the second GOODS/ACS data release (v2.0; Giavalisco et al., 2004, Cat. II/261). We use Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) Wide Field Camera 3 (WFC3)/infrared data from the first data release (DR1, v1.0) for passbands F105W (Y), F125W (J) and F160W (H) (Grogin et al., 2011ApJS..197...35G; Koekemoer et al., 2011ApJS..197...36K). To determine which objects are red, dusty, low-redshift interlopers, we also include the 3.6 and 4.5 micron Spitzer Infrared Array Camera (IRAC) channels. We use SIMPLE image data from the DR1 (van Dokkum et al., 2005, Spitzer Proposal, 2005.20708) and the first version of the extended SIMPLE catalogue by Damen et al. (2011, Cat. J/ApJ/727/1). (6 data files).

Morphology and Structure of Ultraluminous Infrared Galaxies at z ≈ 2 in the EGS Field

NASA Astrophysics Data System (ADS)

Fang, G. W.; Ma, Z. Y.; Chen, Y.; Kong, X.

2014-11-01

Using high-resolution HST WFC3 (Hubble Space Telescope Wide Field Camera 3) F160W imaging from the CANDELS-EGS (Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey-Extended Groth Strip) field, we present the morphology analysis of 9 ultraluminous infrared galaxies (ULIRGs) at z≈2. We find a wide range of morphological diversities for these ULIRGs, from spheroid to multiple bright nuclei or diffuse structures, e.g., double nuclei, bridges, dual asymmetries, irregular, or elliptical structures. In quantitative, these sources show a lower Gini coefficient (G) and a higher moment (M_{20}) in the rest-frame optical morphology, compared to the lower redshift counterparts, indicating less concentrated and symmetric spatial distribution of the stellar mass of ULIRGs at z≈2. Moreover, we derive accurate effective radii of these ULIRGs through 2-D profile fitting, which range from 2.4 to 5.8 kpc, with a mean value of (3.9±1.1) kpc. We find that the sizes of these ULIRGs at z≈2 are on average one to two times smaller than those of the local star-forming galaxies with analogous stellar mass. Our results are consistent with those studies at similar redshift and infrared luminosity.

A volume-limited ROSAT survey of extreme ultraviolet emission from all nondegenerate stars within 10 parsecs

NASA Technical Reports Server (NTRS)

Wood, Brian E.; Brown, Alexander; Linsky, Jeffrey L.; Kellett, Barry J.; Bromage, Gordon E.; Hodgkin, Simon T.; Pye, John P.

1994-01-01

We report the results of a volume-limited ROSAT Wide Field Camera (WFC) survey of all nondegenerate stars within 10 pc. Of the 220 known star systems within 10 pc, we find that 41 are positive detections in at least one of the two WFC filter bandpasses (S1 and S2), while we consider another 14 to be marginal detections. We compute X-ray luminosities for the WFC detections using Einstein Imaging Proportional Counter (IPC) data, and these IPC luminosities are discussed along with the WFC luminosities throughout the paper for purposes of comparison. Extreme ultraviolet (EUV) luminosity functions are computed for single stars of different spectral types using both S1 and S2 luminosities, and these luminosity functions are compared with X-ray luminosity functions derived by previous authors using IPC data. We also analyze the S1 and S2 luminosity functions of the binary stars within 10 pc. We find that most stars in binary systems do not emit EUV radiation at levels different from those of single stars, but there may be a few EUV-luminous multiple-star systems which emit excess EUV radiation due to some effect of binarity. In general, the ratio of X-ray luminosity to EUV luminosity increases with increasing coronal emission, suggesting that coronally active stars have higher coronal temperatures. We find that our S1, S2, and IPC luminosities are well correlated with rotational velocity, and we compare activity-rotation relations determined using these different luminosities. Late M stars are found to be significantly less luminous in the EUV than other late-type stars. The most natural explanation for this results is the concept of coronal saturation -- the idea that late-type stars can emit only a limited fraction of their total luminosity in X-ray and EUV radiation, which means stars with very low bolometric luminosities must have relatively low X-ray and EUV luminosities as well. The maximum level of coronal emission from stars with earlier spectral types is studied also. To understand the saturation levels for these stars, we have compiled a large number of IPC luminosities for stars with a wide variety of spectral types and luminosity classes. We show quantitatively that if the Sun were completely covered with X-ray-emitting coronal loops, it would be near the saturation limit implied by this compilation, supporting the idea that stars near upper limits in coronal activity are completely covered with active regions.

Modeling and Correcting the Time-Dependent ACS PSF

NASA Technical Reports Server (NTRS)

Rhodes, Jason; Massey, Richard; Albert, Justin; Taylor, James E.; Koekemoer, Anton M.; Leauthaud, Alexie

2006-01-01

The ability to accurately measure the shapes of faint objects in images taken with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST) depends upon detailed knowledge of the Point Spread Function (PSF). We show that thermal fluctuations cause the PSF of the ACS Wide Field Camera (WFC) to vary over time. We describe a modified version of the TinyTim PSF modeling software to create artificial grids of stars across the ACS field of view at a range of telescope focus values. These models closely resemble the stars in real ACS images. Using 10 bright stars in a real image, we have been able to measure HST s apparent focus at the time of the exposure. TinyTim can then be used to model the PSF at any position on the ACS field of view. This obviates the need for images of dense stellar fields at different focus values, or interpolation between the few observed stars. We show that residual differences between our TinyTim models and real data are likely due to the effects of Charge Transfer Efficiency (CTE) degradation. Furthermore, we discuss stochastic noise that is added to the shape of point sources when distortion is removed, and we present MultiDrizzle parameters that are optimal for weak lensing science. Specifically, we find that reducing the MultiDrizzle output pixel scale and choosing a Gaussian kernel significantly stabilizes the resulting PSF after image combination, while still eliminating cosmic rays/bad pixels, and correcting the large geometric distortion in the ACS. We discuss future plans, which include more detailed study of the effects of CTE degradation on object shapes and releasing our TinyTim models to the astronomical community.

The Hubble Space Telescope Medium Deep Survey with the Wide Field and Planetary Camera. 1: Methodology and results on the field near 3C 273

NASA Technical Reports Server (NTRS)

Griffiths, R. E.; Ratnatunga, K. U.; Neuschaefer, L. W.; Casertano, S.; Im, M.; Wyckoff, E. W.; Ellis, R. S.; Gilmore, G. F.; Elson, R. A. W.; Glazebrook, K.

1994-01-01

We present results from the Medium Deep Survey (MDS), a Key Project using the Hubble Space Telescope (HST). Wide Field Camera (WFC) images of random fields have been taken in 'parallel mode' with an effective resolution of 0.2 sec full width at half maximum (FWHM) in the V(F555W) and I(F785LP) filters. The exposures presented here were targeted on a field away from 3C 273, and resulted in approximately 5 hr integration time in each filter. Detailed morphological structure is seen in galaxy images with total integrated magnitudes down to V approximately = 22.5 and I approximately = 21.5. Parameters are estimated that best fit the observed galaxy images, and 143 objects are identified (including 23 stars) in the field to a fainter limiting magnitude of I approximately = 23.5. We outline the extragalactic goals of the HST Medium Deep Survey, summarize our basic data reduction procedures, and present number (magnitude) counts, a color-magnitude diagram for the field, surface brightness profiles for the brighter galaxies, and best-fit half-light radii for the fainter galaxies as a function of apparent magnitude. A median galaxy half-light radius of 0.4 sec is measured, and the distribution of galaxy sizes versus magnitude is presented. We observe an apparent deficit of galaxies with half-light radii between approximately 0.6 sec and 1.5 sec, with respect to standard no-evolution or mild evolution cosmological models. An apparent excess of compact objects (half-light radii approximately 0.1 sec) is also observed with respect to those models. Finally, we find a small excess in the number of faint galaxy pairs and groups with respect to a random low-redshift field sample.

Pixel-based CTE Correction of ACS/WFC: Modifications To The ACS Calibration Pipeline (CALACS)

NASA Astrophysics Data System (ADS)

Smith, Linda J.; Anderson, J.; Armstrong, A.; Avila, R.; Bedin, L.; Chiaberge, M.; Davis, M.; Ferguson, B.; Fruchter, A.; Golimowski, D.; Grogin, N.; Hack, W.; Lim, P. L.; Lucas, R.; Maybhate, A.; McMaster, M.; Ogaz, S.; Suchkov, A.; Ubeda, L.

2012-01-01

The Advanced Camera for Surveys (ACS) was installed on the Hubble Space Telescope (HST) nearly ten years ago. Over the last decade, continuous exposure to the harsh radiation environment has degraded the charge transfer efficiency (CTE) of the CCDs. The worsening CTE impacts the science that can be obtained by altering the photometric, astrometric and morphological characteristics of sources, particularly those farthest from the readout amplifiers. To ameliorate these effects, Anderson & Bedin (2010, PASP, 122, 1035) developed a pixel-based empirical approach to correcting ACS data by characterizing the CTE profiles of trails behind warm pixels in dark exposures. The success of this technique means that it is now possible to correct full-frame ACS/WFC images for CTE degradation in the standard data calibration and reduction pipeline CALACS. Over the past year, the ACS team at STScI has developed, refined and tested the new software. The details of this work are described in separate posters. The new code is more effective at low flux levels (< 50 electrons) than the original Anderson & Bedin code, and employs a more accurate time and temperature dependence for CTE. The new CALACS includes the automatic removal of low-level bias stripes (produced by the post-repair ACS electronics) and pixel-based CTE correction. In addition to the standard cosmic ray corrected, flat-fielded and drizzled data products (crj, flt and drz files) there are three new equivalent files (crc, flc and drc) which contain the CTE-corrected data products. The user community will be able to choose whether to use the standard or CTE-corrected products.

First Weak-lensing Results from “See Change”: Quantifying Dark Matter in the Two z ≳ 1.5 High-redshift Galaxy Clusters SPT-CL J2040-4451 and IDCS J1426+3508

NASA Astrophysics Data System (ADS)

Jee, M. James; Ko, Jongwan; Perlmutter, Saul; Gonzalez, Anthony; Brodwin, Mark; Linder, Eric; Eisenhardt, Peter

2017-10-01

We present a weak-lensing study of SPT-CL J2040-4451 and IDCS J1426+3508 at z = 1.48 and 1.75, respectively. The two clusters were observed in our “See Change” program, a Hubble Space Telescope survey of 12 massive high-redshift clusters aimed at high-z supernova measurements and weak-lensing estimation of accurate cluster masses. We detect weak but significant galaxy shape distortions using infrared images from the Wide Field Camera 3 (WFC3), which has not yet been used for weak-lensing studies. Both clusters appear to possess relaxed morphology in projected mass distribution, and their mass centroids agree nicely with those defined by both the galaxy luminosity and X-ray emission. Using a Navarro-Frenk-White profile, for which we assume that the mass is tightly correlated with the concentration parameter, we determine the masses of SPT-CL J2040-4451 and IDCS J1426 + 3508 to be {M}200={8.6}-1.4+1.7× {10}14 {M}⊙ and {2.2}-0.7+1.1× {10}14 {M}⊙ , respectively. The weak-lensing mass of SPT-CL J2040-4451 shows that the cluster is clearly a rare object. Adopting the central value, the expected abundance of such a massive cluster at z≳ 1.48 is only ˜ 0.07 in the parent 2500 sq. deg. survey. However, it is yet premature to claim that the presence of this cluster creates a serious tension with the current ΛCDM paradigm unless that tension will remain in future studies after marginalizing over many sources of uncertainties such as the accuracy of the mass function and the mass-concentration relation at the high-mass end. The mass of IDCS J1426+3508 is in excellent agreement with our previous Advanced Camera for Surveys-based weak-lensing result, while the much higher source density from our WFC3 imaging data makes the current statistical uncertainty ˜ 40% smaller.

Legacy Extragalactic UV Survey (LEGUS) With the Hubble Space Telescope. I. Survey Description

NASA Astrophysics Data System (ADS)

Calzetti, D.; Lee, J. C.; Sabbi, E.; Adamo, A.; Smith, L. J.; Andrews, J. E.; Ubeda, L.; Bright, S. N.; Thilker, D.; Aloisi, A.; Brown, T. M.; Chandar, R.; Christian, C.; Cignoni, M.; Clayton, G. C.; da Silva, R.; de Mink, S. E.; Dobbs, C.; Elmegreen, B. G.; Elmegreen, D. M.; Evans, A. S.; Fumagalli, M.; Gallagher, J. S., III; Gouliermis, D. A.; Grebel, E. K.; Herrero, A.; Hunter, D. A.; Johnson, K. E.; Kennicutt, R. C.; Kim, H.; Krumholz, M. R.; Lennon, D.; Levay, K.; Martin, C.; Nair, P.; Nota, A.; Östlin, G.; Pellerin, A.; Prieto, J.; Regan, M. W.; Ryon, J. E.; Schaerer, D.; Schiminovich, D.; Tosi, M.; Van Dyk, S. D.; Walterbos, R.; Whitmore, B. C.; Wofford, A.

2015-02-01

The Legacy ExtraGalactic UV Survey (LEGUS) is a Cycle 21 Treasury program on the Hubble Space Telescope aimed at the investigation of star formation and its relation with galactic environment in nearby galaxies, from the scales of individual stars to those of ˜kiloparsec-size clustered structures. Five-band imaging from the near-ultraviolet to the I band with the Wide-Field Camera 3 (WFC3), plus parallel optical imaging with the Advanced Camera for Surveys (ACS), is being collected for selected pointings of 50 galaxies within the local 12 Mpc. The filters used for the observations with the WFC3 are F275W(λ2704 Å), F336W(λ3355 Å), F438W(λ4325 Å), F555W(λ5308 Å), and F814W(λ8024 Å) the parallel observations with the ACS use the filters F435W(λ4328 Å), F606W(λ5921 Å), and F814W(λ8057 Å). The multiband images are yielding accurate recent (≲50 Myr) star formation histories from resolved massive stars and the extinction-corrected ages and masses of star clusters and associations. The extensive inventories of massive stars and clustered systems will be used to investigate the spatial and temporal evolution of star formation within galaxies. This will, in turn, inform theories of galaxy evolution and improve the understanding of the physical underpinning of the gas-star formation relation and the nature of star formation at high redshift. This paper describes the survey, its goals and observational strategy, and the initial scientific results. Because LEGUS will provide a reference survey and a foundation for future observations with the James Webb Space Telescope and with ALMA, a large number of data products are planned for delivery to the community. Based on observations obtained with the NASA/ESA Hubble Space Telescope at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy under NASA Contract NAS 5-26555.

The Morphology of Passively Evolving Galaxies at Z-2 from HST/WFC3 in the Hubble Ultra Deep Field

NASA Technical Reports Server (NTRS)

Cassata, P.; Giavalisco, M.; Guo, Yicheng; Ferguson, H.; Koekemoer, A.; Renzini, A.; Fontana, A.; Salimbeni, S.; Dickinson, M.; Casertano, S.;

Simulations of the WFIRST Supernova Survey and Forecasts of Cosmological Constraints

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hounsell, R.; Scolnic, D.; Foley, R. J.

The Wide Field InfraRed Survey Telescope (WFIRST) was the highest rankedlarge space-based mission of the 2010 New Worlds, New Horizons decadal survey.It is now a NASA mission in formulation with a planned launch in themid-2020's. A primary mission objective is to precisely constrain the nature ofdark energy through multiple probes, including Type Ia supernovae (SNe Ia).Here, we present the first realistic simulations of the WFIRST SN survey basedon current hardware specifications and using open-source tools. We simulate SNlight curves and spectra as viewed by the WFIRST wide-field channel (WFC)imager and integral field channel (IFC) spectrometer, respectively. We examine11 survey strategiesmore » with different time allocations between the WFC and IFC,two of which are based upon the strategy described by the WFIRST ScienceDefinition Team, which measures SN distances exclusively from IFC data. Wepropagate statistical and, crucially, systematic uncertainties to predict thedark energy task force figure of merit (DETF FoM) for each strategy. Theincrease in FoM values with SN search area is limited by the overhead times foreach exposure. For IFC-focused strategies the largest individual systematicuncertainty is the wavelength-dependent calibration uncertainty, whereas forWFC-focused strategies, it is the intrinsic scatter uncertainty. We find thatthe best IFC-focused and WFC-exclusive strategies have comparable FoM values.Even without improvements to other cosmological probes, the WFIRST SN surveyhas the potential to increase the FoM by more than an order of magnitude fromthe current values. Although the survey strategies presented here have not beenfully optimized, these initial investigations are an important step in thedevelopment of the final hardware design and implementation of the WFIRSTmission.« less

Change and stability in work-family conflict and mothers' and fathers' mental health: Longitudinal evidence from an Australian cohort.

PubMed

Cooklin, A R; Dinh, H; Strazdins, L; Westrupp, E; Leach, L S; Nicholson, J M

2016-04-01

Work-family conflict (WFC) occurs when work or family demands are 'mutually incompatible', with detrimental effects on mental health. This study contributes to the sparse longitudinal research, addressing the following questions: Is WFC a stable or transient feature of family life for mothers and fathers? What happens to mental health if WFC increases, reduces or persists? What work and family characteristics predict WFC transitions and to what extent are they gendered? Secondary analyses of 5 waves of data (child ages 4-5 to 12-13 years) from employed mothers (n = 2693) and fathers (n = 3460) participating in the Longitudinal Study of Australian Children were conducted. WFC transitions, across four two-year intervals (Waves 1-2, 2-3, 3-4, and 4-5) were classified as never, conscript, exit or chronic. Significant proportions of parents experienced change in WFC, between 12 and 16% of mothers and fathers for each transition 'type'. Parents who remained in chronic WFC reported the poorest mental health (adjusted multiple regression analyses), followed by those who conscripted into WFC. When WFC was relieved (exit), both mothers' and fathers' mental health improved significantly. Predictors of conscript and chronic WFC were somewhat distinct for mothers and fathers (adjusted logit regressions). Poor job quality, a skilled occupation and having more children differentiated chronic fathers' from those who exited WFC. For mothers, work factors only (skilled occupation; work hours; job insecurity) predicted chronic WFC. Findings reflect the persistent, gendered nature of work and care shaped by workplaces, but also offer tailored opportunities to redress WFC for mothers and fathers. We contribute novel evidence that mental health is directly influenced by the WFC interface, both positively and negatively, highlighting WFC as a key social determinant of health. Copyright © 2016. Published by Elsevier Ltd.

Resolved Companions of Cepheids: Testing the Candidates with X-Ray Observations

NASA Astrophysics Data System (ADS)

Evans, Nancy Remage; Pillitteri, Ignazio; Wolk, Scott; Karovska, Margarita; Tingle, Evan; Guinan, Edward; Engle, Scott; Bond, Howard E.; Schaefer, Gail H.; Mason, Brian D.

2016-04-01

We have made XMM-Newton observations of 14 Galactic Cepheids that have candidate resolved (≥5″) companion stars based on our earlier HST Wide Field Camera 3 (WFC3) imaging survey. Main-sequence stars that are young enough to be physical companions of Cepheids are expected to be strong X-ray producers in contrast to field stars. XMM-Newton exposures were set to detect essentially all companions hotter than spectral type M0 (corresponding to 0.5 M⊙). The large majority of our candidate companions were not detected in X-rays, and hence are not confirmed as young companions. One resolved candidate (S Nor #4) was unambiguously detected, but the Cepheid is a member of a populous cluster. For this reason, it is likely that S Nor #4 is a cluster member rather than a gravitationally bound companion. Two further Cepheids (S Mus and R Cru) have X-ray emission that might be produced by either the Cepheid or the candidate resolved companion. A subsequent Chandra observation of S Mus shows that the X-rays are at the location of the Cepheid/spectroscopic binary. R Cru and also V659 Cen (also X-ray bright) have possible companions closer than 5″ (the limit for this study) which are the likely sources of X-rays. One final X-ray detection (V473 Lyr) has no known optical companion, so the prime suspect is the Cepheid itself. It is a unique Cepheid with a variable amplitude. The 14 stars that we observed with XMM constitute 36% of the 39 Cepheids found to have candidate companions in our HST/WFC3 optical survey. No young probable binary companions were found with separations of ≥5″ or 4000 au. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and the USA (NASA).

Work-family conflict in work groups: social information processing, support, and demographic dissimilarity.

PubMed

Bhave, Devasheesh P; Kramer, Amit; Glomb, Theresa M

2010-01-01

We used social information processing theory to examine the effect of work-family conflict (WFC) at the work group level on individuals' experience of WFC. Consistent with hypotheses, results suggest that WFC at the work group level influences individual WFC over and above the shared work environment and job demands. It was also observed that work group support and demographic dissimilarity moderate this relationship. Moderator analyses suggest that work group social support buffers WFC for individuals but is also associated with a stronger effect of work group WFC on individuals' WFC. Moreover, the work group effect on individuals' WFC was shown to be stronger for individuals who were demographically dissimilar to the work group in terms of sex and number of dependents. The interpretations and implications of these findings are discussed. Copyright 2009 APA, all rights reserved.

UVIS CTE Monitor: Star Clusters

NASA Astrophysics Data System (ADS)

Noeske, Kai

2010-09-01

*** NOTE 2: 2ND CHANGE MAR 26 2011: VISIT 13 HAD FAILED. APPROVED FOR REPETITION. ****** NEW VISIT 14 IS IDENTICAL TO FORMER VISIT 13, WITH EXCEPTIONS THAT SOME SUBEXPOSURES ARE REMOVED. ****** SEE OBSERVING DESCRIPTION FOR DETAILS. ****** NOTE: THIS IS A CHANGED PHASE II PROPOSAL AFTER VISITS 1,2,7 HAD BEEN EXECUTED ****** CHANGES BECAME NECESSARY AFTER ANALYSIS OF INCOMING CALIBRATION DATA FROM 12379 AND 12348 ****** THIS REVISED PHASE II {submission 14FEB2011} ADDS THE EVALUATION OF CHARGE INJECTION***The changes amount to:1} dropping the 3rd epoch {August 2011} of external CTE monitoring {3 orbits}2} simplifying the CTE monitor observations in the second epoch {March 2011}, freeing up 1 orbit3} using the freed up orbits from 1} and 2}, together with two additional external orbits that we were granted, to thoroughly assess the data quality of charge - injected data under realistic observing setups.These charge-injected observations will be obtained during the 2nd epoch of the CTE monitor program, in the March 2011 window.------ Original Text prior to 14 Feb 2011 below this line -----------This program extends the Cycle 17 external CTE calibration {CAL/WFC3 ID 11924} program for WFC3/UVIS over Cycle 18. Targets are {i} the sparse cluster NGC 6791 observed in Cycle 17, to continue a consistent set of observations that allows to isolate the time evolution of the CTE, and {ii} a denser field in 47 Tuc {NGC 104}. The latter will provide data to measure the dependence of the CTE on field crowding. It will also provide a consistent comparison between the CTE evolution of WFC3/UVIS and that of ACS/WFC at the same time into the flight {1 year}, because ACS/WFC CTE data were based on 47 Tuc observations. Additional observations of 47 Tuc in the CVZ will provide a wide range of background levels to measure the background dependence of the UVIS CTE.Goals are {i} the continued monitoring of the time evolution of the WFC3/UVIS CTE, {ii} establishing the detector X,Y dependence of the CTE, {iii} CTE dependence of the background level and {iv} an improved CTE correction model based on these measurements. These goals include CTE effects on both photometry and astrometry.

Sub-percent Photometry: Faint DA White Dwarf Spectrophotometric Standards for Astrophysical Observatories

NASA Astrophysics Data System (ADS)

Narayan, Gautham; Axelrod, Tim; Calamida, Annalisa; Saha, Abhijit; Matheson, Thomas; Olszewski, Edward; Holberg, Jay; Holberg, Jay; Bohlin, Ralph; Stubbs, Christopher W.; Rest, Armin; Deustua, Susana; Sabbi, Elena; MacKenty, John W.; Points, Sean D.; Hubeny, Ivan

2018-01-01

We have established a network of faint (16.5 < V < 19) hot DA white dwarfs as spectrophotometric standards for present and future wide-field observatories. Our standards are accessible from both hemispheres and suitable for ground and space-based covering the UV to the near IR. The network is tied directly to the most precise astrophysical reference presently available - the CALSPEC standards - through a multi-cycle program imaging using the Wide-Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). We have developed two independent analyses to forward model all the observed photometry and ground-based spectroscopy and infer a spectral energy distribution for each source using a non-local-thermodynamic-equilibrium (NLTE) DA white dwarf atmosphere extincted by interstellar dust. The models are in excellent agreement with each other, and agree with the observations to better than 0.01 mag in all passbands, and better than 0.005 mag in the optical. The high-precision of these faint sources, tied directly to the most accurate flux standards presently available, make our network of standards ideally suited for any experiments that have very stringent requirements on absolute flux calibration, such as studies of dark energy using the Large Synoptic Survey Telescope (LSST) and the Wide-Field Infrared Survey Telescope (WFIRST).

Hubble Sees A Smiling Lens

NASA Image and Video Library

2015-02-10

In the center of this image, taken with the NASA/ESA Hubble Space Telescope, is the galaxy cluster SDSS J1038+4849 — and it seems to be smiling. You can make out its two orange eyes and white button nose. In the case of this “happy face”, the two eyes are very bright galaxies and the misleading smile lines are actually arcs caused by an effect known as strong gravitational lensing. Galaxy clusters are the most massive structures in the Universe and exert such a powerful gravitational pull that they warp the spacetime around them and act as cosmic lenses which can magnify, distort and bend the light behind them. This phenomenon, crucial to many of Hubble’s discoveries, can be explained by Einstein’s theory of general relativity. In this special case of gravitational lensing, a ring — known as an Einstein Ring — is produced from this bending of light, a consequence of the exact and symmetrical alignment of the source, lens and observer and resulting in the ring-like structure we see here. Hubble has provided astronomers with the tools to probe these massive galaxies and model their lensing effects, allowing us to peer further into the early Universe than ever before. This object was studied by Hubble’s Wide Field and Planetary Camera 2 (WFPC2) and Wide Field Camera 3 (WFC3) as part of a survey of strong lenses. A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Judy Schmidt. Image Credit: NASA/ESA

Hubble PanCET: an isothermal day-side atmosphere for the bloated gas-giant HAT-P-32Ab

NASA Astrophysics Data System (ADS)

Nikolov, N.; Sing, D. K.; Goyal, J.; Henry, G. W.; Wakeford, H. R.; Evans, T. M.; López-Morales, M.; García Muñoz, A.; Ben-Jaffel, L.; Sanz-Forcada, J.; Ballester, G. E.; Kataria, T.; Barstow, J. K.; Bourrier, V.; Buchhave, L. A.; Cohen, O.; Deming, D.; Ehrenreich, D.; Knutson, H.; Lavvas, P.; Lecavelier des Etangs, A.; Lewis, N. K.; Mandell, A. M.; Williamson, M. H.

2018-02-01

We present a thermal emission spectrum of the bloated hot Jupiter HAT-P-32Ab from a single eclipse observation made in spatial scan mode with the Wide Field Camera 3 (WFC3) aboard the Hubble Space Telescope (HST). The spectrum covers the wavelength regime from 1.123 to 1.644 μm which is binned into 14 eclipse depths measured to an averaged precision of 104 parts-per million. The spectrum is unaffected by a dilution from the close M-dwarf companion HAT-P-32B, which was fully resolved. We complemented our spectrum with literature results and performed a comparative forward and retrieval analysis with the 1D radiative-convective ATMO model. Assuming solar abundance of the planet atmosphere, we find that the measured spectrum can best be explained by the spectrum of a blackbody isothermal atmosphere with Tp = 1995 ± 17 K, but can equally well be described by a spectrum with modest thermal inversion. The retrieved spectrum suggests emission from VO at the WFC3 wavelengths and no evidence of the 1.4 μm water feature. The emission models with temperature profiles decreasing with height are rejected at a high confidence. An isothermal or inverted spectrum can imply a clear atmosphere with an absorber, a dusty cloud deck or a combination of both. We find that the planet can have continuum of values for the albedo and recirculation, ranging from high albedo and poor recirculation to low albedo and efficient recirculation. Optical spectroscopy of the planet's day-side or thermal emission phase curves can potentially resolve the current albedo with recirculation degeneracy.

THE INFLUENCE OF NONUNIFORM CLOUD COVER ON TRANSIT TRANSMISSION SPECTRA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Line, Michael R.; Parmentier, Vivien, E-mail: mrline@ucsc.edu

2016-03-20

We model the impact of nonuniform cloud cover on transit transmission spectra. Patchy clouds exist in nearly every solar system atmosphere, brown dwarfs, and transiting exoplanets. Our major findings suggest that fractional cloud coverage can exactly mimic high mean molecular weight atmospheres and vice versa over certain wavelength regions, in particular, over the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) bandpass (1.1–1.7 μm). We also find that patchy cloud coverage exhibits a signature that is different from uniform global clouds. Furthermore, we explain analytically why the “patchy cloud-high mean molecular weight” degeneracy exists. We also explore the degeneracy ofmore » nonuniform cloud coverage in atmospheric retrievals on both synthetic and real planets. We find from retrievals on a synthetic solar composition hot Jupiter with patchy clouds and a cloud-free high mean molecular weight warm Neptune that both cloud-free high mean molecular weight atmospheres and partially cloudy atmospheres can explain the data equally well. Another key finding is that the HST WFC3 transit transmission spectra of two well-observed objects, the hot Jupiter HD 189733b and the warm Neptune HAT-P-11b, can be explained well by solar composition atmospheres with patchy clouds without the need to invoke high mean molecular weight or global clouds. The degeneracy between high molecular weight and solar composition partially cloudy atmospheres can be broken by observing the molecular Rayleigh scattering differences between the two. Furthermore, the signature of partially cloudy limbs also appears as a ∼100 ppm residual in the ingress and egress of the transit light curves, provided that the transit timing is known to seconds.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ballering, Nicholas P.; Su, Kate Y. L.; Rieke, George H.

We investigate whether varying the dust composition (described by the optical constants) can solve a persistent problem in debris disk modeling—the inability to fit the thermal emission without overpredicting the scattered light. We model five images of the β Pictoris disk: two in scattered light from the Hubble Space Telescope ( HST )/Space Telescope Imaging Spectrograph at 0.58 μ m and HST /Wide Field Camera 3 (WFC 3) at 1.16 μ m, and three in thermal emission from Spitzer /Multiband Imaging Photometer for Spitzer (MIPS) at 24 μ m, Herschel /PACS at 70 μ m, and Atacama Large Millimeter/submillimeter Arraymore » at 870 μ m. The WFC3 and MIPS data are published here for the first time. We focus our modeling on the outer part of this disk, consisting of a parent body ring and a halo of small grains. First, we confirm that a model using astronomical silicates cannot simultaneously fit the thermal and scattered light data. Next, we use a simple generic function for the optical constants to show that varying the dust composition can improve the fit substantially. Finally, we model the dust as a mixture of the most plausible debris constituents: astronomical silicates, water ice, organic refractory material, and vacuum. We achieve a good fit to all data sets with grains composed predominantly of silicates and organics, while ice and vacuum are, at most, present in small amounts. This composition is similar to one derived from previous work on the HR 4796A disk. Our model also fits the thermal spectral energy distribution, scattered light colors, and high-resolution mid-IR data from T-ReCS for this disk. Additionally, we show that sub-blowout grains are a necessary component of the halo.« less

A CANDELS WFC3 Grism Study of Emission-Line Galaxies at Z approximates 2: A mix of Nuclear Activity and Low-Metallicity Star Formation

NASA Technical Reports Server (NTRS)

Trump, Jonathan R.; Weiner, Benjamin J.; Scarlata, Claudia; Kocevski, Dale D.; Bell, Eric F.; McGrath, Elizabeth J.; Koo, David C.; Faber, S. M.; Laird, Elise S.; Mozena, Mark;

Evidence for Atmospheric Cold-trap Processes in the Noninverted Emission Spectrum of Kepler-13Ab Using HST /WFC3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beatty, Thomas G.; Zhao, Ming; Gilliland, Ronald L.

We observed two eclipses of the Kepler-13A planetary system, on UT 2014 April 28 and UT 2014 October 13, in the near-infrared using Wide Field Camera 3 on the Hubble Space Telescope . By using the nearby binary stars Kepler-13BC as a reference, we were able to create a differential light curve for Kepler-13A that had little of the systematics typically present in HST /WFC3 spectrophotometry. We measure a broadband (1.1–1.65 μ m) eclipse depth of 734 ± 28 ppm and are able to measure the emission spectrum of the planet at R  ≈ 50 with an average precision of 70 ppm. Wemore » find that Kepler-13Ab possesses a noninverted, monotonically decreasing vertical temperature profile. We exclude an isothermal profile and an inverted profile at more than 3 σ . We also find that the dayside emission of Kepler-13Ab appears generally similar to an isolated M7 brown dwarf at a similar effective temperature. Due to the relatively high mass and surface gravity of Kepler-13Ab, we suggest that the apparent lack of an inversion is due to cold-trap processes in the planet’s atmosphere. Using a toy model for where cold traps should inhibit inversions, as well as observations of other planets in this temperature range with measured emission spectra, we argue that with more detailed modeling and more observations we may be able to place useful constraints on the size of condensates on the daysides of hot Jupiters.« less

VizieR Online Data Catalog: Follow-up photometry of M101 OT2015-1 (Blagorodnova+, 2017)

NASA Astrophysics Data System (ADS)

Blagorodnova, N.; Kotak, R.; Polshaw, J.; Kasliwal, M. M.; Cao, Y.; Cody, A. M.; Doran, G. B.; Elias-Rosa, N.; Fraser, M.; Fremling, C.; Gonzalez-Fernandez, C.; Harmanen, J.; Jencson, J.; Kankare, E.; Kudritzki, R.-P.; Kulkarni, S. R.; Magnier, E.; Manulis, I.; Masci, F. J.; Mattila, S.; Nugent, P.; Ochner, P.; Pastorello, A.; Reynolds, T.; Smith, K.; Sollerman, J.; Taddia, F.; Terreran, G.; Tomasella, L.; Turatto, M.; Vreeswijk, P. M.; Wozniak, P.; Zaggia, S.

2017-07-01

The location of M101-OT2015-1 has been serendipitously imaged by numerous telescopes and instruments over the last 15 years (from 2000 to 2015). Our best quality pre-discovery image (seeing of 0.55") is an r-band exposure at -3625 days pre-peak from the Canada-France-Hawaii Telescope (CFHT). The historical optical data for M101-OT was retrieved from the CFHT MegaPrime and CFHT12K/Mosaic, using single and combined exposures, Pan-STARRS-1/GPC1 (PS1), Isaac Newton Telescope/Wide Field Camera (INT/WFC), and Sloan Digital Sky Survey (SDSS) DR 10 (Ahn+ 2014, see V/147). Unfortunately, there are no HST images covering the location of the source. Post-discovery optical magnitudes were obtained from the reported followup astronomer's telegrams (ATels), Liverpool Telescope (LT), the Nordic Optical Telescope (NOT), and the Palomar P48 and P60 telescopes. The infrared data were retrieved from CFHT/WIRCam, UKIRT/WFCAM, and the Spitzer Infrared Array Camera in 3.6 and 4.5um as part of the SPitzer InfraRed Intensive Transients Survey (SPIRITS) (Kasliwal+, 2017ApJ...839...88K). Details of pre-discovery photometry and post-discovery optical photometry may be found in the Appendices Tables 1 and 2, respectively. We obtained spectra of M101-OT using a range of facilities in 2015 Feb-Jul. (3 data files).

NASA Hubble Sees Sparring Antennae Galaxies

NASA Image and Video Library

2013-11-15

The NASA/ESA Hubble Space Telescope has snapped the best ever image of the Antennae Galaxies. Hubble has released images of these stunning galaxies twice before, once using observations from its Wide Field and Planetary Camera 2 (WFPC2) in 1997, and again in 2006 from the Advanced Camera for Surveys (ACS). Each of Hubble’s images of the Antennae Galaxies has been better than the last, due to upgrades made during the famous servicing missions, the last of which took place in 2009. The galaxies — also known as NGC 4038 and NGC 4039 — are locked in a deadly embrace. Once normal, sedate spiral galaxies like the Milky Way, the pair have spent the past few hundred million years sparring with one another. This clash is so violent that stars have been ripped from their host galaxies to form a streaming arc between the two. In wide-field images of the pair the reason for their name becomes clear — far-flung stars and streamers of gas stretch out into space, creating long tidal tails reminiscent of antennae. This new image of the Antennae Galaxies shows obvious signs of chaos. Clouds of gas are seen in bright pink and red, surrounding the bright flashes of blue star-forming regions — some of which are partially obscured by dark patches of dust. The rate of star formation is so high that the Antennae Galaxies are said to be in a state of starburst, a period in which all of the gas within the galaxies is being used to form stars. This cannot last forever and neither can the separate galaxies; eventually the nuclei will coalesce, and the galaxies will begin their retirement together as one large elliptical galaxy. This image uses visible and near-infrared observations from Hubble’s Wide Field Camera 3 (WFC3), along with some of the previously-released observations from Hubble’s Advanced Camera for Surveys (ACS). Credit: NASA/European Space Agency NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble Sees Pinwheel of Star Birth

NASA Image and Video Library

2017-12-08

NASA image release October 19, 2010 Though the universe is chock full of spiral-shaped galaxies, no two look exactly the same. This face-on spiral galaxy, called NGC 3982, is striking for its rich tapestry of star birth, along with its winding arms. The arms are lined with pink star-forming regions of glowing hydrogen, newborn blue star clusters, and obscuring dust lanes that provide the raw material for future generations of stars. The bright nucleus is home to an older population of stars, which grow ever more densely packed toward the center. NGC 3982 is located about 68 million light-years away in the constellation Ursa Major. The galaxy spans about 30,000 light-years, one-third of the size of our Milky Way galaxy. This color image is composed of exposures taken by the Hubble Space Telescope's Wide Field Planetary Camera 2 (WFPC2), the Advanced Camera for Surveys (ACS), and the Wide Field Camera 3 (WFC3). The observations were taken between March 2000 and August 2009. The rich color range comes from the fact that the galaxy was photographed invisible and near-infrared light. Also used was a filter that isolates hydrogen emission that emanates from bright star-forming regions dotting the spiral arms. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI) conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc. in Washington, D.C. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) Acknowledgment: A. Riess (STScI) NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

Milky Way red dwarfs in the BoRG survey; galactic scale-height and the distribution of dwarf stars in WFC3 imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holwerda, B. W.; Bouwens, R.; Trenti, M.

2014-06-10

We present a tally of Milky Way late-type dwarf stars in 68 Wide Field Camera 3 (WFC3) pure-parallel fields (227 arcmin{sup 2}) from the Brightest of Reionizing Galaxies survey for high-redshift galaxies. Using spectroscopically identified M-dwarfs in two public surveys, the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey and the Early Release Science mosaics, we identify a morphological selection criterion using the half-light radius (r {sub 50}), a near-infrared J – H, G – J color region where M-dwarfs are found, and a V – J relation with M-dwarf subtype. We apply this morphological selection of stellar objects, color-color selectionmore » of M-dwarfs, and optical-near-infrared color subtyping to compile a catalog of 274 M-dwarfs belonging to the disk of the Milky Way with a limiting magnitude of m {sub F125W} < 24(AB). Based on the M-dwarf statistics, we conclude that (1) the previously identified north-south discrepancy in M-dwarf numbers persists in our sample; there are more M-dwarfs in the northern fields on average than in southern ones, (2) the Milky Way's single disk scale-height for M-dwarfs is 0.3-4 kpc, depending on subtype, (3) the scale-height depends on M-dwarf subtype with early types (M0-4) high scale-height (z {sub 0} = 3-4 kpc) and later types M5 and above in the thin disk (z {sub 0} = 0.3-0.5 kpc), (4) a second component is visible in the vertical distribution, with a different, much higher scale-height in the southern fields compared to the northern ones. We report the M-dwarf component of the Sagittarius stream in one of our fields with 11 confirmed M-dwarfs, seven of which are at the stream's distance. In addition to the M-dwarf catalog, we report the discovery of 1 T-dwarfs and 30 L-dwarfs from their near-infrared colors. The dwarf scale-height and the relative low incidence in our fields of L- and T-dwarfs in these fields makes it unlikely that these stars will be interlopers in great numbers in color-selected samples of high-redshift galaxies. The relative ubiquity of M-dwarfs however will make them ideal tracers of Galactic halo substructure with EUCLID and reference stars for James Webb Space Telescope observations.« less

Single Particle Damage Events in Candidate Star Camera Sensors

NASA Technical Reports Server (NTRS)

Marshall, Paul; Marshall, Cheryl; Polidan, Elizabeth; Wacyznski, Augustyn; Johnson, Scott

2005-01-01

Si charge coupled devices (CCDs) are currently the preeminent detector in star cameras as well as in the near ultraviolet (uv) to visible wavelength region for astronomical observations in space and in earth-observing space missions. Unfortunately, the performance of CCDs is permanently degraded by total ionizing dose (TID) and displacement damage effects. TID produces threshold voltage shifts on the CCD gates and displacement damage reduces the charge transfer efficiency (CTE), increases the dark current, produces dark current nonuniformities and creates random telegraph noise in individual pixels. In addition to these long term effects, cosmic ray and trapped proton transients also interfere with device operation on orbit. In the present paper, we investigate the dark current behavior of CCDs - in particular the formation and annealing of hot pixels. Such pixels degrade the ability of a CCD to perform science and also can present problems to the performance of star camera functions (especially if their numbers are not correctly anticipated). To date, most dark current radiation studies have been performed by irradiating the CCDs at room temperature but this can result in a significantly optimistic picture of the hot pixel count. We know from the Hubble Space Telescope (HST) that high dark current pixels (so-called hot pixels or hot spikes) accumulate as a function of time on orbit. For example, the HST Advanced Camera for Surveys/Wide Field Camera instrument performs monthly anneals despite the loss of observational time, in order to partially anneal the hot pixels. Note that the fact that significant reduction in hot pixel populations occurs for room temperature anneals is not presently understood since none of the commonly expected defects in Si (e.g. divacancy, E center, and A-center) anneal at such a low temperature. A HST Wide Field Camera 3 (WFC3) CCD manufactured by E2V was irradiated while operating at -83C and the dark current studied as a function of temperature while the CCD was warmed to a sequence of temperatures up to a maximum of +30C. The device was then cooled back down to -83 and re-measured. Hot pixel populations were tracked during the warm-up and cool-down. Hot pixel annealing began below 40C and the anneal process was largely completed before the detector reached +3OC. There was no apparent sharp temperature dependence in the annealing. Although a large fraction of the hot pixels fell below the threshold to be counted as a hot pixel, they nevertheless remained warmer than the remaining population. The details of the mechanism for the formation and annealing of hot pixels is not presently understood, but it appears likely that hot pixels are associated with displacement damage occurring in high electric field regions.

Moderating Role of Acculturation in a Mediation Model of Work-Family Conflict among Chinese Immigrants in New Zealand.

PubMed

Shang, Sudong; O'Driscoll, Michael P; Roche, Maree

2017-02-01

This study examined the antecedents of work-family conflict (WFC) and the mediation effects of WFC on well-being consequences among Chinese immigrants to New Zealand, along with the moderating role of acculturation. Four types of WFC were explored: time-based and strain-based work interference with family, and time-based and strain-based family interference with work. Data were collected from 577 Chinese immigrants in New Zealand, who had full-time or part-time work and lived with family members in New Zealand. The four types of WFC were differentially related to the antecedents and well-being consequences, providing some evidence that both Chinese and New Zealand cultures may exert influences on Chinese immigrants' experiences of WFC. Both directions of WFC (work interference with family, and family interference with work) were related to job satisfaction and family satisfaction, and strain-based WFC influenced their well-being more than time-based WFC. Most importantly, we found immigrants who were proficient in English perceived greater WFC and psychological strain. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Short-focus and ultra-wide-angle lens design in wavefront coding

NASA Astrophysics Data System (ADS)

Zhang, Jiyan; Huang, Yuanqing; Xiong, Feibing

2016-10-01

Wavefront coding (WFC) is a hybrid technology designed to increase depth of field of conventional optics. The goal of our research is to apply this technology to the short-focus and ultra-wide-angle lens which suffers from the aberration related with large field of view (FOV) such as coma and astigmatism. WFC can also be used to compensate for other aberration which is sensitive to the FOV. Ultra-wide-angle lens has a little depth of focus because it has small F number and short-focus. We design a hybrid lens combing WFC with the ultra-wide-angle lens. The full FOV and relative aperture of the final design are up to170° and 1/1.8 respectively. The focal length is 2 mm. We adopt the cubic phase mask (CPM) in the design. The conventional design will have a wide variation of the point spread function (PSF) across the FOV and it is very sensitive with the variation of the FOV. The new design we obtain the PSF is nearly invariant over the whole FOV. But the result of the design also shows the little difference between the horizontal and vertical length of the PSF. We analyze that the CPM is non-symmetric phase mask and the FOV is so large, which will generate variation in the final image quality. For that reason, we apply a new method to avoid that happened. We try to make the rays incident on the CPM with small angle and decrease the deformation of the PSF. The experimental result shows the new method to optimize the CPM is fit for the ultra-wide-angle lens. The research above will be a helpful instruction to design the ultra-wide-angle lens with WFC.

Does trait affectivity predict work-to-family conflict and enrichment beyond job characteristics?

PubMed

Tement, Sara; Korunka, Christian

2013-01-01

The present study examines whether negative and positive affectivity (NA and PA, respectively) predict different forms of work-to-family conflict (WFC-time, WFC-strain, WFC-behavior) and enrichment (WFE-development, WFE-affect, WFE-capital) beyond job characteristics (workload, autonomy, variety, workplace support). Furthermore, interactions between job characteristics and trait affectivity while predicting WFC and WFE were examined. Using a large sample of Slovenian employees (N = 738), NA and PA were found to explain variance in WFC as well as in WFE above and beyond job characteristics. More precisely, NA significantly predicted WFC, whereas PA significantly predicted WFE. In addition, several interactive effects were found to predict forms of WFC and WFE. These results highlight the importance of trait affectivity in work-family research. They provide further support for the crucial impact of job characteristics as well.

Work-family conflict and mental disorders in the United States: cross-sectional findings from The National Comorbidity Survey.

PubMed

Wang, Jianli; Afifi, Tracie O; Cox, Brian; Sareen, Jitender

2007-02-01

Work-family conflict (WFC) may have negative effects on workers' health and productivity. The objective of this analysis was to assess the association between WFC and mental disorders that occurred in the past month. Data from the U.S. National Comorbidity Survey were used. The 1-month prevalence of mental disorders was estimated by levels of WFC and by gender. Compared to participants who reported low WFC, those who reported high WFC had a significantly higher prevalence of mental and/or substance use related disorders in the past month. Working hours and domestic roles did not have significant impacts on the association between WFC and mental disorders, irrespective of gender. Work and family roles and the balance between the two are important for workers' mental health. The influence of WFC on mental health should be investigated in conjunction with important work environment characteristics in longitudinal studies.

Work-family conflict and neck and back pain in surgical nurses.

PubMed

Baur, Heiner; Grebner, Simone; Blasimann, Angela; Hirschmüller, Anja; Kubosch, Eva Johanna; Elfering, Achim

2018-03-01

Surgical nurses' work is physically and mentally demanding, possibly leading to work-family conflict (WFC). The current study tests WFC to be a risk factor for neck and lower back pain (LBP). Job influence and social support are tested as resources that could buffer the detrimental impact of WFC. Forty-eight surgical nurses from two university hospitals in Germany and Switzerland were recruited. WFC was assessed with the Work-Family Conflict Scale. Job influence and social support were assessed with the Copenhagen Psychosocial Questionnaire, and back pain was assessed with the North American Spine Society Instrument. Multiple linear regression analyses confirmed WFC as a significant predictor of cervical pain (β = 0.45, p < 0.001) and LBP (β = 0.33, p = 0.012). Job influence and social support did not turn out to be significant predictors and were not found to buffer the impact of WFC in moderator analyses. WFC is likely to affect neck and back pain in surgery nurses. Work-life interventions may have the potential to reduce WFC in surgery nurses.

Work-family conflict among athletic trainers in the secondary school setting.

PubMed

Pitney, William A; Mazerolle, Stephanie M; Pagnotta, Kelly D

2011-01-01

Work-family conflict (WFC) negatively affects a professional's ability to function at work or home. To examine perceptions of and contributing factors to WFC among secondary school athletic trainers. Sequential explanatory mixed-methods study. Secondary school. From a random sample of 1325 individuals selected from the National Athletic Trainers' Association Member Services database, 415 individuals (203 women, 212 men; age = 36.8 ± 9.3 years) provided usable online survey data. Fourteen individuals participated in follow-up interviews. Online WFC questionnaire followed by in-depth phone interviews. Descriptive statistics were obtained to examine perceived WFC. Pearson product moment correlations were calculated to examine the relationship between work hours, total athletic training staff, and number of children and WFC score. We performed analysis of variance to examine differences between the independent variables of sex and control over work schedule and the dependent variable of WFC score. The a priori α was set at P ≤ .05. Qualitative data were analyzed using inductive content analysis. Multiple-analyst triangulation and member checks established trustworthiness of the qualitative data. Mean WFC scores were 23.97 ± 7.78 for scale 1 (family defined as having a partner or spouse with or without children) and 23.17 ± 7.69 for scale 2 (family defined as individuals, including parents, siblings, grandparents, and any other close relatives, involved in one's life), indicating moderate perceived WFC. A significant relationship was found between the average hours of work per week and WFC scores: those with less scheduling control experienced more WFC. Two dimensions emerged from the qualitative methods that relate to how WFC is mitigated in the secondary school environment: (1) organizational-having colleagues and administration that understood the role demands and allowed for modifications in schedule and personal time and (2) personal-taking time for oneself and having a family that understands the work demands of an athletic trainer resulted in reduced perceived WFC. A large number of work hours per week and lack of control over work schedules affected the perceived level of WFC.

Work–Family Conflict Among Athletic Trainers in the Secondary School Setting

PubMed Central

Pitney, William A.; Mazerolle, Stephanie M.; Pagnotta, Kelly D.

2011-01-01

Abstract Context: Work–family conflict (WFC) negatively affects a professional's ability to function at work or home. Objective: To examine perceptions of and contributing factors to WFC among secondary school athletic trainers. Design: Sequential explanatory mixed-methods study. Setting: Secondary school. Patients or Other Participants: From a random sample of 1325 individuals selected from the National Athletic Trainers' Association Member Services database, 415 individuals (203 women, 212 men; age = 36.8 ± 9.3 years) provided usable online survey data. Fourteen individuals participated in follow-up interviews. Intervention(s): Online WFC questionnaire followed by in-depth phone interviews. Main Outcome Measure(s): Descriptive statistics were obtained to examine perceived WFC. Pearson product moment correlations were calculated to examine the relationship between work hours, total athletic training staff, and number of children and WFC score. We performed analysis of variance to examine differences between the independent variables of sex and control over work schedule and the dependent variable of WFC score. The a priori α was set at P ≤ .05. Qualitative data were analyzed using inductive content analysis. Multiple-analyst triangulation and member checks established trustworthiness of the qualitative data. Results: Mean WFC scores were 23.97 ± 7.78 for scale 1 (family defined as having a partner or spouse with or without children) and 23.17 ± 7.69 for scale 2 (family defined as individuals, including parents, siblings, grandparents, and any other close relatives, involved in one's life), indicating moderate perceived WFC. A significant relationship was found between the average hours of work per week and WFC scores: those with less scheduling control experienced more WFC. Two dimensions emerged from the qualitative methods that relate to how WFC is mitigated in the secondary school environment: (1) organizational—having colleagues and administration that understood the role demands and allowed for modifications in schedule and personal time and (2) personal—taking time for oneself and having a family that understands the work demands of an athletic trainer resulted in reduced perceived WFC. Conclusions: A large number of work hours per week and lack of control over work schedules affected the perceived level of WFC. PMID:21391804

A Study Of The Kinematics Of Stellar Sub-populations In M31's Disk And Spheroid Using PHAT And SPLASH Data

NASA Astrophysics Data System (ADS)

Guhathakurta, Puragra; Dorman, C.; Seth, A.; Dalcanton, J.; Gilbert, K.; Howley, K.; Johnson, L. C.; Kalirai, J.; Krause, T.; Lang, D.; Williams, B.; PHAT Team; SPLASH Collaboration

2012-01-01

We present a comparative study of the kinematics of different types of stars in the Andromeda galaxy (M31). Our fields of study span a range of projected radii from 2 to 15 kpc in the NE and SE quadrants of M31's disk and spheroid. The kinematical part of this study is based on radial velocity measurements of a few thousand stars obtained using the Keck II telescope and DEIMOS spectrograph as part of the SPLASH survey. The DEIMOS spectra have a spectral resolution of about 1.5 Angstrom (FWHM) and cover the wavelength range 6500-9000 Angstrom. The stellar populations part of this study - specifically, the division of stars into sub-populations - is based on high spatial resolution Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) and Wide-Field Camera 3 (WFC3) images and photometry in six filters: two ultraviolet bands (F275W and F336W), two optical bands (F475W and F814W), and two near-infrared bands (F110W and F160W). The stellar sub-populations we study include metal-rich, metal-intermediate, and metal-poor red giants, asymptotic giant branch stars, He-burning blue loop stars, massive main sequence stars, planetary nebulae, and X-ray binaries. Kinematical information allows us to measure the fraction of each sub-population that is associated with M31's disk versus its spheroid. The excellent synergy between HST and Keck provides insight into the relationship between the dynamical, star formation, and chemical enrichment histories of the structural sub-components of M31 and, by association, other large spiral galaxies. This research was supported by the National Science Foundation, NASA, and the Science Internship Program (SIP) at UCSC.

Hubble Catches a Galaxy Duo by the "Hare"

NASA Image and Video Library

2017-12-08

This image from the NASA/ESA Hubble Space Telescope shows the unusual galaxy IRAS 06076-2139, found in the constellation Lepus (The Hare). Hubble’s Wide Field Camera 3 (WFC3) and Advanced Camera for Surveys (ACS) instruments observed the galaxy from a distance of 500 million light-years. This particular object stands out from the crowd by actually being composed of two separate galaxies rushing past each other at about 2 million kilometers (1,243,000 miles) per hour. This speed is most likely too fast for them to merge and form a single galaxy. However, because of their small separation of only about 20,000 light-years, the galaxies will distort one another through the force of gravity while passing each other, changing their structures on a grand scale. Such galactic interactions are a common sight for Hubble, and have long been a field of study for astronomers. The intriguing behaviors of interacting galaxies take many forms; galactic cannibalism, galaxy harassment and even galaxy collisions. The Milky Way itself will eventually fall victim to the latter, merging with the Andromeda Galaxy in about 4.5 billion years. The fate of our galaxy shouldn’t be alarming though: while galaxies are populated by billions of stars, the distances between individual stars are so large that hardly any stellar collisions will occur. Credit: ESA/Hubble & NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Hubble's Best Image of Alpha Centauri A and B

NASA Image and Video Library

2017-12-08

The closest star system to the Earth is the famous Alpha Centauri group. Located in the constellation of Centaurus (The Centaur), at a distance of 4.3 light-years, this system is made up of the binary formed by the stars Alpha Centauri A and Alpha Centauri B, plus the faint red dwarf Alpha Centauri C, also known as Proxima Centauri. This NASA/ESA Hubble Space Telescope has given us this stunning view of the bright Alpha Centauri A (on the left) and Alpha Centauri B (on the right), shining like huge cosmic headlamps in the dark. The image was captured by the Wide-Field and Planetary Camera 2 (WFPC2). WFPC2 was Hubble’s most used instrument for the first 13 years of the space telescope’s life, being replaced in 2009 by Wide-Field Camera 3 (WFC3) during Servicing Mission 4. This portrait of Alpha Centauri was produced by observations carried out at optical and near-infrared wavelengths. Compared to the sun, Alpha Centauri A is of the same stellar type, G2, and slightly bigger, while Alpha Centauri B, a K1-type star, is slightly smaller. They orbit a common center of gravity once every 80 years, with a minimum distance of about 11 times the distance between Earth and the sun. Because these two stars are, together with their sibling Proxima Centauri, the closest to Earth, they are among the best studied by astronomers. And they are also among the prime targets in the hunt for habitable exoplanets. Using the European Space Organization's HARPS instrument, astronomers already discovered a planet orbiting Alpha Centauri B. Then on Aug. 24, 2016, astronomers announced the intriguing discovery of a nearly Earth-sized planet in the habitable zone orbiting the star Proxima Centauri Image credit: ESA/NASA

The first detection of neutral hydrogen in emission in a strong spiral lens

NASA Astrophysics Data System (ADS)

Lipnicky, Andrew; Chakrabarti, Sukanya; Wright, Melvyn C. H.; Blitz, Leo; Heiles, Carl; Cotton, William; Frayer, David; Blandford, Roger; Shu, Yiping; Bolton, Adam S.

2018-05-01

We report H I observations of eight spiral galaxies that are strongly lensing background sources. Our targets were selected from the Sloan WFC (Wide Field Camera) Edge-on Late-type Lens Survey (SWELLS) using the Arecibo, Karl G. Jansky Very Large Array, and Green Bank telescopes. We securely detect J1703+2451 at z = 0.063 with a signal-to-noise ratio of 6.7 and W50 = 79 ± 13 km s-1, obtaining the first detection of H I emission in a strong spiral lens. We measure a mass of M_{H I} = (1.77± 0.06^{+0.35}_{-0.75})× 10^9 M_{⊙} for this source. We find that this lens is a normal spiral, with observable properties that are fairly typical of spiral galaxies. For three other sources, we did not secure a detection; however, we are able to place strong constraints on the H I masses of those galaxies. The observations for four of our sources were rendered unusable due to strong radio frequency interference.

Hubble Spies Spiral Galaxy

NASA Image and Video Library

2017-12-08

Spiral galaxy NGC 3274 is a relatively faint galaxy located over 20 million light-years away in the constellation of Leo (The Lion). This NASA/ESA Hubble Space Telescope image comes courtesy of Hubble's Wide Field Camera 3 (WFC3), whose multi-color vision allows astronomers to study a wide range of targets, from nearby star formation to galaxies in the most remote regions of the cosmos. This image combines observations gathered in five different filters, bringing together ultraviolet, visible and infrared light to show off NGC 3274 in all its glory. NGC 3274 was discovered by Wilhelm Herschel in 1783. The galaxy PGC 213714 is also visible on the upper right of the frame, located much farther away from Earth. Image Credit: ESA/Hubble & NASA, D. Calzetti NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Spectroscopic redshifts and age dating of a first statistical sample of passive galaxies at z 3

NASA Astrophysics Data System (ADS)

Daddi, Emanuele

2017-08-01

Ultradeep WFC3/G141 observations from one of our past HST programs allowed us to confirm the redshift and measure the age of a quiescent galaxy at z=3. This unique object was found inside a single WFC3 pointing (4 sq. arcmin) suggesting that massive old galaxies even at z 3 are more common than previously thought. The strong correlation observed between evolved stellar populations and a bulge-dominated morphology at least up to z 2 may also imply that the Hubble sequence comes into place at very early times. Guided by the properties of this spectroscopically confirmed z=3 passive galaxy, we have identified a substantial sample of 2.5

Effects of work-family conflict and job insecurity on psychological distress.

PubMed

Mutambudzi, M; Javed, Z; Kaul, S; Prochaska, J; Peek, M K

2017-12-02

Work-family conflict (WFC) and job insecurity are important determinants of workers' mental health. To examine the relationship between WFC and psychological distress, and the co-occurring effects of WFC and job insecurity on distress in US working adults. This study used cross-sectional data from the 2010 National Health Interview Survey (NHIS) for adults aged 18-64 years. The 2010 NHIS included occupational data from the National Institute for Occupational Safety and Health (NIOSH) sponsored Occupational Health Supplement. Logistic regression models were used to examine the independent and co-occurring effects of WFC and job insecurity on distress. The study group consisted of 12059 participants. In the model fully adjusted for relevant occupational, behavioural, sociodemographic and health covariates, WFC and job insecurity were independently significantly associated with increased odds of psychological distress. Relative to participants reporting WFC only, participants reporting no WFC and no job insecurity had lower odds of moderate and severe distress. Co-occurring WFC and job insecurity was associated with significantly higher odds of both moderate [odds ratio (OR) = 1.55; 95% confidence interval (CI) 1.25-1.9] and severe (OR = 3.57; 95% CI 2.66-4.79) distress. Rates of WFC and job insecurity were influenced by differing factors in working adults; however, both significantly increased risk of adverse mental health outcomes, particularly when experienced jointly. Future studies should explore the temporal association between co-occurring WFC and job insecurity and psychological distress. © The Author 2017. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Developmental trajectories of work-family conflict for Finnish workers in midlife.

PubMed

Rantanen, Johanna; Kinnunen, Ulla; Pulkkinen, Lea; Kokko, Katja

2012-07-01

This study investigated the developmental trajectories of work-family conflict among the same participants (n = 277; 48% female) at ages 36, 42, and 50. Across this 14-year time span, with respect to the sample as a whole, there was no significant change in the mean levels of work-to-family conflict (WFC) or family to-work conflict (FWC). However, latent profile analyses revealed four latent trajectories within the sample, showing both mean-level stability and change in WFC and FWC: (1) "WFC decreasing" (n = 151); (2) "WFC and FWC stable low" (n = 105); (3) "WFC and FWC increasing" (n = 14); and (4) "FWC decreasing" (n = 7). Of these trajectories the strongest contrast existed between the WFC and FWC stable low and the WFC and FWC increasing trajectories: the former had the lowest and the latter the highest number of weekly working hours at ages 36, 42, and 50, and in the former but not in the latter the number of children living at home significantly decreased from age 36 to 50. Also, at ages 42 and 50 the WFC and FWC increasing trajectory showed higher job exhaustion and depressive symptoms than the WFC and FWC stable low trajectory. Altogether these findings suggest that work-family conflict is not limited to the early part of employees' working career and that developmental trajectories of work-family conflict exhibit a substantial amount of heterogeneity.

HUBBLE SPACE TELESCOPE SPECTROSCOPY OF BROWN DWARFS DISCOVERED WITH THE WIDE-FIELD INFRARED SURVEY EXPLORER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schneider, Adam C.; Cushing, Michael C.; Kirkpatrick, J. Davy

2015-05-10

We present a sample of brown dwarfs identified with the Wide-field Infrared Survey Explorer (WISE) for which we have obtained Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) near-infrared grism spectroscopy. The sample (22 in total) was observed with the G141 grism covering 1.10–1.70 μm, while 15 were also observed with the G102 grism, which covers 0.90–1.10 μm. The additional wavelength coverage provided by the G102 grism allows us to (1) search for spectroscopic features predicted to emerge at low effective temperatures (e.g.,ammonia bands) and (2) construct a smooth spectral sequence across the T/Y boundary. We find no evidencemore » of absorption due to ammonia in the G102 spectra. Six of these brown dwarfs are new discoveries, three of which are found to have spectral types of T8 or T9. The remaining three, WISE J082507.35+280548.5 (Y0.5), WISE J120604.38+840110.6 (Y0), and WISE J235402.77+024015.0 (Y1), are the 19th, 20th, and 21st spectroscopically confirmed Y dwarfs to date. We also present HST grism spectroscopy and reevaluate the spectral types of five brown dwarfs for which spectral types have been determined previously using other instruments.« less

Determinants of nurses' job satisfaction: the role of work-family conflict, job demand, emotional charge and social support.

PubMed

Cortese, Claudio G; Colombo, Lara; Ghislieri, Chiara

2010-01-01

The aim of the present study was to develop a research model explaining the causal relationship between certain antecedents (job and emotional charge, supportive management and colleagues), work-family conflict (WFC) and job satisfaction. Many research projects in health organizations have highlighted the link between high WFC and lower levels of job satisfaction. The study of these variables is important in understanding the processes of professional nurse retention. The survey was conducted using a questionnaire administered to 351 professional nurses working in a major North Italian hospital. The questionnaire measures six variables: WFC, job satisfaction, job demand, emotional charge, supportive management and supportive colleagues. The data confirmed the connection between WFC and job satisfaction, and showed the importance of some WFC predictors, such as supportive management, emotional charge and job demand, not only for their connections with WFC but also for their direct associations with job satisfaction. WFC, in health organizations, can contribute to a decrease of nurses' job satisfaction. Nursing management could achieve its aim of reducing WFC through the improvement of support from nurse coordinators, the specific organization of work models, ad hoc family-friendly policies and individual counselling programmes for nurses.

VizieR Online Data Catalog: Astrometric monitoring of ultracool dwarf binaries (Dupuy+, 2017)

NASA Astrophysics Data System (ADS)

Dupuy, T. J.; Liu, M. C.

2017-09-01

In Table 1 we list all 33 binaries in our Keck+CFHT astrometric monitoring sample, along with three other binaries that have published orbit and parallax measurements. We began obtaining resolved Keck AO astrometry in 2007-2008, and we combined our new astrometry with available data in the literature or public archives (e.g., HST and Gemini) to refine our orbital period estimates and thereby our prioritization for Keck observations. We present here new Keck/NIRC2 AO imaging and non-redundant aperture-masking observations, in addition to a re-analysis of our own previously published data and publicly available archival data for our sample binaries. Table 2 gives our measured astrometry and flux ratios for all Keck AO data used in our orbital analysis spanning 2003 Apr 15 to 2016 May 13. In total there are 339 distinct measurements (unique bandpass and epoch for a given target), where 302 of these are direct imaging and 37 are non-redundant aperture masking. Eight of the imaging measurements are from six unpublished archival data sets. See section 3.1.1 for further details. In addition to our Keck AO monitoring, we also obtained data for three T dwarf binaries over a three-year HST program using the Advanced Camera for Surveys (ACS) Wide Field Camera (WFC) in the F814W bandpass. See section 3.1.2 for further details. Many of our sample binaries have HST imaging data in the public archive. We have re-analyzed the available archival data coming from the WFPC2 Planetary Camera (WFPC2-PC1), ACS High Resolution Channel (ACS-HRC), and NICMOS Camera 1 (NICMOS-NIC1). See section 3.1.3 for further details. We present here an updated analysis of our data from the Hawaii Infrared Parallax Program that uses the CFHT facility infrared camera WIRCam. Our observing strategy and custom astrometry pipeline are described in detail in Dupuy & Liu (2012, J/ApJS/201/19). See section 3.2 for further explanations. (10 data files).

Work-family conflict, part II: Job and life satisfaction in national collegiate athletic association division I-A certified athletic trainers.

PubMed

Mazerolle, Stephanie M; Bruening, Jennifer E; Casa, Douglas J; Burton, Laura J

2008-01-01

Previous researchers have shown that work-family conflict (WFC) affects the level of a person's job satisfaction, life satisfaction, and job burnout and intentions to leave the profession. However, WFC and its consequences have not yet been fully investigated among certified athletic trainers. To investigate the relationship between WFC and various outcome variables among certified athletic trainers working in National Collegiate Athletic Association Division I-A settings. A mixed-methods design using a 53-item survey questionnaire and follow-up in-depth interviews was used to examine the prevalence of WFC. Division I-A universities sponsoring football. A total of 587 athletic trainers (324 men, 263 women) responded to the questionnaire, and 12 (6 men, 6 women) participated in the qualitative portion of the mixed-methods study. We calculated Pearson correlations to determine the relationship between WFC and job satisfaction, life satisfaction, and job burnout. Regression analyses were run to determine whether WFC was a predictor of job satisfaction, job burnout, or intention to leave the profession. Interviews were transcribed verbatim and then analyzed using the computer program N6 as well as member checks and peer debriefing. Negative relationships were found between WFC and job satisfaction (r = -.52, P < .001). Positive were noted between WFC and job burnout (r = .63, P < .001) and intention to leave the profession (r = .46, P < .001). Regression analyses revealed that WFC directly contributed to job satisfaction (P < .001), job burnout (P < .001), and intention to leave the profession (P < .001). Overall, our findings concur with those of previous researchers on WFC and its negative relationships to job satisfaction and life satisfaction and positive relationship to job burnout and intention to leave an organization. Sources of WFC, such as time, inflexible work schedules, and inadequate staffing, were also related to job burnout and job dissatisfaction in this population.

VizieR Online Data Catalog: Infrared massive stellar content of M83 (Williams+, 2015)

NASA Astrophysics Data System (ADS)

Williams, S. J.; Bonanos, A. Z.; Whitmore, B. C.; Prieto, J. L.; Blair, W. P.

2015-06-01

We extracted the mosaic image of M83 from the Local Volume Legacy Survey (LVL, Dale et al., 2009ApJ...703..517D, Cat. J/ApJ/703/517) in all four of the IRAC bands. The final images analyzed here cover an area of 15' x15' with a pixel scale of 0.75arcsec/pix centered on the nucleus of M83 (J2000.0:RA=13:37:00.9,DE=-29:51:56). Observations of M83 were made in J and Ks with the FourStar instrument attached to the 6.5m Baade Magellan Telescope at Las Campanas Observatory on UT date 2014 Jan. 2. Blair et al. (2014ApJ...788...55B, Cat. J/ApJ/788/55) studied supernova remnants in M83 with seven fields of Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) observations in multiple bandpasses. Two fields come from the Early Release Science Program (ID 11360; R. O'Connell, PI) with the remaining five coming from the cycle 19 HST General Observer program 12513 (W. Blair, PI). These seven fields cover the majority of the bright disk region of M83. We specifically used the imaging and photometry in the F336W (Johnson U), F438W (Johnson B), F555W (Johnson V) or F547M (Stroemgren y, easily converted to Johnson V), and F814W (Johnson I) bands. (2 data files).

Managing work–family conflict in the medical profession: working conditions and individual resources as related factors

PubMed Central

Mache, Stefanie; Bernburg, Monika; Vitzthum, Karin; Groneberg, David A; Klapp, Burghard F; Danzer, Gerhard

2015-01-01

Objectives This study developed and tested a research model that examined the effects of working conditions and individual resources on work–family conflict (WFC) using data collected from physicians working at German clinics. Material and methods This is a cross-sectional study of 727 physicians working in German hospitals. The work environment, WFC and individual resources were measured by the Copenhagen Psychosocial Questionnaire, the WFC Scale, the Brief Resilient Coping Scale and the Questionnaire for Self-efficacy, Optimism and Pessimism. Descriptive, correlation and linear regression analyses were applied. Results Clinical doctors working in German hospitals perceived high levels of WFC (mean=76). Sociodemographic differences were found for age, marital status and presence of children with regard to WFC. No significant gender differences were found. WFCs were positively related to high workloads and quantitative job demands. Job resources (eg, influence at work, social support) and personal resources (eg, resilient coping behaviour and self-efficacy) were negatively associated with physicians’ WFCs. Interaction terms suggest that job and personal resources buffer the effects of job demands on WFC. Conclusions In this study, WFC was prevalent among German clinicians. Factors of work organisation as well as factors of interpersonal relations at work were identified as significant predictors for WFC. Our results give a strong indication that both individual and organisational factors are related to WFC. Results may play an important role in optimising clinical care. Practical implications for physicians’ career planning and recommendations for future research are discussed. PMID:25941177

Bipolar-pulses observed by the LRS/WFC-L onboard KAGUYA - Plausible evidence of lunar dust impact -

NASA Astrophysics Data System (ADS)

Kasahara, Yoshiya; Horie, Hiroki; Hashimoto, Kozo; Omura, Yoshiharu; Goto, Yoshitaka; Kumamoto, Atsushi; Ono, Takayuki; Tsunakawa, Hideo; Lrs/Wfc Team; Map/Lmag Team

2010-05-01

Introduction: The waveform capture (WFC) [1] is one of the subsystems of the Lunar Radar Sounder (LRS) [2] on board the KAGUYA spacecraft. By taking advantage of a moon orbiter, the WFC measures plasma waves and radio emis-sions around the moon. The WFC measures two components of electric wave signals detected by the two orthogonal 30 m tip-to-tip antennas from 100Hz to 1MHz. The WFC consists of the WFC-L which meas-ures electric waveform from 100Hz to 100kHz, and the WFC-H which is a fast sweep frequency analyz-er covering from 1kHz up to 1MHz. The WFC-L has two operation modes: DIFF and MONO. In DIFF mode, signals from two pairs of 30m tip-to-tip dipole antennas are obtained. MONO mode is namely an interferometry mode and we separately measure the signals from a pair of monopole antennas. This mode is dedicated to measure the phase velocities and wave numbers of plasma waves. Bipolar-pulses with their time scales of a few ms upto several tens ms were often observed by the WFC-L. Some of them are classified into elec-trostatic solitary waves (ESW) [3], while another type of bipolar pulses which are supposed to be caused by lunar dust impacts are also observed. In the present paper, we introduce the latter type of bipolar-pulses. Observation: In general, ESWs are caused by electron-holes in the nonlinear evolution of electron beam instability. Therefore waveform of ESW is basically symmetric and its propagation direction is parallel to the am-bient magnetic field. On the other hand, another type of bipolar pulses are characterized by their asymmetric waveforms, that is, the latter half of pulse is longer than the first half. It is also noted that detection probability of such asymmetric bipolar pulses in MONO mode is much higher than that in DIFF mode. This is because bipolar pulses detected by a pair of monopole antennas in MONO mode are almost identical (pulses are simultaneously detected with both monopole anten-nas and the polarities of these pulses are also same) and thus most of bipolar-pulses which can be detected in MONO mode are cancelled in DIFF mode. This fact suggests that these bipolar pulses are not a kind of natural wave but these are caused by instantaneous potential changes of the KAGUYA spacecraft. Discussion: Similar type of bipolar-pulses has been observed by the monopole antenna measurements using Radio and Plasma Wave Science (RPWS) instruments on-board Cassini around Saturn [4]. They demonstrated that these bipolar pulses are caused by impacts of dusts floating around the Saturn. It is well-known that lunar dusts are widely dis-tributed in higher altitude range around the moon and it is plausible that these bipolar pulses are caused by the lunar dust impacts. In the presentation, we show the detailed charac-teristics of bipolar pulses detected by the WFC-L onboard KAGUYA. References: [1] Y. Kasahara et al., Earth, Planets and Space, 60(4), 341-351, 2008. [2] T. Ono et al., Earth, Planets and Space, 60(4), 321-332, 2008. [3] K. Hashimoto et al., The 4th SELENE (KAGUYA) Science Working Team Meeting, (this issue), 2010. [4] W.S. Kurth et al, Planetary and Space Science, 54(9-10), 988-998, 2006.

Star formation in the outskirts of DDO 154: a top-light IMF in a nearly dormant disc

NASA Astrophysics Data System (ADS)

Watts, Adam B.; Meurer, Gerhardt R.; Lagos, Claudia D. P.; Bruzzese, Sarah M.; Kroupa, Pavel; Jerabkova, Tereza

2018-07-01

We present optical photometry of Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS)/Wide Field Camera (WFC) data of the resolved stellar populations in the outer disc of the dwarf irregular galaxy DDO 154. The photometry reveals that young main sequence (MS) stars are almost absent from the outermost H I disc. Instead, most are clustered near the main stellar component of the galaxy. We constrain the stellar initial mass function (IMF) by comparing the luminosity function of the MS stars to simulated stellar populations, assuming a constant star formation rate over the dynamical time-scale. The best-fitting IMF is deficient in high-mass stars compared to a canonical Kroupa IMF, with a best-fitting slope α = -2.45 and upper mass limit MU = 16 M⊙. This top-light IMF is consistent with predictions of the integrated galactic IMF theory. Combining the HST images with H I data from The H I Nearby Galaxy Survey (THINGS), we determine the star formation law (SFL) in the outer disc. The fit has a power-law exponent N = 2.92 ± 0.22 and zero-point A = 4.47 ± 0.65 × 10-7 M⊙ yr-1 kpc-2. This is depressed compared to the Kennicutt-Schmidt SFL, but consistent with weak star formation observed in diffuse H I environments. Extrapolating the SFL over the outer disc implies that there could be significant star formation occurring that is not detectable in H α. Last, we determine the Toomre stability parameter Q of the outer disc of DDO 154 using the THINGS H I rotation curve and velocity dispersion map. 72 per cent of the H I in our field has Q ≤ 4 and this incorporates 96 per cent of the observed MS stars. Hence, 28 per cent of the H I in the field is largely dormant.

Does Work-Family Conflict Mediate the Associations of Job Characteristics With Employees' Mental Health Among Men and Women?

PubMed

Carvalho, Vânia S; Chambel, Maria J; Neto, Mariana; Lopes, Silvia

2018-01-01

Job characteristics are important to work-family conflict (WFC). Additionally, is well established that WFC has a negative impact on mental health. As such, this research aims to examine the role of WFC as a mechanism that explains the relationship between job characteristics (i.e., those establishing by the Job Demands-Control-Support Model) and workers' mental health. Moreover, based on gender inequalities in work and non-work roles, this study analyzed gender as moderator of this mediation. Specifically, the relationship between job characteristics and WFC and the relationship between WFC and mental health could be stronger for women than for men. With a sample of 254 workers from a Portuguese services company, (61% males), and based on a multiple-group analysis, the results indicated that the WFC mediates the relationship between job characteristics (i.e., job demands and job control) and mental health. It was reinforced that job demands and lack of control could contribute to employees' stress and, once individual' energy was drained, the WFC could emerge. Ultimately, may be due to the presence of this conflict that individuals mental health' is negatively affected. Contrary to our expectations, this relationship is not conditioned by gender ( Z -scores were non-significant). The study results have implications for human resource management, enhancing the knowledge on the relationship between the WFC and workers' mental health.

The Work-Family Interface and Sleep Quality.

PubMed

Magee, Christopher A; Robinson, Laura D; McGregor, Alisha

2017-01-18

This article investigated whether work-to-family conflict (WFC) and work-to-family enrichment (WFE) were associated with employee sleep quality. WFC and WFE reflect the potential for experiences at work to negatively and positively influence nonworking life respectively, and may have implications for sleep quality. In this article, we examined whether WFC and WFE were linked with sleep quality via hedonic balance (i.e., positive affect relative to negative affect). The sample included 3,170 employed Australian parents involved in the Household Income and Labour Dynamics in Australia (HILDA) Survey. Information on WFC, WFE, hedonic balance, sleep quality, and relevant covariates was collected through a structured interview and self-completion questionnaire. WFC was associated with poorer sleep quality (β = .27, p < .001), and this relationship was stronger in males than females and in dual parent-single income families. WFC was also found to be indirectly associated with poor sleep quality via a lower hedonic balance (β = .17, 99% confidence interval [.14, .20]). WFE was not directly associated with sleep quality, but was indirectly associated with better sleep quality via a higher hedonic balance (β = -.04 [-.07, -.02]). These results indicate that aspects of the work-family interface are associated with employee sleep quality. Furthermore, affective experiences were found to link WFC and WFE with sleep quality. Workplace interventions that target WFC and WFE may have implications for employee sleep.

Work-Family Conflict, Part II: Job and Life Satisfaction in National Collegiate Athletic Association Division I-A Certified Athletic Trainers

PubMed Central

Mazerolle, Stephanie M; Bruening, Jennifer E; Casa, Douglas J; Burton, Laura J

2008-01-01

Context: Previous researchers have shown that work-family conflict (WFC) affects the level of a person's job satisfaction, life satisfaction, and job burnout and intentions to leave the profession. However, WFC and its consequences have not yet been fully investigated among certified athletic trainers. Objective: To investigate the relationship between WFC and various outcome variables among certified athletic trainers working in National Collegiate Athletic Association Division I-A settings. Design: A mixed-methods design using a 53-item survey questionnaire and follow-up in-depth interviews was used to examine the prevalence of WFC. Setting: Division I-A universities sponsoring football. Patients or Other Participants: A total of 587 athletic trainers (324 men, 263 women) responded to the questionnaire, and 12 (6 men, 6 women) participated in the qualitative portion of the mixed-methods study. Data Collection and Analysis: We calculated Pearson correlations to determine the relationship between WFC and job satisfaction, life satisfaction, and job burnout. Regression analyses were run to determine whether WFC was a predictor of job satisfaction, job burnout, or intention to leave the profession. Interviews were transcribed verbatim and then analyzed using the computer program N6 as well as member checks and peer debriefing. Results: Negative relationships were found between WFC and job satisfaction (r  =  −.52, P < .001). Positive were noted between WFC and job burnout (r  =  .63, P < .001) and intention to leave the profession (r  =  .46, P < .001). Regression analyses revealed that WFC directly contributed to job satisfaction (P < .001), job burnout (P < .001), and intention to leave the profession (P < .001). Conclusions: Overall, our findings concur with those of previous researchers on WFC and its negative relationships to job satisfaction and life satisfaction and positive relationship to job burnout and intention to leave an organization. Sources of WFC, such as time, inflexible work schedules, and inadequate staffing, were also related to job burnout and job dissatisfaction in this population. PMID:18833314

Optical And Near-infrared Variability Among Distant Galactic Nuclei Of The CANDELS EGS Field

NASA Astrophysics Data System (ADS)

Grogin, Norman A.; Dahlen, T.; Donley, J.; Koekemoer, A. M.; Salvato, M.; CANDELS Collaboration

2014-01-01

The CANDELS HST Multi-cycle Treasury Program completed its observations of the EGS field in May 2013. The coverage comprises WFC3/IR exposures in J-band and H-band across a contiguous 200 square arcminutes, and coordinated parallel ACS/WFC exposures in V-band and I-band across a contiguous 270 square arcminutes that largely overlaps the WFC3/IR coverage. These observations were split between two epochs with 52-day spacing for the primary purpose of high-redshift supernovae (SNe) detection and follow-up. However, this combination of sensitivity, high resolution, and time spacing is also well-suited to detect optical and near-infrared variability ("ONIV") among moderate- to high-redshift galaxy nuclei (H<25AB mag; I<26AB mag). These data are sensitive to rest-frame variability time-scales of up to several weeks, and in combination with the original EGS ACS imaging from 2004, to time-scales of up to several years in the V- and I-bands. The overwhelming majority of these variable galaxy nuclei will be AGN; the small fraction arising from SNe have already been meticulously culled by the CANDELS high-redshift SNe search effort. These ONIV galaxy nuclei potentially represent a significant addition to the census of distant lower-luminosity AGN subject to multi-wavelength scrutiny with CANDELS. We present the preliminary results of our EGS variability analysis, including a comparison of the HST ONIVs with the known AGN candidates in the field from deep Spitzer and Chandra imaging, and from extensive ground-based optical spectroscopy as well as HST IR-grism spectroscopy. We also assess the redshift distribution of the ONIVs from both spectroscopy and from robust SED-fitting incorporating ancillary deep ground-based imaging along with the CANDELS VIJH photometry. We compare these results with our prior variability analysis of the similarly-observed CANDELS UDS field from 2011 and CANDELS COSMOS field from 2012.

Work-Life Balance among Married Women Employees.

PubMed

Reddy, N Krishna; Vranda, M N; Ahmed, Atiq; Nirmala, B P; Siddaramu, B

2010-07-01

Family-work conflict (FWC) and work-family conflict (WFC) are more likely to exert negative influences in the family domain, resulting in lower life satisfaction and greater internal conflict within the family. Studies have identified several variables that influence the level of WFC and FWC. Variables such as the size of family, the age of children, the work hours and the level of social support impact the experience of WFC and FWC. However, these variables have been conceptualized as antecedents of WFC and FWC; it is also important to consider the consequences these variables have on psychological distress and wellbeing of the working women. to study various factors which could lead to WFC and FWC among married women employees. The sample consisted of a total of 90 married working women of age between 20 and 50 years. WFC and FWC Scale was administered to measure WFC and FWC of working women. The obtained data were analyzed using descriptive and inferential statistics. Carl Pearson's Correlation was used to find the relationship between the different variables. The findings of the study emphasized the need to formulate guidelines for the management of WFCs at organizational level as it is related to job satisfaction and performance of the employees.

[Determining factors of job-satisfaction: presence of work-family conflict in a sample of Italian nurses].

PubMed

Cortese, C G; Ghislieri, Chiara; Colombo, Lara

2008-01-01

Organization research has shown increasing interest in the dynamics of work-family conflict (w.f.c.). The NEXT study highlights that w.f.c. significantly influences satisfaction for one's job and the decision to quit the nursing profession. This study analyzes w.f.c. in a sample of Italian nurses, with the aim of examining the main differences in relation to personal variables, and understanding the degree to which w.f.c. explains job satisfaction. A self-reporting questionnaire was administered to 325 nurses in different hospitals of Northern Italy. Descriptive, reliability and Anova data analysis was performed. The relationships between variables were analyzed through correlations (Pearson's r); the role of w.f.c. in explaining job satisfaction was estimated via multiple regression. W.f.c. appeared to be more critical in subjects who had care responsibilities and in those who had more demanding work assignments. W.f.c. contributed to explaining job satisfaction, even if it was not its principal determining factor. This area of research appears to be important in that it leads to a better comprehension of the dynamics involved in work satisfaction and can suggest possible initiatives for support and development.

NASA's Hubble Shows Jupiter's Great Red Spot is Smaller than Ever

NASA Image and Video Library

2014-05-15

In this comparison image the photo at the top was taken by Hubble's Wide Field Planetary Camera 2 in 1995 and shows the spot at a diameter of just under 21 000km; the second down shows a 2009 WFC3 photo of the spot at a diameter of just under 18 000km; and the lowest shows the newest image from WFC3 taken in 2014 with the spot at its smallest yet, with diameter of just 16 000km. -- Jupiter's trademark Great Red Spot -- a swirling anti-cyclonic storm larger than Earth -- has shrunk to its smallest size ever measured. According to Amy Simon of NASA's Goddard Space Flight Center in Greenbelt, Maryland, recent NASA Hubble Space Telescope observations confirm the Great Red Spot now is approximately 10,250 miles across. Astronomers have followed this downsizing since the 1930s. Historic observations as far back as the late 1800s gauged the storm to be as large as 25,500 miles on its long axis. NASA Voyager 1 and Voyager 2 flybys of Jupiter in 1979 measured it to be 14,500 miles across. In 1995, a Hubble photo showed the long axis of the spot at an estimated 13,020 miles across. And in a 2009 photo, it was measured at 11,130 miles across. Beginning in 2012, amateur observations revealed a noticeable increase in the rate at which the spot is shrinking -- by 580 miles per year -- changing its shape from an oval to a circle. Read more: 1.usa.gov/1mvuo0R Credit: NASA/ESA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

INFRARED TRANSMISSION SPECTROSCOPY OF THE EXOPLANETS HD 209458b AND XO-1b USING THE WIDE FIELD CAMERA-3 ON THE HUBBLE SPACE TELESCOPE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deming, Drake; Wilkins, Ashlee; McCullough, Peter

Exoplanetary transmission spectroscopy in the near-infrared using the Hubble Space Telescope (HST) NICMOS is currently ambiguous because different observational groups claim different results from the same data, depending on their analysis methodologies. Spatial scanning with HST/WFC3 provides an opportunity to resolve this ambiguity. We here report WFC3 spectroscopy of the giant planets HD 209458b and XO-1b in transit, using spatial scanning mode for maximum photon-collecting efficiency. We introduce an analysis technique that derives the exoplanetary transmission spectrum without the necessity of explicitly decorrelating instrumental effects, and achieves nearly photon-limited precision even at the high flux levels collected in spatial scanmore » mode. Our errors are within 6% (XO-1) and 26% (HD 209458b) of the photon-limit at a resolving power of {lambda}/{delta}{lambda} {approx} 70, and are better than 0.01% per spectral channel. Both planets exhibit water absorption of approximately 200 ppm at the water peak near 1.38 {mu}m. Our result for XO-1b contradicts the much larger absorption derived from NICMOS spectroscopy. The weak water absorption we measure for HD 209458b is reminiscent of the weakness of sodium absorption in the first transmission spectroscopy of an exoplanet atmosphere by Charbonneau et al. Model atmospheres having uniformly distributed extra opacity of 0.012 cm{sup 2} g{sup -1} account approximately for both our water measurement and the sodium absorption. Our results for HD 209458b support the picture advocated by Pont et al. in which weak molecular absorptions are superposed on a transmission spectrum that is dominated by continuous opacity due to haze and/or dust. However, the extra opacity needed for HD 209458b is grayer than for HD 189733b, with a weaker Rayleigh component.« less

Infrared Transmission Spectroscopy of the Exoplanets HD 209458b and XO-1b Using the Wide Field Camera-3 on the Hubble Space Telescope

NASA Astrophysics Data System (ADS)

Deming, Drake; Wilkins, Ashlee; McCullough, Peter; Burrows, Adam; Fortney, Jonathan J.; Agol, Eric; Dobbs-Dixon, Ian; Madhusudhan, Nikku; Crouzet, Nicolas; Desert, Jean-Michel; Gilliland, Ronald L.; Haynes, Korey; Knutson, Heather A.; Line, Michael; Magic, Zazralt; Mandell, Avi M.; Ranjan, Sukrit; Charbonneau, David; Clampin, Mark; Seager, Sara; Showman, Adam P.

2013-09-01

Exoplanetary transmission spectroscopy in the near-infrared using the Hubble Space Telescope (HST) NICMOS is currently ambiguous because different observational groups claim different results from the same data, depending on their analysis methodologies. Spatial scanning with HST/WFC3 provides an opportunity to resolve this ambiguity. We here report WFC3 spectroscopy of the giant planets HD 209458b and XO-1b in transit, using spatial scanning mode for maximum photon-collecting efficiency. We introduce an analysis technique that derives the exoplanetary transmission spectrum without the necessity of explicitly decorrelating instrumental effects, and achieves nearly photon-limited precision even at the high flux levels collected in spatial scan mode. Our errors are within 6% (XO-1) and 26% (HD 209458b) of the photon-limit at a resolving power of λ/δλ ~ 70, and are better than 0.01% per spectral channel. Both planets exhibit water absorption of approximately 200 ppm at the water peak near 1.38 μm. Our result for XO-1b contradicts the much larger absorption derived from NICMOS spectroscopy. The weak water absorption we measure for HD 209458b is reminiscent of the weakness of sodium absorption in the first transmission spectroscopy of an exoplanet atmosphere by Charbonneau et al. Model atmospheres having uniformly distributed extra opacity of 0.012 cm2 g-1 account approximately for both our water measurement and the sodium absorption. Our results for HD 209458b support the picture advocated by Pont et al. in which weak molecular absorptions are superposed on a transmission spectrum that is dominated by continuous opacity due to haze and/or dust. However, the extra opacity needed for HD 209458b is grayer than for HD 189733b, with a weaker Rayleigh component.

Evolution of galaxy structure using visual morphologies in CANDELS and Hydro-ART simulations

NASA Astrophysics Data System (ADS)

Mozena, Mark W.

2013-08-01

The general properties, morphologies, and classes of galaxies in the local Universe are well studied. Most local galaxies are morphologically members of the Hubble sequence and can be crudely separated into elliptical red quiescent galaxies or disky blue star-forming galaxies. This Hubble sequence of relaxed structures has been shown to dominate galaxy populations out to a redshift of z~1. The description of galaxies at earlier times is not well known nor is it understood how and at what epoch the Hubble sequence formed. Of particular interest is the structure of galaxies at z~2. This epoch was an active time for galaxy growth and was the peak epoch for star formation rate, active galactic nuclei activity, and mergers between galaxies. With the installation of the near-infrared Wide Field Camera 3 (WFC3) on the Hubble Space Telescope in 2009, large area photometric surveys of galaxies were able to be performed for the first time at moderate redshifts (z~2) in wavebands that effectively trace the older stellar populations and stellar mass of the galaxies rather than the clumpy star-forming regions. Using WFC3 HST images, an in-depth morphology classification system was developed to probe the galaxy populations at higher redshifts (focusing on z~2). These visual classifications were used with other galaxy parameters (stellar mass, color, star formation rate, radius, Sersic profiles, etc) to identify and quantify the moderate redshift galaxy populations and study how these populations changed with time to form the relaxed Hubble sequence Universe we observe today. Additionally, these same tools that were used to probe galaxy populations at z~2 in the observed Universe were also used on simulated galaxy images produced from state-of-the-art cosmological simulations. These Hydro-ART simulations build artificial galaxies that are compared to observations so as to shed light on the relevant mechanisms in galaxy evolution. By classifying and comparing the populations present in the simulations with our observations, we are able to probe the model's ability to create realistic galaxy populations. The first chapter of this thesis focuses on visually classifying and studying galaxy populations at z~2 and how they change with redshift for a given mass. The second chapter focuses on applying our techniques to Hydro-ART simulations at z~2 and comparing these mock 'observed' simulations with our real WFC3 HST observations. Both of these chapters closely resemble manuscripts in the process of being submitted for independent publication.

Work, family, and personal characteristics explain occupational and gender differences in work-family conflict among Japanese civil servants.

PubMed

Koura, U; Sekine, M; Yamada, M; Tatsuse, T

2017-12-01

A high level of work-family conflict (WFC) is an important risk factor for physical and mental health problems. Although individual work-related factors for WFC have been extensively studied, relatively little is known about whether occupation and gender affect WFC and how such effects might be generated. Cross-sectional study. This study surveyed 3053 civil servants aged 20-65 years working in a local government in the west coast of Japan in 2003. Logistic regression analyses were used to examine whether there are occupational and gender differences in WFC and to clarify the factors underlying these differences. WFC was higher in professional and technical workers compared with other occupations for both men and women, with age-adjusted odds ratios (ORs) for these workers of 1.29 in men and 2.58 in women. In men, occupational differences in WFC disappeared after adjusting for work and family characteristics (OR = 1.15). In women, significant occupational differences remained in the final model, but after adjusting for work characteristics the adjusted OR for professional and technical workers was reduced to 1.69. Women were more likely than men to experience high WFC (OR = 2.52). After controlling for work characteristics, the gender difference was considerably reduced (OR = 1.68). Work characteristics play a fundamental role in the difference in WFC between not only occupational but also gender differences. Stressful work characteristics among professional and technical workers and among women in all work roles should be addressed to reduce occupational and gender differences in WFC in Japan. Copyright © 2017 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Managing work-family conflict in the medical profession: working conditions and individual resources as related factors.

PubMed

Mache, Stefanie; Bernburg, Monika; Vitzthum, Karin; Groneberg, David A; Klapp, Burghard F; Danzer, Gerhard

2015-05-03

This study developed and tested a research model that examined the effects of working conditions and individual resources on work-family conflict (WFC) using data collected from physicians working at German clinics. This is a cross-sectional study of 727 physicians working in German hospitals. The work environment, WFC and individual resources were measured by the Copenhagen Psychosocial Questionnaire, the WFC Scale, the Brief Resilient Coping Scale and the Questionnaire for Self-efficacy, Optimism and Pessimism. Descriptive, correlation and linear regression analyses were applied. Clinical doctors working in German hospitals perceived high levels of WFC (mean=76). Sociodemographic differences were found for age, marital status and presence of children with regard to WFC. No significant gender differences were found. WFCs were positively related to high workloads and quantitative job demands. Job resources (eg, influence at work, social support) and personal resources (eg, resilient coping behaviour and self-efficacy) were negatively associated with physicians' WFCs. Interaction terms suggest that job and personal resources buffer the effects of job demands on WFC. In this study, WFC was prevalent among German clinicians. Factors of work organisation as well as factors of interpersonal relations at work were identified as significant predictors for WFC. Our results give a strong indication that both individual and organisational factors are related to WFC. Results may play an important role in optimising clinical care. Practical implications for physicians' career planning and recommendations for future research are discussed. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

An examination of factors related to work-to-family conflict among employed men and women in Japan.

PubMed

Kato, Michiko; Yamazaki, Yoshihiko

2009-01-01

The aims of this study of Japanese married employees were: 1) to examine the relationship between work-related factors and work-to-family conflict (WFC); 2) to examine the relationship between WFC and fatigue and depression; and 3) to explore the role of family togetherness in a path between WFC and health. A cross-sectional survey was conducted among employees belonging to a labor union federation of the chemical industry. All analyses were conducted by subgroup according to gender and parental status. Data was collected from 12 companies located in the Tokyo metropolitan area from September to October 2005. The data of 961 married employees were analyzed. The main findings by regression analyses were: 1) high job demands, low job control, and unsupportive work-family culture were associated with high level of WFC; 2) WFC was positively associated with fatigue and depression regardless of gender and parental status; and 3) maintaining family togetherness was slightly, yet significantly associated with fatigue in the father group. WFC was unfavorably related to fatigue and depression in both genders regardless of parental status, and plays a role linking unfavorable work situations and health. As possible work-related factors of WFC, the data indicate not only individual workplace variables but also an organizational support. Additionally, maintaining family togetherness appears to benefit fathers by preventing fatigue. Strategies for reduction of WFC are therefore necessary to promote health among married workers of both genders.

CLASH: A census of magnified star-forming galaxies at z ∼ 6-8

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bradley, L. D.; Coe, D.; Postman, M.

2014-09-01

We utilize 16 band Hubble Space Telescope (HST) observations of 18 lensing clusters obtained as part of the Cluster Lensing And Supernova survey with Hubble (CLASH) Multi-Cycle Treasury program to search for z ∼ 6-8 galaxies. We report the discovery of 204, 45, and 13 Lyman-break galaxy candidates at z ∼ 6, z ∼ 7, and z ∼ 8, respectively, identified from purely photometric redshift selections. This large sample, representing nearly an order of magnitude increase in the number of magnified star-forming galaxies at z ∼ 6-8 presented to date, is unique in that we have observations in four WFC3/UVISmore » UV, seven ACS/WFC optical, and all five WFC3/IR broadband filters, which enable very accurate photometric redshift selections. We construct detailed lensing models for 17 of the 18 clusters to estimate object magnifications and to identify two new multiply lensed z ≳ 6 candidates. The median magnifications over the 17 clusters are 4, 4, and 5 for the z ∼ 6, z ∼ 7, and z ∼ 8 samples, respectively, over an average area of 4.5 arcmin{sup 2} per cluster. We compare our observed number counts with expectations based on convolving 'blank' field UV luminosity functions through our cluster lens models and find rough agreement down to ∼27 mag, where we begin to suffer significant incompleteness. In all three redshift bins, we find a higher number density at brighter observed magnitudes than the field predictions, empirically demonstrating for the first time the enhanced efficiency of lensing clusters over field surveys. Our number counts also are in general agreement with the lensed expectations from the cluster models, especially at z ∼ 6, where we have the best statistics.« less

Morphology and Structure of High-redshift Massive Galaxies in the CANDELS Fields

NASA Astrophysics Data System (ADS)

Guan-wen, Fang; Ze-sen, Lin; Xu, Kong

2018-01-01

Using the multi-band photometric data of all five CANDELS (Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey) fields and the near-infrared (F125W and F160W) high-resolution images of HST WFC3 (Hubble Space Telescope Wide Field Camera 3), a quantitative study of morphology and structure of mass-selected galaxies is presented. The sample includes 8002 galaxies with a redshift 1 < z < 3 and stellar mass M*> 1010M⊙. Based on the Convolutional Neural Network (ConvNet) criteria, we classify the sample galaxies into SPHeroids (SPH), Early-Type Disks (ETD), Late-Type Disks (LTD), and IRRegulars (IRR) in different redshift bins. The findings indicate that the galaxy morphology and structure evolve with redshift up to z ∼ 3, from irregular galaxies in the high-redshift universe to the formation of the Hubble sequence dominated by disks and spheroids. For the same redshift interval, the median values of effective radii (re) of different morphological types are in a descending order: IRR, LTD, ETD, and SPH. But for the Sérsic index (n), the order is reversed (SPH, ETD, LTD, and IRR). In the meantime, the evolution of galaxy size (re) with the redshift is explored for the galaxies of different morphological types, and it is confirmed that their size will enlarge with time. However, such a phenomenon is not found in the relations between the redshift (1 < z < 3) and the mean axis ratio (b/a), as well as the Sérsic index (n).

WFC3 Cycle 19 Calibration Program

NASA Astrophysics Data System (ADS)

Sabbi, E.; WFC3 Team

2012-03-01

The Cycle 19 WFC3 Calibration Program runs from October 2011 through September 2012 and is designed to measure and monitor the behavior of both the UVIS and IR channels. The program was prepared with the actual usage of WFC3 in mind, to provide the best calibration data and reference les for the approved scientic programs. During Cycle 19 the WFC3 team is using 125 external and 1587 internal orbits of HST time divided in 29 di erent programs, grouped in six categories: Monitor, Photometry, Spectroscopy, Detectors, Flat-elds, and Image Quality

Work–Life Balance among Married Women Employees

PubMed Central

Reddy, N. Krishna; Vranda, M. N.; Ahmed, Atiq; Nirmala, B. P.; Siddaramu, B.

2010-01-01

Family–work conflict (FWC) and work–family conflict (WFC) are more likely to exert negative influences in the family domain, resulting in lower life satisfaction and greater internal conflict within the family. Studies have identified several variables that influence the level of WFC and FWC. Variables such as the size of family, the age of children, the work hours and the level of social support impact the experience of WFC and FWC. However, these variables have been conceptualized as antecedents of WFC and FWC; it is also important to consider the consequences these variables have on psychological distress and wellbeing of the working women. Aim: to study various factors which could lead to WFC and FWC among married women employees. Materials and Methods: The sample consisted of a total of 90 married working women of age between 20 and 50 years. WFC and FWC Scale was administered to measure WFC and FWC of working women. The obtained data were analyzed using descriptive and inferential statistics. Carl Pearson's Correlation was used to find the relationship between the different variables. Findings and Conclusion: The findings of the study emphasized the need to formulate guidelines for the management of WFCs at organizational level as it is related to job satisfaction and performance of the employees. PMID:21716777

Opening the Window on Galaxy Assembly: Ages and Structural Parameters of Globular Clusters Towards the Galactic Bulge

NASA Astrophysics Data System (ADS)

Cohen, Roger

2015-10-01

The primary aim of this program is to undertake a systematic investigation of highly reddened Galactic globular clusters (GGCs) located towards the Galactic bulge. These clusters have been excluded from deep space-based photometric surveys due to their severe total and differential extinction. We will exploit the photometric depth and homogeneity of two existing Treasury programs (the ACS GGC Treasury Survey and the WFC3 Bulge Treasury Program) along with the unique optical+IR parallel imaging capabilities of HST to finally place the bulge GGCs in the context of their optically well-studied counterparts. Specifically, by leveraging ACS/WFC together with WFC3/IR, we first exploit the reddening sensitivity at optical wavelengths to map severe, small-scale differential reddening in the cluster cores. Corrected two-color WFC3/IR photometry will then be used to measure cluster ages to better than 1 Gyr relative precision, finally completing the age-metallicity relation of the Milky Way GGC system. Ages are obtained using a demonstrated procedure which is strictly differential, and therefore insensitive to total distance, reddening, reddening law, or photometric calibration uncertainties. At the same time, deep archival Treasury survey imaging of the Galactic bulge will be used to decontaminate cluster luminosity functions, yielding measurements of bulge GGC mass functions and mass segregation on par with results from the ACS GGC Treasury survey. Finally, the imaging which we propose will be combined with existing wide-field near-IR PSF photometry, yielding complete radial number density profiles, structural and morphological parameters.

Hubble Sees an Ancient Globular Cluster

NASA Image and Video Library

2017-12-08

This image captures the stunning NGC 6535, a globular cluster 22,000 light-years away in the constellation of Serpens (The Serpent) that measures one light-year across. Globular clusters are tightly bound groups of stars which orbit galaxies. The large mass in the rich stellar centre of the globular cluster pulls the stars inward to form a ball of stars. The word globulus, from which these clusters take their name, is Latin for small sphere. Globular clusters are generally very ancient objects formed around the same time as their host galaxy. To date, no new star formation has been observed within a globular cluster, which explains the abundance of aging yellow stars in this image, most of them containing very few heavy elements. NGC 6535 was first discovered in 1852 by English astronomer John Russell Hind. The cluster would have appeared to Hind as a small, faint smudge through his telescope. Now, over 160 years later, instruments like the Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFC3) on the NASA/ European Space Agency (ESA) Hubble Space Telescope allow us to marvel at the cluster and its contents in greater detail. Credit: ESA/Hubble & NASA, Acknowledgement: Gilles Chapdelaine NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

VizieR Online Data Catalog: 14 unusual IR transients with Spitzer (SPRITEs) (Kasliwal+, 2017)

NASA Astrophysics Data System (ADS)

Kasliwal, M. M.; Bally, J.; Masci, F.; Cody, A. M.; Bond, H. E.; Jencson, J. E.; Tinyanont, S.; Cao, Yi; Contreras, C.; Dykhoff, D. A.; Amodeo, S.; Armus, L.; Boyer, M.; Cantiello, M.; Carlon, R. L.; Cass, A. C.; Cook, D.; Corgan, D. T.; Faella, J.; Fox, O. D.; Green, W.; Gehrz, R. D.; Helou, G.; Hsiao, E.; Johansson, J.; Khan, R. M.; Lau, R. M.; Langer, N.; Levesque, E.; Milne, P.; Mohamed, S.; Morrell, N.; Monson, A.; Moore, A.; Ofek, E. O.; O'Sullivan, D.; Parthasarathy, M.; Perez, A.; Perley, D. A.; Phillips, M.; Prince, T. A.; Shenoy, D.; Smith, N.; Surace, J.; van Dyk, S. D.; Whitelock, P. A.; Williams, R.

2017-11-01

The SPitzer InfraRed Intensive Transients Survey (SPIRITS) survey uses the IRAC instrument (FoV 5'x5') on board the warm Spitzer telescope to search for IR transients at 3.6um ([3.6]) and 4.5um ([4.5]). SPIRITS is a five-year survey from 2014 to 2018 (Kasliwal+ 2013sptz.prop10136K, 2016sptz.prop13053K). We are undertaking concomitant ground-based surveys to monitor the SPIRITS galaxy sample in the near-IR and the optical at roughly a monthly cadence. At the University of Minnesota's Mt. Lemmon Observing Facility (MLOF), we use the three-channel Two Micron All Sky Survey cameras mounted on the 1.52m IR telescope. At Las Campanas, we undertake near-IR monitoring with the Retrocam on Dupont 100 inch telescope and optical monitoring using the CCD on the Swope 40 inch telescope. At Palomar, we use the Samuel Oschin 48 inch (primarily gr-band) and Palomar 60 inch telescopes (gri-bands) for optical monitoring. Using the LCOGT network, we obtain additional optical monitoring in gri-bands. In addition, a follow-up of discovered transients was undertaken by a myriad of facilities including Keck, Magellan, Palomar 200 inch, SALT, and RATIR. Following non-detections from the ground, we were able to set even deeper magnitude limits for two transients based on a small HST Director's Discretionary program (GO/DD-13935, PI H. Bond). We imaged SPIRITS 14aje (in M101) and SPIRITS 14axa (in M81) with the Wide Field Camera 3 (WFC3) in 2014 September. (5 data files).

How job demands affect absenteeism? The mediating role of work-family conflict and exhaustion.

PubMed

Vignoli, Michela; Guglielmi, Dina; Bonfiglioli, Roberta; Violante, Francesco Saverio

2016-01-01

To investigate how psychosocial factors (such as job demands and work-family conflict) produce absenteeism in the workplace, using the health impairment process of the job demands-resources model. According to this model, job demands lead to burnout (often measured with the emotional exhaustion component), which in turn could lead to outcomes (such as absenteeism). Work-family conflict (WFC) was also studied, because of contradictory results collected in the existing literature on absenteeism in the workplace, regarding the role of WFC in causing absenteeism. Data were collected on 245 workers using both subjective (questionnaire on psychological risk factors and work-related health) and objective data (sickness leave frequency records). To test the hypothesis that job demands and WFC contribute to absenteeism in the workplace, a subsequent mediation analysis was used, which analysed both (a) the subsequent mediation of WFC and emotional exhaustion and (b) the separate roles played by the mediators proposed (WFC and emotional exhaustion). Job demands affect absenteeism through the subsequent mediation of WFC and emotional exhaustion. In addition, emotional exhaustion mediates the relationship between job demands and absenteeism, while WFC does not. In conclusion, subsequent mediation highlights the role of emotional exhaustion in causing absenteeism; in fact, when emotional exhaustion is included in the analysis, job demands are associated with higher levels of absenteeism. The results of this study suggest that without the concurrent contribution of emotional exhaustion, WFC does not influence absenteeism in the workplace. Our findings are useful for organizations that aim to reduce absenteeism.

Work-family conflict and prolonged fatigue among Japanese married male physicians.

PubMed

Ohta, Hiroshi; Wada, Koji; Kawashima, Masatoshi; Arimatsu, Mayuri; Higashi, Toshiaki; Yoshikawa, Toru; Aizawa, Yoshiharu

2011-12-01

Fatigue experienced by physicians may not only endanger their own health but may also affect the safety of patients. Such fatigue may be associated with the work environment and personal factors such as work-family conflict (WFC). This study aimed to determine the association between WFC and prolonged fatigue among Japanese married male physicians. Physicians who graduated from a Japanese medical school answered a mailed anonymous self-report questionnaire. For assessment of WFC and prolonged fatigue, the Japanese versions of the WFC scale and the Checklist of Individual Strength questionnaire (CIS) were used. Prolonged fatigue was defined as the upper quartile of total CIS scores. The WFC scale comprises six dimensions. Total scores were divided into tertiles: low, intermediate, and high levels of WFC. A multiple logistic regression analysis was performed to examine the association between WFC and prolonged fatigue. A total of 540 male physicians answered the questionnaire, and the data of 444 married male physicians were analyzed. The data were then adjusted for age and work condition factors. Prolonged fatigue was significantly associated with high strain-based work interference with family (WIF; corrected odds ratio, 5.56; 95% confidence interval, 2.55-12.1), intermediate strain-based WIF (2.53, 1.25-5.10), high time-based family interference with work (FIW; 1.92, 1.08-3.40), and there was a weak association with high strain-based FIW (1.93, 0.98-3.83). Employers should take measures to improve working conditions in hospitals, and give physicians the opportunity to learn how to cope with WFC. These measures could ultimately help prevent prolonged fatigue.

Relationship between work-family conflict and a sense of coherence among Japanese registered nurses.

PubMed

Takeuchi, Tomoko; Yamazaki, Yoshihiko

2010-12-01

Work-family conflict (WFC) refers to the conflict that arises between a person's work and family life. Previous studies have reported workload, job demands, and irregular working shifts as related to the WFC among nurses and have clarified that WFC is a predictor of job satisfaction, morale, and turnover intention. Very few studies have investigated WFC among Japanese nurses and no study has taken into consideration the sense of coherence (SOC) that helps nurses to cope with stress. The present study aimed to determine the relationship between WFC and SOC and to clarify how WFC and a SOC influence the mental and physical health of nurses in order to suggest ways of establishing work environments that enable nurses to achieve a balance between their work and family life. A self-report questionnaire survey of 388 Japanese female nurses was conducted. The data from 138 nurses who were a mother and/or wife were analyzed. Work-family conflict was significantly related to the SOC. It had a larger impact on the physical and mental health of nurses than their work and family characteristics. The SOC also had a major influence on the physical and mental health of nurses, while having a buffering effect on WFC with respect to depression. Our findings underscore the importance of taking organizational steps to create work environments that contribute to an enhanced SOC in order to reduce the WFC among nurses. © 2010 The Authors. Japan Journal of Nursing Science © 2010 Japan Academy of Nursing Science.

The Effects of Home-Based Teleworking on Work-Family Conflict.

ERIC Educational Resources Information Center

Madsen, Susan R.

2003-01-01

Responses from 98 teleworkers and 123 onsite workers found that teleworkers had lower levels of the dimensions of work-family conflict (WFC): time-, strain-, and behavior-based work interference with family and family interference. Male teleworkers had higher levels of WFC; there were no gender differences for nonteleworkers. WFC was significantly…

Work-family conflict and enrichment from the perspective of psychosocial resources: comparing Finnish healthcare workers by working schedules.

PubMed

Mauno, Saija; Ruokolainen, Mervi; Kinnunen, Ulla

2015-05-01

We examined work-family conflict (WFC) and work-family enrichment (WFE) by comparing Finnish nurses, working dayshifts (non-shiftworkers, n = 874) and non-dayshifts. The non-dayshift employees worked either two different dayshifts (2-shiftworkers, n = 490) or three different shifts including nightshifts (3-shiftworkers, n = 270). Specifically, we investigated whether different resources, i.e. job control, managers' work-family support, co-workers' work-family support, control at home, personal coping strategies, and schedule satisfaction, predicted differently WFC and WFE in these three groups. Results showed that lower managers' work-family support predicted higher WFC only among 3-shiftworkers, whereas lower co-workers' support associated with increased WFC only in non-shiftworkers. In addition, shiftworkers reported higher WFC than non-shiftworkers. However, the level of WFE did not vary by schedule types. Moreover, the predictors of WFE varied only very little across schedule types. Shiftwork organizations should pay more attention to family-friendly management in order to reduce WFC among shiftworkers. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Galaxy Assembly and the Evolution of Structure over the First Third of Cosmic Time - III

NASA Astrophysics Data System (ADS)

Faber, Sandra

2011-10-01

This survey will document the first third of galactic evolution fromz=8 to 1.5 andtest for evolution in the properties of Type Ia supernovae to z 2 byimaging more than 250,000 galaxies with WFC3/IR and ACS. Five premiermulti-wavelength regions are selected from within the Spitzer SEDSsurvey, providing complementaryIRAC data down to 26.5 AB mag, a unique resource forstellar masses at high redshifts. The use of five widely separatedfields mitigates cosmic variance and yields statistically robustsamples of galaxies down to 10^9 M_Sun out to z 8.We adopt a two-tiered strategy with a "Wide" component {roughly 2orbits deep over 0.2 sq. degrees} and a "Deep" component {roughly 12orbits deep over 0.04 sq. degrees}. Combining these with ultra-deepimaging from the Cycle 17 HUDF09 program yields a three-tieredstrategy for efficient sampling of both rare/bright and faint/commonobjects.Three of the Wide-survey fields are located in COSMOS, EGS, andUKIDSS/UDS. Each of these consists of roughly 3x15 WFC3/IR tiles.Each WFC3 tile will be observed for 2 orbits, with single orbitsseparated in time to allow a search for high-redshift Type Ia SNe.The co-added exposure times will be approximately 2/3 orbit in J{F125W} and 4/3 orbit in H {F160W}. ACS parallels overlap most of theWFC3 area and will consist of roughly 2/3 orbits in V {F606W} and4/3 orbit in I {F814W}. Because of the larger area of ACS,this results in effective exposures that are twice as long {4/3 in V,8/3 in I}, making a very significant improvement to existing ACSmosaics in COSMOS and EGS and creating a new ACS mosaic in UDS/UKIDSSwhere none now exists. Other Wide-survey components are located inthe GOODS fields {North and South} surrounding the Deep-survey areas.The Deep-survey fields cover roughly half of each GOODS field, withexact areas and placements to be determined as part of the Phase-2process. Each WFC3/IR tile within the Deep regions will receiveapproximately 12 orbits of exposure time split between Y{F105W}, J {F125W}, and H {F160W}. Multi-epoch imaging will provide anefficient search for high-redshift Type Ia SNe here also. ACSparallels are also taken in the Deep regions, with the goal ofassembling enough total exposure time in F850LP and other filters toidentify high redshift z>6 galaxies in concert with WFC3/IR data usingthe Lyman break technique.A portion of the GOODS-N campaign will take place while the field isin the HST Continuous Viewing Zone {CVZ}. The bright time in thoseorbits will be used to obtain UV imaging with WFC3 in the F275W andF336W filters. The exact number of orbits will not be known untilPhase-2 planning is complete, but we anticipate that it will bepossible to schedule at least 100 orbits, resulting in 5-sigmapoint-source depths of 26.6, 26.4 in F275W and F336W,respectively. The science goals include measuring the Lyman-continuumescape fractions for galaxies at z 2.5 and identifying Lyman-breakgalaxies at z 2-3.The Type Ia supernova search program in this proposal is integratedwith that in the Postman cluster MCT proposal, with this one stressingthe more distant supernovae. A combined follow-up program will providelight curves and grism spectra of 15-20 of the best candidates atredshifts 17 galaxies in the Deep regions, inaddition to hundreds of highly-luminous candidates in the Wide regionsfor detailed follow-up. These samples will be used to construct aunified picture of star-formation and stellar mass buildup in earlygalaxies. Extremely deep X-ray data will reveal distant AGNs to z>6,shedding light on the earliest stages of BH growth. In the peak starformation/QSO era, z 2, we will document the properties of earlydisks, the build-up of bulges, the evolution of mergers, and thenature of AGN hosts to construct an integrated model for structuralevolution, star formation quenching, and AGN triggering. Finally, the 8 Type Ia SNe found beyond z>1.5 in the supernova programs willestablish the constancy of these standard candles independent of darkenergy and yield the first measurement of the Type Ia rate at z 2 todistinguish among different progenitor models. Lower-redshift SNe Iaat 1

Perceived Organizational Support Impacts on the Associations of Work-Family Conflict or Family-Work Conflict with Depressive Symptoms among Chinese Doctors.

PubMed

Hao, Junhui; Wang, Jiana; Liu, Li; Wu, Wei; Wu, Hui

2016-03-16

As a common mental disorder, depressive symptoms had been studied extensively all over the world. However, positive resources for combating depressive symptoms among Chinese doctors were rarely studied. Our study aimed to investigate the relationships between work-family conflict (WFC) and family-work conflict (FWC) with depressive symptoms among Chinese doctors. Meanwhile, the role of perceived organizational support (POS) in this association was explored at an organizational level. The investigation was conducted between March and April 2014. Questionnaires that measured WFC, FWC, depressive symptoms and POS were distributed to 1200 doctors in Shenyang, China. The final study subjects were 931 doctors (effective response rate: 77.6%). In all analyses, male and female doctors were analyzed separately because of possible gender differences. Hierarchical linear regression analyses were used to examine the moderating role of POS. Baron and Kenny's technique and asymptotic and resampling strategies were used to explore the mediating role of POS on the associations of WFC or FWC with depressive symptoms. WFC and FWC had positive relations with depressive symptoms among doctors. POS played a partial mediating role on the correlation of FWC with depressive symptoms among male doctors, and POS played a partial mediating role on the correlation of WFC with depressive symptoms among female doctors. POS had a positive moderating effect on the relationship between WFC and depressive symptoms among doctors. WFC and FWC could aggravate doctors' depressive symptoms, and POS, as an organizational resource, could fight against doctors' depressive symptoms. When POS functioned as a mediator, FWC had a negative effect on POS, which could increase male doctors' depressive symptoms, and WFC had a negative effect on POS, which could increase female doctors' depressive symptoms. In the meantime, POS, as a moderator, could enhance the effects of WFC on depressive symptoms.

Perceived Organizational Support Impacts on the Associations of Work-Family Conflict or Family-Work Conflict with Depressive Symptoms among Chinese Doctors

PubMed Central

Hao, Junhui; Wang, Jiana; Liu, Li; Wu, Wei; Wu, Hui

2016-01-01

As a common mental disorder, depressive symptoms had been studied extensively all over the world. However, positive resources for combating depressive symptoms among Chinese doctors were rarely studied. Our study aimed to investigate the relationships between work-family conflict (WFC) and family-work conflict (FWC) with depressive symptoms among Chinese doctors. Meanwhile, the role of perceived organizational support (POS) in this association was explored at an organizational level. The investigation was conducted between March and April 2014. Questionnaires that measured WFC, FWC, depressive symptoms and POS were distributed to 1200 doctors in Shenyang, China. The final study subjects were 931 doctors (effective response rate: 77.6%). In all analyses, male and female doctors were analyzed separately because of possible gender differences. Hierarchical linear regression analyses were used to examine the moderating role of POS. Baron and Kenny’s technique and asymptotic and resampling strategies were used to explore the mediating role of POS on the associations of WFC or FWC with depressive symptoms. WFC and FWC had positive relations with depressive symptoms among doctors. POS played a partial mediating role on the correlation of FWC with depressive symptoms among male doctors, and POS played a partial mediating role on the correlation of WFC with depressive symptoms among female doctors. POS had a positive moderating effect on the relationship between WFC and depressive symptoms among doctors. WFC and FWC could aggravate doctors’ depressive symptoms, and POS, as an organizational resource, could fight against doctors’ depressive symptoms. When POS functioned as a mediator, FWC had a negative effect on POS, which could increase male doctors’ depressive symptoms, and WFC had a negative effect on POS, which could increase female doctors’ depressive symptoms. In the meantime, POS, as a moderator, could enhance the effects of WFC on depressive symptoms. PMID:26999175

Sex and Employment-Setting Differences in Work-Family Conflict in Athletic Training.

PubMed

Mazerolle, Stephanie M; Eason, Christianne M; Pitney, William A; Mueller, Megan N

2015-09-01

Work-family conflict (WFC) has received much attention in athletic training, yet several factors related to this phenomenon have not been examined, specifically a practitioner's sex, occupational setting, willingness to leave the profession, and willingness to use work-leave benefits. To examine how sex and occupational differences in athletic training affect WFC and to examine willingness to leave the profession and use work-leave benefits. Cross-sectional study. Multiple occupational settings, including clinic/outreach, education, collegiate, industrial, professional sports, secondary school, and sales. A total of 246 athletic trainers (ATs) (men = 110, women = 136) participated. Of these, 61.4% (n = 151) were between 20 and 39 years old. Participants responded to a previously validated and reliable WFC instrument. We created and validated a 3-item instrument that assessed willingness to use work-leave benefits, which demonstrated good internal consistency (Cronbach α = 0.88), as well as a single question about willingness to leave the profession. The mean (± SD) WFC score was 16.88 ± 4.4 (range = 5 [least amount of conflict] to 25 [highest amount of conflict]). Men scored 17.01 ± 4.5, and women scored 16.76 ± 4.36, indicating above-average WFC. We observed no difference between men and women based on conflict scores (t244 = 0.492, P = .95) or their willingness to leave the profession (t244 = -1.27, P = .21). We noted differences among ATs in different practice settings (F8,245 = 5.015, P <.001); those in collegiate and secondary school settings had higher reported WFC scores. A negative relationship existed between WFC score and comfort using work-leave benefits (2-tailed r = -0.533, P < .001). Comfort with using work-leave benefits was different among practice settings (F8,245 = 3.01, P = .003). The ATs employed in traditional practice settings reported higher levels of WFC. Male and female ATs had comparable experiences of WFC and willingness to leave the profession.

Gendered depression: Vulnerability or exposure to work and family stressors?

PubMed

Marchand, Alain; Bilodeau, Jaunathan; Demers, Andrée; Beauregard, Nancy; Durand, Pierre; Haines, Victor Y

2016-10-01

Research has shown that employed women are more prone to depression than men, but the pathways linking gender to depression remain poorly understood. The aim of this study was to examine how work and family conditions operated as potentially gendered antecedents of depression. It evaluated more specifically how differences in depressive symptoms in women and men could be explained by their differential vulnerability and exposure to work and family conditions, as well as by the mediating role of work-to-family conflict (WFC) and family-to-work conflict (FWC). Data were collected in 2009-2012 from a sample of 1935 employees (48.9% women) nested in 63 workplaces in the province of Quebec (Canada). Data were analyzed with multilevel path analysis models to test for the differential exposure hypothesis, and stratified by gender to test for the differential vulnerability hypothesis. Results supported both hypothesizes, but only WFC played a mediating role between work-family stressors and depression. Regarding the vulnerability hypothesis, WFC was more strongly associated with women depressive symptoms, and the magnitude of the association between family income and WFC was stronger for women. Overall, the differential exposure hypothesis seemed to reach a greater empirical support. After accounting for work and family stressors as well as WFC, differences in depressive symptoms in women and men were no longer significantly, as WFC, working hours, irregular work schedule and skill utilization acted as mediators. WFC associated with higher depressive symptoms and skill utilization with lower depressive symptoms. WFC related to higher working hours and irregular work schedule. Compared to men, women reported higher WFC, but lower working hours, less irregular work schedule and lower skill utilization at work. Women's higher rate of depression is intrinsically linked to their different social experiences as shaped by a gendered social structure and gendered organizations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Job Demands, Engagement, and Turnover Intentions in Polish Nurses: The Role of Work-Family Interface

PubMed Central

Dåderman, Anna M.; Basinska, Beata A.

2016-01-01

Background: Poland has lower ratios of employed registered nurses per 1,000 inhabitants than the EU average. Polish nurses work under miserable conditions without assisting personnel, and they reconcile their professional demands with responsibilities for their families; 96% of them are women. Rationale/Aims: This study uses Hobfoll’s conservation of resources (CORs) theory to explain the role of various resources in the improvement of work conditions in the nursing profession. Work-family conflict (WFC) and family work conflict (FWC) threaten to deplete nurses’ resources. This paper set out to (1) examine the extent to which perceived job demands (workload and interpersonal conflicts at work) and engagement (vigor, dedication, and absorption) are associated with turnover intentions (the intention to leave the present workplace and the intention to leave the nursing profession); (2) attempt to determine whether levels of WFC and FWC moderate these associations. Design/Method: This study comprised 188 female registered nurses. The inclusion criterion was to live with a partner and/or have children. Results: WFC was moderately related to FWC. Hierarchical regression analyses showed that only high job demands and low vigor were significantly associated with turnover intentions. WFC was experienced more intensively than FWC. Job demands, vigor, dedication, and turnover intentions had a strong effect on WFC, while absorption had a strong effect on FWC. However, levels of WFC and FWC did not significantly moderate these associations. Originality/Conclusion: The study produces new knowledge by examining a constellation of job demands, work engagement and WFC, which reflect the management of personal resources. Results from such a constellation in nurses from countries with a post-transformational economic system have not previously been discussed in the light of COR theory. Most importantly, we conclude that WFC does not intensify turnover intentions. PMID:27847481

Examining the mediating effect of work-to-family conflict on the associations between job stressors and employee psychological distress: a prospective cohort study

PubMed Central

Oshio, Takashi; Inoue, Akiomi; Tsutsumi, Akizumi

2017-01-01

Objectives The mediating effect of work-to-family conflict (WFC) on the associations between eight types of job stressors (measured based on the job demands-control, effort–reward imbalance and organisational justice models) and psychological distress in employees was examined. Design This study employed a prospective design. Setting An occupational cohort study in Japan (Japanese Study of Health, Occupation, and Psychosocial Factors Related Equity; J-HOPE). Participants 5859 men and 1560 women who were working for 11 firms and participated at three consecutive waves of J-HOPE, at 1-year intervals, from 2010 to 2013. Main outcome measures Psychological distress, as measured by Kessler 6 scores. Results Mediation analysis using data on job stressors at baseline, WFC at 1-year follow-up and psychological distress at 2-year follow-up showed that WFC mediated 39.1% (95% CI 29.1% to 49.1%) and 44.5% (95% CI 31.4% to 51.7%) of the associations of psychological distress with job demands and effort, respectively, for men. The mediating effect of WFC was smaller for job stressors indicating reduced job resources, compared with job demands and effort. The mediating effect of WFC was somewhat larger for women than it was for men, with WFC mediating 47.5% (95% CI 22.5% to 72.6%) and 64.0% (95% CI 24.3% to 100.0%) of the associations of psychological distress with job demands and effort, respectively. Conclusions WFC was a key mediator in the associations between most job stressors and employee psychological distress. Results suggest that policy measures and support from supervisors, to prevent job stressors from adding to WFC, are needed to reduce employee psychological distress. PMID:28775183

Comparing and Contrasting Detectors: JWST NIR vs HST WFC3

NASA Technical Reports Server (NTRS)

Rauscher, Bernard J.

2015-01-01

In many ways, WFC3s IR channel is a good indicator for what to expect with JWST. There are some differences, most of which should be beneficial in JWST- JWSTs lower operating temperature will freeze out charge traps that would affect WFC3. Benefits should include lower dark current, lower persistence, and better reciprocity- JWSTs more recent HgCdTe process has lower defect density. The benefits are as described above- JWST uses better indium barriers. The benefits should include fewer RC type pixels. One area where more study might be beneficial is stability. The detector electronics play a significant role in determining how stable a detector system is(v.s. bias drifts and photometry). JWSTs SIDECARs are completely WFC3s Ball electronics- Studies comparing the bias and photometric stability of WFC3 and JWST might be useful to informing data acquisition and calibration strategies for JWST.

Spectroscopic confirmation of the rich z = 1.80 galaxy cluster JKCS 041 using the WFC3 grism: Environmental trends in the ages and structure of quiescent galaxies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Newman, Andrew B.; Ellis, Richard S.; Andreon, Stefano

2014-06-10

We present Hubble Space Telescope imaging and grism spectroscopy in the field of the distant galaxy cluster JKCS 041 using the Wide Field Camera 3. We confirm that JKCS 041 is a rich cluster and derive a redshift z = 1.80 via the spectroscopic identification of 19 member galaxies, of which 15 are quiescent. These are centered upon diffuse X-ray emission seen by the Chandra observatory. As JKCS 041 is the most distant known cluster with such a large, spectroscopically confirmed quiescent population, it provides a unique opportunity to study the effect of the environment on galaxy properties at earlymore » epochs. We construct high-quality composite spectra of the quiescent cluster members that reveal prominent Balmer and metallic absorption lines. Using these, we measure the mean stellar ages in two bins of stellar mass. The quiescent cluster members' ages agree remarkably closely with that inferred by Whitaker et al. for similarly selected samples in the field, supporting the idea that the cluster environment is more efficient at truncating star formation while not having a strong effect on the mean epoch of quenching. We find some evidence (90% confidence) for a lower fraction of disk-like quiescent systems in JKCS 041 compared to a sample of coeval field galaxies drawn from the CANDELS survey. Taking this into account, we do not detect a significant difference between the mass-radius relations of the quiescent JKCS 041 members and our z ∼ 1.8 field sample. Finally, we demonstrate how differences in the morphological mixture of quenched systems can complicate measures of the environmental dependence of size growth.« less

Probable Foreground SN at z=0.39 SN in MACS0744.9+392 galaxy cluster field

NASA Astrophysics Data System (ADS)

Kelly, P.; Schmidt, K. B.; Rodney, S.; Treu, T.; Strolger, L.; Graur, O.

2014-09-01

We report the discovery of a likely supernova in WFC3-IR F105W and F140W images of the MACS0744.9+392 (z=0.698) galaxy cluster field. The HST images were acquired on 20 September 2014 as part of the Grism Lens Amplified Survey from Space (GLASS) to align and calibrate the G102 grism spectra.

HST/WFC3 Observations of Uranus' 2014 Storm Clouds

NASA Astrophysics Data System (ADS)

Irwin, Patrick Gerard Joseph; Simon, Amy A.; Wong, Michael H.; Orton, Glenn S.; Toledo, Daniel

2016-10-01

In November 2014 Uranus was observed with the Wide Field Camera 3 (WFC3) instrument of the Hubble Space Telescope as part of the Hubble 2020: Outer Planet Atmospheres Legacy program, OPAL. OPAL annually maps Jupiter, Uranus and Neptune (and also Saturn from 2018) in several visible/near-IR wavelength filters. The Uranus 2014 OPAL observations were made on the 8 - 9th November at a time when a huge convective storm system, first observed by amateur astronomers, was present at 30 - 40°N. The entire visible atmosphere, including the storm system, was imaged in seven filters spanning 467 - 924 nm, capturing variations in the coloration of Uranus' clouds and also vertical distribution due to wavelength dependent changes in Rayleigh scattering and methane absorption. Here we analyse these new HST observations with the NEMESIS radiative-transfer and retrieval code, in multiple-scattering mode, to determine the vertical cloud structure in and around the convective storm cloud system.The same storm system was also observed in the H-band (1.4 - 1.9 µm) with the SINFONI Integral Field Unit Spectrometer on the Very Large Telescope (VLT) on 31st October and 11th November (Irwin et al., 2016, 10.1016/j.icarus.2015.09.010). To constrain better the cloud particle sizes and scattering properties over a wide wavelength range we also conducted a limb-darkening analysis of the background cloud structure in the 30 - 40°N latitude band by simultaneously fitting: a) these HST/OPAL observations at a range of zenith angles; b) the VLT/SINFONI observations at a range of zenith angles; and c) IRTF/SpeX observations of this latitude band made in 2009 at a single zenith angle of 23°, spanning the wavelength range 0.8 - 1.8 µm (Irwin et al., 2015, 10.1016/j.icarus.2014.12.020).We find that the HST observations and the combined HST/VLT/IRTF observations are well modeled with a three-component cloud comprised of: 1) a thin 'deep' cloud at a pressure of ~2 bars; 2) a methane-ice cloud at the methane-condensation level with variable vertical extent; and 3) a stratospheric haze. We present conclusions on the likely distribution of particle sizes in these clouds/hazes and the likely spectral dependence of their scattering properties.

HST/WFC3 Observations of Giant Hot Exoplanets

NASA Technical Reports Server (NTRS)

Deming, D.

2010-01-01

Low resolution thermal emission spectra of roger two dozen extrasolar planets have been measured using Spitzer, and HST observations of a few key exoplanets have defined molecular abundances via transmission spectroscopy. However, current models for the atmospheric structure of these worlds exhibit degeneracies wherein different combinations of temperature and molecular abundance profiles can fit the same Spitzer data. The advent of the IR capability on HST/WFC3 allows us to address this problem. We are currently obtaining transmission spectroscopy of the 1.4-micron water band in a sample of 13 planets, using the G141 grism on WFC3, Among the abundant molecules, only water absorbs at this wavelength, and our measurement of water abundance will enable us to break the degeneracies in the Spitzer results with minimal model assumptions. We will also use the G141 grism to observe secondary eclipses for 7 very hot giant exoplanets at 1.5-microns, including several bright systems in the Kepler and CoRoT fields. The strong temperature sensitivity of the thermal continuum at 1.5-microns provides high leverage on atmospheric temperature for these worlds, again helping to break degeneracies in interpreting the Spitzer data. We here describe preliminary results for several exoplanets observed in this program,

HST/WFC3 Observations of Giant Hot Exoplanets

NASA Technical Reports Server (NTRS)

Deming, D.; Agol, E.; Burrows, A.; Charbonneau, D.; Clampin, M.; Desert, J.-M.; Gilliland, R.; Knutson, H.; Madhusudhan, N.; Mandell, A.;

Sex and Employment-Setting Differences in Work-Family Conflict in Athletic Training

PubMed Central

Mazerolle, Stephanie M.; Eason, Christianne M.; Pitney, William A.; Mueller, Megan N.

2015-01-01

Context  Work-family conflict (WFC) has received much attention in athletic training, yet several factors related to this phenomenon have not been examined, specifically a practitioner's sex, occupational setting, willingness to leave the profession, and willingness to use work-leave benefits. Objective  To examine how sex and occupational differences in athletic training affect WFC and to examine willingness to leave the profession and use work-leave benefits. Design  Cross-sectional study. Setting  Multiple occupational settings, including clinic/outreach, education, collegiate, industrial, professional sports, secondary school, and sales. Patients or Other Participants  A total of 246 athletic trainers (ATs) (men = 110, women = 136) participated. Of these, 61.4% (n = 151) were between 20 and 39 years old. Main Outcome Measures(s)  Participants responded to a previously validated and reliable WFC instrument. We created and validated a 3-item instrument that assessed willingness to use work-leave benefits, which demonstrated good internal consistency (Cronbach α = 0.88), as well as a single question about willingness to leave the profession. Results  The mean (± SD) WFC score was 16.88 ± 4.4 (range = 5 [least amount of conflict] to 25 [highest amount of conflict]). Men scored 17.01 ± 4.5, and women scored 16.76 ± 4.36, indicating above-average WFC. We observed no difference between men and women based on conflict scores (t244 = 0.492, P = .95) or their willingness to leave the profession (t244 = −1.27, P = .21). We noted differences among ATs in different practice settings (F8,245 = 5.015, P <.001); those in collegiate and secondary school settings had higher reported WFC scores. A negative relationship existed between WFC score and comfort using work-leave benefits (2-tailed r = −0.533, P < .001). Comfort with using work-leave benefits was different among practice settings (F8,245 = 3.01, P = .003). Conclusions  The ATs employed in traditional practice settings reported higher levels of WFC. Male and female ATs had comparable experiences of WFC and willingness to leave the profession. PMID:26381472

Optimization of wavefront coding imaging system using heuristic algorithms

NASA Astrophysics Data System (ADS)

González-Amador, E.; Padilla-Vivanco, A.; Toxqui-Quitl, C.; Zermeño-Loreto, O.

2017-08-01

Wavefront Coding (WFC) systems make use of an aspheric Phase-Mask (PM) and digital image processing to extend the Depth of Field (EDoF) of computational imaging systems. For years, several kinds of PM have been designed to produce a point spread function (PSF) near defocus-invariant. In this paper, the optimization of the phase deviation parameter is done by means of genetic algorithms (GAs). In this, the merit function minimizes the mean square error (MSE) between the diffraction limited Modulated Transfer Function (MTF) and the MTF of the system that is wavefront coded with different misfocus. WFC systems were simulated using the cubic, trefoil, and 4 Zernike polynomials phase-masks. Numerical results show defocus invariance aberration in all cases. Nevertheless, the best results are obtained by using the trefoil phase-mask, because the decoded image is almost free of artifacts.

A Search for z>6.5 Lyman-alpha Emitting Galaxies with WISP

NASA Astrophysics Data System (ADS)

Bagley, Micaela B.; Scarlata, Claudia; Dai, Yu Sophia; Rafelski, Marc; Baronchelli, Ivano; Colbert, James W.; Dominguez, Alberto; Hathi, Nimish P.; Henry, Alaina L.; Malkan, Matthew Arnold; Martin, Crystal L.; Mehta, Vihang; Pahl, Anthony; Ross, Nathaniel; Rutkowski, Michael J.; Teplitz, Harry I.; WISP Team

2016-01-01

The observed number density of Lyman-alpha emitting galaxies at z>6 provides an important probe of the reionization history of the universe. Because Lyman-alpha photons are very sensitive to the presence of neutral hydrogen, the evolution of the galaxy number density above redshift 6 can be used as a measurement on the progress of reionization. However, the Lyman-alpha luminosity function is currently poorly constrained at high-z. We present the results of a systematic search for Lyman-alpha emitters (LAEs) at redshifts of ~6.5 to 7.5 using the HST WFC3 Infrared Spectroscopic Parallels (WISP) survey. WISP's uncorrelated fields are well-suited to the study of bright LAEs, minimizing the effects of clustering introduced by a patchy reionization. From the 30 deepest WISP fields, we compile a sample of single-line emitters, confirm redshifts with broadband colors, and identify LAE candidates that have "dropped out" (are undetected at the 1 sigma level) of the WFC3 UVIS filters. By combining our results with other z~7 studies, we determine whether the number density of LAEs evolves past z~6.5.

Updating the HST/ACS G800L Grism Calibration

NASA Astrophysics Data System (ADS)

Hathi, Nimish P.; Pirzkal, Norbert; Grogin, Norman A.; Chiaberge, Marco; ACS Team

2018-06-01

We present results from our ongoing work on obtaining newly derived trace and wavelength calibrations of the HST/ACS G800L grism and comparing them to previous set of calibrations. Past calibration efforts were based on 2003 observations. New observations of an emission line Wolf-Rayet star (WR96) were recently taken in HST Cycle 25 (PID: 15401). These observations are used to analyze and measure various grism properties, including wavelength calibration, spectral trace/tilt, length/size of grism orders, and spacing between various grism orders. To account for the field dependence, we observe WR96 at 3 different observing positions over the HST/ACS field of view. The three locations are the center of chip 1, the center of chip 2, and the center of the WFC1A-2K subarray (center of WFC Amp A on chip 1). This new data will help us to evaluate any differences in the G800L grism properties compared to previous calibration data, and to apply improved data analysis techniques to update these old measurements.

Work-family conflict in context: the impact of structural and perceived neighborhood disadvantage on work-family conflict.

PubMed

Young, Marisa

2015-03-01

Despite increasing levels of work-family conflict (WFC) among North Americans, few scholars examine the broader contexts in which these conflicts occur. I address this gap by examining how the neighborhood of residence impacts WFC, with a focus on social inequality and disadvantage across neighborhoods. I hypothesize that neighborhood disadvantage may impact WFC directly-by introducing ambient stressors that inhibit individuals from successfully balancing competing domain demands, and indirectly-by undermining the psychological resources that would combat the harmful effects of disadvantaged contexts. Using individual and census-level data from Canada, I consider both objective and subjective measures of neighborhood disadvantage and find that, overall, individuals in more disadvantaged neighborhoods are worse off because these contexts increase WFC, while reducing the psychological resources that would otherwise buffer these deleterious effects. However, some of these associations vary by gender. I discuss the broader implications of these findings for neighborhood effects and WFC research. Copyright © 2014 Elsevier Inc. All rights reserved.

The impact of neighborhood composition on work-family conflict and distress.

PubMed

Young, Marisa; Wheaton, Blair

2013-01-01

Theories of work-family conflict (WFC) and health remain limited because they emphasize individual-level antecedents to the exclusion of broader contexts, such as residential neighborhoods. We address this issue by focusing on the impact of neighborhood social composition on WFC. Among couples with children we assess whether socially similar neighbors relative to oneself reduce perceptions and mental health consequences of WFC, and whether these associations differ by gender. We argue that the convergence of similarities in residents' features relative to the respondent's own may affect WFC by influencing normative expectations about work and family, and assumptions of available support. We use data on intact families with at least one child between the ages of 9 and 16 from Toronto, Canada, linked to census data. Results highlight that greater similarity between respondents and residents reduces perceptions and consequences of WFC for women but not men. We discuss these findings in relation to neighborhood effects and mental health literature.

[Relationships between work-family and family-work conflicts and health of nurses--buffering effects of social support].

PubMed

Baka, Łukasz

2013-01-01

The aim of the study was to investigate the relationships between work-family conflict (WFC), family-work conflict (FWC) and health, as well as the moderating effect of social support. The study was based on the Job Demands-Resources model. There were 567 nurses from 21 Polish hospitals participating in the study. To verify the hypothesis four scales, which measured WFC, FWC, social support, physical complaints and job burnout, were used. The results partially support the hypothesis. As predicted, high WFC and FWC were correlated with low physical (H1) and mental health (H2). Social support moderated negative effects of WFC (but not FWC) on mental health (H3). The effects of WFC and FWC on physical health were not moderated by social support (H4). The results also partially support the notion of the Job Demands-Resources model and provide further insight into processes leading to the high well-being of nurses in the workplace.

HST/WFC3 flux calibration ladder: Vega

NASA Astrophysics Data System (ADS)

Deustua, Susana E.; Bohlin, Ralph; Pirzkal, Nor; MacKenty, John

2014-08-01

Vega is one of only a few stars calibrated against an SI-traceable blackbody, and is the historical flux standard. Photometric zeropoints of the Hubble Space Telescope's instruments rely on Vega, through the transfer of its calibration via stellar atmosphere models to the suite of standard stars. HST's recently implemented scan mode has enabled us to develop a path to an absolute SI traceable calibration for HST IR observations. To fill in the crucial gap between 0.9 and 1.7 micron in the absolute calibration, we acquired -1st order spectra of Vega with the two WFC3 infrared grisms. At the same time, we have improved the calibration of the -1st orders of both WFC3 IR grisms, as well as extended the dynamic range of WFC3 science observations by a factor of 10000. We describe our progress to date on the WFC3 `flux calibration ladder' project to provide currently needed accurate zeropoint measurements in the IR

The bipolar jet of the symbiotic star R Aquarii: A study of its morphology using the high-resolution HST WFC3/UVIS camera

NASA Astrophysics Data System (ADS)

Melnikov, Stanislav; Stute, Matthias; Eislöffel, Jochen

2018-04-01

Context. R Aqr is a symbiotic binary system consisting of a Mira variable with a pulsation period of 387 days and a hot companion which is presumably a white dwarf with an accretion disk. This binary system is the source of a prominent bipolar gaseous outflow. Aims: We use high spatial resolution and sensitive images from the Hubble Space Telescope (HST) to identify and investigate the different structural components that form the complex morphology of the R Aqr jet. Methods: We present new high-resolution HST WFC3/UVIS narrow-band images of the R Aqr jet obtained in 2013/14 using the [OIII]λ5007, [OI]λ6300, [NII]λ6583, and Hα emission lines. These images also allow us to produce detailed maps of the jet flow in several line ratios such as [OIII]λ5007/[OI]λ6300 and [NII]λ6583/[OI]λ6300 which are sensitive to the outflow temperature and its hydrogen ionisation fraction. The new emission maps together with archival HST data are used to derive and analyse the proper motion of prominent emitting features which can be traced over 20 years with the HST observations. Results: The images reveal the fine gas structure of the jet out to distances of a few tens of arcseconds from the central region, as well as in the innermost region, within a few arcseconds around the stellar source. They reveal for the first time the straight, highly collimated jet component which can be traced to up to 900 AU in the NE direction. Images in [OIII]λ5007, [OI]λ6300, and [NII]λ6583 clearly show a helical pattern in the jet beams which may derive from the small-scale precession of the jet. The highly collimated jet is accompanied by a wide opening angle outflow which is filled by low excitation gas. The position angles of the jet structures as well as their opening angles are calculated. Our measurements of the proper motions of some prominent emission knots confirm the scenario of gas acceleration during the propagation of the outflow. Finally, we produce several detailed line ratio maps which present a mosaic combined from the large field and the PSF-subtracted inner region. Conclusions: The high signal-to-noise HST WFC3/UVIS images provide powerful tools for the study of the jet morphology and also bring detailed information about the physical jet gas conditions. The simultaneous observations of [OIII], [OI], [NII], and [SII] would allow us to measure basic parameters of the ionised gas in the R Aqr outflow such as electron density, electron temperature and hydrogen ionisation fraction, and compare them with other stellar jets.

[Job demands and work-family conflict in a health care staff. The role of work shifts].

PubMed

Zito, Margherita; Colombo, Lara; Mura, Gabriella

2013-01-01

Work-family conflict (wfc), that originates from an incompatibility between the job and the family demands, is a very relevant topic in health care context, as suggested by NEXT study. Work overload and schedule organization are dimensions that can affect wfc, and particularly, studies indicate work shifts as one of its main determinants, as they limit the work-family balance and represent one of the prime risk factors for workers' health. The aim of this study was to detect the role of some job demands (both general and specific) and of schedule organization in determining the wfc experience, with particular attention to work shifts. Respondents to our questionnaire are 207 nurses of a north Italian public health organization. They are mostly women (92.8%) and their average age is 42. Data analysis shows that wfc is mostly influenced by work shifts, but also by work overload, cognitive load and by on-call availability. Staff working on shifts and on-call availability perceive a higher wfc than their colleagues without work shifts and on-call availability. The central role of work shifts in determining wfc suggests the need to act on schedule organization and on training programs for supervisors and workers.

Work-family conflict and job satisfaction: emotional intelligence as a moderator.

PubMed

Gao, Yongdong; Shi, Junqi; Niu, Qikun; Wang, Lei

2013-08-01

The negative impact of work-family conflict (WFC) on employees' well-being and job-related outcomes has attracted much research attention recently. A major gap in the literature is which factors could potentially buffer its negative effect on employees. The present study examined the moderating effect of emotional intelligence on the relationship between WFC and job satisfaction in a sample of 212 Chinese high school teachers. On the basis of conservation of resource theory, we hypothesized that emotional intelligence would weaken the negative effect of family-to-work and work-to-family interference on job satisfaction. Results suggested that WFC (work-to-family interference and family-to-work interference) was negatively related to job satisfaction and that emotional intelligence weakened the effect of WFC on job satisfaction. These findings provide implications for theories on WFC and emotional intelligence, such as conservation of resource theory. The current study also provides a test of these theories in Chinese culture to support the generalizability of theories developed in previous research. Practical implications for reducing the negative influence of WFC on employees' job satisfaction are also provided, such as the potential value of emotional intelligence for the training and development of employees in teaching professions. Copyright © 2012 John Wiley & Sons, Ltd.

Gender difference in work-family conflict among Japanese information technology engineers with preschool children.

PubMed

Watai, Izumi; Nishikido, Noriko; Murashima, Sachiyo

2008-01-01

Since the Family Policy Act, which requires companies to develop action plans to support their employees who have children in an attempt to reverse the declining birthrate in Japan, was enacted in 2003, many Japanese organizations and occupational health staff have become interested in work-family conflict (WFC), especially WFC in employees with young children. A cross-sectional survey of regularly employed information technology (IT) engineers with preschool children in Japan was conducted to examine the gender difference in WFC, relationship of WFC with outcomes, and predictors of WFC by gender. Data from 78 male and 102 female respondents were analyzed. There was no significant gender difference in total level of WFC. However, the level of work interference with family (WIF) was significantly higher in males than in females and the level of family interference with work (FIW) was significantly higher in females. Regarding outcomes, WIF was significantly related to depression and fatigue in both genders. Moreover, different predictors were related to WIF and FIW by gender. A family-friendly culture in the company was related to WIF only in males. To prevent depression and cumulative fatigue in employees with young children, occupational practitioners have to pay attention to not only employees' work stress but also their family stress or amount of family role in both genders.

The optical design of GMOX: a next-generation instrument concept for Gemini

NASA Astrophysics Data System (ADS)

Barkhouser, Robert; Robberto, Massimo; Smee, Stephen A.; Ninkov, Zoran; Gennaro, Mario; Heckman, Timothy

2016-08-01

We present the optical design of GMOX, the Gemini Multi-Object eXtra-wide-band spectrograph. GMOX was selected as part of the Gemini Instrument Feasibility Study to develop capabilities and requirements for the next facility instrument (Gen4#3) for the observatory. We envision GMOX covering the entire optical/near-IR wavelength range accessible from the ground, from 3500 Å in the U band up to 2.4 μm in the K band, with nominal resolving power R≃5,000. To maximize efficiency, the bandpass is split into three spectrograph arms - blue, red, and near-infrared - with the near-infrared arm further split into three channels covering the Y+J, H, and K bands. At the heart of each arm is a Digital Micromirror Device (DMD) serving as a programmable slit array. This technology will enable GMOX to simultaneously acquire hundreds of spectra of faint sources in crowded fields with unparalleled spatial resolution, optimally adapting to both seeing-limited and diffraction limited conditions provided by ALTAIR and GeMS at Gemini North and South, respectively. Fed by GeMS at f/33, GMOX can synthesize slits as small as 40 mas (corresponding to a single HST/WFC3 CCD pixel) over its entire 85"x45" field of view. With either ALTAIR or the native telescope focal ratio of f/16, both the slit and field sizes double. In this paper we discuss the conceptual optical design of GMOX including, for each arm: the pre-slit optics, DMD slit array, off-axis Schmidt collimator, VPH grating, and refractive spectrograph and slit-viewing cameras.

Morphology and Structure of Ultraluminous Infrared Galaxies at z ∼ 2 in the EGS Field

NASA Astrophysics Data System (ADS)

Fang, Guan-Wen; Ma, Zhong-Yang; Chen, Yang; Kong, Xu

2015-04-01

Using the high-resolution F160W images observed by the HST WFC3 (Hubble Space Telescope Wide Field Camera 3) in the CANDELS-EGS (Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey-Extended Groth Strip) field, we have studied the morphological and structural features of 9 ultraluminous infrared galaxies (ULIRGs) at z ∼ 2. We find a wide range of morphological diversity for these ULIRGs, from ellipsoids to multiple bright nuclei or diffuse structures, e.g., the double nuclei, gaseous bridges, dual asym- metries, irregular or elliptical structures. In order to study the morphology of these ULIRGs quantitatively, their morphological parameters (the Gini coeffcient G and moment index M20) are measured in the rest-frame optical wave- band. Compared with the low-redshift counterparts, the high-redshift ULIRGs show a smaller value of G and a larger value of M20, indicating a less concen- tricity and a larger asymmetry of the stellar population distribution in these ULIRGs. Based on a 2-D fitting of the brightness profiles of these ULIRGs, we have derived their effective radii, which are distributed in a range from 2.4 to kpc, with a mean value of (3.9 ± 1.1) kpc. Moreover, we find that in average the sizes of the high-redshift ULIRGs are one to two times smaller than those of the nearby star-forming galaxies of analogous stellar mass. Our results are consistent with those of other studies under the similar conditions of redshift and infrared luminosity.

Examining the mediating effect of work-to-family conflict on the associations between job stressors and employee psychological distress: a prospective cohort study.

PubMed

Oshio, Takashi; Inoue, Akiomi; Tsutsumi, Akizumi

2017-08-03

The mediating effect of work-to-family conflict (WFC) on the associations between eight types of job stressors (measured based on the job demands-control, effort-reward imbalance and organisational justice models) and psychological distress in employees was examined. This study employed a prospective design. An occupational cohort study in Japan (Japanese Study of Health, Occupation, and Psychosocial Factors Related Equity; J-HOPE). 5859 men and 1560 women who were working for 11 firms and participated at three consecutive waves of J-HOPE, at 1-year intervals, from 2010 to 2013. Psychological distress, as measured by Kessler 6 scores. Mediation analysis using data on job stressors at baseline, WFC at 1-year follow-up and psychological distress at 2-year follow-up showed that WFC mediated 39.1% (95% CI 29.1% to 49.1%) and 44.5% (95% CI 31.4% to 51.7%) of the associations of psychological distress with job demands and effort, respectively, for men. The mediating effect of WFC was smaller for job stressors indicating reduced job resources, compared with job demands and effort. The mediating effect of WFC was somewhat larger for women than it was for men, with WFC mediating 47.5% (95% CI 22.5% to 72.6%) and 64.0% (95% CI 24.3% to 100.0%) of the associations of psychological distress with job demands and effort, respectively. WFC was a key mediator in the associations between most job stressors and employee psychological distress. Results suggest that policy measures and support from supervisors, to prevent job stressors from adding to WFC, are needed to reduce employee psychological distress. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Deep HST Imaging in 47 Tucanae: A Global Dynamical Model

NASA Astrophysics Data System (ADS)

Heyl, J.; Caiazzo, I.; Richer, H.; Anderson, J.; Kalirai, J.; Parada, J.

2017-12-01

Multi-epoch observations with the Advanced Camera Survey and WFC3 on the Hubble Space Telescope provide a unique and comprehensive probe of stellar dynamics within 47 Tucanae. We confront analytic models of the globular cluster with the observed stellar proper motions that probe along the main sequence from just above 0.8-0.1M ⊙ as well as white dwarfs younger than 1 Gyr. One field lies just beyond the half-light radius where dynamical models (e.g., lowered Maxwellian distributions) make robust predictions for the stellar proper motions. The observed proper motions in this outer field show evidence for anisotropy in the velocity distribution as well as skewness; the latter is evidence of rotation. The measured velocity dispersions and surface brightness distributions agree in detail with a rotating anisotropic model of the stellar distribution function with mild dependence of the proper-motion dispersion on mass. However, the best-fitting models underpredict the rotation and skewness of the stellar velocities. In the second field, centered on the core of the cluster, the mass segregation in proper motion is much stronger. Nevertheless the model developed in the outer field can be extended inward by taking this mass segregation into account in a heuristic fashion. The proper motions of the main-sequence stars yield a mass estimate of the cluster of 1.31+/- 0.02× {10}6{M}⊙ at a distance of 4.7 kpc. By comparing the proper motions of a sample of giant and subgiant stars with the observed radial velocities we estimate the distance to the cluster kinematically to be 4.29 ± 0.47 kpc.

Tracing the Metal-poor M31 Stellar Halo with Blue Horizontal Branch Stars

NASA Astrophysics Data System (ADS)

Williams, Benjamin F.; Dalcanton, Julianne J.; Bell, Eric F.; Gilbert, Karoline M.; Guhathakurta, Puragra; Dorman, Claire; Lauer, Tod R.; Seth, Anil C.; Kalirai, Jason S.; Rosenfield, Philip; Girardi, Leo

2015-03-01

We have analyzed new Hubble Space Telescope (HST)/Advanced Camera for Surveys and HST/WFC3 imaging in F475W and F814W of two previously unobserved fields along the M31 minor axis to confirm our previous constraints on the shape of M31's inner stellar halo. Both of these new data sets reach a depth of at least F814W <27 and clearly detect the blue horizontal branch (BHB) of the field as a distinct feature of the color-magnitude diagram. We measure the density of BHB stars and the ratio of BHB to red giant branch (RGB) stars in each field using techniques identical to our previous work. We find excellent agreement with our previous measurement of a power law for the 2D projected surface density with an index of 2.6-0.2+0.3 outside of 3 kpc, which flattens to α < 1.2 inside of 3 kpc. Our findings confirm our previous suggestion that the field BHB stars in M31 are part of the halo population. However, the total halo profile is now known to differ from this BHB profile, which suggests that we have isolated the metal-poor component. This component appears to have an unbroken power-law profile from 3-150 kpc but accounts for only about half of the total halo stellar mass. Discrepancies between the BHB density profile and other measurements of the inner halo are therefore likely due to the different profile of the metal-rich halo component, which is not only steeper than the profile of the metal-poor component, but also has a larger core radius. These profile differences also help to explain the large ratio of BHB/RGB stars in our observations.

Does work-to-family conflict really matter for health? Cross-sectional, prospective cohort and fixed-effects analyses.

PubMed

Oshio, Takashi; Inoue, Akiomi; Tsutsumi, Akizumi

2017-02-01

It is well known that work-to-family conflict (WFC) is negatively associated with employees' health outcomes, including mental health and health behavior. However, the associations may be overstated because of insufficient control for unobserved individual attributes. To address this possibility, we compared the associations between WFC and health observed from a cross-sectional, prospective cohort and from fixed-effects regression models. We analyzed data from a Japanese occupational cohort survey of 15,102 observations from 7551 individuals (5947 men and 1604 women), which were collected in two waves with a one-year interval. We constructed a binary variable of high WFC and considered psychological distress measured using the Kessler 6 (K6) score, job and life dissatisfaction, and five types of health behavior (current smoking, problem drinking, leisure-time physical inactivity, sickness absence, and refraining from medical care). Results showed that for men, a high WFC increased the probability of reporting psychological distress (K6 score ≥ 5); this increased by 12.4% in a fixed-effects model. The association was substantially limited, as compared to the increase of 30.9% and 23.2% observed in cross-sectional and prospective cohort models, respectively; however, the association remained significant. Similar patterns were observed for job and life dissatisfaction. In contrast, the associations of WFC with all five types of health behavior were non-significant after controlling for fixed effects. We obtained generally similar results for women and found no substantial gender difference in the fixed-effects models. We concluded that the associations of WFC with employees' mental health and subjective well-being were robust, whereas the association between WFC and health behavior was generally limited. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Carnegie-Chicago Hubble Program. II. The Distance to IC 1613: The Tip of the Red Giant Branch and RR Lyrae Period-luminosity Relations

NASA Astrophysics Data System (ADS)

Hatt, Dylan; Beaton, Rachael L.; Freedman, Wendy L.; Madore, Barry F.; Jang, In-Sung; Hoyt, Taylor J.; Lee, Myung Gyoon; Monson, Andrew J.; Rich, Jeffrey A.; Scowcroft, Victoria; Seibert, Mark

2017-08-01

IC 1613 is an isolated dwarf galaxy within the Local Group. Low foreground and internal extinction, low metallicity, and low crowding make it an invaluable testbed for the calibration of the local distance ladder. We present new, high-fidelity distance estimates to IC 1613 via its Tip of the Red Giant Branch (TRGB) and its RR Lyrae (RRL) variables as part of the Carnegie-Chicago Hubble Program, which seeks an alternate local route to H 0 using Population II stars. We have measured a TRGB magnitude {I}{ACS}{TRGB}=20.35+/- {0.01}{stat}+/- {0.01}{sys} mag using wide-field observations obtained from the IMACS camera on the Magellan-Baade telescope. We have further constructed optical and near-infrared RRL light curves using archival BI- and new H-band observations from the ACS/WFC and WFC3/IR instruments on board the Hubble Space Telescope (HST). In advance of future Gaia data releases, we set provisional values for the TRGB luminosity via the Large Magellanic Cloud and Galactic RRL zero-points via HST parallaxes. We find corresponding true distance moduli {μ }0{TRGB}=24.30+/- {0.03}{stat}+/- {0.05}{sys} {mag} and < {μ }0{RRL}> =24.28+/- {0.04}{stat+{sys}} mag. We compare our results to a body of recent publications on IC 1613 and find no statistically significant difference between the distances derived from Population I and II stars. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs #10505 and #13691. Additional observations are credited to the Observatories of the Carnegie Institution of Washington for the use of Magellan-Baade IMACS. Presented as part of a dissertation to the Department of Astronomy and Astrophysics, The University of Chicago, in partial fulfillment of the requirements for the Ph.D. degree.

Hubble Case Studies of Transiting Giant Exoplanets

NASA Astrophysics Data System (ADS)

Wilkins, Ashlee N.; Deming, Drake; Barker, Adrian; Benneke, Björn; Delrez, Laetitia; Gillon, Michaël; Hamilton, Douglas P.; Jehin, Emmanuel; Knutson, Heather; Lewis, Nikole K.; Madhusudhan, Nikku; Mandell, Avi; McCullough, Peter R.; Wakeford, Hannah R.

2017-01-01

The study of planets around other stars has entered a science-rich era of characterization, in which detailed information about individual planets can be inferred from observations beyond mere detection, which only yields bulk properties like mass or radius. Characterization probes more revealing quantities such as chemical abundances, albedo, and temperature/pressure profiles, which allow us to address larger questions of planet formation mechanisms, planetary evolution, and, eventually, habitability and presence of biosignature gases. The primary method for characterization of close-in planets is transit spectroscopy. This dissertation talk will focus on transiting exoplanet case studies with the Hubble Space Telescope’ Wide-Field Camera-3 (WFC-3) as a tool of exoplanet characterization in a near-infrared band dominated by strong water features. I will first present a characterization the WFC-3 systematic effects that must be mitigated to extract the incredibly small (tens to 200 parts per million) signals, and then a study of four transiting giant planets (HATS-7b, HAT-p-3b, HD 149026b, and WASP-18b) in transmission, and two (WASP-18b and CoRoT-2b) in eclipse. Finally, I will discuss the role of transit timing monitoring of WASP-18b with HST and other observatories as another clue to its evolution as a close-in, massive planet. The five planets range from Neptune-class to Super-Jupiter-class in size/mass. Though these planets may be relatively rare, their observability represents a unique opportunity to probe planet formation and evolution, as well as atmospheric structures in a high-irradiation environment. These observations also yield insights into aerosols (i.e. clouds/hazes) in the atmosphere; clouds and/or hazes should significantly impact atmospheric chemistry and observational signatures, and we as a community must get a better handle on the phenomenon of aerosols in advance of the next generation of space observatories, including JWST and WFIRST. Further, as part of a large Hubble program, we are working to advance the state of exoplanet atmosphere observations from single, planet-by-planet, case studies, to an understanding of the large, hot, gaseous planets as a population.

Cloud Atlas: Rotational Modulations in the L/T Transition Brown Dwarf Companion HN Peg B

NASA Astrophysics Data System (ADS)

Zhou, Yifan; Apai, Dániel; Metchev, Stanimir; Lew, Ben W. P.; Schneider, Glenn; Marley, Mark S.; Karalidi, Theodora; Manjavacas, Elena; Bedin, Luigi R.; Cowan, Nicolas B.; Miles-Páez, Paulo A.; Lowrance, Patrick J.; Radigan, Jacqueline; Burgasser, Adam J.

2018-03-01

Time-resolved observations of brown dwarfs’ rotational modulations provide powerful insights into the properties of condensate clouds in ultra-cool atmospheres. Multi-wavelength light curves reveal cloud vertical structures, condensate particle sizes, and cloud morphology, which directly constrain condensate cloud and atmospheric circulation models. We report results from Hubble Space Telescope/Wide Field Camera 3 near-infrared G141 taken in six consecutive orbits observations of HN Peg B, an L/T transition brown dwarf companion to a G0V type star. The best-fit sine wave to the 1.1–1.7 μm broadband light curve has an amplitude of 1.206% ± 0.025% and period of 15.4 ± 0.5 hr. The modulation amplitude has no detectable wavelength dependence except in the 1.4 μm water absorption band, indicating that the characteristic condensate particle sizes are large (>1 μm). We detect significantly (4.4σ) lower modulation amplitude in the 1.4 μm water absorption band and find that HN Peg B’s spectral modulation resembles those of early T type brown dwarfs. We also describe a new empirical interpolation method to remove spectral contamination from the bright host star. This method may be applied in other high-contrast time-resolved observations with WFC3.

Results of a hubble space telescope search for natural satellites of dwarf planet 1 ceres

NASA Astrophysics Data System (ADS)

DeMario, Benjamin E.; Schmidt, Britney E.; Mutchler, Max J.; Li, Jian-Yang; McFadden, Lucy A.; McLean, Brian J.; Russell, Christopher T.

2016-12-01

In order to prepare for the arrival of the Dawn spacecraft at Ceres, a search for satellites was undertaken by the Hubble Space Telescope (HST) to enhance the mission science return and to ensure spacecraft safety. Previous satellite searches from ground-based telescopes have detected no satellites within Ceres' Hill sphere down to a size of 3 km (Gehrels et al. 1987) and early HST investigations searched to a limit of 1-2 km (Bieryla et al. 2011). The Wide Field Camera 3 (WFC3) on board the HST was used to image Ceres between 14 April-28 April 2014. These images cover approximately the inner third of Ceres' Hill sphere, where the Hill sphere is the region surrounding Ceres where stable satellite orbits are possible. We performed a deep search for possible companions orbiting Ceres. No natural companions were located down to a diameter of 48 m, over most of the Hill sphere to a distance of 205,000 km (434 Ceres radii) from the surface of Ceres. It was impossible to search all the way to the surface of Ceres because of scattered light, but at a distance of 2865 km (five Ceres radii), the search limit was determined to be 925 m.

The Complete Transmission Spectrum of WASP-39b with a Precise Water Constraint

NASA Astrophysics Data System (ADS)

Wakeford, H. R.; Sing, D. K.; Deming, D.; Lewis, N. K.; Goyal, J.; Wilson, T. J.; Barstow, J.; Kataria, T.; Drummond, B.; Evans, T. M.; Carter, A. L.; Nikolov, N.; Knutson, H. A.; Ballester, G. E.; Mandell, A. M.

2018-01-01

WASP-39b is a hot Saturn-mass exoplanet with a predicted clear atmosphere based on observations in the optical and infrared. Here, we complete the transmission spectrum of the atmosphere with observations in the near-infrared (NIR) over three water absorption features with the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) G102 (0.8–1.1 μm) and G141 (1.1–1.7 μm) spectroscopic grisms. We measure the predicted high-amplitude H2O feature centered at 1.4 μm and the smaller amplitude features at 0.95 and 1.2 μm, with a maximum water absorption amplitude of 2.4 planetary scale heights. We incorporate these new NIR measurements into previously published observational measurements to complete the transmission spectrum from 0.3 to 5 μm. From these observed water features, combined with features in the optical and IR, we retrieve a well constrained temperature T eq = 1030{}-20+30 K, and atmospheric metallicity {151}-46+48× solar, which is relatively high with respect to the currently established mass–metallicity trends. This new measurement in the Saturn-mass range hints at further diversity in the planet formation process relative to our solar system giants.

The influence of perceived stress on work-family conflict and mental health: the moderating effect of person-environment fit.

PubMed

Chu, Li-Chuan

2014-07-01

This study examines whether higher perceived stress among female hospital workers can result in more serious work-family conflict (WFC) and poorer mental health, and also identifies the role that person-environment (P-E) fit plays in moderating these relationships. Female hospital workers with higher perceived stress tend to report greater WFC and worse mental health than others with less perceived stress. A better fit between a person and her environment may lead to lower perceived stress. As a result, she may experience less WFC and better mental health. This study adopts a longitudinal design with 273 participants, all of whom are employed by hospitals in Taiwan. All hypotheses are tested using hierarchical regression analyses. The results show that perceived stress is an effective predictor of WFC and mental health status, whereas the P-E fit can moderate these relationships. Hospitals should pay more attention to the negative effects of perceived high stress on the WFC levels and mental health of their female employees. The P-E fit can buffer effectively the impact of perceived stress on both WFC and mental health. If hospitals can adopt appropriate human resource management practices as well as monitor and manage the P-E fit continuously, they can better help their employees to fit into the overall hospital environment. © 2012 John Wiley & Sons Ltd.

Application of Wave Distribution Function Method to the ERG/PWE Data

NASA Astrophysics Data System (ADS)

Ota, M.; Kasahara, Y.; Matsuda, S.; Kojima, H.; Matsuoka, A.; Hikishima, M.; Kasaba, Y.; Ozaki, M.; Yagitani, S.; Tsuchiya, F.; Kumamoto, A.

2017-12-01

The ERG (Arase) satellite was launched on 20 December 2016 to study acceleration and loss mechanisms of relativistic electrons in the Earth's magnetosphere. The Plasma Wave Experiment (PWE), which is one of the science instruments on board the ERG satellite, measures electric field and magnetic field. The PWE consists of three sub-systems; EFD (Electric Field Detector), OFA/WFC (Onboard Frequency Analyzer and Waveform Capture), and HFA (High Frequency Analyzer).The OFA/WFC measures electromagnetic field spectra and raw waveforms in the frequency range from few Hz to 20 kHz. The OFA produces three kind of data; OFA-SPEC (power spectrum), OFA-MATRIX (spectral matrix), and OFA-COMPLEX (complex spectrum). The OFA-MATRIX measures ensemble averaged complex cross-spectra of two electric field components, and of three magnetic field components. The OFA-COMPLEX measures instantaneous complex spectra of electric and magnetic fields. These data are produced every 8 seconds in the nominal mode, and it can be used for polarization analysis and wave propagation direction finding.In general, spectral matrix composed by cross-spectra of observed signals is used for direction finding, and many algorithms have been proposed. For example, Means method and SVD method can be applied on the assumption that the spectral matrix is consists of a single plane wave, while wave distribution function (WDF) method is applicable even to the data in which multiple numbers of plane waves are simultaneously included. In this presentation, we introduce the results when the WDF method is applied to the ERG/PWE data.

Spectral and Wavefront Error Performance of WFIRST/AFTA Prototype Filters

NASA Technical Reports Server (NTRS)

Quijada, Manuel; Seide, Laurie; Marx, Cathy; Pasquale, Bert; McMann, Joseph; Hagopian, John; Dominguez, Margaret; Gong, Qian; Morey, Peter

2016-01-01

The Cycle 5 design baseline for the Wide-Field Infrared Survey Telescope Astrophysics Focused Telescope Assets (WFIRSTAFTA) instrument includes a single wide-field channel (WFC) instrument for both imaging and slit-less spectroscopy. The only routinely moving part during scientific observations for this wide-field channel is the element wheel (EW) assembly. This filter-wheel assembly will have 8 positions that will be populated with 6 bandpass filters, a blank position, and a Grism that will consist of a three-element assembly to disperse the full field with an undeviated central wavelength for galaxy redshift surveys. All filter elements in the EW assembly will be made out of fused silica substrates (110 mm diameter) that will have the appropriate bandpass coatings according to the filter designations (Z087, Y106, J129, H158, F184, W149 and Grism). This paper presents and discusses the performance (including spectral transmission and reflectedtransmitted wavefront error measurements) of a subset of bandpass filter coating prototypes that are based on the WFC instrument filter compliment. The bandpass coating prototypes that are tested in this effort correspond to the Z087, W149, and Grism filter elements. These filter coatings have been procured from three different vendors to assess the most challenging aspects in terms of the in-band throughput, out of band rejection (including the cut-on and cutoff slopes), and the impact the wavefront error distortions of these filter coatings will have on the imaging performance of the de-field channel in the WFIRSTAFTA observatory.

4MOST optical system: presentation and design details

NASA Astrophysics Data System (ADS)

Azaïs, Nicolas; Frey, Steffen; Bellido, Olga; Winkler, Roland

2017-09-01

The 4-meter Multi-Object Spectroscopic Telescope (4MOST) is a wide-field, high-multiplex spectroscopic survey facility under development for the Visible and Infrared Survey Telescope for Astronomy (VISTA) 4 meter telescope of the European Southern Observatory (ESO) at Cerro Paranal. The objective of 4MOST is to enable the simultaneous spectroscopy of a significant number of targets within a 2.5° diameter field of view, to allow high-efficiency all-sky spectroscopic surveys. A wide field corrector (WFC) is needed to couple targets across the 2.5° field diameter with the exit pupil concentric with the spherical focal surface where 2400 fibres are configured by a fibre positioner (AESOP). For optimal fibre optic coupling and active optics wavefront sensing the WFC will correct optical aberrations of the primary (M1) and secondary (M2) VISTA optics across the full field of view and provide a well-defined and stable focal surface to which the acquisition/guiding sensors, wavefront sensors, and fibre positioner are interfaced. It will also compensate for the effects of atmospheric dispersion, allowing good chromatic coupling of stellar images with the fibre apertures over a wide range of telescope zenith angles (ZD). The fibres feed three spectrographs; two thirds of the fibres will feed two low resolution spectrographs and the remaining 812 fibres will feed a high-resolution spectrograph. The three spectrographs are fixed-configuration with three channels each. We present the 4MOST optical system together with optical simulation of subsystems.

VizieR Online Data Catalog: GLASS. VII. Hα maps (Vulcani+, 2016)

NASA Astrophysics Data System (ADS)

Vulcani, B.; Treu, T.; Schmidt, K. B.; Morishita, T.; Dressler, A.; Poggianti, B. M.; Abramson, L.; Bradac, M.; Brammer, G. B.; Hoag, A.; Malkan, M.; Pentericci, L.; Trenti, M.

2017-04-01

The Grism Lens-Amplified Survey from Space (GLASS) is a 140 orbit slitless spectroscopic survey conducted with HST in cycle 21. It has observed the cores of 10 massive galaxy clusters with the WFC3 NIR grisms G102 and G141 providing an uninterrupted wavelength coverage from 0.8um to 1.7um. The 10 clusters are listed in Table 1. Observations for GLASS were completed in 2015 January. Building on our pilot study presented in Vulcani+ (2015ApJ...814..161V), we have continued our exploration of the spatial distribution of star formation in galaxies at 0.3<=z<=0.7, as traced by the Hα emission in the field of view of the 10 GLASS clusters, detailing and strengthening our previous results. We have produced Hα maps, taking advantage of the HST/WFC3 G102 and WFC3-G141 data at two orthogonal position angles. In a companion paper (Paper VIII; Vulcani+ 2017ApJ...837..126V), we investigate trends with cluster properties, such as the hot gas density as traced by the X-ray emission, the total surface mass density as inferred from gravitational lens models, and the local number density, to inspect whether or not local cluster conditions have an impact on the extent and location of the star formation. (2 data files).

Probing the Building Blocks of Galactic Disks: An Analysis of Ultraviolet Clumps

NASA Astrophysics Data System (ADS)

Soto, Emmaris

The universe is filled with a diversity of galaxies; however, despite these diversities we are able to group galaxies into morphological categories, such as Hubble types, that may indicate different paths of evolution. In order to understand the evolution of galaxies, such as our own Milk Way, it is necessary to study the underlying star formation over cosmic time. At high redshift (z>2) star-forming galaxies reveal asymmetric and clumpy morphologies. However, the evolutionary process which takes clumpy galaxies from z>2 to the smooth axially symmetric Hubble-type galaxies in place at z˜0.5 is still unknown. Therefore, it is vital to make a connection between the morphologies of galaxies at the peak epoch of cosmic star formation at z˜2 with the galaxies observed in the local universe to better understand the mechanisms that led to their evolution. To address this and chronicle the progression of galaxy evolution, deep high resolution multi-wavelength data is used to study galaxies across cosmic time. This dissertation provides a detailed study of clumpy star-forming galaxies at intermediate redshifts, 0.5 ≤ z ≤ 1.5, focusing on sub-galactic regions of star formation which provide a mechanism to explain the evolution of clumpy galaxies to the spiral galaxies we observe today. We developed a clump-finding algorithm to select a sample of clumpy galaxies from the Ultraviolet Ultra Deep Field (UVUDF). The UVUDF was the first deep image (˜28 AB mag) ever taken with the Hubble Space Telescope (HST) showing the rest-frame far-ultraviolet (FUV, 1500A) at intermediate-z. The rest-frame FUV probes the young star-forming regions which are often seen in clumpy galaxies at high redshift. We identified 209 clumpy galaxies (hereafter host galaxies) from 1,404 candidates at intermediate redshifts. We used the HST Wide Field Camera 3 (WFC3) and the Advanced Camera for Surveys (ACS) broadband images from the UVUDF with observed near-ultraviolet, optical, and near-infrared photometry to determine their stellar properties via spectral energy distribution (SED) fitting. We estimated properties such as the mass, age, star formation rate (SFR), and metallicity of host galaxies. The deep high resolution WFC3 rest-frame FUV data allowed us to detect and measure the sizes of 403 clumps. The results provided evidence to support clump migration as a mechanism for galaxy evolution. We show that clumps make an average contribution of 19% to the total rest-frame FUV flux of their host galaxy. Additionally, individual clumps contribute a median of 5% to the host galaxy SFR and an average of ˜4% to the host galaxy mass, with total clump contributions to the host galaxy stellar mass ranging widely from less than 1% up to 93%. We showed that clumps in the outskirts of galaxies are typically younger, with higher star formation rates than clumps in the inner regions. The results are consistent with clump migration theories in which clumps form through violent gravitational instabilities in gas-rich turbulent disks, eventually migrate toward the center of the galaxies, and coalesce into the bulge.

2MASS J00423991+3017515: An AGN On The Run?

NASA Astrophysics Data System (ADS)

Hogg, James

2016-10-01

We have discovered a peculiar AGN, 2MASS J00423991+3017515, in a local (z=0.14), disturbed galaxy whose optical spectrum has multiple broad lines that are consistently offset from the narrow line emission and host galaxy absorption by 1530 km/s. The morphology of the host galaxy and spectral properties thus suggest this AGN may be a recoiling supermassive black hole (SMBH). Gravitational-wave recoil kicks result from the coalescence of two SMBHs and have implications for the early growth of high-redshift quasars and SMBH-galaxy co-evolution. We propose high-resolution imaging in the NIR, optical, and UV with the WFC3 camera on Hubble and high-resolution X-ray imaging and spectral follow-ups with the ACIS camera on Chandra to determine if the source of the kinematically-offset broad line emission is also spatially offset from the nucleus of the host galaxy. We request 3 orbits with Hubble and 8 ksec with Chandra to conduct these follow-up observations. If a single, spatially offset AGN is detected, this source will be strongest candidate for a recoiling AGN candidate discovered to date, providing a new, indirect constraint on SMBH spin evolution and merger rates.

Depression and work family conflict among corrections officers.

PubMed

Obidoa, Chiwekwu; Reeves, David; Warren, Nicholas; Reisine, Susan; Cherniack, Martin

2011-11-01

This article assessed work-to-family conflict (W-FC) and family-to-work conflict (F-WC) and their impact on depression among corrections officers in two correctional facilities in the United States. The sample consisted of 220 officers who completed questionnaires that included data on demographics, sense of coherence (SOC), physical health, psychosocial job characteristics, and work-family conflict. The Center for Epidemiologic Studies Depression Scale (CES-D-10) assessed depression. The mean CES-D score was 7.8 (SD = 5.2); 31% had scores of 10 or more, indicative of serious psychological distress. The SOC, W-FC, and F-WC were significantly and positively associated with depression; W-FC mediated the effects of SOC on depression. Psychosocial job characteristics were not related to depression. Depressive symptoms were high among officers, and W-FC was a critical factor contributing to psychological distress.

Modification of Wood Fiber for Use in Cement Board

NASA Astrophysics Data System (ADS)

Han, F. Q.; Tan, X.; Zhao, F. Q.

2017-12-01

When ordinary Portland cement is used for wood fiber cement (WFC) board, the setting time is too long, even hard to solidify. Three methods can be used for wood fiber modification, i.e., soaking in water, treated with alkali solution and coated with some substances on the fiber surface. The results show that the proper water-cement ratio of WFC paste is 1:1.3 in the case of wood cement ratio being 1:1. The WFC board from modified wood fiber and cement is better than the control samples, in which the combined treatment, i.e. soaking in hot water and then coating with alkali-BFS-EVA slurry, behaves best. It is proved that ordinary Portland cement can be used to produce WFC board, with the modified wood fiber, which can greatly reduce production costs.

Work-family conflict as a mediator between occupational stress and psychological health among mental health nurses in Japan.

PubMed

Sugawara, Norio; Danjo, Kazuma; Furukori, Hanako; Sato, Yasushi; Tomita, Tetsu; Fujii, Akira; Nakagami, Taku; Kitaoka, Kazuyo; Yasui-Furukori, Norio

2017-01-01

Occupational stress among mental health nurses may affect their psychological health, resulting in reduced performance. To provide high-quality, sustainable nursing care, it is necessary to identify and control the factors associated with psychological health among mental health nurses. The purpose of this study was to examine the role of work-family conflict (WFC) in the well-known relationship between occupational stress and psychological health among mental health nurses in Japan. In this cross-sectional study, data were gathered from 180 mental health nurses who had a coresident child or were married. Data from the Work-Family Conflict Scale, the Generic Job Stress Questionnaire, the Maslach Burnout Inventory-General Survey, and the Center for Epidemiologic Studies for Depression Scale were obtained via self-report questionnaires. The effects of occupational stress and WFC on psychological health were explored by hierarchical linear regression analysis. The relationship between emotional exhaustion and occupational factors, including quantitative workload and the variance in workload, disappeared with the addition of WFC (each work interference with family [WIF] or family interference with work [FIW]). The relationship between emotional exhaustion and mental demands disappeared only with the addition of WIF. The relationship between depressive symptoms and variance in workload disappeared with the addition of WFC (each WIF or FIW). Our findings may encourage hospital administrators to consider the risks of medical staff WFC. Furthermore, longitudinal investigations into the factors associated with WFC are required for administrative and psychological interventions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo Yicheng; Barro, Guillermo; Faber, Sandra M.

We present a UV to mid-infrared multi-wavelength catalog in the CANDELS/GOODS-S field, combining the newly obtained CANDELS HST/WFC3 F105W, F125W, and F160W data with existing public data. The catalog is based on source detection in the WFC3 F160W band. The F160W mosaic includes the data from CANDELS deep and wide observations as well as previous ERS and HUDF09 programs. The mosaic reaches a 5{sigma} limiting depth (within an aperture of radius 0.''17) of 27.4, 28.2, and 29.7 AB for CANDELS wide, deep, and HUDF regions, respectively. The catalog contains 34,930 sources with the representative 50% completeness reaching 25.9, 26.6, andmore » 28.1 AB in the F160W band for the three regions. In addition to WFC3 bands, the catalog also includes data from UV (U band from both CTIO/MOSAIC and VLT/VIMOS), optical (HST/ACS F435W, F606W, F775W, F814W, and F850LP), and infrared (HST/WFC3 F098M, VLT/ISAAC Ks, VLT/HAWK-I Ks, and Spitzer/IRAC 3.6, 4.5, 5.8, 8.0 {mu}m) observations. The catalog is validated via stellar colors, comparison with other published catalogs, zero-point offsets determined from the best-fit templates of the spectral energy distribution of spectroscopically observed objects, and the accuracy of photometric redshifts. The catalog is able to detect unreddened star-forming (passive) galaxies with stellar mass of 10{sup 10} M{sub Sun} at a 50% completeness level to z {approx} 3.4 (2.8), 4.6 (3.2), and 7.0 (4.2) in the three regions. As an example of application, the catalog is used to select both star-forming and passive galaxies at z {approx} 2-4 via the Balmer break. It is also used to study the color-magnitude diagram of galaxies at 0 < z < 4.« less

Basic Use of SExtractor Catalogs With TweakR eg - I

NASA Astrophysics Data System (ADS)

Lucas, Ray A.; Hilbert, Bryan

2015-05-01

We describe using external SExtractor (v2.8.6) catalogs from crclean.fits images to align ACS/WFC images with DrizzlePac/TweakReg. Note that this example was originally created before a more recent update to ACS/WFC geometric distortion files. At the time of this writing, one must follow the advice on the ACS Geometric Distortion web page as the first step in the process. By late 2015, as part of OPUS 2015.3, this part will be included by default in the standard pipeline processing and this will no longer need to be manually done by the user. We describe the rest of the process of preparing images for SExtractor, running SExtractor, and using the ouput catalogs to feed to the TweakReg task for alignment, and show that reasonably good first-cut results can be obtained with mostly default parameters in SExtractor and TweakReg. Better results may be possible with more exacting methods. This describes a method for quick alignment, not the ultimate best alignment. Note also that the use of crclean.fits images may be more suited to provide better results for ACS/WFC and WFC3/UVIS than for WFC3/IR.

Work-family conflict, part I: Antecedents of work-family conflict in national collegiate athletic association division I-A certified athletic trainers.

PubMed

Mazerolle, Stephanie M; Bruening, Jennifer E; Casa, Douglas J

2008-01-01

Work-family conflict (WFC) involves discord that arises when the demands of work interfere with the demands of family or home life. Long work hours, minimal control over work schedules, and time spent away from home are antecedents to WFC. To date, few authors have examined work-family conflict within the athletic training profession. To investigate the occurrence of WFC in certified athletic trainers (ATs) and to identify roots and factors leading to quality-of-life issues for ATs working in the National Collegiate Athletic Association Division I-A setting. Survey questionnaire and follow-up, in-depth, in-person interviews. Division I-A universities sponsoring football. A total of 587 ATs (324 men, 263 women) responded to the questionnaire. Twelve ATs (6 men, 6 women) participated in the qualitative portion: 2 head ATs, 4 assistant ATs, 4 graduate assistant ATs, and 2 AT program directors. Multiple regression analysis was performed to determine whether workload and travel predicted levels of WFC. Analyses of variance were calculated to investigate differences among the factors of sex, marital status, and family status. Interviews were transcribed verbatim and then analyzed using computer software as well as member checks and peer debriefing. The triangulation of the data collection and multiple sources of qualitative analysis were utilized to limit potential researcher prejudices. Regression analyses revealed that long work hours and travel directly contributed to WFC. In addition to long hours and travel, inflexible work schedules and staffing patterns were discussed by the interview participants as antecedents to WFC. Regardless of sex (P = .142), marital status (P = .687), family status (P = .055), or age of children (P = .633), WFC affected Division I-A ATs. No matter their marital or family status, ATs employed at the Division I-A level experienced difficulties balancing their work and home lives. Sources of conflict primarily stemmed from the consuming nature of the profession, travel, inflexible work schedules, and lack of full-time staff members.

How Do Work Engagement, Workaholism, and the Work-to-Family Interface Affect Each Other? A 7-Year Follow-Up Study.

PubMed

Hakanen, Jari; Peeters, Maria

2015-06-01

To investigate the long-term relationships between work engagement, workaholism, work-to-family enrichment, and work-to-family conflict (WFC). We used structural equation modeling and the three-wave 7-year follow-up data of 1580 Finnish dentists to test our hypotheses. Work engagement and work-to-family enrichment mutually predicted each other, and work engagement also negatively predicted WFC. Workaholism predicted WFC, but not vice versa. Work engagement and workaholism were unrelated over time. The results indicate that beyond its suggested benefits for organizations, work engagement may boost the positive interaction between work and family, whereas workaholism is likely to lead to WFC over time. It is valuable for organizations to distinguish work engagement from workaholism and to enhance the former while preventing the latter to have sustainably hardworking working employees with happy home lives.

The Brightest of Reionizing Galaxies Survey: Constraints on the Bright End of the z ~ 8 Luminosity Function

NASA Astrophysics Data System (ADS)

Bradley, L. D.; Trenti, M.; Oesch, P. A.; Stiavelli, M.; Treu, T.; Bouwens, R. J.; Shull, J. M.; Holwerda, B. W.; Pirzkal, N.

2012-12-01

We report the discovery of 33 Lyman-break galaxy candidates at z ~ 8 detected in Hubble Space Telescope Wide Field Camera 3 (WFC3) imaging as part of the Brightest of Reionizing Galaxies (BoRG) pure-parallel survey. The ongoing BoRG survey currently has the largest area (274 arcmin2) with Y 098 (or Y 105), J 125, and H 160 band coverage needed to search for z ~ 8 galaxies, about three times the current CANDELS area, and slightly larger than what will be the final CANDELS wide component with Y 105 data (required to select z ~ 8 sources). Our sample of 33 relatively bright Y 098-dropout galaxies have J 125-band magnitudes between 25.5 and 27.4 mag. This is the largest sample of bright (J 125 <~ 27.4) z ~ 8 galaxy candidates presented to date. Combining our data set with the Hubble Ultra-Deep Field data set, we constrain the rest-frame ultraviolet galaxy luminosity function at z ~ 8 over the widest dynamic range currently available. The combined data sets are well fitted by a Schechter function, i.e., \\phi (L) = \\phi _{*} (L/L_{*})^{\\alpha }\\ e^{-(L/L_{*})}, without evidence for an excess of sources at the bright end. At 68% confidence, for h = 0.7 we derive phi* = (4.3+3.5 -2.1) × 10-4 Mpc-3, M * = -20.26+0.29 -0.34, and a very steep faint-end slope α = -1.98+0.23 -0.22. While the best-fit parameters still have a strong degeneracy, especially between phi* and M *, our improved coverage at the bright end has reduced the uncertainty of the faint-end power-law slope at z ~ 8 compared to the best previous determination at ±0.4. With a future expansion of the BoRG survey, combined with planned ultradeep WFC3/IR observations, it will be possible to further reduce this uncertainty and clearly demonstrate the steepening of the faint-end slope compared to measurements at lower redshift, thereby confirming the key role played by small galaxies in the reionization of the universe. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy under NASA contract NAS5-26555. These observations are associated with programs 11519, 11520, 11524, 11528, 11530, 11533, 11534, 11541, 11700, 11702, 12024, 12025, and 12572.

The Evolution of the Faint End of the UV Luminosity Function during the Peak Epoch of Star Formation (1 < z < 3)

NASA Astrophysics Data System (ADS)

Alavi, Anahita; Siana, Brian; Richard, Johan; Rafelski, Marc; Jauzac, Mathilde; Limousin, Marceau; Freeman, William R.; Scarlata, Claudia; Robertson, Brant; Stark, Daniel P.; Teplitz, Harry I.; Desai, Vandana

2016-11-01

We present a robust measurement of the rest-frame UV luminosity function (LF) and its evolution during the peak epoch of cosmic star formation at 1\\lt z\\lt 3. We use our deep near-ultraviolet imaging from WFC3/UVIS on the Hubble Space Telescope and existing Advanced Camera for Surveys (ACS)/WFC and WFC3/IR imaging of three lensing galaxy clusters, Abell 2744 and MACS J0717 from the Hubble Frontier Field survey and Abell 1689. Combining deep UV imaging and high magnification from strong gravitational lensing, we use photometric redshifts to identify 780 ultra-faint galaxies with {M}{UV}\\lt -12.5 AB mag at 1\\lt z\\lt 3. From these samples, we identified five new, faint, multiply imaged systems in A1689. We run a Monte Carlo simulation to estimate the completeness correction and effective volume for each cluster using the latest published lensing models. We compute the rest-frame UV LF and find the best-fit faint-end slopes of α =-1.56+/- 0.04, α =-1.72+/- 0.04, and α =-1.94+/- 0.06 at 1.0\\lt z\\lt 1.6, 1.6\\lt z\\lt 2.2, and 2.2\\lt z\\lt 3.0, respectively. Our results demonstrate that the UV LF becomes steeper from z˜ 1.3 to z˜ 2.6 with no sign of a turnover down to {M}{UV}=-14 AB mag. We further derive the UV LFs using the Lyman break “dropout” selection and confirm the robustness of our conclusions against different selection methodologies. Because the sample sizes are so large and extend to such faint luminosities, the statistical uncertainties are quite small, and systematic uncertainties (due to the assumed size distribution, for example) likely dominate. If we restrict our analysis to galaxies and volumes above \\gt 50 % completeness in order to minimize these systematics, we still find that the faint-end slope is steep and getting steeper with redshift, though with slightly shallower (less negative) values (α =-1.55+/- 0.06, -1.69 ± 0.07, and -1.79 ± 0.08 for z˜ 1.3, 1.9, and 2.6, respectively). Finally, we conclude that the faint star-forming galaxies with UV magnitudes of -18.5\\lt {M}{UV}\\lt -12.5 covered in this study produce the majority (55%-60%) of the unobscured UV luminosity density at 1\\lt z\\lt 3. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

A 2.4% DETERMINATION OF THE LOCAL VALUE OF THE HUBBLE CONSTANT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riess, Adam G.; Scolnic, Dan; Jones, David O.

We use the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) to reduce the uncertainty in the local value of the Hubble constant from 3.3% to 2.4%. The bulk of this improvement comes from new near-infrared (NIR) observations of Cepheid variables in 11 host galaxies of recent type Ia supernovae (SNe Ia), more than doubling the sample of reliable SNe Ia having a Cepheid-calibrated distance to a total of 19; these in turn leverage the magnitude-redshift relation based on ∼300 SNe Ia at z < 0.15. All 19 hosts as well as the megamaser system NGC 4258more » have been observed with WFC3 in the optical and NIR, thus nullifying cross-instrument zeropoint errors in the relative distance estimates from Cepheids. Other noteworthy improvements include a 33% reduction in the systematic uncertainty in the maser distance to NGC 4258, a larger sample of Cepheids in the Large Magellanic Cloud (LMC), a more robust distance to the LMC based on late-type detached eclipsing binaries (DEBs), HST observations of Cepheids in M31, and new HST -based trigonometric parallaxes for Milky Way (MW) Cepheids. We consider four geometric distance calibrations of Cepheids: (i) megamasers in NGC 4258, (ii) 8 DEBs in the LMC, (iii) 15 MW Cepheids with parallaxes measured with HST /FGS, HST /WFC3 spatial scanning and/or Hipparcos , and (iv) 2 DEBs in M31. The Hubble constant from each is 72.25 ± 2.51, 72.04 ± 2.67, 76.18 ± 2.37, and 74.50 ± 3.27 km s{sup 1} Mpc{sup 1}, respectively. Our best estimate of H {sub 0} = 73.24 ± 1.74 km s{sup 1} Mpc{sup 1} combines the anchors NGC 4258, MW, and LMC, yielding a 2.4% determination (all quoted uncertainties include fully propagated statistical and systematic components). This value is 3.4 σ higher than 66.93 ± 0.62 km s{sup 1} Mpc{sup 1} predicted by ΛCDM with 3 neutrino flavors having a mass of 0.06 eV and the new Planck data, but the discrepancy reduces to 2.1 σ relative to the prediction of 69.3 ± 0.7 km s{sup 1} Mpc{sup 1} based on the comparably precise combination of WMAP +ACT+SPT+BAO observations, suggesting that systematic uncertainties in CMB radiation measurements may play a role in the tension. If we take the conflict between Planck high-redshift measurements and our local determination of H {sub 0} at face value, one plausible explanation could involve an additional source of dark radiation in the early universe in the range of Δ N {sub eff} ≈ 0.4–1. We anticipate further significant improvements in H {sub 0} from upcoming parallax measurements of long-period MW Cepheids.« less

A 2.4% Determination of the Local Value of the Hubble Constant

NASA Astrophysics Data System (ADS)

Riess, Adam G.; Macri, Lucas M.; Hoffmann, Samantha L.; Scolnic, Dan; Casertano, Stefano; Filippenko, Alexei V.; Tucker, Brad E.; Reid, Mark J.; Jones, David O.; Silverman, Jeffrey M.; Chornock, Ryan; Challis, Peter; Yuan, Wenlong; Brown, Peter J.; Foley, Ryan J.

2016-07-01

We use the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) to reduce the uncertainty in the local value of the Hubble constant from 3.3% to 2.4%. The bulk of this improvement comes from new near-infrared (NIR) observations of Cepheid variables in 11 host galaxies of recent type Ia supernovae (SNe Ia), more than doubling the sample of reliable SNe Ia having a Cepheid-calibrated distance to a total of 19; these in turn leverage the magnitude-redshift relation based on ˜300 SNe Ia at z < 0.15. All 19 hosts as well as the megamaser system NGC 4258 have been observed with WFC3 in the optical and NIR, thus nullifying cross-instrument zeropoint errors in the relative distance estimates from Cepheids. Other noteworthy improvements include a 33% reduction in the systematic uncertainty in the maser distance to NGC 4258, a larger sample of Cepheids in the Large Magellanic Cloud (LMC), a more robust distance to the LMC based on late-type detached eclipsing binaries (DEBs), HST observations of Cepheids in M31, and new HST-based trigonometric parallaxes for Milky Way (MW) Cepheids. We consider four geometric distance calibrations of Cepheids: (I) megamasers in NGC 4258, (II) 8 DEBs in the LMC, (III) 15 MW Cepheids with parallaxes measured with HST/FGS, HST/WFC3 spatial scanning and/or Hipparcos, and (IV) 2 DEBs in M31. The Hubble constant from each is 72.25 ± 2.51, 72.04 ± 2.67, 76.18 ± 2.37, and 74.50 ± 3.27 km s-1 Mpc-1, respectively. Our best estimate of H 0 = 73.24 ± 1.74 km s-1 Mpc-1 combines the anchors NGC 4258, MW, and LMC, yielding a 2.4% determination (all quoted uncertainties include fully propagated statistical and systematic components). This value is 3.4σ higher than 66.93 ± 0.62 km s-1 Mpc-1 predicted by ΛCDM with 3 neutrino flavors having a mass of 0.06 eV and the new Planck data, but the discrepancy reduces to 2.1σ relative to the prediction of 69.3 ± 0.7 km s-1 Mpc-1 based on the comparably precise combination of WMAP+ACT+SPT+BAO observations, suggesting that systematic uncertainties in CMB radiation measurements may play a role in the tension. If we take the conflict between Planck high-redshift measurements and our local determination of H 0 at face value, one plausible explanation could involve an additional source of dark radiation in the early universe in the range of ΔN eff ≈ 0.4-1. We anticipate further significant improvements in H 0 from upcoming parallax measurements of long-period MW Cepheids. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

Spectral and Wavefront Error Performance of WFIRST-AFTA Bandpass Filter Coating Prototypes

NASA Technical Reports Server (NTRS)

Quijada, Manuel A.; Seide, Laurie; Pasquale, Bert A.; McMann, Joseph C.; Hagopian, John G.; Dominguez, Margaret Z.; Gong, Quian; Marx, Catherine T.

2016-01-01

The Cycle 5 design baseline for the Wide-Field Infrared Survey Telescope Astrophysics Focused Telescope Assets (WFIRST/AFTA) instrument includes a single wide-field channel (WFC) instrument for both imaging and slit-less spectroscopy. The only routinely moving part during scientific observations for this wide-field channel is the element wheel (EW) assembly. This filter-wheel assembly will have 8 positions that will be populated with 6 bandpass filters, a blank position, and a Grism that will consist of a three-element assembly to disperse the full field with an undeviated central wavelength for galaxy redshift surveys. All filter elements in the EW assembly will be made out of fused silica substrates (110 mm diameter) that will have the appropriate bandpass coatings according to the filter designations (Z087, Y106, J129, H158, F184, W149 and Grism). This paper presents and discusses the performance (including spectral transmission and reflected/transmitted wavefront error measurements) of a subset of bandpass filter coating prototypes that are based on the WFC instrument filter compliment. The bandpass coating prototypes that are tested in this effort correspond to the Z087, W149, and Grism filter elements. These filter coatings have been procured from three different vendors to assess the most challenging aspects in terms of the in-band throughput, out of band rejection (including the cut-on and cutoff slopes), and the impact the wavefront error distortions of these filter coatings will have on the imaging performance of the wide-field channel in the WFIRST/AFTA observatory.

Associations between work family conflict, emotional exhaustion, musculoskeletal pain, and gastrointestinal problems in a sample of business travelers.

PubMed

Jensen, Maria Therese; Rundmo, Torbjørn

2015-02-01

The aim of the study was to examine the associations among work-family conflict (WFC), emotional exhaustion, musculoskeletal (MS) pain, and gastrointestinal problems on a sample of business travelers (n = 2,093). An additional aim was to examine differences in the mentioned relationships among three traveler groups: commuters, national travelers, and international travelers. The study was conducted in a large Norwegian oil and gas company, and the company's business travel database was utilized to examine business travel. Structural equation modeling (SEM) revealed significant relations between WFC and emotional exhaustion and between emotional exhaustion and health problems. Contrary to the expectations, no direct association was found between WFC and health problems. However, we found that emotional exhaustion mediated the relation between WFC and health outcomes. The results from multi-group analysis revealed that associations among WFC, emotional exhaustion, and health-outcomes showed a similar pattern for commuters, national travelers, and international travelers. However, the association between emotional exhaustion and MS pain proved to be significantly stronger for the commuter group compared to the national and international travel groups. Practical implications and the consequences of these findings for future research are discussed. © 2014 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

The Candidate Progenitor of the Type IIn SN 2010jl Is Not an Optically Luminous Star

NASA Technical Reports Server (NTRS)

Fox, Ori D.; Van Dyk, Schuyler D.; Dwek, Eli; Smith, Nathan; Filippenko, Alexei V.; Andrews, Jennifer; Arendt, Richard G.; Foley, Ryan J.; Kelly, Patrick L.; Miller, Adam;

Design and implementation of a scene-dependent dynamically selfadaptable wavefront coding imaging system

NASA Astrophysics Data System (ADS)

Carles, Guillem; Ferran, Carme; Carnicer, Artur; Bosch, Salvador

2012-01-01

A computational imaging system based on wavefront coding is presented. Wavefront coding provides an extension of the depth-of-field at the expense of a slight reduction of image quality. This trade-off results from the amount of coding used. By using spatial light modulators, a flexible coding is achieved which permits it to be increased or decreased as needed. In this paper a computational method is proposed for evaluating the output of a wavefront coding imaging system equipped with a spatial light modulator, with the aim of thus making it possible to implement the most suitable coding strength for a given scene. This is achieved in an unsupervised manner, thus the whole system acts as a dynamically selfadaptable imaging system. The program presented here controls the spatial light modulator and the camera, and also processes the images in a synchronised way in order to implement the dynamic system in real time. A prototype of the system was implemented in the laboratory and illustrative examples of the performance are reported in this paper. Program summaryProgram title: DynWFC (Dynamic WaveFront Coding) Catalogue identifier: AEKC_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKC_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 10 483 No. of bytes in distributed program, including test data, etc.: 2 437 713 Distribution format: tar.gz Programming language: Labview 8.5 and NI Vision and MinGW C Compiler Computer: Tested on PC Intel ® Pentium ® Operating system: Tested on Windows XP Classification: 18 Nature of problem: The program implements an enhanced wavefront coding imaging system able to adapt the degree of coding to the requirements of a specific scene. The program controls the acquisition by a camera, the display of a spatial light modulator and the image processing operations synchronously. The spatial light modulator is used to implement the phase mask with flexibility given the trade-off between depth-of-field extension and image quality achieved. The action of the program is to evaluate the depth-of-field requirements of the specific scene and subsequently control the coding established by the spatial light modulator, in real time.

Association between Work-Family Conflict and Depressive Symptoms among Chinese Female Nurses: The Mediating and Moderating Role of Psychological Capital.

PubMed

Hao, Junhui; Wu, Di; Liu, Li; Li, Xirui; Wu, Hui

2015-06-12

Depressive symptoms have been in the limelight for many kinds of people, but few studies have explored positive resources for combating depressive symptoms among Chinese nurses. The purpose of this study is to explore the association between work-family conflict (WFC) and depressive symptoms among Chinese female nurses, along with the mediating and moderating role of psychological capital (PsyCap) in this relationship. This cross-sectional study was completed during the period of September and October 2013. A questionnaire that consisted of the Center for Epidemiologic Studies Depression Scale, the Work-Family Conflict scale and the Psychological Capital Questionnair scale was distributed to nurses in Shenyang, China. A total of 824 individuals (effective response rate: 74.9%) participated. Asymptotic and resampling strategies explored the mediating role of PsyCap in the relationship between WFC and depressive symptoms. Hierarchical linear regression analyses were performed to explore the moderating role of PsyCap. Both WFC and family-work conflict (FWC) were positively related with depressive symptoms. PsyCap positively moderated the relationship of WFC with depressive symptoms. Self-efficacy and hope positively moderated the relationship of WFC with depressive symptoms. PsyCap partially mediated the relationship of FWC with depressive symptoms. Hope and optimism partially mediated the relationship of FWC with depressive symptoms. Work-family conflict, as the risk factor of depressive symptoms, can increase nurses' depressive symptoms, and PsyCap is a positive resource to combat nurses' depressive symptoms. PsyCap can aggravate the effects of WFC on depressive symptoms and FWC can impact PsyCap to increase nurses' depressive symptoms.

Association between Work-Family Conflict and Depressive Symptoms among Chinese Female Nurses: The Mediating and Moderating Role of Psychological Capital

PubMed Central

Hao, Junhui; Wu, Di; Liu, Li; Li, Xirui; Wu, Hui

2015-01-01

Depressive symptoms have been in the limelight for many kinds of people, but few studies have explored positive resources for combating depressive symptoms among Chinese nurses. The purpose of this study is to explore the association between work-family conflict (WFC) and depressive symptoms among Chinese female nurses, along with the mediating and moderating role of psychological capital (PsyCap) in this relationship. This cross-sectional study was completed during the period of September and October 2013. A questionnaire that consisted of the Center for Epidemiologic Studies Depression Scale, the Work-Family Conflict scale and the Psychological Capital Questionnair scale was distributed to nurses in Shenyang, China. A total of 824 individuals (effective response rate: 74.9%) participated. Asymptotic and resampling strategies explored the mediating role of PsyCap in the relationship between WFC and depressive symptoms. Hierarchical linear regression analyses were performed to explore the moderating role of PsyCap. Both WFC and family-work conflict (FWC) were positively related with depressive symptoms. PsyCap positively moderated the relationship of WFC with depressive symptoms. Self-efficacy and hope positively moderated the relationship of WFC with depressive symptoms. PsyCap partially mediated the relationship of FWC with depressive symptoms. Hope and optimism partially mediated the relationship of FWC with depressive symptoms. Work-family conflict, as the risk factor of depressive symptoms, can increase nurses’ depressive symptoms, and PsyCap is a positive resource to combat nurses’ depressive symptoms. PsyCap can aggravate the effects of WFC on depressive symptoms and FWC can impact PsyCap to increase nurses’ depressive symptoms. PMID:26075725

Early Results from Star Date: M83 - A Citizen Science Project to Age Date Star Clusters in the Southern Pinwheel Galaxy

NASA Astrophysics Data System (ADS)

Heartley, Jeremy; Whitmore, B. C.; Blair, W. P.; Christian, C. A.; Donaldson, T.; Hammer, D.; Smith, S.; Viana, A.

2014-01-01

The M83 Citizen Science Project is a collaborative effort currently in development between the Space Telescope Science Institute (STScI) and Zooniverse under the guidance of Dr. Brad Whitmore as part of Cy 19 proposal 12513 (PI - Dr. William Blair). This unique citizen science project will allow users to analyze individual star clusters within The Southern Pinwheel Galaxy, M83. The project will show users color-composite images taken with Wide Field Camera 3 (WFC3) aboard the Hubble Space Telescope (HST) and ask them to estimate the age of the star cluster. Through a multistage process, the project will educate and familiarize the user with the appearance of each age category based on the presence and shape of H-alpha emission, degree of resolution of the individual stars, and color of the cluster. (Whitmore et al. 2011). Additionally, the project will involve the actual measurement of the star cluster and H-alpha cloud radii to be used for further assessment and reinforcement of age. The data from this project and the statistics it yields will quantify these ages which can then be used to inform the debate between universal and environmental models of star cluster formation and destruction in galaxies. The tentative launch date is December 2013, therefore early results should be available at the time of the conference.

SPECTROSCOPIC EVIDENCE FOR A TEMPERATURE INVERSION IN THE DAYSIDE ATMOSPHERE OF HOT JUPITER WASP-33b

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haynes, Korey; Mandell, Avi M.; Madhusudhan, Nikku

We present observations of two occultations of the extrasolar planet WASP-33b using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope, which allow us to constrain the temperature structure and composition of its dayside atmosphere. WASP-33b is the most highly irradiated hot Jupiter discovered to date, and the only exoplanet known to orbit a δ-Scuti star. We observed in spatial scan mode to decrease instrument systematic effects in the data, and removed fluctuations in the data due to stellar pulsations. The rms for our final, binned spectrum is 1.05 times the photon noise. We compare our final spectrum,more » along with previously published photometric data, to atmospheric models of WASP-33b spanning a wide range in temperature profiles and chemical compositions. We find that the data require models with an oxygen-rich chemical composition and a temperature profile that increases at high altitude. We find that our measured spectrum displays an excess in the measured flux toward short wavelengths that is best explained as emission from TiO. If confirmed by additional measurements at shorter wavelengths, this planet would become the first hot Jupiter with a thermal inversion that can be definitively attributed to the presence of TiO in its dayside atmosphere.« less

Results of a Hubble Space Telescope Search for Natural Satellites of Dwarf Planet 1 Ceres

NASA Astrophysics Data System (ADS)

DeMario, Benjamin; Schmidt, Britney E.; Mutchler, Maximilian J.; Li, Jian-Yang; McFadden, Lucy Ann; McLean, Brian; Russell, Christopher T.

2016-10-01

In order to prepare for the arrival of the Dawn spacecraft at Ceres, a search for satellites was undertaken by the Hubble Space Telescope (HST) to enhance the mission science return and to ensure spacecraft safety. Previous satellite searches from ground-based telescopes have detected no satellites within Ceres' Hill sphere down to a size of 3 km (Gehrels et al. 1987) and early HST investigations searched to a limit of 1-2 km (Bieryla et al. 2011). The Wide Field Camera 3 (WFC3) on board the HST was used to image Ceres between 14 April - 28 April 2014. These images cover approximately the inner third of Ceres' Hill sphere, where the Hill sphere is the region surrounding Ceres where stable satellite orbits are possible. We performed a deep search for possible companions orbiting Ceres. No natural companions were located down to a diameter of 48 meters, over most of the Hill sphere to a distance of 205,000 km (434 Ceres radii) from the surface of Ceres. It was impossible to search all the way to the surface of Ceres because of scattered light, but at a distance of 2865 km (five Ceres radii), the search limit was determined to be 925 meters. The absence of a satellite around Ceres could, in the future, support more refined theories about satellite formation or capture mechanisms in the solar system.

An atmosphere around the super-Earth 55 Cancri e

NASA Astrophysics Data System (ADS)

Tsiaras, Angelos; Rocchetto, Marco; Waldmann, Ingo; Venot, Olivia; Varley, Rayan; Morello, Giuseppe; Damiano, Mario; Tinetti, Giovanna; Barton, Emma; Yurchenko, Sergey; Tennyson, Jonathan; ExoLights, ExoMol

2016-10-01

One of the most successful instruments for observing exoplanetary atmospheres is the Wide Field Camera 3 (WFC3) onboard the Hubble Space Telescope (HST). In particular, the use of the spatial scanning technique has given us the opportunity for even more efficient observations of the brightest targets, achieving the necessary precision of 10 - 100 ppm. With such data and new advanced reduction and statistical techniques, we were able to detect modulations in the spectrum of the hot super-Earth 55 Cancri e, which suggest the existence of a light-weight atmosphere around this planet. Given the brightness of 55 Cancri, the observers adopted a very long scanning length and a very high scanning speed. We took these effects into account, as they can introduce systematics when coupled with the geometrical distortions of the instrument. Our fully Bayesian spectral retrieval code, T-REx, has identified HCN to be the most likely molecular candidate able to explain the features at 1.42 and 1.54 μm. While additional spectroscopic observations in a broader wavelength range in the infrared will be needed to confirm the HCN detection, we used a chemical model, developed with combustion specialists, to explain its pressence. This model indicates that relatively high mixing ratios of HCN may be caused by a high C/O ratio, suggesting this super-Earth is a carbon-rich environment even more exotic than previously thought.

VizieR Online Data Catalog: Properties of giant arcs behind CLASH clusters (Xu+, 2016)

NASA Astrophysics Data System (ADS)

Xu, B.; Postman, M.; Meneghetti, M.; Seitz, S.; Zitrin, A.; Merten, J.; Maoz, D.; Frye, B.; Umetsu, K.; Zheng, W.; Bradley, L.; Vega, J.; Koekemoer, A.

2018-01-01

Giant arcs are found in the CLASH images and in simulated images that mimic the CLASH data, using an efficient automated arc-finding algorithm whose selection function has been carefully quantified. CLASH is a 524-orbit multicycle treasury program that targeted 25 massive clusters with 0.18=6.5 in 20 X-ray-selected CLASH clusters. After applying our minimum arc length criterion l>=6", the arc count drops to 81 giant arcs selected from the 20 X-ray-selected CLASH clusters. (2 data files).

Work-Family Conflict, Part I: Antecedents of Work-Family Conflict in National Collegiate Athletic Association Division I-A Certified Athletic Trainers

PubMed Central

Mazerolle, Stephanie M; Bruening, Jennifer E; Casa, Douglas J

2008-01-01

Context: Work-family conflict (WFC) involves discord that arises when the demands of work interfere with the demands of family or home life. Long work hours, minimal control over work schedules, and time spent away from home are antecedents to WFC. To date, few authors have examined work-family conflict within the athletic training profession. Objective: To investigate the occurrence of WFC in certified athletic trainers (ATs) and to identify roots and factors leading to quality-of-life issues for ATs working in the National Collegiate Athletic Association Division I-A setting. Design: Survey questionnaire and follow-up, in-depth, in-person interviews. Setting: Division I-A universities sponsoring football. Patients or Other Participants: A total of 587 ATs (324 men, 263 women) responded to the questionnaire. Twelve ATs (6 men, 6 women) participated in the qualitative portion: 2 head ATs, 4 assistant ATs, 4 graduate assistant ATs, and 2 AT program directors. Data Collection and Analysis: Multiple regression analysis was performed to determine whether workload and travel predicted levels of WFC. Analyses of variance were calculated to investigate differences among the factors of sex, marital status, and family status. Interviews were transcribed verbatim and then analyzed using computer software as well as member checks and peer debriefing. The triangulation of the data collection and multiple sources of qualitative analysis were utilized to limit potential researcher prejudices. Results: Regression analyses revealed that long work hours and travel directly contributed to WFC. In addition to long hours and travel, inflexible work schedules and staffing patterns were discussed by the interview participants as antecedents to WFC. Regardless of sex (P  =  .142), marital status (P  =  .687), family status (P  =  .055), or age of children (P  =  .633), WFC affected Division I-A ATs. Conclusions: No matter their marital or family status, ATs employed at the Division I-A level experienced difficulties balancing their work and home lives. Sources of conflict primarily stemmed from the consuming nature of the profession, travel, inflexible work schedules, and lack of full-time staff members. PMID:18833313

Physician burnout in Hungary: a potential role for work-family conflict.

PubMed

Adám, Szilvia; Györffy, Zsuzsa; Susánszky, Eva

2008-10-01

In a study among Hungarian physicians (N = 420), we tested the hypothesis that compared to men female physicians experience higher work-family conflict (WFC) and consequent burnout. As predicted, female physicians scored significantly higher on the emotional exhaustion subscale of the Maslach Burnout Inventory and significantly more female physicians experienced high levels of emotional exhaustion compared to male physicians. WFC emerged as a significant predictor of burnout (emotional exhaustion and depersonalization). These findings suggest a potential path from WFC to burnout in a scarcely researched population of physicians in a unique cultural setting and provide further data for cross-cultural burnout research.

Impact of value congruence on work-family conflicts: the mediating role of work-related support.

PubMed

Pan, Su-Ying; Yeh, Ying-Jung Yvonne

2012-01-01

Based on past research regarding the relationship between person-environment fit and work-family conflict (WFC), we examined the mediating effects of perceived organization/supervisor support on the relationship between person-organization/supervisor value congruence and WFC. A structural equation model was used to test three hypotheses using data collected from 637 workers in Taiwan. Person-organization value congruence regarding role boundaries was found to be positively correlated with employee perception of organizational support, resulting in reduced WFC. Person-supervisor value congruence regarding role boundaries also increased employee perception of organizational support, mediated by perceived supervisor support. Research and managerial implications are discussed.

Work-family conflict, lack of time for personal care and leisure, and job strain in migraine: Results of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

PubMed

Griep, Rosane Härter; Toivanen, Susanna; Santos, Itamar S; Rotenberg, Lucia; Juvanhol, Leidjaira Lopes; Goulart, Alessandra C; Aquino, Estela M; Benseñor, Isabela

2016-11-01

Work-family conflict and time scarcity may affect health. We investigated the association between these issues and migraine, taking into account job strain. Baseline data from ELSA-Brasil (6,183 women; 5,664 men) included four indicators of work-family conflict: time- and strain-based interference of work with family (TB-WFC, SB-WFC), interference of family with work (FWC) and lack of time for personal care and leisure (LOT). Migraine was classified according to International Headache Society criteria. Among women, definite migraine was associated with SB-WFC (odds ratio [OR] = 1.28; 95% confidence interval [CI] 1.06-1.55), FWC (OR = 1.32; 1.00-1.75), and LOT (OR = 1.30; 1.08-1.58). Probable migraine was associated with SB-WFC (OR = 1.17; 1.00-1.36). High psychological job demands and low social support interacted with LOT in association with definite migraine. Among men, probable migraine was associated with LOT (OR = 1.34; 1.09-1.64), and there were interactions between job strain and WFC for probable migraine. Balancing the demands of professional and domestic spheres could be highly relevant in the management of migraines. Am. J. Ind. Med. 59:987-1000, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Atmospheric Characterization of Giant Exoplanets in Extreme Environments

NASA Astrophysics Data System (ADS)

Wilkins, Ashlee

The study of planets around other stars has entered a science-rich era of characterization, in which detailed information about individual planets can be inferred from observations beyond discovery and confirmation, which only yield bulk properties like mass or radius. Characterization probes more revealing quantities such as chemical abundances, albedo, and temperature/pressure profiles, allowing us to address larger questions of planet formation mechanisms, planetary evolution, and, eventually, presence of biosignature gases. The primary method for characterization of close-in planets is transit spectroscopy. My dissertation comprises transiting exoplanet case studies using the Hubble Space Telescopes Wide-Field Camera-3 (HST/WFC3) as a tool of exoplanet characterization in a near-infrared band dominated by broad water absorption. Much of my efforts went toward a characterization of the WFC3 systematic effects that must be mitigated to extract the incredibly small (tens to 200 parts per million) signals. The case study subjects in this dissertation are CoRoT-2b (in emission), WASP-18b (in transmission and emission), and HATS-7b (in transmission), along with some partial/preliminary analyses of HAT-p-3b and HD 149026b (both in transmission). I also present an analysis of transit timing of WASP-18b with HST and other observatories as another clue to its evolution as a close-in, extremely massive planet purported to be spiraling in to its host star. The five planets range from super Neptunes to Super-Jupiter in size/mass. The observability of such planets--i.e. giants across a continuum of mass/size in extreme local environments close to their respective host stars,--is a unique opportunity to probe planet formation and evolution, as well as atmospheric structures in a high-irradiation environment. This genre of observations reveal insights into aerosols in the atmosphere; clouds and/or hazes can significantly impact atmospheric chemistry and observational signatures, and the community must better understand the phenomenon of aerosols in advance of the next generation of space observatories, including JWST and WFIRST. In conducting these case studies as part of larger collaborations and HST observing campaigns, my work aids in the advancement of exoplanet atmosphere characterization from single, planetby-planet, case studies, to an understanding of the large, hot, gaseous planets as a population.

UV-CONTINUUM SLOPES AT z {approx} 4-7 FROM THE HUDF09+ERS+CANDELS OBSERVATIONS: DISCOVERY OF A WELL-DEFINED UV COLOR-MAGNITUDE RELATIONSHIP FOR z {>=} 4 STAR-FORMING GALAXIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bouwens, R. J.; Franx, M.; Labbe, I.

2012-08-01

Ultra-deep Advanced Camera for Surveys (ACS) and WFC3/IR HUDF+HUDF09 data, along with the wide-area GOODS+ERS+CANDELS data over the CDF-S GOODS field, are used to measure UV colors, expressed as the UV-continuum slope {beta}, of star-forming galaxies over a wide range of luminosity (0.1L*{sub z=3} to 2L*{sub z=3}) at high redshift (z {approx} 7 to z {approx} 4). {beta} is measured using all ACS and WFC3/IR passbands uncontaminated by Ly{alpha} and spectral breaks. Extensive tests show that our {beta} measurements are only subject to minimal biases. Using a different selection procedure, Dunlop et al. recently found large biases in their {beta}more » measurements. To reconcile these different results, we simulated both approaches and found that {beta} measurements for faint sources are subject to large biases if the same passbands are used both to select the sources and to measure {beta}. High-redshift galaxies show a well-defined rest-frame UV color-magnitude (CM) relationship that becomes systematically bluer toward fainter UV luminosities. No evolution is seen in the slope of the UV CM relationship in the first 1.5 Gyr, though there is a small evolution in the zero point to redder colors from z {approx} 7 to z {approx} 4. This suggests that galaxies are evolving along a well-defined sequence in the L{sub UV}-color ({beta}) plane (a 'star-forming sequence'?). Dust appears to be the principal factor driving changes in the UV color {beta} with luminosity. These new larger {beta} samples lead to improved dust extinction estimates at z {approx} 4-7 and confirm that the extinction is essentially zero at low luminosities and high redshifts. Inclusion of the new dust extinction results leads to (1) excellent agreement between the star formation rate (SFR) density at z {approx} 4-8 and that inferred from the stellar mass density; and (2) to higher specific star formation rates (SSFRs) at z {approx}> 4, suggesting that the SSFR may evolve modestly (by factors of {approx}2) from z {approx} 4-7 to z {approx} 2.« less

Version 1 of the Hubble Source Catalog

NASA Astrophysics Data System (ADS)

Whitmore, Bradley C.; Allam, Sahar S.; Budavári, Tamás; Casertano, Stefano; Downes, Ronald A.; Donaldson, Thomas; Fall, S. Michael; Lubow, Stephen H.; Quick, Lee; Strolger, Louis-Gregory; Wallace, Geoff; White, Richard L.

2016-06-01

The Hubble Source Catalog is designed to help optimize science from the Hubble Space Telescope (HST) by combining the tens of thousands of visit-based source lists in the Hubble Legacy Archive (HLA) into a single master catalog. Version 1 of the Hubble Source Catalog includes WFPC2, ACS/WFC, WFC3/UVIS, and WFC3/IR photometric data generated using SExtractor software to produce the individual source lists. The catalog includes roughly 80 million detections of 30 million objects involving 112 different detector/filter combinations, and about 160,000 HST exposures. Source lists from Data Release 8 of the HLA are matched using an algorithm developed by Budavári & Lubow. The mean photometric accuracy for the catalog as a whole is better than 0.10 mag, with relative accuracy as good as 0.02 mag in certain circumstances (e.g., bright isolated stars). The relative astrometric residuals are typically within 10 mas, with a value for the mode (I.e., most common value) of 2.3 mas. The absolute astrometric accuracy is better than 0''\\hspace{-0.5em}. 1 for most sources, but can be much larger for a fraction of fields that could not be matched to the PanSTARRS, SDSS, or 2MASS reference systems. In this paper we describe the database design with emphasis on those aspects that enable the users to fully exploit the catalog while avoiding common misunderstandings and potential pitfalls. We provide usage examples to illustrate some of the science capabilities and data quality characteristics, and briefly discuss plans for future improvements to the Hubble Source Catalog.

Version 1 of the Hubble Source Catalog

DOE PAGES

Whitmore, Bradley C.; Allam, Sahar S.; Budavari, Tamas; ...

2016-05-11

The Hubble Source Catalog is designed to help optimize science from the Hubble Space Telescope by combining the tens of thousands of visit-based source lists in the Hubble Legacy Archive into a single master catalog. Version 1 of the Hubble Source Catalog includes WFPC2, ACS/WFC, WFC3/UVIS, and WFC3/IR photometric data generated using SExtractor software to produce the individual source lists. The catalog includes roughly 80 million detections of 30 million objects involving 112 different detector/filter combinations, and about 160 thousand HST exposures. Source lists from Data Release 8 of the Hubble Legacy Archive are matched using an algorithm developed by Budavari & Lubow (2012). The mean photometric accuracy for the catalog as a whole is better than 0.10 mag, with relative accuracy as good as 0.02 mag in certain circumstances (e.g., bright isolated stars). The relative astrometric residuals are typically within 10 mas, with a value for the mode (i.e., most common value) of 2.3 mas. The absolute astrometric accuracy is better thanmore » $$\\sim$$0.1 arcsec for most sources, but can be much larger for a fraction of fields that could not be matched to the PanSTARRS, SDSS, or 2MASS reference systems. In this paper we describe the database design with emphasis on those aspects that enable the users to fully exploit the catalog while avoiding common misunderstandings and potential pitfalls. Here, we provide usage examples to illustrate some of the science capabilities and data quality characteristics, and briefly discuss plans for future improvements to the Hubble Source Catalog.« less

SPLAT: Using Spectral Indices to Identify and Characterize Ultracool Stars, Brown Dwarfs and Exoplanets in Deep Surveys and as Companions to Nearby Stars

NASA Astrophysics Data System (ADS)

Aganze, Christian; Burgasser, Adam J.; Martin, Eduardo; Konopacky, Quinn; Masters, Daniel C.

2016-06-01

The majority of ultracool dwarf stars and brown dwarfs currently known were identified in wide-field red optical and infrared surveys, enabling measures of the local, typically isolated, population in a relatively shallow (<100 pc radius) volume. Constraining the properties of the wider Galactic population (scale height, radial distribution, Population II sources), and close brown dwarf and exoplanet companions to nearby stars, requires specialized instrumentation, such as high-contrast, coronagraphic spectrometers (e.g., Gemini/GPI, VLT/Sphere, Project 1640); and deep spectral surveys (e.g., HST/WFC3 parallel fields, Euclid). We present a set of quantitative methodologies to identify and robustly characterize sources for these specific populations, based on templates and tools developed as part of the SpeX Prism Library Analysis Toolkit. In particular, we define and characterize specifically-tuned sets spectral indices that optimize selection of cool dwarfs and distinguish rare populations (subdwarfs, young planetary-mass objects) based on low-resolution, limited-wavelength-coverage spectral data; and present a template-matching classification method for these instruments. We apply these techniques to HST/WFC3 parallel fields data in the WISPS and HST-3D programs, where our spectral index set allows high completeness and low contamination for searches of late M, L and T dwarfs to distances out to ~3 kpc.The material presented here is based on work supported by the National Aeronautics and Space Administration under Grant No. NNX15AI75G.

The Hidden Fortress: structure and substructure of the complex strong lensing cluster SDSS J1029+2623

NASA Astrophysics Data System (ADS)

Oguri, Masamune; Schrabback, Tim; Jullo, Eric; Ota, Naomi; Kochanek, Christopher S.; Dai, Xinyu; Ofek, Eran O.; Richards, Gordon T.; Blandford, Roger D.; Falco, Emilio E.; Fohlmeister, Janine

2013-02-01

We present Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFC3) observations of SDSS J1029+2623, a three-image quasar lens system produced by a foreground cluster at z = 0.584. Our strong lensing analysis reveals six additional multiply imaged galaxies in addition to the multiply imaged quasar. We confirm the complex nature of the mass distribution of the lensing cluster, with a bimodal dark matter distribution which deviates from the Chandra X-ray surface brightness distribution. The Einstein radius of the lensing cluster is estimated to be θE = 15.2 ± 0.5 arcsec for the quasar redshift of z = 2.197. We derive a radial mass distribution from the combination of strong lensing, HST/ACS weak lensing and Subaru/Suprime-cam weak lensing analysis results, finding a best-fitting virial mass of Mvir = 1.55+ 0.40- 0.35 × 1014 h- 1 M⊙ and a concentration parameter of cvir = 25.7+ 14.1- 7.5. The lensing mass estimate at the outer radius is smaller than the X-ray mass estimate by a factor of ˜2. We ascribe this large mass discrepancy to shock heating of the intracluster gas during a merger, which is also suggested by the complex mass and gas distributions and the high value of the concentration parameter. In the HST image, we also identify a probable galaxy, GX, in the vicinity of the faintest quasar image C. In strong lens models, the inclusion of GX explains the anomalous flux ratios between the quasar images. The morphology of the highly elongated quasar host galaxy is also well reproduced. The best-fitting model suggests large total magnifications of 30 for the quasar and 35 for the quasar host galaxy, and has an AB time delay consistent with the measured value.

The JWST North Ecliptic Pole Survey Field for Time-domain Studies

NASA Astrophysics Data System (ADS)

Jansen, Rolf A.; Alpaslan, Mehmet; Ashby, Matthew; Ashcraft, Teresa; Cohen, Seth H.; Condon, James J.; Conselice, Christopher; Ferrara, Andrea; Frye, Brenda L.; Grogin, Norman A.; Hammel, Heidi B.; Hathi, Nimish P.; Joshi, Bhavin; Kim, Duho; Koekemoer, Anton M.; Mechtley, Matt; Milam, Stefanie N.; Rodney, Steven A.; Rutkowski, Michael J.; Strolger, Louis-Gregory; Trujillo, Chadwick A.; Willmer, Christopher; Windhorst, Rogier A.; Yan, Haojing

2017-01-01

The JWST North Ecliptic Pole (NEP) Survey field is located within JWST's northern Continuous Viewing Zone, will span ˜14‧ in diameter (˜10‧ with NIRISS coverage) and will be roughly circular in shape (initially sampled during Cycle 1 at 4 distinct orientations with JWST/NIRCam's 4.4‧×2.2‧ FoV —the JWST “windmill”) and will have NIRISS slitless grism spectroscopy taken in parallel, overlapping an alternate NIRCam orientation. This is the only region in the sky where JWST can observe a clean extragalactic deep survey field (free of bright foreground stars and with low Galactic foreground extinction AV) at arbitrary cadence or at arbitrary orientation. This will crucially enable a wide range of new and exciting time-domain science, including high redshift transient searches and monitoring (e.g., SNe), variability studies from Active Galactic Nuclei to brown dwarf atmospheres, as well as proper motions of extreme scattered Kuiper Belt and Oort Cloud Objects, and of nearby Galactic brown dwarfs, low-mass stars, and ultracool white dwarfs. We therefore welcome and encourage follow-up through GO programs of the initial GTO observations to realize its potential as a JWST time-domain community field. The JWST NEP Survey field was selected from an analysis of WISE 3.4+4.6 micron, 2MASS JHKs, and SDSS ugriz source counts and of Galactic foreground extinction, and is one of very few such ˜10‧ fields that are devoid of sources brighter than mAB = 16 mag. We have secured deep (mAB ˜ 26 mag) wide-field (˜23‧×25‧) Ugrz images of this field and its surroundings with LBT/LBC. We also expect that deep MMT/MMIRS YJHK images, deep 8-12 GHz VLA radio observations (pending), and possibly HST ACS/WFC and WFC3/UVIS ultraviolet-visible images will be available before JWST launches in Oct 2018.

The JWST North Ecliptic Pole Survey Field for Time-domain Studies

NASA Astrophysics Data System (ADS)

Jansen, Rolf A.; Webb Medium Deep Fields IDS GTO Team, the NEPTDS-VLA/VLBA Team, and the NEPTDS-Chandra Team

2017-06-01

The JWST North Ecliptic Pole (NEP) Survey field is located within JWST's northern Continuous Viewing Zone, will span ~14‧ in diameter (~10‧ with NIRISS coverage) and will be roughly circular in shape (initially sampled during Cycle 1 at 4 distinct orientations with JWST/NIRCam's 4.4‧×2.2‧ FoV —the JWST "windmill") and will have NIRISS slitless grism spectroscopy taken in parallel, overlapping an alternate NIRCam orientation. This is the only region in the sky where JWST can observe a clean extragalactic deep survey field (free of bright foreground stars and with low Galactic foreground extinction AV) at arbitrary cadence or at arbitrary orientation. This will crucially enable a wide range of new and exciting time-domain science, including high redshift transient searches and monitoring (e.g., SNe), variability studies from Active Galactic Nuclei to brown dwarf atmospheres, as well as proper motions of extreme scattered Kuiper Belt and Oort Cloud Objects, and of nearby Galactic brown dwarfs, low-mass stars, and ultracool white dwarfs. We therefore welcome and encourage follow-up through GO programs of the initial GTO observations to realize its potential as a JWST time-domain community field. The JWST NEP Survey field was selected from an analysis of WISE 3.4+4.6 μm, 2MASS JHKs, and SDSS ugriz source counts and of Galactic foreground extinction, and is one of very few such ~10‧ fields that are devoid of sources brighter than mAB = 16 mag. We have secured deep (mAB ~ 26 mag) wide-field (~23‧×25‧) Ugrz images of this field and its surroundings with LBT/LBC. We also expect that deep MMT/MMIRS YJHK images, deep 3-4.5 GHz VLA and VLBA radio observations, and possibly HST ACS/WFC and WFC3/UVIS ultraviolet-visible (pending) and Chandra/ACIS X-ray (pending) images will be available before JWST launches in Oct 2018.

A detailed comparison of single-camera light-field PIV and tomographic PIV

NASA Astrophysics Data System (ADS)

Shi, Shengxian; Ding, Junfei; Atkinson, Callum; Soria, Julio; New, T. H.

2018-03-01

This paper conducts a comprehensive study between the single-camera light-field particle image velocimetry (LF-PIV) and the multi-camera tomographic particle image velocimetry (Tomo-PIV). Simulation studies were first performed using synthetic light-field and tomographic particle images, which extensively examine the difference between these two techniques by varying key parameters such as pixel to microlens ratio (PMR), light-field camera Tomo-camera pixel ratio (LTPR), particle seeding density and tomographic camera number. Simulation results indicate that the single LF-PIV can achieve accuracy consistent with that of multi-camera Tomo-PIV, but requires the use of overall greater number of pixels. Experimental studies were then conducted by simultaneously measuring low-speed jet flow with single-camera LF-PIV and four-camera Tomo-PIV systems. Experiments confirm that given a sufficiently high pixel resolution, a single-camera LF-PIV system can indeed deliver volumetric velocity field measurements for an equivalent field of view with a spatial resolution commensurate with those of multi-camera Tomo-PIV system, enabling accurate 3D measurements in applications where optical access is limited.

New Supernova in the HST Frontier Field MACSJ0717.5+4745

NASA Astrophysics Data System (ADS)

Brammer, Gabriel; Kelly, Patrick; Rodney, Steve; Schmidt, Kasper Borello; Treu, Tommaso

2014-01-01

We report a supernova (SN) discovery in HST imaging of the Frontier Fields galaxy cluster MACSJ0717.5+3745 (z=0.5458) acquired as part of the Grism Lens Amplified Survey from Space (GLASS). The SN is designated HFF13cha (nicknamed "SN Chapel"), and was detected in WFC3-IR F105W (Y) and F140W (JH) images taken to calibrate and align the G102 and G141 grisms. A finder chart and the discovery images are available athttp://archive.stsci.edu/pub/ffsn/macs0717/HFF13cha/snChapelHostFinder.pdf.

VizieR Online Data Catalog: Hubble Source Catalog (V1 and V2) (Whitmore+, 2016)

NASA Astrophysics Data System (ADS)

Whitmore, B. C.; Allam, S. S.; Budavari, T.; Casertano, S.; Downes, R. A.; Donaldson, T.; Fall, S. M.; Lubow, S. H.; Quick, L.; Strolger, L.-G.; Wallace, G.; White, R. L.

2016-10-01

The HSC v1 contains members of the WFPC2, ACS/WFC, WFC3/UVIS and WFC3/IR Source Extractor source lists from HLA version DR8 (data release 8). The crossmatching process involves adjusting the relative astrometry of overlapping images so as to minimize positional offsets between closely aligned sources in different images. After correction, the astrometric residuals of crossmatched sources are significantly reduced, to typically less than 10mas. The relative astrometry is supported by using Pan-STARRS, SDSS, and 2MASS as the astrometric backbone for initial corrections. In addition, the catalog includes source nondetections. The crossmatching algorithms and the properties of the initial (Beta 0.1) catalog are described in Budavari & Lubow (2012ApJ...761..188B). The HSC v2 contains members of the WFPC2, ACS/WFC, WFC3/UVIS and WFC3/IR Source Extractor source lists from HLA version DR9.1 (data release 9.1). The crossmatching process involves adjusting the relative astrometry of overlapping images so as to minimize positional offsets between closely aligned sources in different images. After correction, the astrometric residuals of crossmatched sources are significantly reduced, to typically less than 10mas. The relative astrometry is supported by using Pan-STARRS, SDSS, and 2MASS as the astrometric backbone for initial corrections. In addition, the catalog includes source nondetections. The crossmatching algorithms and the properties of the initial (Beta 0.1) catalog are described in Budavari & Lubow (2012ApJ...761..188B). Hubble Source Catalog Acknowledgement: Based on observations made with the NASA/ESA Hubble Space Telescope, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESAC/ESA) and the Canadian Astronomy Data Centre (CADC/NRC/CSA). (2 data files).

Experiences of Work-Life Conflict for the Athletic Trainer Employed Outside the National Collegiate Athletic Association Division I Clinical Setting.

PubMed

Mazerolle, Stephanie M; Pitney, William A; Eason, Christianne M

2015-07-01

The intercollegiate setting receives much of the scholarly attention related to work-life conflict (WLC). However research has been focused on the National Collegiate Athletic Association Division I setting. Multiple factors can lead to WLC for the athletic trainer (AT), including hours, travel, and lack of flexibility in work schedules. To investigate the experiences of WLC among ATs working in the non-Division I collegiate setting and to identify factors that contribute to fulfillment of work-life balance in this setting. Qualitative study. Institutions in the National Collegiate Athletic Association Divisions II and III, the National Association of Intercollegiate Athletics, and the National Junior College Athletic Association. A total of 244 ATs (128 women, 114 men; age = 37.5 ± 13.3 years, experience = 14 ± 12 years) completed phase I. Thirteen participants (8 women, 5 men; age = 38 ± 13 years, experience = 13.1 ± 11.4 years) completed phase II. For phase I, participants completed a previously validated and reliable (Cronbach α > .90) Web-based survey measuring their levels of WLC and work-family conflict (WFC). This phase included 2 WFC scales defining family; scale 1 defined family as having a partner or spouse with or without children, and scale 2 defined family as those individuals, including parents, siblings, grandparents, and any other close relatives, involved in one's life. Phase II consisted of an interview. Qualitative data were evaluated using content analysis. Data source and multiple-analyst triangulation secured credibility. The WFC scores were 26.33 ± 7.37 for scale 1 and 20.46 ± 10.14 for scale 2, indicating a moderate level of WFC for scale 1 and a low level of WFC for scale 2. Qualitative analyses revealed that organizational dimensions, such as job demands and staffing issues, can negatively affect WLC, whereas a combination of organizational and personal dimensions can positively affect WLC. Overload continues to be a prevalent factor in negatively influencing WLC and WFC. Supervisor and peer support, personal networks, and time away from the role positively influenced work-life balance and WFC. Athletic trainers are encouraged to support one another in the workplace, especially when providing flexibility in scheduling.

Experiences of Work-Life Conflict for the Athletic Trainer Employed Outside the National Collegiate Athletic Association Division I Clinical Setting

PubMed Central

Mazerolle, Stephanie M.; Pitney, William A.; Eason, Christianne M.

2015-01-01

Context The intercollegiate setting receives much of the scholarly attention related to work-life conflict (WLC). However research has been focused on the National Collegiate Athletic Association Division I setting. Multiple factors can lead to WLC for the athletic trainer (AT), including hours, travel, and lack of flexibility in work schedules. Objective To investigate the experiences of WLC among ATs working in the non-Division I collegiate setting and to identify factors that contribute to fulfillment of work-life balance in this setting. Design Qualitative study. Setting Institutions in the National Collegiate Athletic Association Divisions II and III, the National Association of Intercollegiate Athletics, and the National Junior College Athletic Association. Patients or Other Participants A total of 244 ATs (128 women, 114 men; age = 37.5 ± 13.3 years, experience = 14 ± 12 years) completed phase I. Thirteen participants (8 women, 5 men; age = 38 ± 13 years, experience = 13.1 ± 11.4 years) completed phase II. Data Collection and Analysis For phase I, participants completed a previously validated and reliable (Cronbach α > .90) Web-based survey measuring their levels of WLC and work-family conflict (WFC). This phase included 2 WFC scales defining family; scale 1 defined family as having a partner or spouse with or without children, and scale 2 defined family as those individuals, including parents, siblings, grandparents, and any other close relatives, involved in one's life. Phase II consisted of an interview. Qualitative data were evaluated using content analysis. Data source and multiple-analyst triangulation secured credibility. Results The WFC scores were 26.33 ± 7.37 for scale 1 and 20.46 ± 10.14 for scale 2, indicating a moderate level of WFC for scale 1 and a low level of WFC for scale 2. Qualitative analyses revealed that organizational dimensions, such as job demands and staffing issues, can negatively affect WLC, whereas a combination of organizational and personal dimensions can positively affect WLC. Conclusions Overload continues to be a prevalent factor in negatively influencing WLC and WFC. Supervisor and peer support, personal networks, and time away from the role positively influenced work-life balance and WFC. Athletic trainers are encouraged to support one another in the workplace, especially when providing flexibility in scheduling. PMID:25879575

The Candidate Progenitor of the Type IIn SN 2010jl Is Not an Optically Luminous Star

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fox, Ori D.; Dyk, Schuyler D. Van; Dwek, Eli

A blue source in pre-explosion Hubble Space Telescope ( HST )/Wide-Field Planetary Camera 2 (WFPC2) images falls within the 5 σ astrometric error circle (∼0.″24) derived from post-explosion ground-based imaging of SN 2010jl. At the time the ground-based astrometry was published, however, the SN had not faded sufficiently for post-explosion HST follow-up observations to determine a more precise astrometric solution and/or confirm if the pre-explosion source had disappeared, both of which are necessary to ultimately disentangle the possible progenitor scenarios. Here we present HST /WFC3 imaging of the SN 2010jl field obtained in 2014, 2015, and 2016 when the SNmore » had faded sufficiently to allow for new constraints on the progenitor. The SN, which is still detected in the new images, is offset by 0.″061 ± 0.″008 (15 ± 2 pc) from the underlying and extended source of emission that contributes at least partially, if not entirely, to the blue source previously suggested as the candidate progenitor in the WFPC2 data. This point alone rules out the possibility that the blue source in the pre-explosion images is the exploding star, but may instead suggest an association with a young (<5–6 Myr) cluster and still argues for a massive (>30 M {sub ⊙}) progenitor. We obtain new upper limits on the flux from a single star at the SN position in the pre-explosion WFPC2 and Spitzer /IRAC images that may ultimately be used to constrain the progenitor properties.« less

The Resolved Stellar Population in 50 Regions of M83 from HST/WFC3 Early Release Science Observations

NASA Technical Reports Server (NTRS)

Kim, Hwihyun; Whitmore, Bradley C.; Chandar, Rupali; Saha, Abhijit; Kaleida, Catherine C.; Mutchler, Max; Cohen, Seth H.; Calzetti, Daniela; O’Connell, Robert W.; Windhorst, Rogier A.;

The Factor Structure of the Work-Family Conflict Multidimensional Scale: Exploring the Expectations of College Students

ERIC Educational Resources Information Center

Gaffey, Abigail R.; Rottinghaus, Patrick J.

2009-01-01

Work-family conflict (WFC) has been examined from a unidimensional approach, yet recent research has revealed three types (i.e., time, strain, and behavior) and two directions of work-family conflict. Previous researchers suggested that college students are unable to discern between the multiple-facets of WFC, thus measured anticipated WFC…

Anticipated Work-Family Conflict: Effects of Gender, Self-Efficacy, and Family Background

ERIC Educational Resources Information Center

Cinamon, Rachel Gali

2006-01-01

Anticipated levels of 2 types of work-family conflict (WFC) were studied among 358 students from 2 universities. The study examined the contribution of gender, parental models of child care and housework, and self-efficacy to the variance in anticipated WFC. Findings demonstrated that the bidirectionality of the relations between work and family…

VizieR Online Data Catalog: STAGGER-grid of 3D stellar models. V. (Chiavassa+, 2018)

NASA Astrophysics Data System (ADS)

Chiavassa, A.; Casagrande, L.; Collet, R.; Magic, Z.; Bigot, L.; Thevenin, F.; Asplund, M.

2018-01-01

Table B0: RHD simulations' stellar parameters, bolometric magnitude, and bolometric correction for Johnson-Cousins, 2MASS, SDSS (columns 13 to 17), and Gaia systems Table 4: RHD simulations' stellar parameters, bolometric magnitude, and bolometric correction for SkyMapper photometric system, and Stroemgren index b-y, m1=(v-b)-(b-y), and c1=(u-v)-(v-b) Table 5: RHD simulations' stellar parameters, bolometric magnitude, and bolometric correction for the HST-WFC3 in VEGA system Table 6: RHD simulations' stellar parameters, bolometric magnitude, and bolometric correction for the HST-WFC3 in ST system Table 7: RHD simulations' stellar parameters, bolometric magnitude, and bolometric correction for the HST-WFC3 in AB system (5 data files).

VizieR Online Data Catalog: SG1120-1202 members HST imaging & 24um fluxes (Monroe+, 2017)

NASA Astrophysics Data System (ADS)

Monroe, J. T.; Tran, K.-V. H.; Gonzalez, A. H.

2017-09-01

We employ HST imaging of an ~8'x12' mosaic across three filters: F390W (WFC3/UVIS), F606W (ACS/WFC), and F814W (ACS/WFC) for a total of 44 pointings (combined primary and parallels) during cycles 14 (GO 10499) and 19 (GO 12470). We use the Spitzer MIPS 24um fluxes from Saintonge+ (2008ApJ...685L.113S) and Tran+ (2009ApJ...705..809T). The 24um observations were retrieved from the Spitzer archive. For details on spectroscopy from multi-band ground-based observations using Magellan (in 2006), MMT, and VLT/VIMOS (in 2003), we refer the reader to Tran+ (2009ApJ...705..809T). (1 data file).

Accurate calibration of waveform data measured by the Plasma Wave Experiment on board the ARASE satellite

NASA Astrophysics Data System (ADS)

Kitahara, M.; Katoh, Y.; Hikishima, M.; Kasahara, Y.; Matsuda, S.; Kojima, H.; Ozaki, M.; Yagitani, S.

2017-12-01

The Plasma Wave Experiment (PWE) is installed on board the ARASE satellite to measure the electric field in the frequency range from DC to 10 MHz, and the magnetic field in the frequency range from a few Hz to 100 kHz using two dipole wire-probe antennas (WPT) and three magnetic search coils (MSC), respectively. In particular, the Waveform Capture (WFC), one of the receivers of the PWE, can detect electromagnetic field waveform in the frequency range from a few Hz to 20 kHz. The Software-type Wave Particle Interaction Analyzer (S-WPIA) is installed on the ARASE satellite to measure the energy exchange between plasma waves and particles. Since S-WPIA uses the waveform data measured by WFC to calculate the relative phase angle between the wave magnetic field and velocity of energetic electrons, the high-accuracy is required to calibration of both amplitude and phase of the waveform data. Generally, the calibration procedure of the signal passed through a receiver consists of three steps; the transformation into spectra, the calibration by the transfer function of a receiver, and the inverse transformation of the calibrated spectra into the time domain. Practically, in order to reduce the side robe effect, a raw data is filtered by a window function in the time domain before applying Fourier transform. However, for the case that a first order differential coefficient of the phase transfer function of the system is not negligible, the phase of the window function convoluted into the calibrated spectra is shifted differently at each frequency, resulting in a discontinuity in the time domain of the calibrated waveform data. To eliminate the effect of the phase shift of a window function, we suggest several methods to calibrate a waveform data accurately and carry out simulations assuming simple sinusoidal waves as an input signal and using transfer functions of WPT, MSC, and WFC obtained in pre-flight tests. In consequence, we conclude that the following two methods can reduce an error contaminated through the calibration to less than 0.1 % of amplitude of input waves; (1) a Turkey-type window function with a flat top region of one-third of the window length and (2) modification of the window function for each frequency by referring the estimation of the phase shift due to the first order differential coefficient from the transfer functions.

3-D Flow Visualization with a Light-field Camera

NASA Astrophysics Data System (ADS)

Thurow, B.

2012-12-01

Light-field cameras have received attention recently due to their ability to acquire photographs that can be computationally refocused after they have been acquired. In this work, we describe the development of a light-field camera system for 3D visualization of turbulent flows. The camera developed in our lab, also known as a plenoptic camera, uses an array of microlenses mounted next to an image sensor to resolve both the position and angle of light rays incident upon the camera. For flow visualization, the flow field is seeded with small particles that follow the fluid's motion and are imaged using the camera and a pulsed light source. The tomographic MART algorithm is then applied to the light-field data in order to reconstruct a 3D volume of the instantaneous particle field. 3D, 3C velocity vectors are then determined from a pair of 3D particle fields using conventional cross-correlation algorithms. As an illustration of the concept, 3D/3C velocity measurements of a turbulent boundary layer produced on the wall of a conventional wind tunnel are presented. Future experiments are planned to use the camera to study the influence of wall permeability on the 3-D structure of the turbulent boundary layer.Schematic illustrating the concept of a plenoptic camera where each pixel represents both the position and angle of light rays entering the camera. This information can be used to computationally refocus an image after it has been acquired. Instantaneous 3D velocity field of a turbulent boundary layer determined using light-field data captured by a plenoptic camera.

The influence of work-family conflict trajectories on self-rated health trajectories in Switzerland: a life course approach.

PubMed

Cullati, Stéphane

2014-07-01

Self-rated health (SRH) trajectories tend to decline over a lifetime. Moreover, the Cumulative Advantage and Disadvantage (CAD) model indicates that SRH trajectories are known to consistently diverge along socioeconomic positions (SEP) over the life course. However, studies of working adults to consider the influence of work and family conflict (WFC) on SRH trajectories are scarce. We test the CAD model and hypothesise that SRH trajectories diverge over time according to socioeconomic positions and WFC trajectories accentuate this divergence. Using longitudinal data from the Swiss Household Panel (N = 2327 working respondents surveyed from 2004 to 2010), we first examine trajectories of SRH and potential divergence over time across age, gender, SEP and family status using latent growth curve analysis. Second, we assess changes in SRH trajectories in relation to changes in WFC trajectories and divergence in SRH trajectories according to gender, SEP and family status using parallel latent growth curve analysis. Three measures of WFC are used: exhaustion after work, difficulty disconnecting from work, and work interference in private family obligations. The results show that SRH trajectories slowly decline over time and that the rate of change is not influenced by age, gender or SEP, a result which does not support the CAD model. SRH trajectories are significantly correlated with exhaustion after work trajectories but not the other two WFC measures. When exhaustion after work trajectories are taken into account, SRH trajectories of higher educated people decline slower compared to less educated people, supporting the CAD hypothesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Work-family conflict and job performance in nurses: the moderating effects of social support.

PubMed

Wang, Mei-Ling; Tsai, Li-Jane

2014-09-01

A large number of women are employed in the labor market. This phenomenon has widely supplanted the traditional family model of full-time working fathers and full-time housewives with the dual-income family model. Most nurses have both family and work responsibilities and hope to balance these two aspects of their lives. Work-family conflict (WFC) is thus a significant issue faced by professional nurses. This study examines the relationship between WFC and job performance in the nursing context and explores the moderating effects of different sources of social support. This study questionnaire used a self-reporting scale. To avoid common method variance, research data were collected at two time points. Five hundred twenty questionnaires were sent to nurses working at five hospitals in Taiwan, and 501 were returned, of which 495 were valid and used in analysis. Hierarchical regression analysis was used to test study hypotheses. Study findings were (a) degree of family-to-work conflict influenced job performance negatively, (b) level of WFC did not significantly affect job performance, (c) support from friends strengthened the negative effect of family-to-work conflict on job performance, and (d) support from coworkers weakened the relationship between WFC and job performance. It is hoped that the findings of this study will be useful for nursing managers, organizations, and future research. Hospital organizations and nursing departments have a positive role to play in fostering an organizational culture that helps its staffs balance work and family responsibilities. A strategy of human resource management that is consistent with the demands of nurses may help reduce WFC.

What the Person Brings to the Table: Personality, Coping, and Work-Family Conflict

ERIC Educational Resources Information Center

Andreassi, Jeanine K.

2011-01-01

Employees (N = 291) of various industries and companies were surveyed to study how individual factors (coping and personality) affect work-family conflict: strain-based work-to-family conflict (S-WFC), time-based work-to-family conflict (T-WFC), strain-based family-to-work conflict (S-FWC), and time-based family-to-work conflict (T-FWC). As…

Convergence between Measures of Work-to-Family and Family-to-Work Conflict: A Meta-Analytic Examination

ERIC Educational Resources Information Center

Mesmer-Magnus, Jessica R.; Viswesvaran, Chockalingam

2005-01-01

The overlap between measures of work-to-family (WFC) and family-to-work conflict (FWC) was meta-analytically investigated. Researchers have assumed WFC and FWC to be distinct, however, this assumption requires empirical verification. Across 25 independent samples (total N=9079) the sample size weighted mean observed correlation was .38 and the…

Relationship of work-family conflict with burnout and marital satisfaction: cross-domain or source attribution relations?

PubMed

Bagherzadeh, Razieh; Taghizadeh, Ziba; Mohammadi, Eesa; Kazemnejad, Anoshirvan; Pourreza, Abolghasem; Ebadi, Abbas

2016-01-01

The present study was conducted to examine the relationship between two dimensions of work-family conflict (WFC) with marital satisfaction and burnout in a society in which few studies have been done about the consequences of WFC. A cross-sectional study was conducted in 2015. Surveys were distributed to 420 employed married women with various jobs living in Bushehr province, Iran. Data were collected using a questionnaire for demographic characteristic, the Netmeyer's WFC questionnaire, Maslach Burnout Inventory: General Survey (MBI-GS), and Enrich maritalsatisfaction questionnaire. The data were analyzed using descriptive and inferential statistics. There was a negatively significant association between work interference with family(WIF) and overall burnout as well as emotional exhaustion (P < .01). Family interference with work (FIW) was significantly associated with depersonalization (P < .01). The overall marital satisfaction and its subscales were significantly associated with WIF (P < .01) and FIW (P < .01 for overall marital satisfaction and P < .05 for its subscales). In terms of practical implication, to avoid creating disadvantages of WIF and FIW,facilitation in two domains of improving work and family conditions can be a useful means to prevent WFC and its consequences.

How job demands affect an intimate partner: a test of the spillover-crossover model in Japan.

PubMed

Shimazu, Akihito; Bakker, Arnold B; Demerouti, Evangelia

2009-01-01

The present study examined how job demands affect an intimate partner's well-being. We hypothesized that job demands have a negative influence on partner well-being through the experience of work-family conflict (WFC) and an impaired quality of the relationship (reduced social support and increased social undermining towards the partner). The participants of this study were 99 couples of dual-earner parents in Japan. Consistent with hypotheses, men's job demands (i.e. overload and emotional demands) were positively related to their own reports of WFC, and indirectly to women's ratings of men's WFC. Consequently, women's ratings of men's WFC were negatively related to the quality of the relationship (i.e. decreased social support from and increased social undermining by men), which, in turn, led to women's ill-health (i.e. depressive symptoms and physical complaints). We found similar findings for the model starting with women's job demands; gender did not affect the strength of the relationships in the model. These findings suggest that high job demands initiate a process of work-family conflict and poor relationship quality, which may eventually affect the intimate partner's well-being in an unfavorable way.

Measuring full-field displacement spectral components using photographs taken with a DSLR camera via an analogue Fourier integral

NASA Astrophysics Data System (ADS)

Javh, Jaka; Slavič, Janko; Boltežar, Miha

2018-02-01

Instantaneous full-field displacement fields can be measured using cameras. In fact, using high-speed cameras full-field spectral information up to a couple of kHz can be measured. The trouble is that high-speed cameras capable of measuring high-resolution fields-of-view at high frame rates prove to be very expensive (from tens to hundreds of thousands of euro per camera). This paper introduces a measurement set-up capable of measuring high-frequency vibrations using slow cameras such as DSLR, mirrorless and others. The high-frequency displacements are measured by harmonically blinking the lights at specified frequencies. This harmonic blinking of the lights modulates the intensity changes of the filmed scene and the camera-image acquisition makes the integration over time, thereby producing full-field Fourier coefficients of the filmed structure's displacements.

RELICS: Strong Lens Models for Five Galaxy Clusters from the Reionization Lensing Cluster Survey

NASA Astrophysics Data System (ADS)

Cerny, Catherine; Sharon, Keren; Andrade-Santos, Felipe; Avila, Roberto J.; Bradač, Maruša; Bradley, Larry D.; Carrasco, Daniela; Coe, Dan; Czakon, Nicole G.; Dawson, William A.; Frye, Brenda L.; Hoag, Austin; Huang, Kuang-Han; Johnson, Traci L.; Jones, Christine; Lam, Daniel; Lovisari, Lorenzo; Mainali, Ramesh; Oesch, Pascal A.; Ogaz, Sara; Past, Matthew; Paterno-Mahler, Rachel; Peterson, Avery; Riess, Adam G.; Rodney, Steven A.; Ryan, Russell E.; Salmon, Brett; Sendra-Server, Irene; Stark, Daniel P.; Strolger, Louis-Gregory; Trenti, Michele; Umetsu, Keiichi; Vulcani, Benedetta; Zitrin, Adi

2018-06-01

Strong gravitational lensing by galaxy clusters magnifies background galaxies, enhancing our ability to discover statistically significant samples of galaxies at {\\boldsymbol{z}}> 6, in order to constrain the high-redshift galaxy luminosity functions. Here, we present the first five lens models out of the Reionization Lensing Cluster Survey (RELICS) Hubble Treasury Program, based on new HST WFC3/IR and ACS imaging of the clusters RXC J0142.9+4438, Abell 2537, Abell 2163, RXC J2211.7–0349, and ACT-CLJ0102–49151. The derived lensing magnification is essential for estimating the intrinsic properties of high-redshift galaxy candidates, and properly accounting for the survey volume. We report on new spectroscopic redshifts of multiply imaged lensed galaxies behind these clusters, which are used as constraints, and detail our strategy to reduce systematic uncertainties due to lack of spectroscopic information. In addition, we quantify the uncertainty on the lensing magnification due to statistical and systematic errors related to the lens modeling process, and find that in all but one cluster, the magnification is constrained to better than 20% in at least 80% of the field of view, including statistical and systematic uncertainties. The five clusters presented in this paper span the range of masses and redshifts of the clusters in the RELICS program. We find that they exhibit similar strong lensing efficiencies to the clusters targeted by the Hubble Frontier Fields within the WFC3/IR field of view. Outputs of the lens models are made available to the community through the Mikulski Archive for Space Telescopes.

The HST Frontier Field MACS 1159.5+2223: Flanking Observations for Intracluster Light

NASA Astrophysics Data System (ADS)

Gonzalez, Anthony

2017-08-01

We propose a 6 orbit WFC3/IR imaging program targeting the environs of the HST Frontier Field cluster MACS 1149.5+2223 to obtain a comprehensive view of the intracluster stellar population in a massive galaxy cluster. WFC3/IR enables a vast improvement over ground-based studies in mapping emission from diffuse stellar populations. Our proposed observations are designed to build upon the existing investment in the Frontier Fields to conduct a new, more complete census of the intracluster light (ICL) extending out to 750 kpc. The requested observations are constructed to span the gap between the primary and parallel HFF pointings, detecting ICL to a surface brightness of 29.5 mag per square arcsec in F160W (equivalent to 31.5 mag per square arcsec in V-band). This depth is sufficient to trace the radial ICL profile out to 750 kpc from the BCG. These data will also yield a high-fidelity calibration of the background sky level, enabling two-dimensional mapping of the distribution and color of intracluster light down to 27 mag per square arcsec in F160W. From these maps we will quantify spatial variation in the ratio of the stellar baryons to the ICM, establishing whether the observed low scatter in the global ratio masks underlying smaller scale inhomogeneities due to astrophysical processes in the cluster. The requested observations further serve as a pilot program, enabling future similar analyses with the full ensemble of HFF clusters, and developing techniques that will be required for such low surface brightness programs with upcoming facilities including Euclid and WFIRST.

Optical properties of potential condensates in exoplanetary atmospheres

NASA Astrophysics Data System (ADS)

Kitzmann, Daniel; Heng, Kevin

2018-03-01

The prevalence of clouds in currently observable exoplanetary atmospheres motivates the compilation and calculation of their optical properties. First, we present a new open-source Mie scattering code known as LX-MIE, which is able to consider large-size parameters (˜107) using a single computational treatment. We validate LX-MIE against the classical MIEVO code as well as previous studies. Secondly, we embark on an expanded survey of the published literature for both the real and imaginary components of the refractive indices of 32 condensate species. As much as possible, we rely on experimental measurements of the refractive indices and resort to obtaining the real from the imaginary component (or vice versa), via the Kramers-Kronig relation, only in the absence of data. We use these refractive indices as input for LX-MIE to compute the absorption, scattering and extinction efficiencies of all 32 condensate species. Finally, we use a three-parameter function to provide convenient fits to the shape of the extinction efficiency curve. We show that the errors associated with these simple fits in the Wide Field Camera 3 (WFC3), J, H, and K wavebands are ˜ 10 per cent. These fits allow for the extinction cross-section or opacity of the condensate species to be easily included in retrieval analyses of transmission spectra. We discuss prospects for future experimental work. The compilation of the optical constants and LX-MIE is publicly available as part of the open-source Exoclime Simulation Platform (http://www.exoclime.org).

A Star-Formation Laboratory

NASA Image and Video Library

2011-05-13

The dwarf galaxy NGC 4214 is ablaze with young stars and gas clouds. Located around 10 million light-years away in the constellation of Canes Venatici (The Hunting Dogs), the galaxy's close proximity, combined with the wide variety of evolutionary stages among the stars, make it an ideal laboratory to research the triggers of star formation and evolution. Intricate patterns of glowing hydrogen formed during the star-birthing process, cavities blown clear of gas by stellar winds, and bright stellar clusters of NGC 4214 can be seen in this optical and near-infrared image. Observations of this dwarf galaxy have also revealed clusters of much older red supergiant stars. Additional older stars can be seen dotted all across the galaxy. The variety of stars at different stages in their evolution indicates that the recent and ongoing starburst periods are not the first, and the galaxy's abundant supply of hydrogen means that star formation will continue into the future. This color image was taken using the Wide Field Camera 3 in December 2009. Credit: NASA, ESA, and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration Acknowledgment: R. O'Connell (University of Virginia) and the WFC3 Scientific Oversight Committee NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

RCS2 J232727.6-020437: An Efficient Cosmic Telescope at z=0.6986

NASA Astrophysics Data System (ADS)

Hoag, A.; Bradač, M.; Huang, K. H.; Ryan, R. E., Jr.; Sharon, K.; Schrabback, T.; Schmidt, K. B.; Cain, B.; Gonzalez, A. H.; Hildebrandt, H.; Hinz, J.; Lemaux, B. C.; von der Linden, A.; Lubin, L. M.; Treu, T.; Zaritsky, D.

2015-11-01

We present a detailed gravitational lens model of the galaxy cluster RCS2 J232727.6-020437. Due to cosmological dimming of cluster members and intra-cluster light, its high redshift (z = 0.6986) makes it ideal for studying high-redshift background galaxies. Using new Advanced Camera for Surveys and WFC3/IR Hubble Space Telescope data, we identify 16 new multiple images belonging to 6 distinct source galaxies. From Multi-object Spectrometer for Infrared Exploration (MOSFIRE) follow-up, we identify a strong emission line in the spectrum of one multiple image, measuring the redshift of that system to z = 2.083. With a highly magnified (μ ≳ 3) source plane area of ∼0.9 arcmin2 at z = 7, RCS2 J232727.6-020437 has a lensing efficiency comparable to the Hubble Frontier Fields clusters. We discover four highly magnified z ∼ 7 candidate Lyman-break galaxies behind the cluster. Correcting for magnification, we find that all four galaxies are fainter than 0.5{L}\\star . One candidate is detected at >10σ in both Spitzer/IRAC [3.6] and [4.5] channels. A spectroscopic follow-up with MOSFIRE does not result in the detection of the Lyα emission line from any of the four candidates. From the MOSFIRE spectra, we place median upper limits on the Lyα flux of (3-11)× {10}-19 {erg} {{{s}}}-1 {{cm}}-2 (5σ).

Vertical Cloud Structure Of The 2009 Jupiter Impact Based On HST/WFC3 Observations

NASA Astrophysics Data System (ADS)

Perez-Hoyos, Santiago; Sanz-Requena, J. F.; Sanchez-Lavega, A.; Wong, M.; Hueso, R.; Hammel, H. B.; Orton, G. S.; Fletcher, L. N.; de Pater, I.; Simon-Miller, A. A.; Clarke, J. T.; Noll, K.; Yanamandra-Fisher, P. A.

2010-10-01

The impact of a body of unknown origin with Jupiter in July 2009 (Sánchez-Lavega et al., Astrophys. J. Lett, Vol. 715, L155. 2010) produced an intense perturbation of the planet's atmosphere at the visible levels. The perturbation was caused by dense aerosol material; this strongly absorbing material expanded steadily as it was advected by the local winds. This phenomenon was observed at high spatial resolution by the Hubble Space Telescope in July, August, September and November 2009 with recently installed Wide Field Camera 3. In this work, we present radiative transfer modeling of the observed reflectivity in the near UV (200nm) to near IR (950nm) range. The geometrical and spectral variations of reflectivity elucidate the main particle properties (optical thickness, size, imaginary refractive index) and their temporal evolution. The aerosol particles that formed during the impact have a mean radius of about 1 micron and are located high in the atmosphere (above 10 mbar), in good agreement ith ground-based observations in deep methane absorption bands in the near infrared. The density of this particle layer decreases with time until it approaches that of the pre-impact atmosphere. These results are also discussed in terms of what we know from other impacts in Jupiter (1994's SL9 event and 2010's bolide). Acknowledgements: SPH, ASL and RH are supported by the Spanish MICIIN AYA2009-10701 with FEDER and Grupos Gobierno Vasco IT-464-07.

CHARACTERIZING THE ATMOSPHERES OF THE HR8799 PLANETS WITH HST/WFC3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rajan, Abhijith; Patience, Jennifer; Barman, Travis

We present results from a Hubble Space Telescope (HST) program characterizing the atmospheres of the outer two planets in the HR8799 system. The images were taken over 15 orbits in three near-infrared (near-IR) medium-band filters—F098M, F127M, and F139M—using the Wide Field Camera 3. One of the three filters is sensitive to a water absorption band inaccessible from ground-based observations, providing a unique probe of the thermal emission from the atmospheres of these young giant planets. The observations were taken at 30 different spacecraft rolls to enable angular differential imaging (ADI), and the full data set was analyzed with the Karhunen–Loévemore » Image Projection routine, an advanced image processing algorithm adapted to work with HST data. To achieve the required high contrast at subarcsecond resolution, we utilized the pointing accuracy of HST in combination with an improved pipeline designed to combine the dithered ADI data with an algorithm designed to both improve the image resolution and accurately measure the photometry. The results include F127M (J) detections of the outer planets, HR8799b and c, and the first detection of HR8799b in the water-band (F139M) filter. The F127M photometry for HR8799c agrees well with fitted atmospheric models, resolving the longstanding difficulty in consistently modeling the near-IR flux of the planet.« less

The M31 Velocity Vector. I. Hubble Space Telescope Proper-motion Measurements

NASA Astrophysics Data System (ADS)

Sohn, Sangmo Tony; Anderson, Jay; van der Marel, Roeland P.

2012-07-01

We present the first proper-motion (PM) measurements for the galaxy M31. We obtained new V-band imaging data with the Hubble Space Telescope ACS/WFC and the WFC3/UVIS instruments of three fields: a spheroid field near the minor axis, an outer disk field along the major axis, and a field on the Giant Southern Stream. The data provide five to seven year time baselines with respect to pre-existing deep first-epoch observations of the same fields. We measure the positions of thousands of M31 stars and hundreds of compact background galaxies in each field. High accuracy and robustness is achieved by building and fitting a unique template for each individual object. The average PM for each field is obtained from the average motion of the M31 stars between the epochs with respect to the background galaxies. For the three fields, the observed PMs (μ W , μ N ) are, in units of mas yr-1, (- 0.0458, -0.0376) ± (0.0165, 0.0154), (- 0.0533, -0.0104) ± (0.0246, 0.0244), and (- 0.0179, -0.0357) ± (0.0278, 0.0272), respectively. The ability to average over large numbers of objects and over the three fields yields a final displacement accuracy of a few thousandths of a pixel, corresponding to only 12 μas yr-1. This is comparable to what has been achieved for other Local Group galaxies using Very Long Baseline Array observations of water masers. Potential systematic errors are controlled by an analysis strategy that corrects for detector charge transfer inefficiency, spatially and time-dependent geometric distortion, and point-spread function variations. The robustness of the PM measurements and uncertainties are supported by the fact that data from different instruments, taken at different times and with different telescope orientations, as well as measurements of different fields, all yield statistically consistent results. Papers II and III of this series explore the implications of the new measurements for our understanding of the history, future, and mass of the Local Group.

VizieR Online Data Catalog: Milky Way L/T/M-dwarfs identified in BoRG survey (Holwerda+, 2014)

NASA Astrophysics Data System (ADS)

Holwerda, B. W.; Trenti, M.; Clarkson, W.; Sahu, K.; Bradley, L.; Stiavelli, M.; Pirzkal, N.; de Marchi, G.; Andersen, M.; Bouwens, R.; Ryan, R.

2017-07-01

Our principal data set is the WFC3 data from the BoRG (HST GO/PAR-11700; Trenti et al. 2011ApJ...727L..39T; Bradley et al. 2012ApJ...760..108B) survey to identify Milky Way dwarf stars from their morphology and color. The BoRG observations are undithered HST/WFC3 conducted in pure-parallel with the telescope pointing to a primary spectroscopic target with the Cosmic Origin Spectrograph (COS; typically a high-z QSO at high Galactic latitude). The limitations for such observations are primarily that no dithering strategy can be used (final images are at WFC3 native pixel scale) and total exposure times are dictated by the primary program. (5 data files).

Stellar photometry in the inner bulge of M31 using the Hubble Space Telescope wide field camera

NASA Technical Reports Server (NTRS)

Rich, R. M.; Mighell, K. J.

1995-01-01

We present photometry of two fields in the M31 bulge imaged with the Hubble Space Telescope (HST) Wide-Field Camara (WFC). The nuclear field (r less than 40 arcsecs = 150 pc) giant branch extends to I = 19.5, M(sub I) = -5 (Cousins system), a full 0.9 mag brighter than the giant-branch tips of metal-poor Galactic globular clusters and M31 halo fields. This is also approximately = 1.5 mag brighter than the giant branches of metal-rich Galactic globular clusters, but is no brighter than Mould's (1986) M31 bulge field 1 kpc from the nucleus. The data also suggest that the brighter stars may be preferentially concentrated to the center. The 648 luminous stars detected in 2 x 10(exp 9) solar luminosity is approximately = 25% that expected from a hypothetical population of evolved asymptotic giant branch (AGB) stars with lifetimes approximately = 10(exp 5) yr, with the cautionary note that we are near the detection limit. The number of bright stars is also consistent with the progeny of blue stragglers, if one uses a lifetime for the thermal-pulsing AGB of 2 x 10(exp 6) yr. We strongly caution that incompleteness becomes severe below I = 19.9 mag and that future surveys are likely to find numbers of bright stars too large to accomodate the blue straggler progeny hypothesis. We have imaged an additional field 2 arcmin = 500 pc south of the nucleus. The brightest stars in this field are also I = 19.5, but bright stars appear less numerous than in the nuclear field. If the population resembles that of the Galactic bulge, then M(sub bol) = -4.5 is a lower limit to the giant-branch tip luminosity; infrared studies should reveal stars 0.5 mag or more brighter. Either high-metallicity or (more likely) age approximately = 10 Gyr may be responsible for the presence of these luminous AGB stars. These observations confirm that previous ground-based infrared studies (e.g., Rich & Mould 1991) very likely detect an extended giant branch and not spurious luminous stars caused by crowding or disk contamination. However, published integrated colors for the M31 bulge/nucleus are extremely red, making it difficult to accomodate a young or intermediate-age population.

NASA's Hubble Zooms in on a Space Oddity

NASA Image and Video Library

2011-01-11

NASA image release January 10, 2011 In this image by NASA's Hubble Space Telescope, an unusual, ghostly green blob of gas appears to float near a normal-looking spiral galaxy. The bizarre object, dubbed Hanny's Voorwerp (Hanny's Object in Dutch), is the only visible part of a 300,000-light-year-long streamer of gas stretching around the galaxy, called IC 2497. The greenish Voorwerp is visible because a searchlight beam of light from the galaxy's core illuminated it. This beam came from a quasar, a bright, energetic object that is powered by a black hole. The quasar may have turned off about 200,000 years ago. This Hubble view uncovers a pocket of star clusters, the yellowish-orange area at the tip of Hanny's Voorwerp. The star clusters are confined to an area that is a few thousand light-years wide. The youngest stars are a couple of million years old. The Voorwerp is the size of our Milky Way galaxy, and its bright green color is from glowing oxygen. Hubble also shows that gas flowing from IC 2497 may have instigated the star birth by compressing the gas in Hanny's Voorwerp. The galaxy is located about 650 million light-years from Earth. What appears to be a gaping hole in Hanny's Voorwerp actually may be a shadow cast by an object in the quasar's light path. The feature gives the illusion of a hole about 20,000 light-years wide. Hubble reveals sharp edges but no other changes in the gas around the apparent opening, suggesting that an object close to the quasar may have blocked some of the light and projected a shadow on the Voorwerp. This phenomenon is similar to a fly on a movie projector lens casting a shadow on a movie screen. An interaction between IC 2497 and another galaxy about a billion years ago may have created Hanny's Voorwerp and fueled the quasar. The Hubble image shows that IC 2497 has been disturbed, with complex dust patches, warped spiral arms, and regions of star formation around its core. These features suggest the aftermath of a galaxy merger. The bright spots in the central part of the galaxy are star-forming regions. The small, pinkish object to the lower right of IC 2497 is an edge-on spiral galaxy in the background. The image was made by combining data from the Advanced Camera for Surveys (ACS) and the Wide Field Camera 3 (WFC3). The ACS exposures were taken April 12, 2010; the WFC3 data, April 4, 2010. Object Names: Hanny's Voorwerp, IC 2497 Image Type: Astronomical Credit: NASA, ESA, W. Keel (University of Alabama), and the Galaxy Zoo Team NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

Self-Efficacy for Managing Work-Family Conflict: Validating the English Language Version of a Hebrew Scale

ERIC Educational Resources Information Center

Hennessy, Kelly D.; Lent, Robert W.

2008-01-01

The Self-Efficacy for Work-Family Conflict Management Scale (SE-WFC), developed in Israel, was designed to assess beliefs regarding one's ability to manage conflict between work and family roles. This study examined the factor structure, reliability, and validity of an English language version of the SE-WFC in a sample of 159 working mothers in…

The combined effects of job demand and control, effort-reward imbalance and work-family conflicts on the risk of major depressive episode: a 4-year longitudinal study.

PubMed

Nigatu, Yeshambel T; Wang, JianLi

2018-01-01

Work-related psychosocial factors may precipitate the onset of depression. In occupational mental health research, there are three widely used theoretical models, namely, job demand and control (JD-C), effort-reward imbalance (ERI) and work-family conflicts (WFC). However, the interaction between these models and their combined effect on the risk of major depression in the workplace is largely unknown. The aim of this study is to examine the longitudinal combined effects of JD-C, ERI and WFC on the risk of major depression in the working population. Longitudinal data (2008-2013) were collected on randomly selected participants (n=4200) from the working population of the province of Alberta, Canada, at baseline and 1-, 2-, 3- and 4-year follow-up. Data about JD-C, ERI, WFC and major depression were collected by trained interviewers using a computer-assisted telephone interviewing method. Generalised estimating equations for longitudinal modelling were used. There was an independent association between high ERI and high WFC at t x and major depression at t x+1 (OR 1.56, 95% CI 1.25 to 1.96; OR 1.33, 95% CI 1.16 to 1.52), respectively. The combined effects of JD-C and ERI, ERI and WFC, and WFC and JD-C on the risk of major depression were as follows: OR 1.71, 95% CI 1.22 to 2.42, OR 2.47, 95% CI 1.99 to 3.49 and OR 2.21, 95% CI 1.48 to 3.30, respectively. The relative excess risks attributable to the interactions were statistically non-significant. Work-related psychosocial factors are associated with increased risk of major depression over time, but their combined effect is not synergistic. The effects of the factors depicted in the three occupational health models on the risk of major depression appear to be additive. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Wire Probe Antenna (WPT) and Electric Field Detector (EFD0 of Plasma Wave Experiment (PWE) aboard ARASE: Specifications and Evaluation results

NASA Astrophysics Data System (ADS)

Matsuda, S.; Kasaba, Y.; Ishisaka, K.; Kasahara, Y.; Imachi, T.; Yagitani, S.; Kojima, H.; Kurita, S.; Shoji, M.; Hori, T.; Shinbori, A.; Teramoto, M.; Miyoshi, Y.; Nakagawa, T.; Takahashi, N.; Nishimura, Y.; Matsuoka, A.; Tsuchiya, F.; Kumamoto, A.; Nomura, R.

2017-12-01

This paper summarizes the specifications and the evaluation results of Wire Probe Antenna (WPT) and Electric Field Detector (EFD), which are the key parts of Plasma Wave Experiment (PWE) aboard the Arase satellite, in their initial operations and the beginning phase of the full observations. WPT consists of the two dipole antennas as electric field sensors with 32m tip-to-tip length, with a sphere probe (6 cm diameter) attached at each end of wires (length: 15-m). They are extended orthogonally in the spin plane which is roughly perpendicular to the Sun. It enables the PWE to measure the E-field from DC to 10 MHz. This system is almost compatible to the WPT of the Plasma Wave Investigation (PWI) aboard BepiColombo Mercury Magnetospheric Orbiter, except the material of the spherical probe (ERG: Aluminium alloy, MMO: Titanium-alloy). This paper shows the extended length evaluated by the Lorentz force (spacecraft velocity x B-field) and the antenna impedance as the basic information of the E-field measurement capability of the PWE E-field receivers, with the evaluation for the possible degradation of the probe surface coated by TiAlN as BepiColombo. EFD is the 2-channel low frequency electric receiver as a part of EWO (EFD/WFC/OFA), for the measurement of 2ch electric field in the spin-plane with the sampling rate of 512 Hz (dynamic range: +-200 mV/m, +-3 V/m) and the 4ch spacecraft potential with the sampling rate of 128 Hz (dynamic range: +-100 V), respectively, with the bias control capability fed to the WPT probes. The electric field in DC - 232Hz provides the capability to detect (1) the fundamental information of the plasma dynamics and accelerations and (2) the characteristics of MHD and ion waves with their Poynting vectors with the data measured by MGF and PWE/WFC-B connected to PWE/SCM. The spacecraft potential provides the electron density information with UHR frequency. This paper also introduces the data sets and their calibration status.

The Emergent 1.1-1.7 μm Spectrum of the Exoplanet CoRoT-2b as Measured Using the Hubble Space Telescope

NASA Astrophysics Data System (ADS)

Wilkins, Ashlee N.; Deming, Drake; Madhusudhan, Nikku; Burrows, Adam; Knutson, Heather; McCullough, Peter; Ranjan, Sukrit

2014-03-01

We have used Hubble/WFC3 and the G141 grism to measure the secondary eclipse of the transiting, very hot Jupiter CoRoT-2b in the 1.1-1.7 μm spectral region. We find an eclipse depth averaged over this band equal to 395^{+69}_{-45} parts per million, equivalent to a blackbody temperature of 1788 ± 18 K. We study and characterize several WFC3 instrumental effects, especially the "hook" phenomenon described by Deming et al. We use data from several transiting exoplanet systems to find a quantitative relation between the amplitude of the hook and the exposure level of a given pixel. Although the uncertainties in this relation are too large to allow us to develop an empirical correction for our data, our study provides a useful guide for optimizing exposure levels in future WFC3 observations. We derive the planet's spectrum using a differential method. The planet-to-star contrast increases to longer wavelength within the WFC3 bandpass, but without water absorption or emission to a 3σ limit of 85 ppm. The slope of the WFC3 spectrum is significantly less than the slope of the best-fit blackbody. We compare all existing eclipse data for this planet to a blackbody spectrum, and to spectra from both solar abundance and carbon-rich (C/O = 1) models. A blackbody spectrum is an acceptable fit to the full data set. Extra continuous opacity due to clouds or haze, and flattened temperature profiles, are strong candidates to produce quasi-blackbody spectra, and to account for the amplitude of the optical eclipses. Our results show ambiguous evidence for a temperature inversion in this planet.

Conflict between the work and family domains and exhaustion among vocationally active men and women.

PubMed

Canivet, Catarina; Ostergren, Per-Olof; Lindeberg, Sara I; Choi, BongKyoo; Karasek, Robert; Moghaddassi, Mahnaz; Isacsson, Sven-Olof

2010-04-01

Exhaustion is consistently found to be more prevalent in women than in men. Women suffer from job strain more often, which may constitute a partial explanation for this phenomenon, but experienced shortcomings in combining work and family demands may also contribute to ill health. The aim of this study was to investigate, and analyse by gender, how work-related and family-related factors, as well as the interface between them, i.e. work-to-family conflict (WFC) and family-to-work conflict (FWC), are related to exhaustion. The study was cross-sectional with self-administered questionnaires assessing exposures and outcome with previously well-validated instruments. The participants were 2726 men and 2735 women, aged 45-64, vocationally active, and residing in Malmö, Sweden. Sixteen percent of the women and 8% of the men considered themselves exhausted. WFC, FWC, job strain, and low job support were all strongly correlated to exhaustion in both genders. In the multivariate analyses, adjusting for other work and family risk factors, WFC and FWC remained statistically significant risk factors for exhaustion in both men and women. Job strain, low job support, and having a somatic disorder were also independently associated with exhaustion. While WFC was more prevalent among men, it was more strongly associated with exhaustion in women than in men. In women, WFC and FWC contributed to a larger part of the explanatory power of the model, which amounted to 22% of the variance in women and 14% in men. The results imply that the concept of 'work stress' should be regarded in a wider context in order to understand gender related issues of exhaustion among vocationally active individuals. Copyright 2010 Elsevier Ltd. All rights reserved.

The UV Spectral Components in RE1938-461, the Brightest ROSAT WFC Discovered Polar with a High Euv/optical Ratio: CYCLE4 Medium.

NASA Astrophysics Data System (ADS)

Rosen, Simon

1994-01-01

Eight new magnetic cataclysmic variables were discovered during the ROSAT WFC survey. Seven of these have been identified with polar (or AM Her) systems. A striking result that has emerged is that the new polars appear to populate a region of high EUV/optical flux ratio when compared to that measured for the previously known systems that were also detected in the WFC survey. It is highly likely that these new polars also possess large soft/hard X-ray flux ratios. In this case, the WFC result suggests that a) polars with large soft excesses are more common than previously believed and b) that the mode of accretion in these particular systems is likely to be via the direct penetration of the white dwarf's surface by blobs of accreting material rather than by the formation of a hard X-ray emitting column above the surface. The new polars will have a direct bearing on the division between the two different modes of accretion. They also provide the means to probe the detailed nature of the processes occurring in the accretion region. We are proposing low resolution HST FOS observations of the brightest of these EUV luminous polars discovered in the WFC survey to a) search for the tail of the emission component from the heated region around the accreting pole to constrain the luminosity, size and temperature of this constituent and b) to perform an initial study of the UV emission lines, measuring their flux and radial velocity motion to constrain the dynamics and physical (ionization) structure within the accretion flow.

Shift Work and Quality of Personal, Professional, and Family Life among Health Care Workers in a Rehabilitation Center in Greece.

PubMed

Skoufi, Georgia I; Lialios, Georgios A; Papakosta, Styliani; Constantinidis, Theodoros C; Galanis, Petros; Nena, Evangelia

2017-01-01

Adverse work schedules and conditions may affect the physical, mental, and social wellbeing of workers, impairing quality of life and causing conflict between family and work roles. To compare quality of life, professional quality of life (ProQOL), and work/family conflict (WFC) between shift workers and nonshift workers and explore possible associations with demographic characteristics. : A cross-sectional study was conducted in a rehabilitation center in Central Greece, recording demographic, occupational, and family characteristics. Participants answered the World Health Organization-5 Well-Being Index, the ProQOL questionnaire [compassion satisfaction (CS), and the burnout (BO) and secondary traumatic stress scales], and the WFC scale. IBM Statistical Package for the Social Sciences version 19.0 for Windows. Ninety-one employees (68.7% shift workers) participated, with mean age 33.5. Females reported higher compassion/satisfaction level ( P = 0.031). Nursing profession was associated with higher levels of BO ( P = 0.021), impact of work to family life ( P = 0.008), and impact of family to work (FtW), and WFC ( P = 0.008). Parenthood increased the impact of FtW ( P = 0.008) and predispose to WFC ( P = 0.023). In general, wellbeing was significantly correlated with CS ( r = 0.368, P < 0.01), BO ( r = -0.538, P < 0.01), and levels of WFC ( P = 0.003). Work and family roles conflict was statistically significantly correlated with levels of BO ( r = 0.497, P < 0.01), and CS ( r = -0.288, P < 0.01). The interaction between general, professional, and family quality of life can guide interventions in the workplace in order to improve workers' quality of life and promote workers' health.

Work-family conflict and self-rated health among dwellers in Minia, Egypt: Financial strain vs social support.

PubMed

Eshak, E S; Kamal, N N; Seedhom, A E; Kamal, N N

2018-04-01

Egypt's economic reform is accompanied by both financial and social strains. Due to lack of evidence, we examined the associations between work-family conflict in its 2 directions, work-to-family conflicts (WFCs), and family-to-work conflicts (FWCs) and self-rated health in Minia, Egypt, and whether the association will vary by being financially responsible for others and by the level of perceived social support. A cross-sectional study that included 1021 healthy participants aged 18-60 years from Minia district. Data on participants' work-family conflict, social, and demographic data and individual self-rated health were collected by a questionnaire survey. Multivariable logistic regression analyses were used to calculate the odds ratios (ORs) with its 95% confidence intervals (CIs) for poor self-rated health according to categories of work-family conflict. There were significant positive associations between the poor self-rated health and both high WFC and FWC. Compared with participants with low WFC and low FWC, participants with high WFC low FWC, low WFC high FWC, and high WFC high FWC had multivariable-adjusted ORs (95% CIs) for poor self-rated health of 6.93 (3.02-13.13), 2.09 (1.06-4.12), and 10.05 (4.98-20.27), respectively. Giving financial support to others but not the level of perceived social support from others was an effect modifier of the association. Work-family conflict was positively associated with the self-report of poor health, especially in those who were financially responsible for other family members. Copyright © 2018 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

The emergent 1.1-1.7 μm spectrum of the exoplanet COROT-2B as measured using the Hubble space telescope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilkins, Ashlee N.; Deming, Drake; Madhusudhan, Nikku

2014-03-10

We have used Hubble/WFC3 and the G141 grism to measure the secondary eclipse of the transiting, very hot Jupiter CoRoT-2b in the 1.1-1.7 μm spectral region. We find an eclipse depth averaged over this band equal to 395{sub −45}{sup +69} parts per million, equivalent to a blackbody temperature of 1788 ± 18 K. We study and characterize several WFC3 instrumental effects, especially the 'hook' phenomenon described by Deming et al. We use data from several transiting exoplanet systems to find a quantitative relation between the amplitude of the hook and the exposure level of a given pixel. Although the uncertaintiesmore » in this relation are too large to allow us to develop an empirical correction for our data, our study provides a useful guide for optimizing exposure levels in future WFC3 observations. We derive the planet's spectrum using a differential method. The planet-to-star contrast increases to longer wavelength within the WFC3 bandpass, but without water absorption or emission to a 3σ limit of 85 ppm. The slope of the WFC3 spectrum is significantly less than the slope of the best-fit blackbody. We compare all existing eclipse data for this planet to a blackbody spectrum, and to spectra from both solar abundance and carbon-rich (C/O = 1) models. A blackbody spectrum is an acceptable fit to the full data set. Extra continuous opacity due to clouds or haze, and flattened temperature profiles, are strong candidates to produce quasi-blackbody spectra, and to account for the amplitude of the optical eclipses. Our results show ambiguous evidence for a temperature inversion in this planet.« less

Shift Work and Quality of Personal, Professional, and Family Life among Health Care Workers in a Rehabilitation Center in Greece

PubMed Central

Skoufi, Georgia I.; Lialios, Georgios A.; Papakosta, Styliani; Constantinidis, Theodoros C.; Galanis, Petros; Nena, Evangelia

2017-01-01

Context: Adverse work schedules and conditions may affect the physical, mental, and social wellbeing of workers, impairing quality of life and causing conflict between family and work roles. Aims: To compare quality of life, professional quality of life (ProQOL), and work/family conflict (WFC) between shift workers and nonshift workers and explore possible associations with demographic characteristics. Settings and Design : A cross-sectional study was conducted in a rehabilitation center in Central Greece, recording demographic, occupational, and family characteristics. Materials and Methods: Participants answered the World Health Organization-5 Well-Being Index, the ProQOL questionnaire [compassion satisfaction (CS), and the burnout (BO) and secondary traumatic stress scales], and the WFC scale. Statistical Analysis Used: IBM Statistical Package for the Social Sciences version 19.0 for Windows. Results: Ninety-one employees (68.7% shift workers) participated, with mean age 33.5. Females reported higher compassion/satisfaction level (P = 0.031). Nursing profession was associated with higher levels of BO (P = 0.021), impact of work to family life (P = 0.008), and impact of family to work (FtW), and WFC (P = 0.008). Parenthood increased the impact of FtW (P = 0.008) and predispose to WFC (P = 0.023). In general, wellbeing was significantly correlated with CS (r = 0.368, P < 0.01), BO (r = −0.538, P < 0.01), and levels of WFC (P = 0.003). Work and family roles conflict was statistically significantly correlated with levels of BO (r = 0.497, P < 0.01), and CS (r = −0.288, P < 0.01). Conclusions: The interaction between general, professional, and family quality of life can guide interventions in the workplace in order to improve workers' quality of life and promote workers' health. PMID:29618910

Work-family conflict, job satisfaction and spousal support: an exploratory study of nurses' experience.

PubMed

Patel, C J; Beekhan, A; Paruk, Z; Ramgoon, S

2008-03-01

In recognising the highly stressful nature of the nursing profession, the added burden of hospital staff shortages, and patient overload, the present study explored the impact of work on family functioning, its relationship to job satisfaction and the role of spousal support in a group of 80 female nurses working in a government hospital. Using a descriptive, correlational design, the relationships among job satisfaction, work-family conflict (WFC) and spousal/partner support were explored. The hypotheses that job satisfaction and WFC would be negatively correlated, that job satisfaction and spousal support would be positively correlated, and that WFC and spousal support would be negatively correlated, were tested using correlation techniques. All hypotheses were confirmed. The role of spousal support in the relationship between job satisfaction and work -family conflict was highlighted.

WFC3/IR Blob Monitoring

NASA Astrophysics Data System (ADS)

Sunnquist, Ben

2018-06-01

Throughout the lifetime of WFC3, a growing number of 'blobs' (small, circular regions with slightly decreased sensitivity) have appeared in WFC3/IR images. In this report, we present the current workflow used for identifying, characterizing and flagging new IR blobs. We also describe the methods currently used to monitor the repeatability of the channel select mechanism (CSM) movements as a way to ensure that the CSM is still operating normally as these new blobs form. A full listing of all known blobs, which incorporates the work from past blob monitoring efforts, is presented in the Appendix as well as all of the IR bad pixel tables generated to include the strongest of these blobs. These tables, along with all of the other relevant figures and tables in this report, will be continuously updated as new blobs form.

Beyond the tradition: test of an integrative conceptual model on nurse turnover.

PubMed

Battistelli, A; Portoghese, I; Galletta, M; Pohl, S

2013-03-01

This paper aimed to extend research on nurse turnover by developing and testing a theoretical model of turnover intention that includes two emergent key off-the-job constructs, work-family conflict (WFC) and community embeddedness (CE). Nurse turnover is considered one of the most significant issues in health care. There is a considerable body of knowledge that has focused on the study of the on-the-job factors of nurse turnover, showing the important role of job attitudes. Recently, WFC and job embeddedness (JE) have been identified as variables that could help explain levels of nurse turnover. Using structural equation modelling from a cross-sectional survey, the relationships between the variables were explored in a sample of 440 nurses from an Italian public hospital. The questionnaire measures demographic data and psychosocial factors such as job satisfaction, organizational commitment, WFC, CE and turnover intentions. The findings supported the importance of non-work dimensions in turnover models. The results suggest that when studying turnover phenomena in health organizations, the extra-work domains (WFC and JE) can contribute to a decrease in the intention to leave, in addition to the more typically emphasized attitude dimension. © 2012 The Authors. International Nursing Review © 2012 International Council of Nurses.

Snapshot Survey of the Globular Cluster Populations of Isolated Early Type Galaxies

NASA Astrophysics Data System (ADS)

Gregg, Michael

2017-08-01

We propose WFC3/UVIS snapshot observations of a sample of 75 isolated early type galaxiesresiding in cosmic voids or extremely low density regions. The primary aim is to usetheir globular cluster populations to reconstruct their evolutionary history, revealingif, how, and why void ellipticals differ from cluster ellipticals. The galaxies span arange of luminosities, providing a varied sample for comparison with the well-documentedglobular cluster populations in denser environments. This proposed WFC3 study of isolatedearly type galaxies breaks new ground by targeting a sample which has thus far receivedlittle attention, and, significantly, this will be the first such study with HST.Characterizing early type galaxies in voids and their GC systems promises to increase ourunderstanding of galaxy formation and evolution of galaxies in general because isolatedobjects are the best approximation to a control sample that we have for understanding theinfluence of environment on formation and evolution. Whether these isolated objects turnout to be identical to or distinct from counterparts in other regions of the Universe,they will supply insight into the formation and evolution of all galaxies. Parallel ACSimaging will help to characterize the near field environments of the sample.

Accuracy of the HST Standard Astrometric Catalogs w.r.t. Gaia

NASA Astrophysics Data System (ADS)

Kozhurina-Platais, V.; Grogin, N.; Sabbi, E.

2018-02-01

The goal of astrometric calibration of the HST ACS/WFC and WFC3/UVIS imaging instruments is to provide a coordinate system free of distortion to the precision level of 0.1 pixel 4-5 mas or better. This astrometric calibration is based on two HST astrometric standard fields in the vicinity of the globular clusters, 47 Tuc and omega Cen, respectively. The derived calibration of the geometric distortion is assumed to be accurate down to 2-3 mas. Is this accuracy in agreement with the true value? Now, with the access to globally accurate positions from the first Gaia data release (DR1), we found that there are measurable offsets, rotation, scale and other deviations of distortion parameters in two HST standard astrometric catalogs. These deviations from the distortion-free and properly aligned coordinate system should be accounted and corrected for, so that the high precision HST positions are free of any systematic errors. We also found that the precision of the HST pixel coordinates is substantially better than the accuracy listed in the Gaia DR1. Therefore, in order to finalize the components of distortion in the HST standard catalogs, the next release of Gaia data is needed.

The Spectral Energy Distributions of z ~ 8 Galaxies from the IRAC Ultra Deep Fields: Emission Lines, Stellar Masses, and Specific Star Formation Rates at 650 Myr

NASA Astrophysics Data System (ADS)

Labbé, I.; Oesch, P. A.; Bouwens, R. J.; Illingworth, G. D.; Magee, D.; González, V.; Carollo, C. M.; Franx, M.; Trenti, M.; van Dokkum, P. G.; Stiavelli, M.

2013-11-01

Using new ultradeep Spitzer/InfraRed Array Camera (IRAC) photometry from the IRAC Ultra Deep Field program, we investigate the stellar populations of a sample of 63 Y-dropout galaxy candidates at z ~ 8, only 650 Myr after the big bang. The sources are selected from HST/ACS+WFC3/IR data over the Hubble Ultra Deep Field (HUDF), two HUDF parallel fields, and wide area data over the CANDELS/GOODS-South. The new Spitzer/IRAC data increase the coverage in [3.6] and [4.5] to ~120h over the HUDF reaching depths of ~28 (AB,1σ). The improved depth and inclusion of brighter candidates result in direct >=3σ InfraRed Array Camera (IRAC) detections of 20/63 sources, of which 11/63 are detected at >=5σ. The average [3.6]-[4.5] colors of IRAC detected galaxies at z ~ 8 are markedly redder than those at z ~ 7, observed only 130 Myr later. The simplest explanation is that we witness strong rest-frame optical emission lines (in particular [O III] λλ4959, 5007 + Hβ) moving through the IRAC bandpasses with redshift. Assuming that the average rest-frame spectrum is the same at both z ~ 7 and z ~ 8 we estimate a rest-frame equivalent width of {W}_{[O\\,\\scriptsize{III}]\\ \\lambda \\lambda 4959,5007+H\\beta }=670^{+260}_{-170} Å contributing 0.56^{+0.16}_{-0.11} mag to the [4.5] filter at z ~ 8. The corresponding {W}_{H\\alpha }=430^{+160}_{-110} Å implies an average specific star formation rate of sSFR=11_{-5}^{+11} Gyr-1 and a stellar population age of 100_{-50}^{+100} Myr. Correcting the spectral energy distribution for the contribution of emission lines lowers the average best-fit stellar masses and mass-to-light ratios by ~3 ×, decreasing the integrated stellar mass density to \\rho ^*(z=8,M_{\\rm{UV}}<-18)=0.6^{+0.4}_{-0.3}\\times 10^6 \\,M_\\odot Mpc-3. Based on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs #11563, 9797. Based on observations with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under NASA contract 1407. Support for this work was provided by NASA through contract 125790 issued by JPL/Caltech. Based on service mode observations collected at the European Southern Observatory, Paranal, Chile (ESO Program 073.A-0764A). Based on data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

Two-Camera Acquisition and Tracking of a Flying Target

NASA Technical Reports Server (NTRS)

Biswas, Abhijit; Assad, Christopher; Kovalik, Joseph M.; Pain, Bedabrata; Wrigley, Chris J.; Twiss, Peter

2008-01-01

A method and apparatus have been developed to solve the problem of automated acquisition and tracking, from a location on the ground, of a luminous moving target in the sky. The method involves the use of two electronic cameras: (1) a stationary camera having a wide field of view, positioned and oriented to image the entire sky; and (2) a camera that has a much narrower field of view (a few degrees wide) and is mounted on a two-axis gimbal. The wide-field-of-view stationary camera is used to initially identify the target against the background sky. So that the approximate position of the target can be determined, pixel locations on the image-detector plane in the stationary camera are calibrated with respect to azimuth and elevation. The approximate target position is used to initially aim the gimballed narrow-field-of-view camera in the approximate direction of the target. Next, the narrow-field-of view camera locks onto the target image, and thereafter the gimbals are actuated as needed to maintain lock and thereby track the target with precision greater than that attainable by use of the stationary camera.

Analysis of calibration accuracy of cameras with different target sizes for large field of view

NASA Astrophysics Data System (ADS)

Zhang, Jin; Chai, Zhiwen; Long, Changyu; Deng, Huaxia; Ma, Mengchao; Zhong, Xiang; Yu, Huan

2018-03-01

Visual measurement plays an increasingly important role in the field o f aerospace, ship and machinery manufacturing. Camera calibration of large field-of-view is a critical part of visual measurement . For the issue a large scale target is difficult to be produced, and the precision can not to be guaranteed. While a small target has the advantage of produced of high precision, but only local optimal solutions can be obtained . Therefore, studying the most suitable ratio of the target size to the camera field of view to ensure the calibration precision requirement of the wide field-of-view is required. In this paper, the cameras are calibrated by a series of different dimensions of checkerboard calibration target s and round calibration targets, respectively. The ratios of the target size to the camera field-of-view are 9%, 18%, 27%, 36%, 45%, 54%, 63%, 72%, 81% and 90%. The target is placed in different positions in the camera field to obtain the camera parameters of different positions . Then, the distribution curves of the reprojection mean error of the feature points' restructure in different ratios are analyzed. The experimental data demonstrate that with the ratio of the target size to the camera field-of-view increas ing, the precision of calibration is accordingly improved, and the reprojection mean error changes slightly when the ratio is above 45%.

Is the Size Evolution of Massive Galaxies Accelerated in Cluster Environments?

NASA Astrophysics Data System (ADS)

Wilson, Gillian

2013-10-01

At z 1.6 the main progenitors of present-day massive clusters are undergoing rapid collapse, and have the highest rates of galaxy merging and assembly. Recent observational studies have hinted at accelerated galaxy evolution in dense environments at this epoch, including increased merger rates and rapid growth in galaxy size relative to the field. We propose WFC3 G102 spectroscopy and F125W {Broad J} imaging of a sample of four massive spectroscopically-confirmed clusters at z = 1.6. Our primary scientific goal is to leverage the CANDELS Wide Legacy dataset to carry out a head-to-head comparison of the sizes of cluster members relative to the field {as a function of stellar mass and Sersic index}, and quantify the role of environment in the observed rapid evolution in galaxy sizes since z = 2. These clusters are four of the highest significance overdensities in the 50 square degree SWIRE fields, and will evolve over time to have present-day masses similar to Coma. They were detected using IRAC [3.6]-[4.5] color, which identifies galaxy overdensities regardless of optically red or blue color. A heroic ground-based spectroscopic campaign has resulted in 44 spectroscopically-confirmed members. However this sample is heavily biased toward star-forming {SF} galaxies, and WFC3 spectroscopy is essential to definitively determine cluster membership for 200 members, without bias with respect to quiescent or SF type. The F125W {rest-frame V-band} imaging is necessary to measure the sizes and morphologies of cluster members. 17-passband broadband imaging spanning UV, optical, near-IR, Spitzer IR and Herschel far-IR is already in hand.

Do Typical Galaxies in Adolescence Already Host Growing Black Holes?

NASA Astrophysics Data System (ADS)

Trump, Jonathan

2012-10-01

This archival grism proposal achieves a 100-fold gain in high-quality {5+sigma} information for discovering which properties of adolescent {0.7

Quantifying Bursty Star Formation and Dust Extinction in Dwarf Galaxies at 0.75 < z < 1.5

NASA Astrophysics Data System (ADS)

Siana, Brian

2014-10-01

Using the magnification provided by gravitational lensing, our team has recently uncovered an important population of star-forming dwarf galaxies at 1

Service workers' chain reactions to daily customer mistreatment: Behavioral linkages, mechanisms, and boundary conditions.

PubMed

Chi, Nai-Wen; Yang, Jixia; Lin, Chia-Ying

2018-01-01

Drawing on the stressor-emotion model, we examine how customer mistreatment can evoke service workers' passive forms of deviant behaviors (i.e., work withdrawal behavior [WWB]) and negative impacts on their home life (i.e., work-family conflict [WFC]), and whether individuals' core self-evaluations and customer service training can buffer the negative effects of customer mistreatment. Using the experience sampling method, we collect daily data from 77 customer service employees for 10 consecutive working days, yielding 546 valid daily responses. The results show that daily customer mistreatment increases service workers' daily WWB and WFC through negative emotions. Furthermore, employees with high core self-evaluations and employees who received customer service training are less likely to experience negative emotions when faced with customer mistreatment, and thus are less likely to engage in WWB or provoke WFC. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Persistence in the WFC3 IR Detector: An Area Dependent Model

NASA Astrophysics Data System (ADS)

Long, Knox S.; Baggett, Sylvia M.

2018-05-01

When the IR detector on WFC3 is exposed to a bright source or sources, the sources not only appear in the original exposure, but can appear as afterimages in later exposures, a phenomenon known as persistence. The magnitude and duration of persistence for a fixed stimulus varies somewhat across the face of the detector. Our previous attempts to characterize this variation were limited to a correction that captures only the variation in the magnitude. Here we describe a simple model which allows for variations both in the magnitude and the duration of the persistence, and then evaluate quantitatively how much improvement this model provides. We conclude that while this was a useful experiment, it does not result in a marked improvement in our ability to predict persistence in the WFC3/IR array. We discuss why this was the case, and possible paths forward.

Multi-focused microlens array optimization and light field imaging study based on Monte Carlo method.

PubMed

Li, Tian-Jiao; Li, Sai; Yuan, Yuan; Liu, Yu-Dong; Xu, Chuan-Long; Shuai, Yong; Tan, He-Ping

2017-04-03

Plenoptic cameras are used for capturing flames in studies of high-temperature phenomena. However, simulations of plenoptic camera models can be used prior to the experiment improve experimental efficiency and reduce cost. In this work, microlens arrays, which are based on the established light field camera model, are optimized into a hexagonal structure with three types of microlenses. With this improved plenoptic camera model, light field imaging of static objects and flame are simulated using the calibrated parameters of the Raytrix camera (R29). The optimized models improve the image resolution, imaging screen utilization, and shooting range of depth of field.

UV--Visible observations with HST in the JWST North Ecliptic Pole Time-Domain Field

NASA Astrophysics Data System (ADS)

Jansen, Rolf A.; Windhorst, Rogier; Grogin, Norman; Koekemoer, Anton; Royle, Patricia; Hathi, Nimish; Jones, Victoria; Cohen, Seth; Ashcraft, Teresa; Willmer, Christopher; Conselice, Christopher; White, Cameron; Frye, Brenda; HST-GO-15278 team; and the Webb Medium Deep Fields IDS GTO team.

2018-01-01

We report the first results from a UV–Visible HST imaging survey of the JWST North Ecliptic Pole (NEP) Time-Domain Field (TDF). Using CVZ and near-CVZ opportunities we observed the first two out of nine tiles with WFC3/UVIS in F275W and with ACS/WFC in F435W and F606W. Over the course of the next 13 months, this survey is designed to provide near-contiguous 3-filter coverage of the central r ≤ 5‧ of this new community field for time-domain science with JWST. The JWST NEP TDF is located within JWST's northern Continuous Viewing Zone, will span ~14‧ in diameter (~10‧ with NIRISS coverage), is devoid of sources bright enough to saturate the NIRCam detectors, has low Galactic foreground extinction, and will be roughly circular in shape (initially sampled during Cycle 1 at 4 distinct orientations with JWST/NIRCam — the JWST “windmill”). NIRISS slitless grism spectroscopy will be taken in parallel, overlapping an alternate NIRCam orientation. This is the only region in the sky where JWST can observe a clean extragalactic deep survey field of this size at arbitrary cadence or at arbitrary orientation. This will crucially enable a wide range of new and exciting time-domain science, including high redshift transient searches and monitoring (e.g., SNe), variability studies from Active Galactic Nuclei to brown dwarf atmospheres, as well as proper motions of extreme scattered Kuiper Belt and Oort Cloud Objects, and of nearby Galactic brown dwarfs, low-mass stars, and ultracool white dwarfs. Ancillary data across the electromagnetic spectrum will exist for this field when JWST science operations commence in the second half of 2019. This includes deep (mAB ~ 26 mag) wide-field (~23‧×25‧) Ugriz photometry of this field and its surroundings from LBT/LBC and Subaru/HSC, JHK from MMT/MMIRS, VLA 3 GHz and VLBA 4.5 GHz radio observations, and Chandra/ACIS X-ray images. Proposals for (sub)mm observations and spectroscopy to mAB ~ 24 mag are pending.

3D for the people: multi-camera motion capture in the field with consumer-grade cameras and open source software

PubMed Central

Evangelista, Dennis J.; Ray, Dylan D.; Hedrick, Tyson L.

2016-01-01

ABSTRACT Ecological, behavioral and biomechanical studies often need to quantify animal movement and behavior in three dimensions. In laboratory studies, a common tool to accomplish these measurements is the use of multiple, calibrated high-speed cameras. Until very recently, the complexity, weight and cost of such cameras have made their deployment in field situations risky; furthermore, such cameras are not affordable to many researchers. Here, we show how inexpensive, consumer-grade cameras can adequately accomplish these measurements both within the laboratory and in the field. Combined with our methods and open source software, the availability of inexpensive, portable and rugged cameras will open up new areas of biological study by providing precise 3D tracking and quantification of animal and human movement to researchers in a wide variety of field and laboratory contexts. PMID:27444791

Research into a Single-aperture Light Field Camera System to Obtain Passive Ground-based 3D Imagery of LEO Objects

NASA Astrophysics Data System (ADS)

Bechis, K.; Pitruzzello, A.

2014-09-01

This presentation describes our ongoing research into using a ground-based light field camera to obtain passive, single-aperture 3D imagery of LEO objects. Light field cameras are an emerging and rapidly evolving technology for passive 3D imaging with a single optical sensor. The cameras use an array of lenslets placed in front of the camera focal plane, which provides angle of arrival information for light rays originating from across the target, allowing range to target and 3D image to be obtained from a single image using monocular optics. The technology, which has been commercially available for less than four years, has the potential to replace dual-sensor systems such as stereo cameras, dual radar-optical systems, and optical-LIDAR fused systems, thus reducing size, weight, cost, and complexity. We have developed a prototype system for passive ranging and 3D imaging using a commercial light field camera and custom light field image processing algorithms. Our light field camera system has been demonstrated for ground-target surveillance and threat detection applications, and this paper presents results of our research thus far into applying this technology to the 3D imaging of LEO objects. The prototype 3D imaging camera system developed by Northrop Grumman uses a Raytrix R5 C2GigE light field camera connected to a Windows computer with an nVidia graphics processing unit (GPU). The system has a frame rate of 30 Hz, and a software control interface allows for automated camera triggering and light field image acquisition to disk. Custom image processing software then performs the following steps: (1) image refocusing, (2) change detection, (3) range finding, and (4) 3D reconstruction. In Step (1), a series of 2D images are generated from each light field image; the 2D images can be refocused at up to 100 different depths. Currently, steps (1) through (3) are automated, while step (4) requires some user interaction. A key requirement for light field camera operation is that the target must be within the near-field (Fraunhofer distance) of the collecting optics. For example, in visible light the near-field of a 1-m telescope extends out to about 3,500 km, while the near-field of the AEOS telescope extends out over 46,000 km. For our initial proof of concept, we have integrated our light field camera with a 14-inch Meade LX600 advanced coma-free telescope, to image various surrogate ground targets at up to tens of kilometers range. Our experiments with the 14-inch telescope have assessed factors and requirements that are traceable and scalable to a larger-aperture system that would have the near-field distance needed to obtain 3D images of LEO objects. The next step would be to integrate a light field camera with a 1-m or larger telescope and evaluate its 3D imaging capability against LEO objects. 3D imaging of LEO space objects with light field camera technology can potentially provide a valuable new tool for space situational awareness, especially for those situations where laser or radar illumination of the target objects is not feasible.

Can light-field photography ease focusing on the scalp and oral cavity?

PubMed

Taheri, Arash; Feldman, Steven R

2013-08-01

Capturing a well-focused image using an autofocus camera can be difficult in oral cavity and on a hairy scalp. Light-field digital cameras capture data regarding the color, intensity, and direction of rays of light. Having information regarding direction of rays of light, computer software can be used to focus on different subjects in the field after the image data have been captured. A light-field camera was used to capture the images of the scalp and oral cavity. The related computer software was used to focus on scalp or different parts of oral cavity. The final pictures were compared with pictures taken with conventional, compact, digital cameras. The camera worked well for oral cavity. It also captured the pictures of scalp easily; however, we had to repeat clicking between the hairs on different points to choose the scalp for focusing. A major drawback of the system was the resolution of the resulting pictures that was lower than conventional digital cameras. Light-field digital cameras are fast and easy to use. They can capture more information on the full depth of field compared with conventional cameras. However, the resolution of the pictures is relatively low. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A practical implementation of wave front construction for 3-D isotropic media

NASA Astrophysics Data System (ADS)

Chambers, K.; Kendall, J.-M.

2008-06-01

Wave front construction (WFC) methods are a useful tool for tracking wave fronts and are a natural extension to standard ray shooting methods. Here we describe and implement a simple WFC method that is used to interpolate wavefield properties throughout a 3-D heterogeneous medium. Our approach differs from previous 3-D WFC procedures primarily in the use of a ray interpolation scheme, based on approximating the wave front as a `locally spherical' surface and a `first arrival mode', which reduces computation times, where only first arrivals are required. Both of these features have previously been included in 2-D WFC algorithms; however, until now they have not been extended to 3-D systems. The wave front interpolation scheme allows for rays to be traced from a nearly arbitrary distribution of take-off angles, and the calculation of derivatives with respect to take-off angles is not required for wave front interpolation. However, in regions of steep velocity gradient, the locally spherical approximation is not valid, and it is necessary to backpropagate rays to a sufficiently homogenous region before interpolation of the new ray. Our WFC technique is illustrated using a realistic velocity model, based on a North Sea oil reservoir. We examine wavefield quantities such as traveltimes, ray angles, source take-off angles and geometrical spreading factors, all of which are interpolated on to a regular grid. We compare geometrical spreading factors calculated using two methods: using the ray Jacobian and by taking the ratio of a triangular area of wave front to the corresponding solid angle at the source. The results show that care must be taken when using ray Jacobians to calculate geometrical spreading factors, as the poles of the source coordinate system produce unreliable values, which can be spread over a large area, as only a few initial rays are traced in WFC. We also show that the use of the first arrival mode can reduce computation time by ~65 per cent, with the accuracy of the interpolated traveltimes, ray angles and source take-off angles largely unchanged. However, the first arrival mode does lead to inaccuracies in interpolated angles near caustic surfaces, as well as small variations in geometrical spreading factors for ray tubes that have passed through caustic surfaces.

New Technologies Smart, or Harm Work-Family Boundaries Management? Gender Differences in Conflict and Enrichment Using the JD-R Theory

PubMed Central

Ghislieri, Chiara; Emanuel, Federica; Molino, Monica; Cortese, Claudio G.; Colombo, Lara

2017-01-01

Background: The relationship between technology-assisted supplemental work and well-being outcomes is a recent issue in scientific literature. Whether the use of technology for work purpose in off-work time may have a positive or negative impact on work-family balance remains an open question and the role of gender in this relationship is poorly understood. Aim: According to the JD-R theory, this study aimed to investigate the relationship between off-work hours technology assisted job demand (off-TAJD) and both work-family conflict (WFC) and work-family enrichment (WFE). Moreover, it considered two general job demands, workload and emotional dissonance, and one job resource, supervisory coaching. Method: The hypotheses were tested with a convenience sample of 671 workers. Data were collected with a self-report questionnaire and analyzed with SPSS 23 and through multi-group structural equation model (SEM) (Mplus 7). Results: The estimated SEM [Chi-square (510) = 1041.29; p < 0.01; CFI = 0.95; TLI = 0.95; RMSEA = 0.06 (0.05, 0.06); SRMR = 0.05. M = 319/F = 352] showed that off-TAJD was positively related to WFC in both subsamples; off-TAJD was positively related also to WFE only in the Male group. Workload was positively related to WFC in both Male and Female subsamples. Emotional dissonance was positively related to WFC in both subsamples and was negatively related to WFE. Supervisory coaching was strongly, positively related to WFE in both groups, and only in the Male subsample presented a low negative relationship with WFC. Conclusion: This study contributes to the literature on new challenges in work-life interface by analyzing the association between off-TAJD and WFC and Enrichment. Our findings suggest it is important to pay attention to gender differences in the study of the impact of supplemental work carried out during off-work hours using technology on the work-life interface. In fact, employee perception of Company demands of being available during off-work time, with the use of technology, may have different consequences for men and women, indicating potential differences in the centrality of the working role. Practical implications, at both cultural and organizational levels, should address the use of technology during leisure time. PMID:28713300

New Technologies Smart, or Harm Work-Family Boundaries Management? Gender Differences in Conflict and Enrichment Using the JD-R Theory.

PubMed

Ghislieri, Chiara; Emanuel, Federica; Molino, Monica; Cortese, Claudio G; Colombo, Lara

2017-01-01

Background: The relationship between technology-assisted supplemental work and well-being outcomes is a recent issue in scientific literature. Whether the use of technology for work purpose in off-work time may have a positive or negative impact on work-family balance remains an open question and the role of gender in this relationship is poorly understood. Aim: According to the JD-R theory, this study aimed to investigate the relationship between off-work hours technology assisted job demand (off-TAJD) and both work-family conflict (WFC) and work-family enrichment (WFE). Moreover, it considered two general job demands, workload and emotional dissonance, and one job resource, supervisory coaching. Method: The hypotheses were tested with a convenience sample of 671 workers. Data were collected with a self-report questionnaire and analyzed with SPSS 23 and through multi-group structural equation model (SEM) (Mplus 7). Results: The estimated SEM [Chi-square (510) = 1041.29; p < 0.01; CFI = 0.95; TLI = 0.95; RMSEA = 0.06 (0.05, 0.06); SRMR = 0.05. M = 319/F = 352] showed that off-TAJD was positively related to WFC in both subsamples; off-TAJD was positively related also to WFE only in the Male group. Workload was positively related to WFC in both Male and Female subsamples. Emotional dissonance was positively related to WFC in both subsamples and was negatively related to WFE. Supervisory coaching was strongly, positively related to WFE in both groups, and only in the Male subsample presented a low negative relationship with WFC. Conclusion: This study contributes to the literature on new challenges in work-life interface by analyzing the association between off-TAJD and WFC and Enrichment. Our findings suggest it is important to pay attention to gender differences in the study of the impact of supplemental work carried out during off-work hours using technology on the work-life interface. In fact, employee perception of Company demands of being available during off-work time, with the use of technology, may have different consequences for men and women, indicating potential differences in the centrality of the working role. Practical implications, at both cultural and organizational levels, should address the use of technology during leisure time.

Light field rendering with omni-directional camera

NASA Astrophysics Data System (ADS)

Todoroki, Hiroshi; Saito, Hideo

2003-06-01

This paper presents an approach to capture visual appearance of a real environment such as an interior of a room. We propose the method for generating arbitrary viewpoint images by building light field with the omni-directional camera, which can capture the wide circumferences. Omni-directional camera used in this technique is a special camera with the hyperbolic mirror in the upper part of a camera, so that we can capture luminosity in the environment in the range of 360 degree of circumferences in one image. We apply the light field method, which is one technique of Image-Based-Rendering(IBR), for generating the arbitrary viewpoint images. The light field is a kind of the database that records the luminosity information in the object space. We employ the omni-directional camera for constructing the light field, so that we can collect many view direction images in the light field. Thus our method allows the user to explore the wide scene, that can acheive realistic representation of virtual enviroment. For demonstating the proposed method, we capture image sequence in our lab's interior environment with an omni-directional camera, and succesfully generate arbitray viewpoint images for virual tour of the environment.

Neptune's New Dark Vortex: Imaging with HST/WFC3

NASA Astrophysics Data System (ADS)

Wong, M. H.; Tollefson, J.; De Pater, I.; de Kleer, K.; Hammel, H. B.; Luszcz-Cook, S.; Hueso, R.; Sanchez-Lavega, A.; Simon, A. A.; Delcroix, M.; Sromovsky, L. A.; Fry, P. M.; Orton, G. S.; Baranec, C.

2016-12-01

A bright, unusually long-lived outburst of cloud activity on Neptune was observed in 2015 (Hueso et al. 2015, DPS 400.02). This led to speculation about whether the clouds were convective in nature, or bright companions to an unseen dark vortex (similar to the Great Dark Spot studied in detail by Voyager 2: Smith et al. 1989, Science 246, 1422). HST OPAL images at blue wavelengths finally answered this question by discovering a new dark vortex at 45 deg S. We call this feature SDS-2015, for "southern dark spot discovered in 2015" (Wong et al. 2016, CBET 4278). Dark vortices on Neptune are rare; SDS-2015 is only the fifth ever seen. All five were diverse in terms of size and shape, the distribution of bright companion clouds, and horizontal motions (oscillations and drifts). The drift of these vortices is highly sensitive to horizontal and vertical wind shear, making them valuable probes into the structure of Neptune's atmospheric jets. We will present imaging observations of SDS-2015 obtained with the WFC3/UVIS camera on the Hubble Space Telescope, covering the discovery of the vortex in September 2015 and follow-up observations in May 2016. No significant latitudinal drift was seen over this time span. We will compare size estimates, which are complicated by the continual presence of companion clouds, and by the low contrast between the vortex and its surroundings. The 2015 observations included 7 filters spanning 467-845 nm, weighted toward longer wavelengths to study general cloud motions and vertical distributions. The 2016 observations included 7 filters spanning 336-763 nm, weighted toward shorter wavelengths where the dark spot itself can be detected. A companion abstract (Tollefson et al., this meeting) will present results from radiative transfer modeling of the multispectral data. [This conference abstract is based on observations made with the NASA/ESA Hubble Space Telescope, associated with programs GO-13937 ("OPAL") and GO-14492.

Jupiter cloud morphology and zonal winds from ground-based observations before and during Juno exploration

NASA Astrophysics Data System (ADS)

Sanchez-Lavega, A.; Hueso, R.; Perez-Hoyos, S.; Iñurrigarro, P.; Mendikoa, I.; Rojas, J. F.

2016-12-01

We present the results of a long term campaign between September 2015 and August 2016 of imaging of Jupiter's cloud morphology and zonal winds in the 0.38 - 1.7 μm wavelength spectral range. We use PlanetCam lucky imaging camera at the 2.2m telescope at Calar Alto Observatory in Spain, and for the optical range, the contribution of a network of observers to the Planetary Virtual Observatory Laboratory database (PVOL-IOPW at http://pvol.ehu.eus). We have complemented the study with Hubble Space Telescope WFC3 camera images taken in the 0.275 - 0.89 μm wavelength spectral range during the OPAL program on 9 February 2016. The PlanetCam images have been calibrated in radiance using spectrophotometric standard stars providing absolute reflectivity across the disk in a large series of broadband and narrowband filters sensitive to the altitude distribution and size of aerosols above the ammonia cloud level, and to the spectral dependence of the chromophore coloring agents. The cloud morphology evolution has been studied with an horizontal resolution ranging from 150 to 1000 km. Zonal wind profiles have been retrieved along the whole observing period from tracking cloud motions that span the latitude range from -80° to +77º. Combining all these results we characterized the 3D-dynamical state and cloud and haze distribution in Jupiter's atmosphere in the altitude range between 10 mbar and 1.5 bar before and during Juno initial exploration.

Mapping Excitation in the Inner Regions of the Planetary Nebula NGC 5189 Using HST WFC3 Imaging

NASA Astrophysics Data System (ADS)

Danehkar, Ashkbiz; Karovska, Margarita; Maksym, W. Peter; Montez, Rodolfo, Jr.

2018-01-01

The planetary nebula (PN) NGC 5189 around a Wolf–Rayet [WO] central star demonstrates one of the most remarkable complex morphologies among PNe with many multiscale structures, showing evidence of multiple outbursts from an asymptotic giant branch (AGB) progenitor. In this study, we use multiwavelength Hubble Space Telescope Wide Field Camera 3 observations to study the morphology of the inner 0.3 pc × 0.2 pc region surrounding the central binary that appears to be a relic of a more recent outburst of the progenitor AGB star. We applied diagnostic diagrams based on emission-line ratios of Hα λ6563, [O III] λ5007, and [S II] λ λ 6716,6731 images to identify the location and morphology of low-ionization structures within the inner nebula. We distinguished two inner, low-ionization envelopes from the ionized gas, within a radius of 55 arcsec (∼0.15 pc) extending from the central star: a large envelope expanding toward the northeast, and its smaller counterpart envelope in the opposite direction toward the southwest of the nebula. These low-ionization envelopes are surrounded by a highly ionized gaseous environment. We believe that these low-ionization expanding envelopes are a result of a powerful outburst from the post-AGB star that created shocked wind regions as they propagate through the previously expelled material along a symmetric axis. Our diagnostic mapping using high-angular resolution line-emission imaging can provide a novel approach to detection of low-ionization regions in other PNe, especially those showing a complex multiscale morphology.

NASA's Hubble Shows Jupiter's Great Red Spot is Smaller than Ever

NASA Image and Video Library

2014-05-15

This full-disc image of Jupiter was taken on 21 April 2014 with Hubble's Wide Field Camera 3 (WFC3). -- Jupiter's trademark Great Red Spot -- a swirling anti-cyclonic storm larger than Earth -- has shrunk to its smallest size ever measured. According to Amy Simon of NASA's Goddard Space Flight Center in Greenbelt, Maryland, recent NASA Hubble Space Telescope observations confirm the Great Red Spot now is approximately 10,250 miles across. Astronomers have followed this downsizing since the 1930s. Historic observations as far back as the late 1800s gauged the storm to be as large as 25,500 miles on its long axis. NASA Voyager 1 and Voyager 2 flybys of Jupiter in 1979 measured it to be 14,500 miles across. In 1995, a Hubble photo showed the long axis of the spot at an estimated 13,020 miles across. And in a 2009 photo, it was measured at 11,130 miles across. Beginning in 2012, amateur observations revealed a noticeable increase in the rate at which the spot is shrinking -- by 580 miles per year -- changing its shape from an oval to a circle. Read more: 1.usa.gov/1mvuo0R Credit: NASA/ESA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Global Observations of Aerosols and Clouds from Combined Lidar and Passive Instruments to Improve Radiation Budget and Climate Studies

NASA Technical Reports Server (NTRS)

Winker, David M.

1999-01-01

Current uncertainties in the effects of clouds and aerosols on the Earth radiation budget limit our understanding of the climate system and the potential for global climate change. Pathfinder Instruments for Cloud and Aerosol Spaceborne Observations - Climatologie Etendue des Nuages et des Aerosols (PICASSO-CENA) is a recently approved satellite mission within NASA's Earth System Science Pathfinder (ESSP) program which will address these uncertainties with a unique suite of active and passive instruments. The Lidar In-space Technology Experiment (LITE) demonstrated the potential benefits of space lidar for studies of clouds and aerosols. PICASSO-CENA builds on this experience with a payload consisting of a two-wavelength polarization-sensitive lidar, an oxygen A-band spectrometer (ABS), an imaging infrared radiometer (IIR), and a wide field camera (WFC). Data from these instruments will be used to measure the vertical distributions of aerosols and clouds in the atmosphere, as well as optical and physical properties of aerosols and clouds which influence the Earth radiation budget. PICASSO-CENA will be flown in formation with the PM satellite of the NASA Earth Observing System (EOS) to provide a comprehensive suite of coincident measurements of atmospheric state, aerosol and cloud optical properties, and radiative fluxes. The mission will address critical uncertainties iin the direct radiative forcing of aerosols and clouds as well as aerosol influences on cloud radiative properties and cloud-climate radiation feedbacks. PICASSO-CENA is planned for a three year mission, with a launch in early 2003. PICASSO-CENA is being developed within the framework of a collaboration between NASA and CNES.

Revealing the Host Galaxy of a Quasar 2175 Å Dust Absorber at z =  2.12

NASA Astrophysics Data System (ADS)

Ma, Jingzhe; Brammer, Gabriel; Ge, Jian; Prochaska, J. Xavier; Lundgren, Britt

2018-04-01

We report the first detection of the host galaxy of a strong 2175 Å dust absorber at z = 2.12 toward the background quasar SDSS J121143.42+083349.7 using Hubble Space Telescope/Wide Field Camera 3 (HST/WFC3) IR F140W direct imaging and G141 grism spectroscopy. The spectroscopically confirmed host galaxy is located at a small impact parameter of ∼5.5 kpc (∼0.″65). The F140W image reveals a disk-like morphology with an effective radius of 2.24 ± 0.08 kpc. The extracted 1D spectrum is dominated by a continuum with weak emission lines ([O III] and [O II]). The [O III]-based unobscured star formation rate (SFR) is 9.4 ± 2.6 M ⊙ yr‑1, assuming an [O III]/Hα ratio of 1. The moderate 4000 Å break (Dn(4000) index ∼1.3) and Balmer absorption lines indicate that the host galaxy contains an evolved stellar population with an estimated stellar mass M * of (3–7) × 1010 M ⊙. The SFR and M * of the host galaxy are comparable to, though slightly lower than, those of typical emission-selected galaxies at z ∼ 2. As inferred from our absorption analysis in Ma et al., the host galaxy is confirmed to be a chemically enriched, evolved, massive, and star-forming disk-like galaxy that is likely in the transition from a blue star-forming galaxy to a red quiescent galaxy.

Work-family conflict as a mediator in the association between work stress and depressive symptoms: cross-sectional evidence from the German lidA-cohort study.

PubMed

du Prel, Jean-Baptist; Peter, Richard

2015-04-01

The demographic change leads to a shrinking German work force. Depressive symptoms cause many days absent at work, loss of productivity and early retirement. Therefore, pathways for prevention of depressive symptoms are important for the maintenance of global competitiveness. We investigated the role of work-family conflict (WFC) in the well-known association between work stress and depressive symptoms. A total of 6,339 employees subject to social insurance, born in 1959 or 1965 and randomly drawn from 222 sample points in Germany participated in the first wave of the leben in der Arbeit-study. In the analysis, 5,906 study subjects working in full-time or part-time positions were included. Work stress was measured by effort-reward imbalance ratio, depressive symptoms by the applied Becks depression inventory (BDI-V) and WFC by items of the Copenhagen Psychosocial Questionnaire (COPSOQ)-scale. Multiple linear regression analysis adjusted for age, education, negative affectivity (PANAS), overcommitment and number of children was performed. Mediation was defined according to the criteria of Baron and Kenny. Work stress was significantly associated with depressive symptoms (BDI-V) in all full-time [ß1female = 6.61 (95 % CI 3.95-9.27); ß1male = 8.02 (95 % CI 5.94-10.09)] and female part-time employees [ß2female = 4.87 (95 % CI 2.16-7.59)]. When controlling for WFC effect, estimates became smaller in men and were even halved in women. WFC was also significantly associated with work stress and depressive symptoms: All criteria for partial mediation between work stress and depressiveness were fulfilled. Prevention of WFC may help to reduce days absent at work and early retirement due to work stress-related depressive symptoms in middle-aged women and men.

NONLINEAR COLOR-METALLICITY RELATIONS OF GLOBULAR CLUSTERS. III. ON THE DISCREPANCY IN METALLICITY BETWEEN GLOBULAR CLUSTER SYSTEMS AND THEIR PARENT ELLIPTICAL GALAXIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoon, Suk-Jin; Lee, Sang-Yoon; Cho, Jaeil

2011-12-20

One of the conundrums in extragalactic astronomy is the discrepancy in observed metallicity distribution functions (MDFs) between the two prime stellar components of early-type galaxies-globular clusters (GCs) and halo field stars. This is generally taken as evidence of highly decoupled evolutionary histories between GC systems and their parent galaxies. Here we show, however, that new developments in linking the observed GC colors to their intrinsic metallicities suggest nonlinear color-to-metallicity conversions, which translate observed color distributions into strongly peaked, unimodal MDFs with broad metal-poor tails. Remarkably, the inferred GC MDFs are similar to the MDFs of resolved field stars in nearbymore » elliptical galaxies and those produced by chemical evolution models of galaxies. The GC MDF shape, characterized by a sharp peak with a metal-poor tail, indicates a virtually continuous chemical enrichment with a relatively short timescale. The characteristic shape emerges across three orders of magnitude in the host galaxy mass, suggesting a universal process of chemical enrichment among various GC systems. Given that GCs are bluer than field stars within the same galaxy, it is plausible that the chemical enrichment processes of GCs ceased somewhat earlier than that of the field stellar population, and if so, GCs preferentially trace the major, vigorous mode of star formation events in galactic formation. We further suggest a possible systematic age difference among GC systems, in that the GC systems in more luminous galaxies are older. This is consistent with the downsizing paradigm whereby stars of brighter galaxies, on average, formed earlier than those of dimmer galaxies; this additionally supports the similar nature shared by GCs and field stars. Although the sample used in this study (the Hubble Space Telescope Advanced Camera for Surveys/Wide Field Channel, WFPC2, and WFC3 photometry for the GC systems in the Virgo galaxy cluster) confines our discussion to R {approx}< R{sub e} for giant ellipticals and {approx}<10 R{sub e} for normal ellipticals, our findings suggest that GC systems and their parent galaxies have shared a more common origin than previously thought, and hence greatly simplify theories of galaxy formation.« less

Space telescope phase B definition study. Volume 2A: Science instruments, f24 field camera

NASA Technical Reports Server (NTRS)

Grosso, R. P.; Mccarthy, D. J.

1976-01-01

The analysis and design of the F/24 field camera for the space telescope are discussed. The camera was designed for application to the radial bay of the optical telescope assembly and has an on axis field of view of 3 arc-minutes by 3 arc-minutes.

Updates to WFC3/UVIS Filter-Dependent and Filter-Distinct Distortion Corrections

NASA Astrophysics Data System (ADS)

Martlin, Catherine; Kozhurina-Platais, Vera; McKay, Myles; Sabbi, Elena

2018-06-01

The WFC3/UVIS filter wheel contains 63 filters that cover a large range of wavelengths from near ultraviolet to the near infrared. Previously, analysis was completed on the 14 most used UVIS filters to calibrate geometric distortions. These distortions are due to a combination of the optical assembly of HST as well as the variabilities in the composition of individual filters. We report recent updates to reference files that aid in correcting for these distortions of an additional 22 UVIS narrow and medium band filters and 4 unique UVIS filters. They were created following a calibration of the large-scale optical distortions and fine-scale filter-dependent distortions. Furthermore, we present results on a study into a selection of unique polynomial coefficient terms from all solved filters which allows us to better investigate the filter-dependent patterns across a large range of wavelengths.These updates will provide important enhancements for HST/WFC3 users as they allow more accurate alignment of images across the range of UVIS filters.

WFC3 Micro-arcsecond astrometry of the possible SNIa progenitor BPM 71214

NASA Astrophysics Data System (ADS)

Debes, John

2012-10-01

We propose to use the newly commissioned scanning mode on WFC3 to obtain astrometric measurements of the ~0.008 AU WD/M dwarf binary BPM 71214. This system is a fascinating mystery for post-common envelope binary evolution and may be a SN1a progenitor. COS spectra of the WD in the system shows that it is rapidly rotating with a vsin i of 200 km/s, implying that it has already accreted significant mass from its companion, but mass transfer has since stopped. The COS spectra imply a near Chandrasekar mass for the WD, while optical spectroscopy suggests a mass of 0.8 M_Sun. We propose to take four orbits of WFC3 observations in scanning mode to obtain astrometric measurements of this system at a per-measurement precision of ~30~micro-arcseconds. Such measurements will definitively constrain the mass of the WD and fully solve for both masses in the binary.

Imaging and image restoration of an on-axis three-mirror Cassegrain system with wavefront coding technology.

PubMed

Guo, Xiaohu; Dong, Liquan; Zhao, Yuejin; Jia, Wei; Kong, Lingqin; Wu, Yijian; Li, Bing

2015-04-01

Wavefront coding (WFC) technology is adopted in the space optical system to resolve the problem of defocus caused by temperature difference or vibration of satellite motion. According to the theory of WFC, we calculate and optimize the phase mask parameter of the cubic phase mask plate, which is used in an on-axis three-mirror Cassegrain (TMC) telescope system. The simulation analysis and the experimental results indicate that the defocused modulation transfer function curves and the corresponding blurred images have a perfect consistency in the range of 10 times the depth of focus (DOF) of the original TMC system. After digital image processing by a Wiener filter, the spatial resolution of the restored images is up to 57.14 line pairs/mm. The results demonstrate that the WFC technology in the TMC system has superior performance in extending the DOF and less sensitivity to defocus, which has great value in resolving the problem of defocus in the space optical system.

Shock Energy in Merging Systems: The Elephant in the Room.

NASA Astrophysics Data System (ADS)

Kewley, Lisa

2011-10-01

The relationship between shocks, star formation and the evolution of merging galaxies is not well understood. We are now poised to gain major insight in this area, thanks to the high resolution narrow-band imaging capabilities of WFC3 and recent major advances in theoretical shock and and photoionization models. Shocks and star formation in merging galaxies are regulated by fundamental physical properties of the ISM such as dust, gas density, ionized gas structure, and the presence of galactic winds and outflows. We aim to uncover the relationship between shocks, galactic winds, and the fundamental ISM properties in two famous mergers NGC 6240 and Arp 220. These two galaxies are currently transitioning from disk galaxies into spheroids and they are close enough to achieve the spatial scales required to resolve individual supernova remnants with WFC3 imaging. We propose to image NGC 6240 and Arp 220 in key shock and photoionization sensitive diagnostic lines [OII], [OIII], H-beta, [NII]+H-alpha, [SII], and {where possible} [OI] to {1} resolve the source of the ionizing radiation field {shocks versus photoionization by hot stars} at spatial scales of 25-35 pc, and {2} map the distribution of the star formation and ionized gas to search for links with merger-driven shocks and large-scale gas flows.

Measuring Low Mass Galaxies In The WFC3 Infrared Spectroscopic Parallels Survey

NASA Astrophysics Data System (ADS)

Colbert, James; Teplitz, Harry; Scarlata, Claudia; Siana, Brian; Malkan, Matt; McCarthy, Patrick; Henry, Alaina; Atek, Hakim; Fosbury, Robert; Ross, Nathanial; Hathi, Nimish; Bridge, Carrie; Bunker, Andrew; Dressler, Alan; Shim, Hyunjin; Bedregal, Alejandro; Dominguez, Alberto; Rafelski, Marc; Masters, Dan; Martin, Crystal; Dai, Sophia

2015-10-01

The WFC3 Infrared Spectroscopic Parallel (WISP) Survey uses over 1800 HST orbits to study galaxy evolution over a majority of cosmic history. Its slitless grism spectroscopy over a wide, continuous spectral range (0.8-1.7 micron) provides an unbiased selection of thousands of emission line galaxies over 0.5 < z < 2.5. Hundreds of these galaxies are detected in multiple emission lines, allowing for important diagnostics of metallicity and dust extinction. We propose deep 3.6 micron imaging (5 sigma, 0.9 micro-Jy) of 60 of the deepest WISP fields observed with the combination of G102+G141 grisms, in order to detect emission-line galaxies down to 0.1 L* and masses below 10^8 Mo. Combined with our HST optical and near-IR photometry, these IRAC data will be critical to determining accurate stellar masses for both passive and active galaxies in our survey. We will determine the evolution of the faint end slope of the stellar mass function and the mass-metallicity relation down to low-mass galaxies. The addition of the IRAC photometry will also provide much stronger constraints on dust extinction and star formation history, especially when combined with information available from the emission lines themselves.

The Hubble Legacy Archive: Data Processing in the Era of AstroDrizzle

NASA Astrophysics Data System (ADS)

Strolger, Louis-Gregory; Hubble Legacy Archive Team, The Hubble Source Catalog Team

2015-01-01

The Hubble Legacy Archive (HLA) expands the utility of Hubble Space Telescope wide-field imaging data by providing high-level composite images and source lists, perusable and immediately available online. The latest HLA data release (DR8.0) marks a fundamental change in how these image combinations are produced, using DrizzlePac tools and Astrodrizzle to reduce geometric distortion and provide improved source catalogs for all publicly available data. We detail the HLA data processing and source list schemas, what products are newly updated and available for WFC3 and ACS, and how these data products are further utilized in the production of the Hubble Source Catalog. We also discuss plans for future development, including updates to WFPC2 products and field mosaics.

VizieR Online Data Catalog: GLASS. IX. Structural param. from HFF & GLASS (Morishita+, 2017)

NASA Astrophysics Data System (ADS)

Morishita, T.; Abramson, L. E.; Treu, T.; Vulcani, B.; Schmidt, K. B.; Dressler, A.; Poggianti, B. M.; Malkan, M. A.; Wang, X.; Huang, K.-H.; Trenti, M.; Bradac, M.; Hoag, A.

2017-09-01

We base our analysis on Hubble Frontier Fields (HFF; Lotz+ 2017ApJ...837...97L) imaging and Grism Survey from Space (GLASS; Schmidt+ 2014ApJ...782L..36S; Treu+, 2015, J/ApJ/812/114) HST spectroscopy for the first four HFF clusters with complete data: Abell2744 (z=0.308), MACS0416 (0.396), MACS0717 (0.548), and MACS1149 (0.544). HFF imaging spans ACS F435/606/814W through WFC3IR F105/125/140/160W filters (seven bands). Our final catalog consists of 3948 galaxies, with 2200 in clusters and 1748 in field environments. A total of 298 have ground-based and 168 have GLASS spectroscopic redshifts. (1 data file).

Relating transverse ray error and light fields in plenoptic camera images

NASA Astrophysics Data System (ADS)

Schwiegerling, Jim; Tyo, J. Scott

2013-09-01

Plenoptic cameras have emerged in recent years as a technology for capturing light field data in a single snapshot. A conventional digital camera can be modified with the addition of a lenslet array to create a plenoptic camera. The camera image is focused onto the lenslet array. The lenslet array is placed over the camera sensor such that each lenslet forms an image of the exit pupil onto the sensor. The resultant image is an array of circular exit pupil images, each corresponding to the overlying lenslet. The position of the lenslet encodes the spatial information of the scene, whereas as the sensor pixels encode the angular information for light incident on the lenslet. The 4D light field is therefore described by the 2D spatial information and 2D angular information captured by the plenoptic camera. In aberration theory, the transverse ray error relates the pupil coordinates of a given ray to its deviation from the ideal image point in the image plane and is consequently a 4D function as well. We demonstrate a technique for modifying the traditional transverse ray error equations to recover the 4D light field of a general scene. In the case of a well corrected optical system, this light field is easily related to the depth of various objects in the scene. Finally, the effects of sampling with both the lenslet array and the camera sensor on the 4D light field data are analyzed to illustrate the limitations of such systems.

VizieR Online Data Catalog: Bgri light curves of PTF11kmb and PTF12bho (Lunnan+, 2017)

NASA Astrophysics Data System (ADS)

Lunnan, R.; Kasliwal, M. M.; Cao, Y.; Hangard, L.; Yaron, O.; Parrent, J. T.; McCully, C.; Gal-Yam, A.; Mulchaey, J. S.; Ben-Ami, S.; Filippenko, A. V.; Fremling, C.; Fruchter, A. S.; Howell, D. A.; Koda, J.; Kupfer, T.; Kulkarni, S. R.; Laher, R.; Masci, F.; Nugent, P. E.; Ofek, E. O.; Yagi, M.; Yan, L.

2017-09-01

The objects PTF11kmb and PTF12bho were found as part of the Palomar Transient Factory (PTF). PTF11kmb was discovered in data taken with the 48 inch Samuel Oschin Telescope at Palomar Observatory (P48) on 2011 August 16.25 at a magnitude r=19.8mag. A spectrum was taken with the Low Resolution Imaging Spectrometer (LRIS) on the 10m Keck I telescope on 2011 August 28, showing SN features consistent with a SN Ib at a redshift z=0.017. The source PTF12bho was discovered in P48 data on 2012 February 25.25 at a magnitude of r=20.52mag. A spectrum taken with LRIS on 2012 March 15 yields z=0.023 based on the SN features. We obtained R- and g-band photometry of PTF11kmb and PTF12bho with the P48 CFH12K camera. Additional follow-up photometry was conducted with the automated 60-inch telescope at Palomar (P60) in the Bgri bands, and with the Las Cumbres Observatory (LCO) Faulkes Telescope North in gri. PTF12bho was also observed with the Swift Ultra-Violet/Optical Telescope (UVOT) and the Swift X-ray telescope (XRT) on 2012 March 17.8 for 3ks. We obtained a sequence of spectra for both PTF11kmb and PTF12bho using LRIS on Keck I, the DEep Imaging Multi-Object Spectrograph (DEIMOS) on the 10m Keck II telescope, and the Double Spectrograph (DPSP) on the 200-inch Hale telescope at Palomar Observatory (P200) spanning 2011 Aug 28.5 to 2014 Jul 2.5. We obtained deep imaging of the fields of PTF11kmb using WFC3/UVIS on the Hubble Space Telescope (HST) through program GO-13864 (PI Kasliwal) in 2015 Jul 12. This program also covered the field of SN 2005E (2014 Dec 10). (1 data file).

The HDUV Survey: Six Lyman Continuum Emitter Candidates at z ˜ 2 Revealed by HST UV Imaging

NASA Astrophysics Data System (ADS)

Naidu, R. P.; Oesch, P. A.; Reddy, N.; Holden, B.; Steidel, C. C.; Montes, M.; Atek, H.; Bouwens, R. J.; Carollo, C. M.; Cibinel, A.; Illingworth, G. D.; Labbé, I.; Magee, D.; Morselli, L.; Nelson, E. J.; van Dokkum, P. G.; Wilkins, S.

2017-09-01

We present six galaxies at z˜ 2 that show evidence of Lyman continuum (LyC) emission based on the newly acquired UV imaging of the Hubble Deep UV legacy survey (HDUV) conducted with the WFC3/UVIS camera on the Hubble Space Telescope (HST). At the redshift of these sources, the HDUV F275W images partially probe the ionizing continuum. By exploiting the HST multiwavelength data available in the HDUV/GOODS fields, models of the UV spectral energy distributions, and detailed Monte Carlo simulations of the intergalactic medium absorption, we estimate the absolute ionizing photon escape fractions of these galaxies to be very high—typically > 60 % (> 13 % for all sources at 90% likelihood). Our findings are in broad agreement with previous studies that found only a small fraction of galaxies with high escape fraction. These six galaxies compose the largest sample yet of LyC leaking candidates at z˜ 2 whose inferred LyC flux has been observed at HST resolution. While three of our six candidates show evidence of hosting an active galactic nucleus, two of these are heavily obscured and their LyC emission appears to originate from star-forming regions rather than the central nucleus. Extensive multiwavelength data in the GOODS fields, especially the near-IR grism spectra from the 3D-HST survey, enable us to study the candidates in detail and tentatively test some recently proposed indirect methods to probe LyC leakage. High-resolution spectroscopic follow-up of our candidates will help constrain such indirect methods, which are our only hope of studying f esc at z˜ 5-9 in the JWST era. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

Improving accuracy of Plenoptic PIV using two light field cameras

NASA Astrophysics Data System (ADS)

Thurow, Brian; Fahringer, Timothy

2017-11-01

Plenoptic particle image velocimetry (PIV) has recently emerged as a viable technique for acquiring three-dimensional, three-component velocity field data using a single plenoptic, or light field, camera. The simplified experimental arrangement is advantageous in situations where optical access is limited and/or it is not possible to set-up the four or more cameras typically required in a tomographic PIV experiment. A significant disadvantage of a single camera plenoptic PIV experiment, however, is that the accuracy of the velocity measurement along the optical axis of the camera is significantly worse than in the two lateral directions. In this work, we explore the accuracy of plenoptic PIV when two plenoptic cameras are arranged in a stereo imaging configuration. It is found that the addition of a 2nd camera improves the accuracy in all three directions and nearly eliminates any differences between them. This improvement is illustrated using both synthetic and real experiments conducted on a vortex ring using both one and two plenoptic cameras.

VizieR Online Data Catalog: WASP-31b:HST/Spitzer transmission spectral survey (Sing+, 2015)

NASA Astrophysics Data System (ADS)

Sing, D. K.; Wakeford, H. R.; Showman, A. P.; Nikolov, N.; Fortney, J. J.; Burrows, A. S.; Ballester, G. E.; Deming, D.; Aigrain, S.; Desert, J.-M.; Gibson, N. P.; Henry, G. W.; Knutson, H.; Lecavelier Des Etangs, A.; Pont, F.; Vidal-Madjar, A.; Williamson, M. W.; Wilson, P. A.

2017-11-01

We observed two transits of WASP-31b with the HST STIS G430L grating during 2012 June 13 and 26, as well as one transit with the STIS G750L during 2012 July 10. In addition to the STIS data, observations of WASP-31b were also conducted in the infrared with WFC3 on the HST. Observations began on 2012 May 13 at 12:53 using the IR G141 grism in forward spatial scan mode over five HST orbits. We analyse two transit observations obtained using the Infrared Array Camera (IRAC) instrument (Programme 90092 with P.I. Desert) on the Spitzer space telescope in the 3.6 μm and 4.5 μm channels in subarray mode (32x32 pixel, or 39 centred on the planets host). The 3.6 μm observation was performed on UT 2013 March 9 (between 06:59 and 11:37) and the 4.5 observation was performed on UT 2013 March 19 (between 12:19 and 16:58). (1 data file).

The Globular Cluster System of the Coma cD Galaxy NGC 4874 from Hubble Space Telescope ACS and WFC3/IR Imaging

NASA Astrophysics Data System (ADS)

Cho, Hyejeon; Blakeslee, John P.; Chies-Santos, Ana L.; Jee, M. James; Jensen, Joseph B.; Peng, Eric W.; Lee, Young-Wook

2016-05-01

We present new Hubble Space Telescope (HST) optical and near-infrared (NIR) photometry of the rich globular cluster (GC) system NGC 4874, the cD galaxy in the core of the Coma cluster (Abell 1656). NGC 4874 was observed with the HST Advanced Camera for Surveys in the F475W (g 475) and F814W (I 814) passbands and with the Wide Field Camera 3 IR Channel in F160W (H 160). The GCs in this field exhibit a bimodal optical color distribution with more than half of the GCs falling on the red side at g 475-I 814 > 1. Bimodality is also present, though less conspicuously, in the optical-NIR I 814-H 160 color. Consistent with past work, we find evidence for nonlinearity in the g 475-I 814 versus I 814-H 160 color-color relation. Our results thus underscore the need for understanding the detailed form of the color-metallicity relations in interpreting observational data on GC bimodality. We also find a very strong color-magnitude trend, or “blue tilt,” for the blue component of the optical color distribution of the NGC 4874 GC system. A similarly strong trend is present for the overall mean I 814-H 160 color as a function of magnitude; for M 814 < -10 mag, these trends imply a steep mass-metallicity scaling with Z\\propto {M}{{GC}}1.4+/- 0.4, but the scaling is not a simple power law and becomes much weaker at lower masses. As in other similar systems, the spatial distribution of the blue GCs is more extended than that of the red GCs, partly because of blue GCs associated with surrounding cluster galaxies. In addition, the center of the GC system is displaced by 4 ± 1 kpc toward the southwest from the luminosity center of NGC 4874, in the direction of NGC 4872. Finally, we remark on a dwarf elliptical galaxy with a noticeably asymmetrical GC distribution. Interestingly, this dwarf has a velocity of nearly -3000 km s-1 with respect to NGC 4874; we suggest it is on its first infall into the cluster core and is undergoing stripping of its GC system by the cluster potential. Based on observations with the NASA/ESA Hubble Space Telescope, obtained from the Space Telescope Science Institute (STScI), which is operated by AURA, Inc., under NASA contract NAS 5-26555. These observations are associated with program #11712.

Infrared Color Selection of Massive Galaxies at z > 3

NASA Astrophysics Data System (ADS)

Wang, T.; Elbaz, D.; Schreiber, C.; Pannella, M.; Shu, X.; Willner, S. P.; Ashby, M. L. N.; Huang, J.-S.; Fontana, A.; Dekel, A.; Daddi, E.; Ferguson, H. C.; Dunlop, J.; Ciesla, L.; Koekemoer, A. M.; Giavalisco, M.; Boutsia, K.; Finkelstein, S.; Juneau, S.; Barro, G.; Koo, D. C.; Michałowski, M. J.; Orellana, G.; Lu, Y.; Castellano, M.; Bourne, N.; Buitrago, F.; Santini, P.; Faber, S. M.; Hathi, N.; Lucas, R. A.; Pérez-González, P. G.

2016-01-01

We introduce a new color selection technique to identify high-redshift, massive galaxies that are systematically missed by Lyman-break selection. The new selection is based on the H160 (H) and Infrared Array Camera (IRAC) 4.5 μm bands, specifically H-[4.5]\\gt 2.25 mag. These galaxies, called “HIEROs,” include two major populations that can be separated with an additional J - H color. The populations are massive and dusty star-forming galaxies at z\\gt 3 ({JH}-{blue}) and extremely dusty galaxies at z≲ 3 ({JH}-{red}). The 350 arcmin2 of the GOODS-North and GOODS-South fields with the deepest Hubble Space Telescope (HST)/Wide Field Camera 3 (WFC3) near-infrared and IRAC data contain as many as 285 HIEROs down to [4.5]\\lt 24 mag. Inclusion of the most extreme HIEROs, not even detected in the H band, makes this selection particularly complete for the identification of massive high-redshift galaxies. We focus here primarily on {JH}-{blue} (z\\gt 3) HIEROs, which have a median photometric redshift < z> ˜ 4.4 and stellar mass {M}*˜ {10}10.6 {M}⊙ and are much fainter in the rest-frame UV than similarly massive Lyman-break galaxies (LBGs). Their star formation rates (SFRs), derived from their stacked infrared spectral energy distributions (SEDs), reach ˜240 {M}⊙ yr-1, leading to a specific SFR, {{sSFR}}\\equiv {{SFR}}/{M}*˜ 4.2 Gyr-1, suggesting that the sSFRs for massive galaxies continue to grow at z\\gt 2 but at a lower growth rate than from z = 0 to z = 2. With a median half-light radius of 2 kpc, including ˜ 20% as compact as quiescent (QS) galaxies at similar redshifts, {JH}-{blue} HIEROs represent perfect star-forming progenitors of the most massive ({M}*≳ {10}11.2 {M}⊙ ) compact QS galaxies at z˜ 3 and have the right number density. HIEROs make up ˜ 60% of all galaxies with {M}*\\gt {10}10.5 {M}⊙ identified at z\\gt 3 from their photometric redshifts. This is five times more than LBGs with nearly no overlap between the two populations. While HIEROs make up 15%-25% of the total SFR density at z˜ 4-5, they completely dominate the SFR density taking place in {M}*\\gt {10}10.5 {M}⊙ galaxies, and HIEROs are therefore crucial to understanding the very early phase of massive galaxy formation.

Completing the Legacy of Hubble's Wide/Deep Fields: An Aligned Complete Dataset of 1220 Orbits on the GOODS-N/CANDELS-N Region

NASA Astrophysics Data System (ADS)

Illingworth, Garth

2017-08-01

The GOODS-N/CANDELS-N region is second only to the GOODS-S/ECDF-S region in the extent of its HST and Spitzer coverage, making it a remarkable science resource. Yet of 1220 orbits of ACS and WFC3/IR imaging from 27 programs on the GOODS-N region, fully 42% of the total, about 520 orbits of imaging data from 22 programs, remains unavailable in MAST as a high-level science data product (HLSP). The GOODS-N region dataset is a key Legacy field ( 3 Msec from HST, 6 Msec from Spitzer, and 2 Msec from Chandra). We propose to deliver, with catalogs, HST ACS and WFC3/IR HLSPs to MAST for all 1220 orbits of GOODS-N data. We will also deliver HLSPs for the EGS, UDS and the COSMOS CANDELS regions, including new data not included to date. These four HLSPs, 2300 orbits of HST data ( 75% of a HST Cycle ), will add substantially to (1) our understanding of the build-up of galaxies to z 6 in the first Gyr during reionization, (2) the development of galaxies over the subsequent Gyr to the peak of the star formation rate in the universe at z 2-3, and (3) the transition at z<2 of early star-forming galaxies to the full splendor of the Hubble sequence. We can do this major AR Legacy program, having submitted a HLSP of ALL 2442 orbits of HST data on the GOODS- S region (>950 orbits new). The total volume of data in the GOODS-S Hubble Legacy Field (HLF-GOODS-S) is 5.8 Msec in 7211 exposures ( 70% of a HST cycle). The HLF-GOODS-S includes 4 new deep areas akin to the HUDF/XDF. The four proposed NEW Hubble Legacy Field datasets will complement the Frontier Field datasets and our recent HLF-GOODS-S and HUDF/XDF HLSP submissions. They will be cornerstones of Hubble's Legacy as the JWST era dawns.

The Hubble Space Telescope Frontier Fields Program

NASA Astrophysics Data System (ADS)

Koekemoer, Anton M.; Mack, Jennifer; Lotz, Jennifer M.; Borncamp, David; Khandrika, Harish G.; Lucas, Ray A.; Martlin, Catherine; Porterfield, Blair; Sunnquist, Ben; Anderson, Jay; Avila, Roberto J.; Barker, Elizabeth A.; Grogin, Norman A.; Gunning, Heather C.; Hilbert, Bryan; Ogaz, Sara; Robberto, Massimo; Sembach, Kenneth; Flanagan, Kathryn; Mountain, Matt

2017-08-01

The Hubble Space Telescope Frontier Fields program is a large Director's Discretionary program of 840 orbits, to obtain ultra-deep observations of six strong lensing clusters of galaxies, together with parallel deep blank fields, making use of the strong lensing amplification by these clusters of distant background galaxies to detect the faintest galaxies currently observable in the high-redshift universe. The entire program has now completed successfully for all 6 clusters, namely Abell 2744, Abell S1063, Abell 370, MACS J0416.1-2403, MACS J0717.5+3745 and MACS J1149.5+2223,. Each of these was observed over two epochs, to a total depth of 140 orbits on the main cluster and an associated parallel field, obtaining images in ACS (F435W, F606W, F814W) and WFC3/IR (F105W, F125W, F140W, F160W) on both the main cluster and the parallel field in all cases. Full sets of high-level science products have been generated for all these clusters by the team at STScI, including cumulative-depth data releases during each epoch, as well as full-depth releases after the completion of each epoch. These products include all the full-depth distortion-corrected drizzled mosaics and associated products for each cluster, which are science-ready to facilitate the construction of lensing models as well as enabling a wide range of other science projects. Many improvements beyond default calibration for ACS and WFC3/IR are implemented in these data products, including corrections for persistence, time-variable sky, and low-level dark current residuals, as well as improvements in astrometric alignment to achieve milliarcsecond-level accuracy. The full set of resulting high-level science products and mosaics are publicly delivered to the community via the Mikulski Archive for Space Telescopes (MAST) to enable the widest scientific use of these data, as well as ensuring a public legacy dataset of the highest possible quality that is of lasting value to the entire community.

The HST Frontier Fields: Complete High-Level Science Data Products for All 6 Clusters

NASA Astrophysics Data System (ADS)

Koekemoer, Anton M.; Mack, Jennifer; Lotz, Jennifer M.; Borncamp, David; Khandrika, Harish G.; Lucas, Ray A.; Martlin, Catherine; Porterfield, Blair; Sunnquist, Ben; Anderson, Jay; Avila, Roberto J.; Barker, Elizabeth A.; Grogin, Norman A.; Gunning, Heather C.; Hilbert, Bryan; Ogaz, Sara; Robberto, Massimo; Sembach, Kenneth; Flanagan, Kathryn; Mountain, Matt; HST Frontier Fields Team

2017-01-01

The Hubble Space Telescope Frontier Fields program (PI: J. Lotz) is a large Director's Discretionary program of 840 orbits, to obtain ultra-deep observations of six strong lensing clusters of galaxies, together with parallel deep blank fields, making use of the strong lensing amplification by these clusters of distant background galaxies to detect the faintest galaxies currently observable in the high-redshift universe. The entire program has now completed successfully for all 6 clusters, namely Abell 2744, Abell S1063, Abell 370, MACS J0416.1-2403, MACS J0717.5+3745 and MACS J1149.5+2223,. Each of these was observed over two epochs, to a total depth of 140 orbits on the main cluster and an associated parallel field, obtaining images in ACS (F435W, F606W, F814W) and WFC3/IR (F105W, F125W, F140W, F160W) on both the main cluster and the parallel field in all cases. Full sets of high-level science products have been generated for all these clusters by the team at STScI, including cumulative-depth data releases during each epoch, as well as full-depth releases after the completion of each epoch. These products include all the full-depth distortion-corrected drizzled mosaics and associated products for each cluster, which are science-ready to facilitate the construction of lensing models as well as enabling a wide range of other science projects. Many improvements beyond default calibration for ACS and WFC3/IR are implemented in these data products, including corrections for persistence, time-variable sky, and low-level dark current residuals, as well as improvements in astrometric alignment to achieve milliarcsecond-level accuracy. The full set of resulting high-level science products and mosaics are publicly delivered to the community via the Mikulski Archive for Space Telescopes (MAST) to enable the widest scientific use of these data, as well as ensuring a public legacy dataset of the highest possible quality that is of lasting value to the entire community.

The HST Frontier Fields: Complete Observations and High-Level Science Data Products for All 6 Clusters

NASA Astrophysics Data System (ADS)

Koekemoer, Anton M.; Mack, Jennifer; Lotz, Jennifer M.; Borncamp, David; Khandrika, Harish G.; Lucas, Ray A.; Martlin, Catherine; Martlin, Catherine; Porterfield, Blair; Sunnquist, Ben; Anderson, Jay; Avila, Roberto J.; Barker, Elizabeth A.; Grogin, Norman A.; Gunning, Heather C.; Hilbert, Bryan; Ogaz, Sara; Robberto, Massimo; Sembach, Kenneth; Flanagan, Kathryn; Mountain, Matt; HST Frontier Fields Team

2017-06-01

The Hubble Space Telescope Frontier Fields program is a large Director's Discretionary program of 840 orbits, to obtain ultra-deep observations of six strong lensing clusters of galaxies, together with parallel deep blank fields, making use of the strong lensing amplification by these clusters of distant background galaxies to detect the faintest galaxies currently observable in the high-redshift universe. The entire program has now completed successfully for all 6 clusters, namely Abell 2744, Abell S1063, Abell 370, MACS J0416.1-2403, MACS J0717.5+3745 and MACS J1149.5+2223,. Each of these was observed over two epochs, to a total depth of 140 orbits on the main cluster and an associated parallel field, obtaining images in ACS (F435W, F606W, F814W) and WFC3/IR (F105W, F125W, F140W, F160W) on both the main cluster and the parallel field in all cases. Full sets of high-level science products have been generated for all these clusters by the team at STScI, including cumulative-depth data releases during each epoch, as well as full-depth releases after the completion of each epoch. These products include all the full-depth distortion-corrected drizzled mosaics and associated products for each cluster, which are science-ready to facilitate the construction of lensing models as well as enabling a wide range of other science projects. Many improvements beyond default calibration for ACS and WFC3/IR are implemented in these data products, including corrections for persistence, time-variable sky, and low-level dark current residuals, as well as improvements in astrometric alignment to achieve milliarcsecond-level accuracy. The full set of resulting high-level science products and mosaics are publicly delivered to the community via the Mikulski Archive for Space Telescopes (MAST) to enable the widest scientific use of these data, as well as ensuring a public legacy dataset of the highest possible quality that is of lasting value to the entire community.

Onboard software of Plasma Wave Experiment aboard Arase: instrument management and signal processing of Waveform Capture/Onboard Frequency Analyzer

NASA Astrophysics Data System (ADS)

Matsuda, Shoya; Kasahara, Yoshiya; Kojima, Hirotsugu; Kasaba, Yasumasa; Yagitani, Satoshi; Ozaki, Mitsunori; Imachi, Tomohiko; Ishisaka, Keigo; Kumamoto, Atsushi; Tsuchiya, Fuminori; Ota, Mamoru; Kurita, Satoshi; Miyoshi, Yoshizumi; Hikishima, Mitsuru; Matsuoka, Ayako; Shinohara, Iku

2018-05-01

We developed the onboard processing software for the Plasma Wave Experiment (PWE) onboard the Exploration of energization and Radiation in Geospace, Arase satellite. The PWE instrument has three receivers: Electric Field Detector, Waveform Capture/Onboard Frequency Analyzer (WFC/OFA), and the High-Frequency Analyzer. We designed a pseudo-parallel processing scheme with a time-sharing system and achieved simultaneous signal processing for each receiver. Since electric and magnetic field signals are processed by the different CPUs, we developed a synchronized observation system by using shared packets on the mission network. The OFA continuously measures the power spectra, spectral matrices, and complex spectra. The OFA obtains not only the entire ELF/VLF plasma waves' activity but also the detailed properties (e.g., propagation direction and polarization) of the observed plasma waves. We performed simultaneous observation of electric and magnetic field data and successfully obtained clear wave properties of whistler-mode chorus waves using these data. In order to measure raw waveforms, we developed two modes for the WFC, `chorus burst mode' (65,536 samples/s) and `EMIC burst mode' (1024 samples/s), for the purpose of the measurement of the whistler-mode chorus waves (typically in a frequency range from several hundred Hz to several kHz) and the EMIC waves (typically in a frequency range from a few Hz to several hundred Hz), respectively. We successfully obtained the waveforms of electric and magnetic fields of whistler-mode chorus waves and ion cyclotron mode waves along the Arase's orbit. We also designed the software-type wave-particle interaction analyzer mode. In this mode, we measure electric and magnetic field waveforms continuously and transfer them to the mission data recorder onboard the Arase satellite. We also installed an onboard signal calibration function (onboard SoftWare CALibration; SWCAL). We performed onboard electric circuit diagnostics and antenna impedance measurement of the wire-probe antennas along the orbit. We utilize the results obtained using the SWCAL function when we calibrate the spectra and waveforms obtained by the PWE.[Figure not available: see fulltext.

Constrained optimization for position calibration of an NMR field camera.

PubMed

Chang, Paul; Nassirpour, Sahar; Eschelbach, Martin; Scheffler, Klaus; Henning, Anke

2018-07-01

Knowledge of the positions of field probes in an NMR field camera is necessary for monitoring the B 0 field. The typical method of estimating these positions is by switching the gradients with known strengths and calculating the positions using the phases of the FIDs. We investigated improving the accuracy of estimating the probe positions and analyzed the effect of inaccurate estimations on field monitoring. The field probe positions were estimated by 1) assuming ideal gradient fields, 2) using measured gradient fields (including nonlinearities), and 3) using measured gradient fields with relative position constraints. The fields measured with the NMR field camera were compared to fields acquired using a dual-echo gradient recalled echo B 0 mapping sequence. Comparisons were done for shim fields from second- to fourth-order shim terms. The position estimation was the most accurate when relative position constraints were used in conjunction with measured (nonlinear) gradient fields. The effect of more accurate position estimates was seen when compared to fields measured using a B 0 mapping sequence (up to 10%-15% more accurate for some shim fields). The models acquired from the field camera are sensitive to noise due to the low number of spatial sample points. Position estimation of field probes in an NMR camera can be improved using relative position constraints and nonlinear gradient fields. Magn Reson Med 80:380-390, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Field Test Data for Detecting Vibrations of a Building Using High-Speed Video Cameras

DTIC Science & Technology

2017-10-01

ARL-TR-8185 ● OCT 2017 US Army Research Laboratory Field Test Data for Detecting Vibrations of a Building Using High -Speed Video...Field Test Data for Detecting Vibrations of a Building Using High -Speed Video Cameras by Caitlin P Conn and Geoffrey H Goldman Sensors and...June 2016 – October 2017 4. TITLE AND SUBTITLE Field Test Data for Detecting Vibrations of a Building Using High -Speed Video Cameras 5a. CONTRACT

Contributed Review: Camera-limits for wide-field magnetic resonance imaging with a nitrogen-vacancy spin sensor

NASA Astrophysics Data System (ADS)

Wojciechowski, Adam M.; Karadas, Mürsel; Huck, Alexander; Osterkamp, Christian; Jankuhn, Steffen; Meijer, Jan; Jelezko, Fedor; Andersen, Ulrik L.

2018-03-01

Sensitive, real-time optical magnetometry with nitrogen-vacancy centers in diamond relies on accurate imaging of small (≪10-2), fractional fluorescence changes across the diamond sample. We discuss the limitations on magnetic field sensitivity resulting from the limited number of photoelectrons that a camera can record in a given time. Several types of camera sensors are analyzed, and the smallest measurable magnetic field change is estimated for each type. We show that most common sensors are of a limited use in such applications, while certain highly specific cameras allow achieving nanotesla-level sensitivity in 1 s of a combined exposure. Finally, we demonstrate the results obtained with a lock-in camera that paves the way for real-time, wide-field magnetometry at the nanotesla level and with a micrometer resolution.

Situational Awareness from a Low-Cost Camera System

NASA Technical Reports Server (NTRS)

Freudinger, Lawrence C.; Ward, David; Lesage, John

2010-01-01

A method gathers scene information from a low-cost camera system. Existing surveillance systems using sufficient cameras for continuous coverage of a large field necessarily generate enormous amounts of raw data. Digitizing and channeling that data to a central computer and processing it in real time is difficult when using low-cost, commercially available components. A newly developed system is located on a combined power and data wire to form a string-of-lights camera system. Each camera is accessible through this network interface using standard TCP/IP networking protocols. The cameras more closely resemble cell-phone cameras than traditional security camera systems. Processing capabilities are built directly onto the camera backplane, which helps maintain a low cost. The low power requirements of each camera allow the creation of a single imaging system comprising over 100 cameras. Each camera has built-in processing capabilities to detect events and cooperatively share this information with neighboring cameras. The location of the event is reported to the host computer in Cartesian coordinates computed from data correlation across multiple cameras. In this way, events in the field of view can present low-bandwidth information to the host rather than high-bandwidth bitmap data constantly being generated by the cameras. This approach offers greater flexibility than conventional systems, without compromising performance through using many small, low-cost cameras with overlapping fields of view. This means significant increased viewing without ignoring surveillance areas, which can occur when pan, tilt, and zoom cameras look away. Additionally, due to the sharing of a single cable for power and data, the installation costs are lower. The technology is targeted toward 3D scene extraction and automatic target tracking for military and commercial applications. Security systems and environmental/ vehicular monitoring systems are also potential applications.

An Automatic Portable Telecine Camera.

DTIC Science & Technology

1978-08-01

five television frames to achieve synchronous operation, that is about 0.2 second. 6.3 Video recorder noise imnunity The synchronisation pulse separator...display is filmed by a modified 16 am cine camera driven by a control unit in which the camera supply voltage is derived from the field synchronisation ...pulses of the video signal. Automatic synchronisation of the camera mechanism is achieved over a wide range of television field frequencies and the

Persistence in the WFC3 IR Detector: Intrinsic Variability

NASA Astrophysics Data System (ADS)

Long, Knox S.; Baggett, Sylvia M.

2018-03-01

When the WFC3 IR detector is exposed to a bright source or sources, the sources can appear as afterimages in subsequent exposures, a phenomenon known as persistence. This can affect the science obtained with the IR channel. We have been involved in an effort to predict the brightness of the afterimages so that users can (at a minimum) flag the affected pixels and remove them from their analysis or (even better) subtract the afterimages from their science images to salvage the data. The ability of any model to remove afterimages depends on the degree to which persistence is the same for identical sets of exposures. We investigate possible time variability of persistence in the WFC3 detector using sets of (almost) identical visits comprised of single exposures of Omega Cen followed by a series of darks in which persistence is measured. We analyze 8 data sets, each consisting of two or three identical visits, with stimulus exposures between 49 and 1199 s, and find clear evidence of variability in several of the datasets in darks taken within 1000 s of the stimulus exposure. In most of the datasets, the difference in persistence for saturated pixels in the stimulus exposure is < 0.01 e-/s for darks taken 1000 s after the initial exposure. One of three 274-second visits has significantly more persistence than its two identical visits. Persistence in this visit was higher in all 4 detector quadrants. The persistence in all three visits is well modeled as a power law decay; the visit with higher persistence has a higher power law amplitude. There was nothing unusual about the observing conditions preceding and during each of these visits that can explain the discrepancy in persistence levels. Variation in persistence implies that: (1) Unless and until the source of the variability is understood, any persistence model for the WFC3 array will be limited in its ability to predict persistence in a single observation, and, (2) as a consequence, users should always carefully inspect the results of any attempt to subtract persistence from WFC3 IR data based on a model prediction.

3D surface pressure measurement with single light-field camera and pressure-sensitive paint

NASA Astrophysics Data System (ADS)

Shi, Shengxian; Xu, Shengming; Zhao, Zhou; Niu, Xiaofu; Quinn, Mark Kenneth

2018-05-01

A novel technique that simultaneously measures three-dimensional model geometry, as well as surface pressure distribution, with single camera is demonstrated in this study. The technique takes the advantage of light-field photography which can capture three-dimensional information with single light-field camera, and combines it with the intensity-based pressure-sensitive paint method. The proposed single camera light-field three-dimensional pressure measurement technique (LF-3DPSP) utilises a similar hardware setup to the traditional two-dimensional pressure measurement technique, with exception that the wind-on, wind-off and model geometry images are captured via an in-house-constructed light-field camera. The proposed LF-3DPSP technique was validated with a Mach 5 flared cone model test. Results show that the technique is capable of measuring three-dimensional geometry with high accuracy for relatively large curvature models, and the pressure results compare well with the Schlieren tests, analytical calculations, and numerical simulations.

The Hydrogen Content of a Rocky Earth-Size Exoplanet

NASA Astrophysics Data System (ADS)

Berta-Thompson, Zach

2016-10-01

The composition of a terrestrial planet's atmosphere results from a complex interplay of accretion, escape, and outgassing. We have little data on how such processes proceed for planets around stars other than our Sun. The warm, Earth-size planet GJ1132b transits a late M dwarf and offers a unique opportunity for studying the atmospheric composition of a rocky exoplanet. Thanks to this transiting planet's proximity (12pc) and large transit depth (0.3%), possible scenarios for GJ1132b's atmospheric transmission spectrum can be observed with the Hubble Space Telescope. Here, we propose to use WFC3/IR to observe five transits of GJ1132b, to search for absorption features from a cloud-free, hydrogen-rich atmosphere. Such an atmosphere could potentially arise from late outgassing of volatiles from the planetary interior. The detection of molecular absorption in GJ1132b's atmosphere is an important step toward the long-term goal of characterizing the atmospheres of cooler habitable planets, and GJ1132b is a favorable target for JWST observations. The results of this Hubble/WFC3 investigation would inform the optimal strategy to observe GJ1132b with JWST. If we detect deep absorption features with WFC3, JWST should observe GJ1132b across its entire wavelength range. If we do not, JWST may first need to focus more intensely on smaller individual wavelength windows. This planet provides the first chance for WFC3 to study the atmosphere of an exoplanet that almost resembles terrestrial worlds in our own Solar System.

Single lens 3D-camera with extended depth-of-field

NASA Astrophysics Data System (ADS)

Perwaß, Christian; Wietzke, Lennart

2012-03-01

Placing a micro lens array in front of an image sensor transforms a normal camera into a single lens 3D camera, which also allows the user to change the focus and the point of view after a picture has been taken. While the concept of such plenoptic cameras is known since 1908, only recently the increased computing power of low-cost hardware and the advances in micro lens array production, have made the application of plenoptic cameras feasible. This text presents a detailed analysis of plenoptic cameras as well as introducing a new type of plenoptic camera with an extended depth of field and a maximal effective resolution of up to a quarter of the sensor resolution.

Statis omnidirectional stereoscopic display system

NASA Astrophysics Data System (ADS)

Barton, George G.; Feldman, Sidney; Beckstead, Jeffrey A.

1999-11-01

A unique three camera stereoscopic omnidirectional viewing system based on the periscopic panoramic camera described in the 11/98 SPIE proceedings (AM13). The 3 panoramic cameras are equilaterally combined so each leg of the triangle approximates the human inter-ocular spacing allowing each panoramic camera to view 240 degree(s) of the panoramic scene, the most counter clockwise 120 degree(s) being the left eye field and the other 120 degree(s) segment being the right eye field. Field definition may be by green/red filtration or time discrimination of the video signal. In the first instance a 2 color spectacle is used in viewing the display or in the 2nd instance LCD goggles are used to differentiate the R/L fields. Radially scanned vidicons or re-mapped CCDs may be used. The display consists of three vertically stacked 120 degree(s) segments of the panoramic field of view with 2 fields/frame. Field A being the left eye display and Field B the right eye display.

Grand Swirls from NASA's Hubble

NASA Image and Video Library

2014-06-06

This new Hubble image shows NGC 1566, a beautiful galaxy located approximately 40 million light-years away in the constellation of Dorado (The Dolphinfish). NGC 1566 is an intermediate spiral galaxy, meaning that while it does not have a well-defined bar-shaped region of stars at its center — like barred spirals — it is not quite an unbarred spiral either. The small but extremely bright nucleus of NGC 1566 is clearly visible in this image, a telltale sign of its membership of the Seyfert class of galaxies. The centers of such galaxies are very active and luminous, emitting strong bursts of radiation and potentially harboring supermassive black holes that are many millions of times the mass of the sun. NGC 1566 is not just any Seyfert galaxy; it is the second brightest Seyfert galaxy known. It is also the brightest and most dominant member of the Dorado Group, a loose concentration of galaxies that together comprise one of the richest galaxy groups of the southern hemisphere. This image highlights the beauty and awe-inspiring nature of this unique galaxy group, with NGC 1566 glittering and glowing, its bright nucleus framed by swirling and symmetrical lavender arms. This image was taken by Hubble’s Wide Field Camera 3 (WFC3) in the near-infrared part of the spectrum. European Space Agency Credit: ESA/Hubble & NASA, Acknowledgement: Flickr user Det58 NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

NASA's Hubble Sees A Majestic Disk of Stars

NASA Image and Video Library

2011-02-17

NASA image release Feb. 17, 2011 To see a hd vidoe of this sprial galaxy go to: www.flickr.com/photos/gsfc/5453173577/ The Hubble Space Telescope revealed this majestic disk of stars and dust lanes in this view of the spiral galaxy NGC 2841. A bright cusp of starlight marks the galaxy's center. Spiraling outward are dust lanes that are silhouetted against the population of whitish middle-aged stars. Much younger blue stars trace the spiral arms. Notably missing are pinkish emission nebulae indicative of new star birth. It is likely that the radiation and supersonic winds from fiery, super-hot, young blue stars cleared out the remaining gas (which glows pink), and hence shut down further star formation in the regions in which they were born. NGC 2841 currently has a relatively low star formation rate compared to other spirals that are ablaze with emission nebulae. NGC 2841 lies 46 million light-years away in the constellation of Ursa Major (The Great Bear). This image was taken in 2010 through four different filters on Hubble’s Wide Field Camera 3. Wavelengths range from ultraviolet light through visible light to near-infrared light. NASA, ESA, and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration; Acknowledgment: M. Crockett and S. Kaviraj (Oxford University, UK), R. O’Connell (University of Virginia), B. Whitmore (STScI), and the WFC3 Scientific Oversight Committee NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

VizieR Online Data Catalog: Follow-up study of gal. & AGNs in z>1 clusters (Alberts+, 2016)

NASA Astrophysics Data System (ADS)

Alberts, S.; Pope, A.; Brodwin, M.; Chung, S. M.; Cybulski, R.; Dey, A.; Eisenhardt, P. R. M.; Galametz, A.; Gonzalez, A. H.; Jannuzi, B. T.; Stanford, S. A.; Snyder, G. F.; Stern, D.; Zeimann, G. R.

2016-08-01

In this work, we concentrate our analysis on 11 spectroscopically confirmed clusters from the IRAC Shallow/Distant Cluster Survey (ISCS/IDCS) that we observed with Herschel/PACS at 100 and 160um, obtained during Open Time 2 observing (PID: OT2apope3) (summary of imaging in table 6 spanning from June 2012 to January 2013). Given the resolution of PACS (FWHM~6.7" at 100um and 11" at 160um), we expect the majority of sources and all cluster galaxies in our maps to be point sources. See sections 2.1 and 2.3 for further details. The IRAC Shallow Survey (ISS) was followed up with three more observations as part of SDWFS (Ashby et al. 2009, see J/ApJ/716/530), providing a factor of 2 deeper IRAC catalog with an aperture-corrected 5σ limit of 5.2uJy at 4.5um ([4.5]=18.83mag). Spitzer/MIPS observations are available from the MIPS AGM and Galaxy Evolution Survey (MAGES; Jannuzi et al. 2010AAS...21547001J). See section 2.4 for further details. Targeted follow up campaigns by our group have obtained spectroscopic redshifts for galaxies and AGNs in z>1 clusters using multi-object Keck optical spectroscopy and Wide Field Camera 3 (WFC3) slitless NIR grism spectroscopy from the Hubble Space Telescope (HST). The reader is directed to Brodwin et al. (2013ApJ...779..138B), Zeimann et al. (2013, J/ApJ/779/137), and references therein for a detailed description of the targeted spectroscopy. Some spectroscopic redshifts are additionally provided by the AGN and Galaxy Evolution Survey (AGES; Kochanek et al. 2012, J/ApJS/200/8). See section 2.2. (3 data files).

External Mask Based Depth and Light Field Camera

DTIC Science & Technology

2013-12-08

laid out in the previous light field cameras. A good overview of the sampling of the plenoptic function can be found in the survey work by Wetzstein et...view is shown in Figure 6. 5. Applications High spatial resolution depth and light fields are a rich source of information about the plenoptic ...http://www.pelicanimaging.com/. [4] E. Adelson and J. Wang. Single lens stereo with a plenoptic camera. Pattern Analysis and Machine Intelligence

Development of a high sensitivity pinhole type gamma camera using semiconductors for low dose rate fields

NASA Astrophysics Data System (ADS)

Ueno, Yuichiro; Takahashi, Isao; Ishitsu, Takafumi; Tadokoro, Takahiro; Okada, Koichi; Nagumo, Yasushi; Fujishima, Yasutake; Yoshida, Akira; Umegaki, Kikuo

2018-06-01

We developed a pinhole type gamma camera, using a compact detector module of a pixelated CdTe semiconductor, which has suitable sensitivity and quantitative accuracy for low dose rate fields. In order to improve the sensitivity of the pinhole type semiconductor gamma camera, we adopted three methods: a signal processing method to set the discriminating level lower, a high sensitivity pinhole collimator and a smoothing image filter that improves the efficiency of the source identification. We tested basic performances of the developed gamma camera and carefully examined effects of the three methods. From the sensitivity test, we found that the effective sensitivity was about 21 times higher than that of the gamma camera for high dose rate fields which we had previously developed. We confirmed that the gamma camera had sufficient sensitivity and high quantitative accuracy; for example, a weak hot spot (0.9 μSv/h) around a tree root could be detected within 45 min in a low dose rate field test, and errors of measured dose rates with point sources were less than 7% in a dose rate accuracy test.

HST WFC3/IR Calibration Updates

NASA Astrophysics Data System (ADS)

Durbin, Meredith; Brammer, Gabriel; Long, Knox S.; Pirzkal, Norbert; Ryan, Russell E.; McCullough, Peter R.; Baggett, Sylvia M.; Gosmeyer, Catherine; Bourque, Matthew; HST WFC3 Team

2016-01-01

We report on several improvements to the characterization, monitoring, and calibration of the HST WFC3/IR detector. The detector performance has remained overall stable since its installation during HST Servicing Mission 4 in 2009. We present an updated persistence model that takes into account effects of exposure time and spatial variations in persistence across the detector, new grism wavelength solutions and master sky images, and a new SPARS sample sequence. We also discuss the stability of the IR gain, the time evolution and photometric properties of IR "snowballs," and the effect of IR "blobs" on point-source photometry.

Quasi-microscope concept for planetary missions.

PubMed

Huck, F O; Arvidson, R E; Burcher, E E; Giat, O; Wall, S D

1977-09-01

Viking lander cameras have returned stereo and multispectral views of the Martian surface with a resolution that approaches 2 mm/lp in the near field. A two-orders-of-magnitude increase in resolution could be obtained for collected surface samples by augmenting these cameras with auxiliary optics that would neither impose special camera design requirements nor limit the cameras field of view of the terrain. Quasi-microscope images would provide valuable data on the physical and chemical characteristics of planetary regoliths.

Electronic Still Camera view of Aft end of Wide Field/Planetary Camera in HST

NASA Image and Video Library

1993-12-06

S61-E-015 (6 Dec 1993) --- A close-up view of the aft part of the new Wide Field/Planetary Camera (WFPC-II) installed on the Hubble Space Telescope (HST). WFPC-II was photographed with the Electronic Still Camera (ESC) from inside Endeavour's cabin as astronauts F. Story Musgrave and Jeffrey A. Hoffman moved it from its stowage position onto the giant telescope. Electronic still photography is a relatively new technology which provides the means for a handheld camera to electronically capture and digitize an image with resolution approaching film quality. The electronic still camera has flown as an experiment on several other shuttle missions.

Far ultraviolet wide field imaging and photometry - Spartan-202 Mark II Far Ultraviolet Camera

NASA Technical Reports Server (NTRS)

Carruthers, George R.; Heckathorn, Harry M.; Opal, Chet B.; Witt, Adolf N.; Henize, Karl G.

1988-01-01

The U.S. Naval Research Laboratory' Mark II Far Ultraviolet Camera, which is expected to be a primary scientific instrument aboard the Spartan-202 Space Shuttle mission, is described. This camera is intended to obtain FUV wide-field imagery of stars and extended celestial objects, including diffuse nebulae and nearby galaxies. The observations will support the HST by providing FUV photometry of calibration objects. The Mark II camera is an electrographic Schmidt camera with an aperture of 15 cm, a focal length of 30.5 cm, and sensitivity in the 1230-1600 A wavelength range.

A Robust Mechanical Sensing System for Unmanned Sea Surface Vehicles

NASA Technical Reports Server (NTRS)

Kulczycki, Eric A.; Magnone, Lee J.; Huntsberger, Terrance; Aghazarian, Hrand; Padgett, Curtis W.; Trotz, David C.; Garrett, Michael S.

2009-01-01

The need for autonomous navigation and intelligent control of unmanned sea surface vehicles requires a mechanically robust sensing architecture that is watertight, durable, and insensitive to vibration and shock loading. The sensing system developed here comprises four black and white cameras and a single color camera. The cameras are rigidly mounted to a camera bar that can be reconfigured to mount multiple vehicles, and act as both navigational cameras and application cameras. The cameras are housed in watertight casings to protect them and their electronics from moisture and wave splashes. Two of the black and white cameras are positioned to provide lateral vision. They are angled away from the front of the vehicle at horizontal angles to provide ideal fields of view for mapping and autonomous navigation. The other two black and white cameras are positioned at an angle into the color camera's field of view to support vehicle applications. These two cameras provide an overlap, as well as a backup to the front camera. The color camera is positioned directly in the middle of the bar, aimed straight ahead. This system is applicable to any sea-going vehicle, both on Earth and in space.

Event-Driven Random-Access-Windowing CCD Imaging System

NASA Technical Reports Server (NTRS)

Monacos, Steve; Portillo, Angel; Ortiz, Gerardo; Alexander, James; Lam, Raymond; Liu, William

2004-01-01

A charge-coupled-device (CCD) based high-speed imaging system, called a realtime, event-driven (RARE) camera, is undergoing development. This camera is capable of readout from multiple subwindows [also known as regions of interest (ROIs)] within the CCD field of view. Both the sizes and the locations of the ROIs can be controlled in real time and can be changed at the camera frame rate. The predecessor of this camera was described in High-Frame-Rate CCD Camera Having Subwindow Capability (NPO- 30564) NASA Tech Briefs, Vol. 26, No. 12 (December 2002), page 26. The architecture of the prior camera requires tight coupling between camera control logic and an external host computer that provides commands for camera operation and processes pixels from the camera. This tight coupling limits the attainable frame rate and functionality of the camera. The design of the present camera loosens this coupling to increase the achievable frame rate and functionality. From a host computer perspective, the readout operation in the prior camera was defined on a per-line basis; in this camera, it is defined on a per-ROI basis. In addition, the camera includes internal timing circuitry. This combination of features enables real-time, event-driven operation for adaptive control of the camera. Hence, this camera is well suited for applications requiring autonomous control of multiple ROIs to track multiple targets moving throughout the CCD field of view. Additionally, by eliminating the need for control intervention by the host computer during the pixel readout, the present design reduces ROI-readout times to attain higher frame rates. This camera (see figure) includes an imager card consisting of a commercial CCD imager and two signal-processor chips. The imager card converts transistor/ transistor-logic (TTL)-level signals from a field programmable gate array (FPGA) controller card. These signals are transmitted to the imager card via a low-voltage differential signaling (LVDS) cable assembly. The FPGA controller card is connected to the host computer via a standard peripheral component interface (PCI).

On HMI's Mod-L Sequence: Test and Evaluation

NASA Astrophysics Data System (ADS)

Liu, Yang; Baldner, Charles; Bogart, R. S.; Bush, R.; Couvidat, S.; Duvall, Thomas L.; Hoeksema, Jon Todd; Norton, Aimee Ann; Scherrer, Philip H.; Schou, Jesper

2016-05-01

HMI Mod-L sequence can produce full Stokes parameters at a cadence of 90 seconds by combining filtergrams from both cameras, the front camera and the side camera. Within the 90-second, the front camera takes two sets of Left and Right Circular Polarizations (LCP and RCP) at 6 wavelengths; the side camera takes one set of Linear Polarizations (I+/-Q and I+/-U) at 6 wavelengths. By combining two cameras, one can obtain full Stokes parameters of [I,Q,U,V] at 6 wavelengths in 90 seconds. In norminal Mod-C sequence that HMI currently uses, the front camera takes LCP and RCP at a cadence of 45 seconds, while the side camera takes observation of the full Stokes at a cadence of 135 seconds. Mod-L should be better than Mod-C for providing vector magnetic field data because (1) Mod-L increases cadence of full Stokes observation, which leads to higher temporal resolution of vector magnetic field measurement; (2) decreases noise in vector magnetic field data because it uses more filtergrams to produce [I,Q,U,V]. There are two potential issues in Mod-L that need to be addressed: (1) scaling intensity of the two cameras’ filtergrams; and (2) if current polarization calibration model, which is built for each camera separately, works for the combined data from both cameras. This presentation will address these questions, and further place a discussion here.

Phase and amplitude wave front sensing and reconstruction with a modified plenoptic camera

NASA Astrophysics Data System (ADS)

Wu, Chensheng; Ko, Jonathan; Nelson, William; Davis, Christopher C.

2014-10-01

A plenoptic camera is a camera that can retrieve the direction and intensity distribution of light rays collected by the camera and allows for multiple reconstruction functions such as: refocusing at a different depth, and for 3D microscopy. Its principle is to add a micro-lens array to a traditional high-resolution camera to form a semi-camera array that preserves redundant intensity distributions of the light field and facilitates back-tracing of rays through geometric knowledge of its optical components. Though designed to process incoherent images, we found that the plenoptic camera shows high potential in solving coherent illumination cases such as sensing both the amplitude and phase information of a distorted laser beam. Based on our earlier introduction of a prototype modified plenoptic camera, we have developed the complete algorithm to reconstruct the wavefront of the incident light field. In this paper the algorithm and experimental results will be demonstrated, and an improved version of this modified plenoptic camera will be discussed. As a result, our modified plenoptic camera can serve as an advanced wavefront sensor compared with traditional Shack- Hartmann sensors in handling complicated cases such as coherent illumination in strong turbulence where interference and discontinuity of wavefronts is common. Especially in wave propagation through atmospheric turbulence, this camera should provide a much more precise description of the light field, which would guide systems in adaptive optics to make intelligent analysis and corrections.

The HST Frontier Fields: High-Level Science Data Products for the First 4 Completed Clusters, and Latest Data on the Remaining Clusters

NASA Astrophysics Data System (ADS)

Koekemoer, Anton M.; Mack, Jennifer; Lotz, Jennifer; Anderson, Jay; Avila, Roberto J.; Barker, Elizabeth A.; Borncamp, David; Gunning, Heather C.; Hilbert, Bryan; Khandrika, Harish G.; Lucas, Ray A.; Ogaz, Sara; Porterfield, Blair; Grogin, Norman A.; Robberto, Massimo; Flanagan, Kathryn; Mountain, Matt; HST Frontier Fields Team

2016-01-01

The Hubble Space Telescope Frontier Fields program is a large Director's Discretionary program of 840 orbits, to obtain ultra-deep observations of six strong lensing clusters of galaxies, together with parallel deep blank fields, making use of the strong lensing amplification by these clusters of distant background galaxies to detect the faintest galaxies currently observable in the high-redshift universe. The first four of these clusters are now complete, namely Abell 2744, MACS J0416.1-2403, MACS J0717.5+3745 and MACS J1149.5+2223, with each of these having been observed over two epochs, to a total depth of 140 orbits on the main cluster and an associated parallel field, using ACS (F435W, F606W, F814W) and WFC3/IR (F105W, F125W, F140W, F160W). The remaining two clusters, Abell 370 and Abell S1063, are currently in progress. Full sets of high-level science products have been generated for all these clusters by the team at STScI, including a total of 24 separate cumulative-depth data releases during each epoch, as well as full-depth version 1.0 releases at the end of each completed epoch. These products include all the full-depth distortion-corrected mosaics and associated products for each cluster, which are science-ready to facilitate the construction of lensing models as well as enabling a wide range of other science projects. Many improvements beyond default calibration for ACS and WFC3/IR are implemented in these data products, including corrections for persistence, time-variable sky, and low-level dark current residuals, as well as improvements in astrometric alignment to achieve milliarcsecond-level accuracy. The resulting high-level science products are delivered via the Mikulski Archive for Space Telescopes (MAST) to the community on a rapid timescale to enable the widest scientific use of these data, as well as ensuring a public legacy dataset of the highest possible quality that is of lasting value to the entire community.

The HST Frontier Fields: High-Level Science Data Products for the First 4 Completed Clusters, and for the Last 2 Clusters Currently in Progress

NASA Astrophysics Data System (ADS)

Koekemoer, Anton M.; Mack, Jennifer; Lotz, Jennifer M.; Anderson, Jay; Avila, Roberto J.; Barker, Elizabeth A.; Borncamp, David; Gunning, Heather C.; Hilbert, Bryan; Khandrika, Harish G.; Lucas, Ray A.; Ogaz, Sara; Porterfield, Blair; Sunnquist, Ben; Grogin, Norman A.; Robberto, Massimo; Sembach, Kenneth; Flanagan, Kathryn; Mountain, Matt; HST Frontier Fields Team

2016-06-01

The Hubble Space Telescope Frontier Fields program (PI: J. Lotz) is a large Director's Discretionary program of 840 orbits, to obtain ultra-deep observations of six strong lensing clusters of galaxies, together with parallel deep blank fields, making use of the strong lensing amplification by these clusters of distant background galaxies to detect the faintest galaxies currently observable in the high-redshift universe. The first four of these clusters are now complete, namely Abell 2744, MACS J0416.1-2403, MACS J0717.5+3745 and MACS J1149.5+2223, with each of these having been observed over two epochs, to a total depth of 140 orbits on the main cluster and an associated parallel field, using ACS (F435W, F606W, F814W) and WFC3/IR (F105W, F125W, F140W, F160W). The remaining two clusters, Abell 370 and Abell S1063, are currently in progress, with the first epoch for each having been completed. Full sets of high-level science products have been generated for all these clusters by the team at STScI, including cumulative-depth v0.5 data releases during each epoch, as well as full-depth version 1.0 releases after the completion of each epoch. These products include all the full-depth distortion-corrected mosaics and associated products for each cluster, which are science-ready to facilitate the construction of lensing models as well as enabling a wide range of other science projects. Many improvements beyond default calibration for ACS and WFC3/IR are implemented in these data products, including corrections for persistence, time-variable sky, and low-level dark current residuals, as well as improvements in astrometric alignment to achieve milliarcsecond-level accuracy. The full set of resulting high-level science products are publicly delivered to the community via the Mikulski Archive for Space Telescopes (MAST) to enable the widest scientific use of these data, as well as ensuring a public legacy dataset of the highest possible quality that is of lasting value to the entire community.

How a 2.4 meter telescope makes WFIRST a more powerful and wide-randing mission

NASA Astrophysics Data System (ADS)

Spergel, David N.

2014-01-01

A 2.4-meter space telescope equipped with a very wide-field infrared camera would revolutionize astrophysics. The transfer of this telescope asset to NASA is a boon to the US scientific community that should be utilized to produce transformative science. If used for the WFIRST mission, the 2.4-meter telescope would be significantly more capable than the smaller versions of WFIRST studied in previous SDTs. As we show here in this Report, by dividing the time on WFIRST-2.4 between dark energy, micro- lensing, and guest observer observations, gains of 50- 100% or more are expected for all. Furthermore, the 2.4-m telescope makes possible new science at the lim- it of, and beyond, what was achievable with earlier WFIRST designs. WFIRST-2.4 is not only capable of wide-field near-IR observations that are key to many of the frontier areas of astrophysics, but will do so at the resolution of HST. The 2.4-m aperture of WFIRST-2.4 collects almost 3 times as much light as the unobstructed 1.3-m SDT- DRM1 and offers a factor of 1.9 improvement in spatial resolution (point spread function effective area-- PSF), which itself provides another factor-of-two improvement in accomplishing many science programs. Compared to SDT-DRM1, the design presented in our report has a ~30% smaller field-of-view (FOV) that moderates these gains, but the higher spatial resolution takes the WFIRST-2.4 program to the “next level” and sets it apart from DRM1 and — for the dark energy program specifically — the Euclid mission. In particular, having the greater speed of the larger aperture and the sharper PSF allows WFIRST-2.4 to reach a factor-of-two deep- er per unit time over an unprecedentedly large field for a large space telescope, ~90 times bigger than the HST-ACS FOV, and ~200 times bigger than the IR channel of WFC3 that has been a tremendously successful scientific tool. A coronagraph on WFIRST-2.4 would be an ex- citing extension in its capability that would not only characterize giant planets around the nearest stars, but also be an important step towards detecting habitable exoEarths:

Looking for the Coldest Atmospheres: a Search for Planetary Mass Companions around T and Y Brown Dwarfs

NASA Astrophysics Data System (ADS)

Fontanive, Clemence

2017-08-01

We propose to obtain WFC3/IR imaging of the very coolest brown dwarfs (T < 800 K) to search for substellar and planetary-mass companions to these objects. Companions discovered by this program would likely be analogues of the 250 K brown dwarf WISE 0855 and would provide vital benchmark objects for theoretical models, closing the gap in mass and temperature between brown dwarfs and planets. Finding such an object as a member of a binary system would be even more valuable as it would allow for the measurement of dynamical masses. We recently placed the first constraints to date on the binary frequency for brown dwarfs with spectral types >T8. This program will triple our current sample size, a requirement in order to confirm our current results and compare substellar binary properties for various spectral type and age populations. The WFC3/IR plate will allow us to probe near equal-mass binaries down to separations of 0.2 (2-3 AU for the typical distances of our targets). True cool companions should show strong absorption around 1.4 um as a result of the deep water absorption band observed at that wavelength in substellar spectra. We therefore propose observations in the WFC3 F127M and F139M filters which will allow us to robustly identify bona fide candidates and distinguish them from background stars based on this spectral feature. Most of our targets lack suitable NGS AO guide stars or LGS AO tip-tilt stars to be observed with ground-based telescopes, and the 1.4 um water band is often unobservable from the ground due to telluric water absorption. WFC3 on HST is thus the only instrument suitable for these observations.

Gendered Pathways to Burnout: Results from the SALVEO Study.

PubMed

Beauregard, Nancy; Marchand, Alain; Bilodeau, Jaunathan; Durand, Pierre; Demers, Andrée; Haines, Victor Y

2018-04-18

Burnout is a pervasive mental health problem in the workforce, with mounting evidence suggesting ties with occupational and safety outcomes such as work injuries, critical events and musculoskeletal disorders. While environmental [work and non-work, work-to-family conflict (WFC)] and individual (personality) pathways to burnout are well documented, little is known about how gender comes to influence such associative patterns. The aim of the study consisted in examining gendered pathways to burnout. Data were derived from the SALVEO study, a cross-sectional study of 2026 workers from 63 workplaces from the province of Québec (Canada). Data were analyzed using multilevel path analysis. Direct effects of gendered pathways were evidenced for work (e.g. decision latitude) and non-work (e.g. child-related strains) environmental pathways, as well as for individual pathways (i.e. internal locus of control). Indirect effects of gendered pathways were also evidenced, with women reporting higher levels of burnout compared to men due to lower levels of decision latitude and of self-esteem, as well as higher levels of WFC. Women also reported lower burnout levels through investing more time into domestic tasks, which could represent a recovery strategy to highly demanding work. WFC further mediated the associations between working hours and burnout, as well as the between irregular work schedules and burnout. These result suggest than men distinctively reported higher levels of burnout due to the specific nature of their work contract negatively impacting on WFC, and incidentally, on their mental health. Study results supported our hypotheses positing that gender distinctively shapes environmental and individual pathways to burnout. OHS prevention efforts striving for better mental health outcomes in the workforce could relevantly be informed by a gendered approach to burnout.

Are status inconsistency, work stress and work-family conflict associated with depressive symptoms? Testing prospective evidence in the lidA study.

PubMed

Peter, Richard; March, Stefanie; du Prel, Jean-Baptist

2016-02-01

Depressive symptoms are common and economically relevant. Women suffer more often than men do. We analyze associations between social status inconsistency, psychosocial factors, and depressive symptoms stratified by gender. In the present study, 3340 employees of two age cohorts (1959, 1965) working in two waves (2011, 2014) of the prospective German lidA-study and who gave written consent to link register data regarding their employment histories were included. Gender-specific influences of social status inconsistency (deviation of observed income from expected average income based on acquired education) on depressive symptoms and mediation of these associations by work stress in terms of effort-reward-imbalance (ERI) and work-family-conflict (WFC) were analyzed with confirmatory cross-lagged path models. Among men, consistent status (i.e., average income in a specific educational group) increased the frequency of depressive symptoms. No association between negative SSI (i.e., income below the average income given a specific educational attainment) or positive SSI (i.e., income above the average income given a specific educational attainment) and depressive symptoms was observed among men or women. ERI and WFC were longitudinally associated with the outcome and differed slightly regarding gender, i.e., showing stronger effects of ERI for women and of WFC for men. Mediation of the association between social status and depressive symptoms was observed for men and for consistent status (path: consistent status → ERI → depressive symptoms) but not for SSI. ERI and WFC increase the risk of future episodes with depressive symptoms in men and in women irrespective of SSI, occupational position, full- or part-time work, regional factors or individual characteristics. Copyright © 2016. Published by Elsevier Ltd.

Imaging Shock Fronts in the Outer Ejecta of Eta Carinae

NASA Astrophysics Data System (ADS)

Smith, Nathan

2017-08-01

Although Eta Car has been imaged many times with HST to monitor the central star and the bright Homunculus Nebula, we propose the first WFC3 imaging of Eta Car to study the more extended Outer Ejecta from previous eruptions. WFC3 has two key filters that have not been used before to image Eta Car, which will provide critical physical information about its eruptive history: (1) F280N with WFC3/UVIS will produce the first Mg II 2800 image of Eta Car, the sharpest image of its complex Outer Ejecta, and will unambiguously trace shock fronts, and (2) F126N with WFC3/IR will sample [Fe II] 12567 arising in the densest post-shock gas. Eta Car is surrounded by a bright, soft X-ray shell seen in Chandra images, which arises from the fastest 1840s ejecta overtaking slower older material. Our recent proper motion measurements show that the outer knots were ejected in two outbursts several hundred years before the 1840s eruption, and spectroscopy of light echoes has recently revealed extremely fast ejecta during the 1840s that indicate an explosive event. Were those previous eruptions explosive as well? If so, were they as energetic, did they also have such fast ejecta, and did they have the same geometry? The structure and excitation of the Outer Ejecta hold unique clues for reconstructing Eta Car's violent mass loss history. The locations of shock fronts in circumstellar material provide critical information, because they identify past discontinuities in the mass loss. This is one of the only ways to investigate the long term (i.e. centuries) evolution and duty cycle of eruptive mass loss in the most massive stars.

A characterization of persistence at short times in the WFC3/IR detector

NASA Astrophysics Data System (ADS)

Gennaro, M.; Bajaj, V.; Long, K.

2018-05-01

Persistence in the WFC3/IR detector appears to decay as a power law as a function of time elapsed since the end of a stimulus. In this report we study departures from the power law at times shorter than a few hundreds seconds after the stimulus. In order to have better short-time cadence, we use the Multiaccum (.ima) files, which trace the accumulated charge in the pixels as function of time, rather than the final pipeline products (.flt files), which instead report the electron rate estimated via a linear fit to the accumulated charge vs. time relation. We note that at short times after the stimulus, the absolute change in persistence is the strongest, thus a linear fit to the accumulated signal (the .flt values) can be a poor representation of the strongly varying persistence signal. The already observed power-law decay of the persistence signal, still holds at shorter times, with typical values of the power law index, gamma in [-0.8,-1] for stimuli that saturate the WFC3 pixels. To a good degree of approximation, a single power law is a good fit to the persistence signal decay from 100 to 5000 seconds. We also detect a tapering-off in the power-law decay at increasingly shorter times. This change in behavior is of the order of Delta Gamma 0.02 - 0.05 when comparing power-law fits performed to the persistence signal from 0 up to 250 seconds and from 0 up to 4000 seconds after the stimulus, indicating that persistence decays slightly more rapidly as time progresses. Our results may suggest that for even shorter times, not probed by our study, the WFC3 persistence signal might deviate from a single power-law model.

Focusing and depth of field in photography: application in dermatology practice.

PubMed

Taheri, Arash; Yentzer, Brad A; Feldman, Steven R

2013-11-01

Conventional photography obtains a sharp image of objects within a given 'depth of field'; objects not within the depth of field are out of focus. In recent years, digital photography revolutionized the way pictures are taken, edited, and stored. However, digital photography does not result in a deeper depth of field or better focusing. In this article, we briefly review the concept of depth of field and focus in photography as well as new technologies in this area. A deep depth of field is used to have more objects in focus; a shallow depth of field can emphasize a subject by blurring the foreground and background objects. The depth of field can be manipulated by adjusting the aperture size of the camera, with smaller apertures increasing the depth of field at the cost of lower levels of light capture. Light-field cameras are a new generation of digital cameras that offer several new features, including the ability to change the focus on any object in the image after taking the photograph. Understanding depth of field and camera technology helps dermatologists to capture their subjects in focus more efficiently. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

High-Redshift SNe with Subaru and HST

NASA Astrophysics Data System (ADS)

Rubin, David; Suzuki, Nao; Regnault, Nicolas; Aldering, Gregory; Amanullah, Rahman; Antilogus, Pierre; Astier, Pierre; Barbary, Kyle; Betoule, Marc; Boone, Kyle Robert; Currie, Miles; Deustua, Susana; Doi, Mamoru; Fruchter, Andrew; Goobar, Ariel; Hayden, Brian; Hazenberg, Francois; Hook, Isobel; Huang, Xiaosheng; Jiang, Jian; Kato, Takahiro; Kim, Alex; Kowalski, Marek; Lidman, Chris; Linder, Eric; Maeda, Keiichi; Morokuma, Tomoki; Nordin, Jakob; Pain, Reynald; Perlmutter, Saul; Ruiz-Lapuente, Pilar; Sako, Masao; Myers Saunders, Clare; Spadafora, Anthony L.; Tanaka, Masaomi; Tominaga, Nozomu; Yasuda, Naoki; Yoshida, Naoki

2018-01-01

High-redshift type Ia supernovae are crucial for constraining any time variation in dark energy. Here, we present the first discoveries and light curves from the SUbaru Supernovae with Hubble Infrared (SUSHI) program, which combines high-redshift SN discoveries from the Subaru Strategic Program (SSP, as well as other Subaru time) with HST WFC3 IR followup. This program efficiently uses the wide field and high collecting area of Subaru Hyper Suprime-Cam for optical light curves, but still obtains a precision NIR color. We are on track to double the number of well-measured SNe Ia at z > 1.1, triggering on 23 SNe Ia in our first season.

Video systems for real-time oil-spill detection

NASA Technical Reports Server (NTRS)

Millard, J. P.; Arvesen, J. C.; Lewis, P. L.; Woolever, G. F.

1973-01-01

Three airborne television systems are being developed to evaluate techniques for oil-spill surveillance. These include a conventional TV camera, two cameras operating in a subtractive mode, and a field-sequential camera. False-color enhancement and wavelength and polarization filtering are also employed. The first of a series of flight tests indicates that an appropriately filtered conventional TV camera is a relatively inexpensive method of improving contrast between oil and water. False-color enhancement improves the contrast, but the problem caused by sun glint now limits the application to overcast days. Future effort will be aimed toward a one-camera system. Solving the sun-glint problem and developing the field-sequential camera into an operable system offers potential for color 'flagging' oil on water.

Lensless imaging for wide field of view

NASA Astrophysics Data System (ADS)

Nagahara, Hajime; Yagi, Yasushi

2015-02-01

It is desirable to engineer a small camera with a wide field of view (FOV) because of current developments in the field of wearable cameras and computing products, such as action cameras and Google Glass. However, typical approaches for achieving wide FOV, such as attaching a fisheye lens and convex mirrors, require a trade-off between optics size and the FOV. We propose camera optics that achieve a wide FOV, and are at the same time small and lightweight. The proposed optics are a completely lensless and catoptric design. They contain four mirrors, two for wide viewing, and two for focusing the image on the camera sensor. The proposed optics are simple and can be simply miniaturized, since we use only mirrors for the proposed optics and the optics are not susceptible to chromatic aberration. We have implemented the prototype optics of our lensless concept. We have attached the optics to commercial charge-coupled device/complementary metal oxide semiconductor cameras and conducted experiments to evaluate the feasibility of our proposed optics.

Volumetric particle image velocimetry with a single plenoptic camera

NASA Astrophysics Data System (ADS)

Fahringer, Timothy W.; Lynch, Kyle P.; Thurow, Brian S.

2015-11-01

A novel three-dimensional (3D), three-component (3C) particle image velocimetry (PIV) technique based on volume illumination and light field imaging with a single plenoptic camera is described. A plenoptic camera uses a densely packed microlens array mounted near a high resolution image sensor to sample the spatial and angular distribution of light collected by the camera. The multiplicative algebraic reconstruction technique (MART) computed tomography algorithm is used to reconstruct a volumetric intensity field from individual snapshots and a cross-correlation algorithm is used to estimate the velocity field from a pair of reconstructed particle volumes. This work provides an introduction to the basic concepts of light field imaging with a plenoptic camera and describes the unique implementation of MART in the context of plenoptic image data for 3D/3C PIV measurements. Simulations of a plenoptic camera using geometric optics are used to generate synthetic plenoptic particle images, which are subsequently used to estimate the quality of particle volume reconstructions at various particle number densities. 3D reconstructions using this method produce reconstructed particles that are elongated by a factor of approximately 4 along the optical axis of the camera. A simulated 3D Gaussian vortex is used to test the capability of single camera plenoptic PIV to produce a 3D/3C vector field, where it was found that lateral displacements could be measured to approximately 0.2 voxel accuracy in the lateral direction and 1 voxel in the depth direction over a 300× 200× 200 voxel volume. The feasibility of the technique is demonstrated experimentally using a home-built plenoptic camera based on a 16-megapixel interline CCD camera and a 289× 193 array of microlenses and a pulsed Nd:YAG laser. 3D/3C measurements were performed in the wake of a low Reynolds number circular cylinder and compared with measurements made using a conventional 2D/2C PIV system. Overall, single camera plenoptic PIV is shown to be a viable 3D/3C velocimetry technique.

High Speed Digital Camera Technology Review

NASA Technical Reports Server (NTRS)

Clements, Sandra D.

2009-01-01

A High Speed Digital Camera Technology Review (HSD Review) is being conducted to evaluate the state-of-the-shelf in this rapidly progressing industry. Five HSD cameras supplied by four camera manufacturers participated in a Field Test during the Space Shuttle Discovery STS-128 launch. Each camera was also subjected to Bench Tests in the ASRC Imaging Development Laboratory. Evaluation of the data from the Field and Bench Tests is underway. Representatives from the imaging communities at NASA / KSC and the Optical Systems Group are participating as reviewers. A High Speed Digital Video Camera Draft Specification was updated to address Shuttle engineering imagery requirements based on findings from this HSD Review. This draft specification will serve as the template for a High Speed Digital Video Camera Specification to be developed for the wider OSG imaging community under OSG Task OS-33.

LSST Camera Optics Design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riot, V J; Olivier, S; Bauman, B

2012-05-24

The Large Synoptic Survey Telescope (LSST) uses a novel, three-mirror, telescope design feeding a camera system that includes a set of broad-band filters and three refractive corrector lenses to produce a flat field at the focal plane with a wide field of view. Optical design of the camera lenses and filters is integrated in with the optical design of telescope mirrors to optimize performance. We discuss the rationale for the LSST camera optics design, describe the methodology for fabricating, coating, mounting and testing the lenses and filters, and present the results of detailed analyses demonstrating that the camera optics willmore » meet their performance goals.« less

Systems and methods for maintaining multiple objects within a camera field-of-view

DOEpatents

Gans, Nicholas R.; Dixon, Warren

2016-03-15

In one embodiment, a system and method for maintaining objects within a camera field of view include identifying constraints to be enforced, each constraint relating to an attribute of the viewed objects, identifying a priority rank for the constraints such that more important constraints have a higher priority that less important constraints, and determining the set of solutions that satisfy the constraints relative to the order of their priority rank such that solutions that satisfy lower ranking constraints are only considered viable if they also satisfy any higher ranking constraints, each solution providing an indication as to how to control the camera to maintain the objects within the camera field of view.

Feasibility and accuracy assessment of light field (plenoptic) PIV flow-measurement technique

NASA Astrophysics Data System (ADS)

Shekhar, Chandra; Ogawa, Syo; Kawaguchi, Tatsuya

A light field camera can enable measurement of all the three velocity components of a flow field inside a three-dimensional volume when implemented in a PIV measurement. Due to the usage of only one camera, the measurement procedure gets greatly simplified, as well as measurement of the flows with limited visual access also becomes possible. Due to these advantages, light field cameras and their usage in PIV measurements are actively studied. The overall procedure of obtaining an instantaneous flow field consists of imaging a seeded flow at two closely separated time instants, reconstructing the two volumetric distributions of the particles using algorithms such as MART, followed by obtaining the flow velocity through cross-correlations. In this study, we examined effects of various configuration parameters of a light field camera on the in-plane and the depth resolutions, obtained near-optimal parameters in a given case, and then used it to simulate a PIV measurement scenario in order to assess the reconstruction accuracy.

Reigniting the Debate: First Spectroscopic Evidence for Stratospheres In Hot Jupiters

NASA Astrophysics Data System (ADS)

Mandell, Avi M.; Haynes, Korey; Madhusudhan, Nikku; Deming, Drake; Knutson, Heather

2015-12-01

Hot Jupiters represent an extreme end of the exoplanet distribution: they orbit very close to their host stars, which subjects them to an intense heating from stellar radiation. An inverted temperature structure (i.e. a stratosphere) was an early observable prediction from atmospheric models of these planets, which demonstrated that high-temperature absorbers such as TiO and VO could reprocess incident UV/visible irradiation to heat the upper layers of the atmosphere.Evidence for such thermal inversions began with the first secondary eclipse measurements of transiting hot Jupiters taken with the IRAC camera on Spitzer, offering the chance to physical processe at work in the atmospheres of hot exoplanets. However, these efforts have been stymied by recent revelations of significant systematic biases and uncertainties buried within older Spitzer results, calling into question whether or not temperature inversions are actually present in hot Jupiters.We have recently published spectroscopy of secondary eclipses of the extrasolar planet WASP-33b using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope, which allow us to constrain the temperature structure and composition of its dayside atmosphere. WASP-33b is one of the most highly irradiated hot Jupiters discovered to date and orbits a relatively inactive A star, making it an excellent candidate for eclipse spectroscopy at NIR wavelengths (1.1 - 1.7 µm). We find that a fit to combined data from HST, Spitzer and ground-based photometry can rule out models without a temperature inversion; additionally, we find that our measured spectrum displays excess in the measured flux toward short wavelengths that is best explained as emission from TiO.This discovery re-opens the debate on the presence and origin of stratospheres in hot Jupiters, but it also confirms that the combination of HST spectroscopy and a robust analysis of Spitzer and ground-based photometry can conclusively detect thermally inverted atmospheres. In this talk I will present the theoretical underpinnings of temperature inversions in hot Jupiters, discuss the current state of observational evidence including our results for WASP-33b, and describe a path forward for how we can leverage future measurements of exoplanet atmospheric temperature structure to inform our understanding of the composition and formation of exoplanets.

VizieR Online Data Catalog: Jellyfish galaxy candidates in galaxy clusters (Poggianti+, 2016)

NASA Astrophysics Data System (ADS)

Poggianti, B. M.; Fasano, G.; Omizzolo, A.; Gullieuszik, M.; Bettoni, D.; Moretti, A.; Paccagnella, A.; Jaffe, Y. L.; Vulcani, B.; Fritz, J.; Couch, W.; D'Onofrio, M.

2016-10-01

WIde-field Nearby Galaxy-cluster Survey (WINGS) is a large survey targeting 76 clusters of galaxies selected on the basis of their X-ray luminosity (Ebeling et al. 1996, Cat. J/MNRAS/281/799; Ebeling et al. 1998, Cat. J/MNRAS/301/881; Ebeling et al. 2000, Cat. J/MNRAS/318/333), covering a wide range in cluster masses (σ=500-1200+km/s, logLX=43.3-45erg/s, Fasano et al. 2006A&A...445..805F). The original WINGS data set consisted of B and V deep photometry of a 34'*34' field of view with the WFC@INT and the WFC@2.2mMPG/ESO (Varela et al. 2009, Cat. J/A+A/497/667), spectroscopic follow-ups with 2dF@AAT and WYFFOS@WHT (Cava et al. 2009, Cat. J/A+A/495/707), plus J and K imaging with WFC@UKIRT (Valentinuzzi et al. 2009, Cat. J/A+A/501/851) and some U-band imaging (Omizzolo et al. 2014, Cat. J/A+A/561/A111). This database is presented in Moretti et al. 2014A&A...564A.138M and has been employed for a number of studies (see https://sites.google.com/site/wingsomegawings/). OmegaCAM-VST observations of WINGS galaxy clusters (OMEGAWINGS) is a recent extention of this project, that quadruples the area covered (1deg2) and allows to reach up to ~2.5 cluster virial radii. OMEGAWINGS is based on two OmegaCAM@VST GTO programs for 46 WINGS clusters: a B and V campaign completed in P93, and an ongoing u-band programme. The B and V data, the data reduction and the photometric catalogs are presented in Gullieuszik et al. 2015 (Cat. J/A+A/581/A41). Spectra are obtained with AAOmega@AAT on the OmegaCAM field. So far, we have secured high quality spectra for ~30 OMEGAWINGS clusters, reaching very high spectroscopic completeness levels for galaxies brighter than V=20 from the cluster cores to their periphery (A. Moretti et al. 2016, in preparation). Galaxies are considered cluster members if they are within 3σ from the cluster redshift. The mean redshift uncertainty, computed from the differences between WINGS and OMEGAWINGS redshift values of repeated objects, is Δz=0.0002. For this paper we consider the 41 OMEGAWINGS clusters with an OmegaCAM B and/or V-band seeing {<=}1.2arcsec, listed in Table1. To complete the search within the WINGS sample, we used the old WINGS images for other 31 clusters not observed with OmegaCAM (Table1). The reference comparison field sample for WINGS and OMEGAWINGS is the Padova Millennium Galaxy and Group Catalog (PM2GC; Calvi et al. 2011, Cat. J/MNRAS/416/727), built from the Millennium Galaxy Catalogue (MGC; Liske et al. 2003, Cat. VII/240), a deep 38deg2 INT B-imaging survey with a highly complete spectroscopic follow-up (96% at B=20, Driver et al. 2005, Cat. VII/240). (3 data files).

Spatial and Angular Resolution Enhancement of Light Fields Using Convolutional Neural Networks

NASA Astrophysics Data System (ADS)

Gul, M. Shahzeb Khan; Gunturk, Bahadir K.

2018-05-01

Light field imaging extends the traditional photography by capturing both spatial and angular distribution of light, which enables new capabilities, including post-capture refocusing, post-capture aperture control, and depth estimation from a single shot. Micro-lens array (MLA) based light field cameras offer a cost-effective approach to capture light field. A major drawback of MLA based light field cameras is low spatial resolution, which is due to the fact that a single image sensor is shared to capture both spatial and angular information. In this paper, we present a learning based light field enhancement approach. Both spatial and angular resolution of captured light field is enhanced using convolutional neural networks. The proposed method is tested with real light field data captured with a Lytro light field camera, clearly demonstrating spatial and angular resolution improvement.

Spatial and Angular Resolution Enhancement of Light Fields Using Convolutional Neural Networks.

PubMed

Gul, M Shahzeb Khan; Gunturk, Bahadir K

2018-05-01

Light field imaging extends the traditional photography by capturing both spatial and angular distribution of light, which enables new capabilities, including post-capture refocusing, post-capture aperture control, and depth estimation from a single shot. Micro-lens array (MLA) based light field cameras offer a cost-effective approach to capture light field. A major drawback of MLA based light field cameras is low spatial resolution, which is due to the fact that a single image sensor is shared to capture both spatial and angular information. In this paper, we present a learning based light field enhancement approach. Both spatial and angular resolution of captured light field is enhanced using convolutional neural networks. The proposed method is tested with real light field data captured with a Lytro light field camera, clearly demonstrating spatial and angular resolution improvement.

Work-family conflict in Japan: how job and home demands affect psychological distress.

PubMed

Shimazu, Akihito; Bakker, Arnold B; Demerouti, Evangelia; Peeters, Maria C W

2010-01-01

The aim of the present study was to examine how job and home demands are related to psychological distress in a sample of Japanese working parents with preschool children (n=196). We expected that job and home demands are partially related to psychological distress through work-to-family conflict (WFC) and family-to-work conflict (FWC), respectively. Structural equation modeling showed that, as expected, home demands were partially related to psychological distress, both directly and indirectly through FWC. In contrast, job demands were only directly related to psychological distress. The differences between the roles of FWC and WFC are discussed using identity theory.

Astrometric Calibrations of HST Images in the Era of Gaia.

NASA Astrophysics Data System (ADS)

Kozhurina-Platais, Vera; Grogin, Norman A.; Sabbi, Elena

2018-06-01

It is well-known that HST images, taken with ACS/WFC and WFC3/UVIS, have substantial geometric distortion. Over the years our knowledge about this distortion has been vastly improved. Nevertheless, in certain applications it may not be good enough. Preliminary results of comparison state-of-the-art HST astrometric standards and the Gaia DR1 indicate significant scale difference, global rotation, and edge effects in the HST data. However, in terms of positional precision the HST standards are not surpassed yet. The next release of Gaia data DR2 were used to finalize and improve the HST astrometric calibrations down to 0.5 mas or better.

Living the academic life: A model for work-family conflict.

PubMed

Beigi, Mina; Shirmohammadi, Melika; Kim, Sehoon

2015-01-01

Work-family conflict (WFC) is an inter-role conflict, which suggests that fulfilling expectations of family roles makes it difficult to satisfy expectations of work roles, and vice versa. Living an academic life includes balancing multiple work demands and family responsibilities, which may generate WFC for many faculty members. Researchers have emphasized the need for further studies of how faculty integrate work and family demands. This study explores WFC among Iranian faculty. We examine relationships among work hours, time spent with family, work-interference with family (WIF), family-interference with work (FIW), and job satisfaction. Faculty members from 25 Iranian public universities completed a questionnaire. Structural equation modeling was used to test hypotheses in a single model. Findings suggest a positive relationship between faculty weekly work hours and WIF, and between time spent with family and FIW. WIF correlated negatively with job satisfaction, and work hours correlated positively with job satisfaction. Time spent with family and FIW had no influence on job satisfaction, and spouse employment moderated the relationship between WIF and job satisfaction. Findings have implications for human resources and organizational development professionals seeking insight into how faculty members and other knowledge workers experience work-family interrelationships.

VizieR Online Data Catalog: GLASS. IV. Lensing cluster Abell 2744 (Wang+, 2015)

NASA Astrophysics Data System (ADS)

Wang, X.; Hoag, A.; Huang, K.-H.; Treu, T.; Bradac, M.; Schmidt, K. B.; Brammer, G. B.; Vulcani, B.; Jones, T. A.; Ryan, R. E. Jr; Amorin, R.; Castellano, M.; Fontana, A.; Merlin, E.; Trenti, M.

2016-02-01

The two position angles (P.A.s) of Grism Lens-Amplified Survey from Space (GLASS) data analyzed in this study were taken on 2014 August 22 and 23 (P.A.=135) and 2014 October 24 and 25 (P.A.=233), respectively. The Hubble Frontier Fields initiative (HFF, P.I. Lotz) is a Director's Discretionary Time legacy program with HST devoting 840 orbits of HST time to acquire optical ACS and NIR WFC3 imaging of six of the strongest lensing galaxy clusters on the sky. All six HFF clusters are included in the GLASS sample. The Spitzer Frontier Fields program (P.I. Soifer) is a Director's Discretionary Time program that images all six strong lensing galaxy clusters targeted by the HFF in both warm IRAC channels (3.6 and 4.5um). (2 data files).

Wide Field and Planetary Camera for Space Telescope

NASA Technical Reports Server (NTRS)

Lockhart, R. F.

1982-01-01

The Space Telescope's Wide Field and Planetary Camera instrument, presently under construction, will be used to map the observable universe and to study the outer planets. It will be able to see 1000 times farther than any previously employed instrument. The Wide Field system will be located in a radial bay, receiving its signals via a pick-off mirror centered on the optical axis of the telescope assembly. The external thermal radiator employed by the instrument for cooling will be part of the exterior surface of the Space Telescope. In addition to having a larger (1200-12,000 A) wavelength range than any of the other Space Telescope instruments, its data rate, at 1 Mb/sec, exceeds that of the other instruments. Attention is given to the operating modes and projected performance levels of the Wide Field Camera and Planetary Camera.

Small format digital photogrammetry for applications in the earth sciences

NASA Astrophysics Data System (ADS)

Rieke-Zapp, Dirk

2010-05-01

Small format digital photogrammetry for applications in the earth sciences Photogrammetry is often considered one of the most precise and versatile surveying techniques. The same camera and analysis software can be used for measurements from sub-millimetre to kilometre scale. Such a measurement device is well suited for application by earth scientists working in the field. In this case a small toolset and a straight forward setup best fit the needs of the operator. While a digital camera is typically already part of the field equipment of an earth scientist the main focus of the field work is often not surveying. Lack in photogrammetric training at the same time requires an easy to learn, straight forward surveying technique. A photogrammetric method was developed aimed primarily at earth scientists for taking accurate measurements in the field minimizing extra bulk and weight of the required equipment. The work included several challenges. A) Definition of an upright coordinate system without heavy and bulky tools like a total station or GNS-Sensor. B) Optimization of image acquisition and geometric stability of the image block. C) Identification of a small camera suitable for precise measurements in the field. D) Optimization of the workflow from image acquisition to preparation of images for stereo measurements. E) Introduction of students and non-photogrammetrists to the workflow. Wooden spheres were used as target points in the field. They were more rugged and available in different sizes than ping pong balls used in a previous setup. Distances between three spheres were introduced as scale information in a photogrammetric adjustment. The distances were measured with a laser distance meter accurate to 1 mm (1 sigma). The vertical angle between the spheres was measured with the same laser distance meter. The precision of the measurement was 0.3° (1 sigma) which is sufficient, i.e. better than inclination measurements with a geological compass. The upright coordinate system is important to measure the dip angle of geologic features in outcrop. The planimetric coordinate systems would be arbitrary, but may easily be oriented to compass north introducing a direction measurement of a compass. Wooden spheres and a Leica disto D3 laser distance meter added less than 0.150 kg to the field equipment considering that a suitable digital camera was already part of it. Identification of a small digital camera suitable for precise measurements was a major part of this work. A group of cameras were calibrated several times over different periods of time on a testfield. Further evaluation involved an accuracy assessment in the field comparing distances between signalized points calculated form a photogrammetric setup with coordinates derived from a total station survey. The smallest camera in the test required calibration on the job as the interior orientation changed significantly between testfield calibration and use in the field. We attribute this to the fact that the lens was retracted then the camera was switched off. Fairly stable camera geometry in a compact size camera with lens retracting system was accomplished for Sigma DP1 and DP2 cameras. While the pixel count of the cameras was less than for the Ricoh, the pixel pitch in the Sigma cameras was much larger. Hence, the same mechanical movement would have less per pixel effect for the Sigma cameras than for the Ricoh camera. A large pixel pitch may therefore compensate for some camera instability explaining why cameras with large sensors and larger pixel pitch typically yield better accuracy in object space. Both Sigma cameras weigh approximately 0.250 kg and may even be suitable for use with ultralight aerial vehicles (UAV) which have payload restriction of 0.200 to 0.300 kg. A set of other cameras that were available were also tested on a calibration field and on location showing once again that it is difficult to reason geometric stability from camera specifications. Image acquisition with geometrically stable cameras was fairly straight forward to cover the area of interest with stereo pairs for analysis. We limited our tests to setups with three to five images to minimize the amount of post processing. The laser dot of the laser distance meter was not visible for distances farther than 5-7 m with the naked eye which also limited the maximum stereo area that may be covered with this technique. Extrapolating the setup to fairly large areas showed no significant decrease in accuracy accomplished in object space. Working with a Sigma SD14 SLR camera on a 6 x 18 x 20 m3 volume the maximum length measurement error ranged between 20 and 30 mm depending on image setup and analysis. For smaller outcrops even the compact cameras yielded maximum length measurement errors in the mm range which was considered sufficient for measurements in the earth sciences. In many cases the resolution per pixel was the limiting factor of image analysis rather than accuracy. A field manual was developed guiding novice users and students to this technique. The technique does not simplify ease of use for precision; therefore successful users of the presented method easily grow into more advanced photogrammetric methods for high precision applications. Originally camera calibration was not part of the methodology for the novice operators. Recent introduction of Camera Calibrator which is a low cost, well automated software for camera calibration, allowed beginners to calibrate their camera within a couple minutes. The complete set of calibration parameters can be applied in ERDAS LPS software easing the workflow. Image orientation was performed in LPS 9.2 software which was also used for further image analysis.

Application of infrared camera to bituminous concrete pavements: measuring vehicle

NASA Astrophysics Data System (ADS)

Janků, Michal; Stryk, Josef

2017-09-01

Infrared thermography (IR) has been used for decades in certain fields. However, the technological level of advancement of measuring devices has not been sufficient for some applications. Over the recent years, good quality thermal cameras with high resolution and very high thermal sensitivity have started to appear on the market. The development in the field of measuring technologies allowed the use of infrared thermography in new fields and for larger number of users. This article describes the research in progress in Transport Research Centre with a focus on the use of infrared thermography for diagnostics of bituminous road pavements. A measuring vehicle, equipped with a thermal camera, digital camera and GPS sensor, was designed for the diagnostics of pavements. New, highly sensitive, thermal cameras allow to measure very small temperature differences from the moving vehicle. This study shows the potential of a high-speed inspection without lane closures while using IR thermography.

Adaptive DOF for plenoptic cameras

NASA Astrophysics Data System (ADS)

Oberdörster, Alexander; Lensch, Hendrik P. A.

2013-03-01

Plenoptic cameras promise to provide arbitrary re-focusing through a scene after the capture. In practice, however, the refocusing range is limited by the depth of field (DOF) of the plenoptic camera. For the focused plenoptic camera, this range is given by the range of object distances for which the microimages are in focus. We propose a technique of recording light fields with an adaptive depth of focus. Between multiple exposures { or multiple recordings of the light field { the distance between the microlens array (MLA) and the image sensor is adjusted. The depth and quality of focus is chosen by changing the number of exposures and the spacing of the MLA movements. In contrast to traditional cameras, extending the DOF does not necessarily lead to an all-in-focus image. Instead, the refocus range is extended. There is full creative control about the focus depth; images with shallow or selective focus can be generated.

High-Resolution Large Field-of-View FUV Compact Camera

NASA Technical Reports Server (NTRS)

Spann, James F.

2006-01-01

The need for a high resolution camera with a large field of view and capable to image dim emissions in the far-ultraviolet is driven by the widely varying intensities of FUV emissions and spatial/temporal scales of phenomena of interest in the Earth% ionosphere. In this paper, the concept of a camera is presented that is designed to achieve these goals in a lightweight package with sufficient visible light rejection to be useful for dayside and nightside emissions. The camera employs the concept of self-filtering to achieve good spectral resolution tuned to specific wavelengths. The large field of view is sufficient to image the Earth's disk at Geosynchronous altitudes and capable of a spatial resolution of >20 km. The optics and filters are emphasized.

Imaging experiment: The Viking Lander

USGS Publications Warehouse

Mutch, T.A.; Binder, A.B.; Huck, F.O.; Levinthal, E.C.; Morris, E.C.; Sagan, C.; Young, A.T.

1972-01-01

The Viking Lander Imaging System will consist of two identical facsimile cameras. Each camera has a high-resolution mode with an instantaneous field of view of 0.04??, and survey and color modes with instantaneous fields of view of 0.12??. Cameras are positioned one meter apart to provide stereoscopic coverage of the near-field. The Imaging Experiment will provide important information about the morphology, composition, and origin of the Martian surface and atmospheric features. In addition, lander pictures will provide supporting information for other experiments in biology, organic chemistry, meteorology, and physical properties. ?? 1972.

Video Capture of Plastic Surgery Procedures Using the GoPro HERO 3+.

PubMed

Graves, Steven Nicholas; Shenaq, Deana Saleh; Langerman, Alexander J; Song, David H

2015-02-01

Significant improvements can be made in recoding surgical procedures, particularly in capturing high-quality video recordings from the surgeons' point of view. This study examined the utility of the GoPro HERO 3+ Black Edition camera for high-definition, point-of-view recordings of plastic and reconstructive surgery. The GoPro HERO 3+ Black Edition camera was head-mounted on the surgeon and oriented to the surgeon's perspective using the GoPro App. The camera was used to record 4 cases: 2 fat graft procedures and 2 breast reconstructions. During cases 1-3, an assistant remotely controlled the GoPro via the GoPro App. For case 4 the GoPro was linked to a WiFi remote, and controlled by the surgeon. Camera settings for case 1 were as follows: 1080p video resolution; 48 fps; Protune mode on; wide field of view; 16:9 aspect ratio. The lighting contrast due to the overhead lights resulted in limited washout of the video image. Camera settings were adjusted for cases 2-4 to a narrow field of view, which enabled the camera's automatic white balance to better compensate for bright lights focused on the surgical field. Cases 2-4 captured video sufficient for teaching or presentation purposes. The GoPro HERO 3+ Black Edition camera enables high-quality, cost-effective video recording of plastic and reconstructive surgery procedures. When set to a narrow field of view and automatic white balance, the camera is able to sufficiently compensate for the contrasting light environment of the operating room and capture high-resolution, detailed video.

Accuracy evaluation of optical distortion calibration by digital image correlation

NASA Astrophysics Data System (ADS)

Gao, Zeren; Zhang, Qingchuan; Su, Yong; Wu, Shangquan

2017-11-01

Due to its convenience of operation, the camera calibration algorithm, which is based on the plane template, is widely used in image measurement, computer vision and other fields. How to select a suitable distortion model is always a problem to be solved. Therefore, there is an urgent need for an experimental evaluation of the accuracy of camera distortion calibrations. This paper presents an experimental method for evaluating camera distortion calibration accuracy, which is easy to implement, has high precision, and is suitable for a variety of commonly used lens. First, we use the digital image correlation method to calculate the in-plane rigid body displacement field of an image displayed on a liquid crystal display before and after translation, as captured with a camera. Next, we use a calibration board to calibrate the camera to obtain calibration parameters which are used to correct calculation points of the image before and after deformation. The displacement field before and after correction is compared to analyze the distortion calibration results. Experiments were carried out to evaluate the performance of two commonly used industrial camera lenses for four commonly used distortion models.

Engineering design criteria for an image intensifier/image converter camera

NASA Technical Reports Server (NTRS)

Sharpsteen, J. T.; Lund, D. L.; Stoap, L. J.; Solheim, C. D.

1976-01-01

The design, display, and evaluation of an image intensifier/image converter camera which can be utilized in various requirements of spaceshuttle experiments are described. An image intensifier tube was utilized in combination with two brassboards as power supply and used for evaluation of night photography in the field. Pictures were obtained showing field details which would have been undistinguishable to the naked eye or to an ordinary camera.

Plenoptic Image Motion Deblurring.

PubMed

Chandramouli, Paramanand; Jin, Meiguang; Perrone, Daniele; Favaro, Paolo

2018-04-01

We propose a method to remove motion blur in a single light field captured with a moving plenoptic camera. Since motion is unknown, we resort to a blind deconvolution formulation, where one aims to identify both the blur point spread function and the latent sharp image. Even in the absence of motion, light field images captured by a plenoptic camera are affected by a non-trivial combination of both aliasing and defocus, which depends on the 3D geometry of the scene. Therefore, motion deblurring algorithms designed for standard cameras are not directly applicable. Moreover, many state of the art blind deconvolution algorithms are based on iterative schemes, where blurry images are synthesized through the imaging model. However, current imaging models for plenoptic images are impractical due to their high dimensionality. We observe that plenoptic cameras introduce periodic patterns that can be exploited to obtain highly parallelizable numerical schemes to synthesize images. These schemes allow extremely efficient GPU implementations that enable the use of iterative methods. We can then cast blind deconvolution of a blurry light field image as a regularized energy minimization to recover a sharp high-resolution scene texture and the camera motion. Furthermore, the proposed formulation can handle non-uniform motion blur due to camera shake as demonstrated on both synthetic and real light field data.

a Spatio-Spectral Camera for High Resolution Hyperspectral Imaging

NASA Astrophysics Data System (ADS)

Livens, S.; Pauly, K.; Baeck, P.; Blommaert, J.; Nuyts, D.; Zender, J.; Delauré, B.

2017-08-01

Imaging with a conventional frame camera from a moving remotely piloted aircraft system (RPAS) is by design very inefficient. Less than 1 % of the flying time is used for collecting light. This unused potential can be utilized by an innovative imaging concept, the spatio-spectral camera. The core of the camera is a frame sensor with a large number of hyperspectral filters arranged on the sensor in stepwise lines. It combines the advantages of frame cameras with those of pushbroom cameras. By acquiring images in rapid succession, such a camera can collect detailed hyperspectral information, while retaining the high spatial resolution offered by the sensor. We have developed two versions of a spatio-spectral camera and used them in a variety of conditions. In this paper, we present a summary of three missions with the in-house developed COSI prototype camera (600-900 nm) in the domains of precision agriculture (fungus infection monitoring in experimental wheat plots), horticulture (crop status monitoring to evaluate irrigation management in strawberry fields) and geology (meteorite detection on a grassland field). Additionally, we describe the characteristics of the 2nd generation, commercially available ButterflEYE camera offering extended spectral range (475-925 nm), and we discuss future work.

Single-camera displacement field correlation method for centrosymmetric 3D dynamic deformation measurement

NASA Astrophysics Data System (ADS)

Zhao, Jiaye; Wen, Huihui; Liu, Zhanwei; Rong, Jili; Xie, Huimin

2018-05-01

Three-dimensional (3D) deformation measurements are a key issue in experimental mechanics. In this paper, a displacement field correlation (DFC) method to measure centrosymmetric 3D dynamic deformation using a single camera is proposed for the first time. When 3D deformation information is collected by a camera at a tilted angle, the measured displacement fields are coupling fields of both the in-plane and out-of-plane displacements. The features of the coupling field are analysed in detail, and a decoupling algorithm based on DFC is proposed. The 3D deformation to be measured can be inverted and reconstructed using only one coupling field. The accuracy of this method was validated by a high-speed impact experiment that simulated an underwater explosion. The experimental results show that the approach proposed in this paper can be used in 3D deformation measurements with higher sensitivity and accuracy, and is especially suitable for high-speed centrosymmetric deformation. In addition, this method avoids the non-synchronisation problem associated with using a pair of high-speed cameras, as is common in 3D dynamic measurements.

Optical Meteor Systems Used by the NASA Meteoroid Environment Office

NASA Technical Reports Server (NTRS)

Kingery, A. M.; Blaauw, R. C.; Cooke, W. J.; Moser, D. E.

2015-01-01

The NASA Meteoroid Environment Office (MEO) uses two main meteor camera networks to characterize the meteoroid environment: an all sky system and a wide field system to study cm and mm size meteors respectively. The NASA All Sky Fireball Network consists of fifteen meteor video cameras in the United States, with plans to expand to eighteen cameras by the end of 2015. The camera design and All-Sky Guided and Real-time Detection (ASGARD) meteor detection software [1, 2] were adopted from the University of Western Ontario's Southern Ontario Meteor Network (SOMN). After seven years of operation, the network has detected over 12,000 multi-station meteors, including meteors from at least 53 different meteor showers. The network is used for speed distribution determination, characterization of meteor showers and sporadic sources, and for informing the public on bright meteor events. The NASA Wide Field Meteor Network was established in December of 2012 with two cameras and expanded to eight cameras in December of 2014. The two camera configuration saw 5470 meteors over two years of operation with two cameras, and has detected 3423 meteors in the first five months of operation (Dec 12, 2014 - May 12, 2015) with eight cameras. We expect to see over 10,000 meteors per year with the expanded system. The cameras have a 20 degree field of view and an approximate limiting meteor magnitude of +5. The network's primary goal is determining the nightly shower and sporadic meteor fluxes. Both camera networks function almost fully autonomously with little human interaction required for upkeep and analysis. The cameras send their data to a central server for storage and automatic analysis. Every morning the servers automatically generates an e-mail and web page containing an analysis of the previous night's events. The current status of the networks will be described, alongside with preliminary results. In addition, future projects, CCD photometry and broadband meteor color camera system, will be discussed.

Localization and Mapping Using a Non-Central Catadioptric Camera System

NASA Astrophysics Data System (ADS)

Khurana, M.; Armenakis, C.

2018-05-01

This work details the development of an indoor navigation and mapping system using a non-central catadioptric omnidirectional camera and its implementation for mobile applications. Omnidirectional catadioptric cameras find their use in navigation and mapping of robotic platforms, owing to their wide field of view. Having a wider field of view, or rather a potential 360° field of view, allows the system to "see and move" more freely in the navigation space. A catadioptric camera system is a low cost system which consists of a mirror and a camera. Any perspective camera can be used. A platform was constructed in order to combine the mirror and a camera to build a catadioptric system. A calibration method was developed in order to obtain the relative position and orientation between the two components so that they can be considered as one monolithic system. The mathematical model for localizing the system was determined using conditions based on the reflective properties of the mirror. The obtained platform positions were then used to map the environment using epipolar geometry. Experiments were performed to test the mathematical models and the achieved location and mapping accuracies of the system. An iterative process of positioning and mapping was applied to determine object coordinates of an indoor environment while navigating the mobile platform. Camera localization and 3D coordinates of object points obtained decimetre level accuracies.

Assessment of the metrological performance of an in situ storage image sensor ultra-high speed camera for full-field deformation measurements

NASA Astrophysics Data System (ADS)

Rossi, Marco; Pierron, Fabrice; Forquin, Pascal

2014-02-01

Ultra-high speed (UHS) cameras allow us to acquire images typically up to about 1 million frames s-1 for a full spatial resolution of the order of 1 Mpixel. Different technologies are available nowadays to achieve these performances, an interesting one is the so-called in situ storage image sensor architecture where the image storage is incorporated into the sensor chip. Such an architecture is all solid state and does not contain movable devices as occurs, for instance, in the rotating mirror UHS cameras. One of the disadvantages of this system is the low fill factor (around 76% in the vertical direction and 14% in the horizontal direction) since most of the space in the sensor is occupied by memory. This peculiarity introduces a series of systematic errors when the camera is used to perform full-field strain measurements. The aim of this paper is to develop an experimental procedure to thoroughly characterize the performance of such kinds of cameras in full-field deformation measurement and identify the best operative conditions which minimize the measurement errors. A series of tests was performed on a Shimadzu HPV-1 UHS camera first using uniform scenes and then grids under rigid movements. The grid method was used as full-field measurement optical technique here. From these tests, it has been possible to appropriately identify the camera behaviour and utilize this information to improve actual measurements.

The Surgeon's View: Comparison of Two Digital Video Recording Systems in Veterinary Surgery.

PubMed

Giusto, Gessica; Caramello, Vittorio; Comino, Francesco; Gandini, Marco

2015-01-01

Video recording and photography during surgical procedures are useful in veterinary medicine for several reasons, including legal, educational, and archival purposes. Many systems are available, such as hand cameras, light-mounted cameras, and head cameras. We chose a reasonably priced head camera that is among the smallest video cameras available. To best describe its possible uses and advantages, we recorded video and images of eight different surgical cases and procedures, both in hospital and field settings. All procedures were recorded both with a head-mounted camera and a commercial hand-held photo camera. Then sixteen volunteers (eight senior clinicians and eight final-year students) completed an evaluation questionnaire. Both cameras produced high-quality photographs and videos, but observers rated the head camera significantly better regarding point of view and their understanding of the surgical operation. The head camera was considered significantly more useful in teaching surgical procedures. Interestingly, senior clinicians tended to assign generally lower scores compared to students. The head camera we tested is an effective, easy-to-use tool for recording surgeries and various veterinary procedures in all situations, with no need for assistance from a dedicated operator. It can be a valuable aid for veterinarians working in all fields of the profession and a useful tool for veterinary surgical education.

Local sensitivity analysis for inverse problems solved by singular value decomposition

USGS Publications Warehouse

Hill, M.C.; Nolan, B.T.

2010-01-01

Local sensitivity analysis provides computationally frugal ways to evaluate models commonly used for resource management, risk assessment, and so on. This includes diagnosing inverse model convergence problems caused by parameter insensitivity and(or) parameter interdependence (correlation), understanding what aspects of the model and data contribute to measures of uncertainty, and identifying new data likely to reduce model uncertainty. Here, we consider sensitivity statistics relevant to models in which the process model parameters are transformed using singular value decomposition (SVD) to create SVD parameters for model calibration. The statistics considered include the PEST identifiability statistic, and combined use of the process-model parameter statistics composite scaled sensitivities and parameter correlation coefficients (CSS and PCC). The statistics are complimentary in that the identifiability statistic integrates the effects of parameter sensitivity and interdependence, while CSS and PCC provide individual measures of sensitivity and interdependence. PCC quantifies correlations between pairs or larger sets of parameters; when a set of parameters is intercorrelated, the absolute value of PCC is close to 1.00 for all pairs in the set. The number of singular vectors to include in the calculation of the identifiability statistic is somewhat subjective and influences the statistic. To demonstrate the statistics, we use the USDA’s Root Zone Water Quality Model to simulate nitrogen fate and transport in the unsaturated zone of the Merced River Basin, CA. There are 16 log-transformed process-model parameters, including water content at field capacity (WFC) and bulk density (BD) for each of five soil layers. Calibration data consisted of 1,670 observations comprising soil moisture, soil water tension, aqueous nitrate and bromide concentrations, soil nitrate concentration, and organic matter content. All 16 of the SVD parameters could be estimated by regression based on the range of singular values. Identifiability statistic results varied based on the number of SVD parameters included. Identifiability statistics calculated for four SVD parameters indicate the same three most important process-model parameters as CSS/PCC (WFC1, WFC2, and BD2), but the order differed. Additionally, the identifiability statistic showed that BD1 was almost as dominant as WFC1. The CSS/PCC analysis showed that this results from its high correlation with WCF1 (-0.94), and not its individual sensitivity. Such distinctions, combined with analysis of how high correlations and(or) sensitivities result from the constructed model, can produce important insights into, for example, the use of sensitivity analysis to design monitoring networks. In conclusion, the statistics considered identified similar important parameters. They differ because (1) with CSS/PCC can be more awkward because sensitivity and interdependence are considered separately and (2) identifiability requires consideration of how many SVD parameters to include. A continuing challenge is to understand how these computationally efficient methods compare with computationally demanding global methods like Markov-Chain Monte Carlo given common nonlinear processes and the often even more nonlinear models.

Probing Minor-merger-driven Star Formation In Early-type Galaxies Using Spatially-resolved Spectro-photometric Studies

NASA Astrophysics Data System (ADS)

Kaviraj, Sugata; Crockett, M.; Silk, J.; O'Connell, R. W.; Whitmore, B.; Windhorst, R.; Cappellari, M.; Bureau, M.; Davies, R.

2012-01-01

Recent studies that leverage the rest-frame ultraviolet (UV) spectrum have revealed widespread recent star formation in early-type galaxies (ETGs), traditionally considered to be old, passively-evolving systems. This recent star formation builds 20% of the ETG stellar mass after z 1, driven by repeated minor mergers between ETGs and small, gas-rich satellites. We demonstrate how spatially-resolved studies, using a combination of high-resolution UV-optical imaging and integral-field spectroscopy (IFS), is a powerful tool to quantify the assembly history of individual ETGs and elucidate the poorly-understood minor-merger process. Using a combination of WFC3 UV-optical (2500-8200 angstroms) imaging and IFS from the SAURON project of the ETG NGC 4150, we show that this galaxy experienced a merger with mass ratio 1:15 around 0.9 Gyr ago, which formed 3% of its stellar mass and a young kinematically-decoupled core. A UV-optical analysis of its globular cluster system shows that the bulk of the stars locked up in these clusters likely formed 6-7 Gyrs in the past. We introduce a new HST-WFC3 programme, approved in Cycle 19, which will leverage similar UV-optical imaging of a representative sample of nearby ETGs from SAURON to study the recent star formation and its drivers in unprecedented detail and put definitive constraints on minor-merger-driven star formation in massive galaxies at late epochs.