XMM-Newton Mobile Web Application

NASA Astrophysics Data System (ADS)

Ibarra, A.; Kennedy, M.; Rodríguez, P.; Hernández, C.; Saxton, R.; Gabriel, C.

2013-10-01

We present the first XMM-Newton web mobile application, coded using new web technologies such as HTML5, the Query mobile framework, and D3 JavaScript data-driven library. This new web mobile application focuses on re-formatted contents extracted directly from the XMM-Newton web, optimizing the contents for mobile devices. The main goals of this development were to reach all kind of handheld devices and operating systems, while minimizing software maintenance. The application therefore has been developed as a web mobile implementation rather than a more costly native application. New functionality will be added regularly.

A systematic analysis of the XMM-Newton background: I. Dataset and extraction procedures

NASA Astrophysics Data System (ADS)

Marelli, Martino; Salvetti, David; Gastaldello, Fabio; Ghizzardi, Simona; Molendi, Silvano; Luca, Andrea De; Moretti, Alberto; Rossetti, Mariachiara; Tiengo, Andrea

2017-12-01

XMM-Newton is the direct precursor of the future ESA ATHENA mission. A study of its particle-induced background provides therefore significant insight for the ATHENA mission design. We make use of ˜12 years of data, products from the third XMM-Newton catalog as well as FP7 EXTraS project to avoid celestial sources contamination and to disentangle the different components of the XMM-Newton particle-induced background. Within the ESA R&D AREMBES collaboration, we built new analysis pipelines to study the different components of this background: this covers time behavior as well as spectral and spatial characteristics.

XMM-Newton Remote Interface to Science Analysis Software: First Public Version

NASA Astrophysics Data System (ADS)

Ibarra, A.; Gabriel, C.

2011-07-01

We present the first public beta release of the XMM-Newton Remote Interface to Science Analysis (RISA) software, available through the official XMM-Newton web pages. In a nutshell, RISA is a web based application that encapsulates the XMM-Newton data analysis software. The client identifies observations and creates XMM-Newton workflows. The server processes the client request, creates job templates and sends the jobs to a computer. RISA has been designed to help, at the same time, non-expert and professional XMM-Newton users. Thanks to the predefined threads, non-expert users can easily produce light curves and spectra. And on the other hand, expert user can use the full parameter interface to tune their own analysis. In both cases, the VO compliant client/server design frees the users from having to install any specific software to analyze XMM-Newton data.

XMM-Newton 13H deep field - I. X-ray sources

NASA Astrophysics Data System (ADS)

Loaring, N. S.; Dwelly, T.; Page, M. J.; Mason, K.; McHardy, I.; Gunn, K.; Moss, D.; Seymour, N.; Newsam, A. M.; Takata, T.; Sekguchi, K.; Sasseen, T.; Cordova, F.

2005-10-01

We present the results of a deep X-ray survey conducted with XMM-Newton, centred on the UK ROSAT13H deep field area. This region covers 0.18 deg2, and is the first of the two areas covered with XMM-Newton as part of an extensive multiwavelength survey designed to study the nature and evolution of the faint X-ray source population. We have produced detailed Monte Carlo simulations to obtain a quantitative characterization of the source detection procedure and to assess the reliability of the resultant sourcelist. We use the simulations to establish a likelihood threshold, above which we expect less than seven (3 per cent) of our sources to be spurious. We present the final catalogue of 225 sources. Within the central 9 arcmin, 68 per cent of source positions are accurate to 2 arcsec, making optical follow-up relatively straightforward. We construct the N(>S) relation in four energy bands: 0.2-0.5, 0.5-2, 2-5 and 5-10 keV. In all but our highest energy band we find that the source counts can be represented by a double power law with a bright-end slope consistent with the Euclidean case and a break around 10-14yergcm-2s-1. Below this flux, the counts exhibit a flattening. Our source counts reach densities of 700, 1300, 900 and 300 deg-2 at fluxes of 4.1 × 10-16,4.5 × 10-16,1.1 × 10-15 and 5.3 × 10-15ergcm-2s-1 in the 0.2-0.5, 0.5-2, 2-5 and 5-10 keV energy bands, respectively. We have compared our source counts with those in the two Chandra deep fields and Lockman hole, and found our source counts to be amongst the highest of these fields in all energy bands. We resolve >51 per cent (>50 per cent) of the X-ray background emission in the 1-2 keV (2-5 keV) energy bands.

The XMM-Newton Survey of the Small Magellanic Cloud

NASA Technical Reports Server (NTRS)

Haberl, F.; Sturm, R.; Ballet, J.; Bomans, D. J.; Buckley, D. A. H.; Coe, M. J.; Corbet, R.; Ehle, M.; Filipovic, M. D.; Gilfanov, M.;

XMM-Newton On-demand Reprocessing Using SaaS Technology

NASA Astrophysics Data System (ADS)

Ibarra, A.; Fajersztejn, N.; Loiseau, N.; Gabriel, C.

2014-05-01

We present here the architectural design of the new on-the-fly reprocessing capabilities that will be soon developed and implemented in the new XMM-Newton Science Operation Centre. The inclusion of processing capabilities into the archive, as we plan, will be possible thanks to the recent refurbishment of the XMM-Newton science archive, its alignment with the latest web technologies and the XMM-Newton Remote Interface for Science Analysis (RISA), a revolutionary idea of providing processing capabilities through internet services.

An X-Ray Investigation of the NGC346 Field in the SMC (3): XMM-Newton Data

NASA Technical Reports Server (NTRS)

Naze, Yael; Manfroid, Jean; Corcoran, Michael F.; Stevens, Ian R.

2004-01-01

We present new XMM-Newton results on the field around the NGC346 star cluster in the SMC. This continues and extends previously published work on Chandra observations of the same field. The two XMM-Newton observations were obtained, respectively, six months before and six months after the previously published Chandra data. Of the 51 X-ray sources detected with XMM-Newton, 29 were already detected with Chandru. Comparing the properties of these X-ray sources in each of our three datasets has enabled us to investigate their variability on times scales of a year. Changes in the flux levels and/or spectral properties were observed for 21 of these sources. In addition, we discovered long-term variations in the X-ray properties of the peculiar system HD5980, a luminous blue variable star, that is likely to be a colliding wind binary system, which displays the largest luminosity during the first XMM-Newton observation.

XMM-Newton, powerful AGN winds and galaxy feedback

NASA Astrophysics Data System (ADS)

Pounds, K.; King, A.

2016-06-01

The discovery that ultra-fast ionized winds - sufficiently powerful to disrupt growth of the host galaxy - are a common feature of luminous AGN is major scientific breakthrough led by XMM-Newton. An extended observation in 2014 of the prototype UFO, PG1211+143, has revealed an unusually complex outflow, with distinct and persisting velocities detected in both hard and soft X-ray spectra. While the general properties of UFOs are consistent with being launched - at the local escape velocity - from the inner disc where the accretion rate is modestly super-Eddington (King and Pounds, Ann Rev Astron Astro- phys 2015), these more complex flows have raised questions about the outflow geometry and the importance of shocks and enhanced cooling. XMM-Newton seems likely to remain the best Observatory to study UFOs prior to Athena, and further extended observations, of PG1211+143 and other bright AGN, have the exciting potential to establish the typical wind dynamics, while providing new insights on the accretion geometry and continuum source structure. An emphasis on such large, coordinated observing programmes with XMM-Newton over the next decade will continue the successful philosophy pioneered by EXOSAT, while helping to inform the optimum planning for Athena

Analysis of XMM-Newton Data from Extended Sources and the Diffuse X-Ray Background

NASA Technical Reports Server (NTRS)

Snowden, Steven

2011-01-01

Reduction of X-ray data from extended objects and the diffuse background is a complicated process that requires attention to the details of the instrumental response as well as an understanding of the multiple background components. We present methods and software that we have developed to reduce data from XMM-Newton EPIC imaging observations for both the MOS and PN instruments. The software has now been included in the Science Analysis System (SAS) package available through the XMM-Newton Science Operations Center (SOC).

Resolving galaxy cluster gas properties at z ˜ 1 with XMM-Newton and Chandra

NASA Astrophysics Data System (ADS)

Bartalucci, I.; Arnaud, M.; Pratt, G. W.; Démoclès, J.; van der Burg, R. F. J.; Mazzotta, P.

2017-02-01

Massive, high-redshift, galaxy clusters are useful laboratories to test cosmological models and to probe structure formation and evolution, but observations are challenging due to cosmological dimming and angular distance effects. Here we present a pilot X-ray study of the five most massive (M500 > 5 × 1014M⊙), distant (z 1), clusters detected via the Sunyaev-Zel'Dovich effect. We optimally combine XMM-Newton and Chandra X-ray observations by leveraging the throughput of XMM-Newton to obtain spatially-resolved spectroscopy, and the spatial resolution of Chandra to probe the bright inner parts and to detect embedded point sources. Capitalising on the excellent agreement in flux-related measurements, we present a new method to derive the density profiles, which are constrained in the centre by Chandra and in the outskirts by XMM-Newton. We show that the Chandra-XMM-Newton combination is fundamental for morphological analysis at these redshifts, the Chandra resolution being required to remove point source contamination, and the XMM-Newton sensitivity allowing higher significance detection of faint substructures. Measuring the morphology using images from both instruments, we found that the sample is dominated by dynamically disturbed objects. We use the combined Chandra-XMM-Newton density profiles and spatially-resolved temperature profiles to investigate thermodynamic quantities including entropy and pressure. From comparison of the scaled profiles with the local REXCESS sample, we find no significant departure from standard self-similar evolution, within the dispersion, at any radius, except for the entropy beyond 0.7 R500. The baryon mass fraction tends towards the cosmic value, with a weaker dependence on mass than that observed in the local Universe. We make a comparison with the predictions from numerical simulations. The present pilot study demonstrates the utility and feasibility of spatially-resolved analysis of individual objects at high-redshift through

ESO imaging survey: optical follow-up of 12 selected XMM-Newton fields

NASA Astrophysics Data System (ADS)

Dietrich, J. P.; Miralles, J.-M.; Olsen, L. F.; da Costa, L.; Schwope, A.; Benoist, C.; Hambaryan, V.; Mignano, A.; Motch, C.; Rité, C.; Slijkhuis, R.; Tedds, J.; Vandame, B.; Watson, M. G.; Zaggia, S.

2006-04-01

This paper presents the data recently released for the XMM-Newton/WFI survey carried out as part of the ESO Imaging Survey (EIS) project. The aim of this survey is to provide optical imaging follow-up data in BVRI for identification of serendipitously detected X-ray sources in selected XMM-Newton fields. In this paper, fully calibrated individual and stacked images of 12 fields as well as science-grade catalogs for the 8 fields located at high-galactic latitude are presented. These products were created, calibrated and released using the infrastructure provided by the EIS Data Reduction system and its associated EIS/MVM image processing engine, both of which are briefly described here. The data covers an area of ~3 square degrees for each of the four passbands. The median seeing as measured in the final stacked images is 0.94 arcsec, ranging from 0.60 arcsec and 1.51 arcsec. The median limiting magnitudes (AB system, 2´´ aperture, 5σ detection limit) are 25.20, 24.92, 24.66, and 24.39 mag for B-, V-, R-, and I-band, respectively. When only the 8 high-galactic latitude fields are included these become 25.33, 25.05, 25.36, and 24.58 mag, in good agreement with the planned depth of the survey. Visual inspection of images and catalogs, comparison of statistics derived from the present data with those obtained by other authors and model predictions, as well as direct comparison of the results obtained from independent reductions of the same data, demonstrate the science-grade quality of the automatically produced final images and catalogs. These survey products, together with their logs, are available to the community for science exploitation in conjunction with their X-ray counterparts. Preliminary results from the X-ray/optical cross-correlation analysis show that about 61% of the detected X-ray point sources in deep XMM-Newton exposures have at least one optical counterpart within 2´´ radius down to R ≃ 25 mag, 50% of which are so faint as to require VLT

Efficient management of high level XMM-Newton science data products

NASA Astrophysics Data System (ADS)

Zolotukhin, Ivan

2015-12-01

Like it is the case for many large projects, XMM-Newton data have been used by the community to produce many valuable higher level data products. However, even after 15 years of the successful mission operation, the potential of these data is not yet fully uncovered, mostly due to the logistical and data management issues. We present a web application, http://xmm-catalog.irap.omp.eu, to highlight an idea that existing public high level data collections generate significant added research value when organized and exposed properly. Several application features such as access to the all-time XMM-Newton photon database and online fitting of extracted sources spectra were never available before. In this talk we share best practices we worked out during the development of this website and discuss their potential use for other large projects generating astrophysical data.

ESA's XMM-Newton gains deep insights into the distant Universe

NASA Astrophysics Data System (ADS)

2003-07-01

First image from the XMM-LSS survey hi-res Size hi-res: 87 kb Credits: ESA First image from the XMM-LSS survey The first image from the XMM-LSS survey is actually a combination of fourteen separate 'pointings' of the space observatory. It represents a region of the sky eight times larger than the full Moon and contains around 25 clusters. The circles represent the sources previously known from the 1991 ROSAT All-Sky Survey. A computer programme zooms in on an interesting region hi-res Size hi-res: 86 kb Credits: ESA A computer programme zooms in on an interesting region A computer programme zooms in on an interesting region of the image and identifies the possible cluster. Each point on this graph represents a single X-ray photons detected by XMM-Newton. Most come from distant actie galaxies and the computer must perform a sophisticated, statistical computation to determine which X-ray come from clusters. Contour map of clusters hi-res Size hi-res: 139 kb Credits: ESA Contour map of clusters The computer programme transforms the XMM-Newton data into a contour map of the cluster's probable extent and superimposes it over the CFHT snapshot, allowing the individual galaxies in the cluster to be targeted for further observations with ESO's VLT, to measure its distance and locate the cluster in the universe. Unlike grains of sand on a beach, matter is not uniformly spread throughout the Universe. Instead, it is concentrated into galaxies like our own which themselves congregate into clusters. These clusters are 'strung' throughout the Universe in a web-like structure. Astronomers have studied this large-scale structure of the nearby Universe but have lacked the instruments to extend the search to the large volumes of the distant Universe. Thanks to its unrivalled sensitivity, in less than three hours, ESA's X-ray observatory XMM-Newton can see back about 7000 million years to a cosmological era when the Universe was about half its present size, and clusters of galaxies

Recovering galaxy cluster gas density profiles with XMM-Newton and Chandra

NASA Astrophysics Data System (ADS)

Bartalucci, I.; Arnaud, M.; Pratt, G. W.; Vikhlinin, A.; Pointecouteau, E.; Forman, W. R.; Jones, C.; Mazzotta, P.; Andrade-Santos, F.

2017-12-01

We examined the reconstruction of galaxy cluster radial density profiles obtained from Chandra and XMM-Newton X-ray observations, using high quality data for a sample of twelve objects covering a range of morphologies and redshifts. By comparing the results obtained from the two observatories and by varying key aspects of the analysis procedure, we examined the impact of instrumental effects and of differences in the methodology used in the recovery of the density profiles. We find that the final density profile shape is particularly robust. We adapted the photon weighting vignetting correction method developed for XMM-Newton for use with Chandra data, and confirm that the resulting Chandra profiles are consistent with those corrected a posteriori for vignetting effects. Profiles obtained from direct deprojection and those derived using parametric models are consistent at the 1% level. At radii larger than 6″, the agreement between Chandra and XMM-Newton is better than 1%, confirming an excellent understanding of the XMM-Newton PSF. Furthermore, we find no significant energy dependence. The impact of the well-known offset between Chandra and XMM-Newton gas temperature determinations on the density profiles is found to be negligible. However, we find an overall normalisation offset in density profiles of the order of 2.5%, which is linked to absolute flux cross-calibration issues. As a final result, the weighted ratios of Chandra to XMM-Newton gas masses computed at R2500 and R500 are r = 1.03 ± 0.01 and r = 1.03 ± 0.03, respectively. Our study confirms that the radial density profiles are robustly recovered, and that any differences between Chandra and XMM-Newton can be constrained to the 2.5% level, regardless of the exact data analysis details. These encouraging results open the way for the true combination of X-ray observations of galaxy clusters, fully leveraging the high resolution of Chandra and the high throughput of XMM-Newton.

VizieR Online Data Catalog: XMM-Newton slew survey Source Catalogue, version 2.0 (XMM-SSC, 2017)

NASA Astrophysics Data System (ADS)

XMM-SSC

2018-01-01

XMMSL2 is the second catalogue of X-ray sources found in slew data taken from the European Space Agency's (ESA) XMM-Newton observatory, and has been constructed by members of the XMM SOC and the EPIC consortium on behalf of ESA. This release uses results of work which has been carried out within the framework of the EXTraS project ("Exploring the X-ray variable and Transient Sky"), funded from the EU's Seventh Framework Programme under grant agreement no.607452. This is the first release of XMMSL2 which contains data taken between revolutions 314 and 2758. The previous catalogue was called XMMSL1_Delta6 and contained slews up to revolution 2441. The release includes two FITS files. A full catalogue (xmmsl2_total.fits.gz), containing 72352 detections found with a likelihood of DETML>8 and a "clean" catalogue (xmmsl2clean.fits.gz) where all known bad sources have been removed and where the detection limit has been raised to DETML>10.5 in general and DETML>15.5 for sources found in images with a higher than usual background. Efforts have been made to identify spurious detections and 3017 have been flagged as such in the full catalogue. (3 data files).

A Deep XMM-Newton Survey of M33: Point-source Catalog, Source Detection, and Characterization of Overlapping Fields

NASA Astrophysics Data System (ADS)

Williams, Benjamin F.; Wold, Brian; Haberl, Frank; Garofali, Kristen; Blair, William P.; Gaetz, Terrance J.; Kuntz, K. D.; Long, Knox S.; Pannuti, Thomas G.; Pietsch, Wolfgang; Plucinsky, Paul P.; Winkler, P. Frank

2015-05-01

We have obtained a deep 8 field XMM-Newton mosaic of M33 covering the galaxy out to the D25 isophote and beyond to a limiting 0.2-4.5 keV unabsorbed flux of 5 × 10-16 erg cm-2 s-1 (L \\gt 4 × 1034 erg s-1 at the distance of M33). These data allow complete coverage of the galaxy with high sensitivity to soft sources such as diffuse hot gas and supernova remnants (SNRs). Here, we describe the methods we used to identify and characterize 1296 point sources in the 8 fields. We compare our resulting source catalog to the literature, note variable sources, construct hardness ratios, classify soft sources, analyze the source density profile, and measure the X-ray luminosity function (XLF). As a result of the large effective area of XMM-Newton below 1 keV, the survey contains many new soft X-ray sources. The radial source density profile and XLF for the sources suggest that only ˜15% of the 391 bright sources with L \\gt 3.6 × 1035 erg s-1 are likely to be associated with M33, and more than a third of these are known SNRs. The log(N)-log(S) distribution, when corrected for background contamination, is a relatively flat power law with a differential index of 1.5, which suggests that many of the other M33 sources may be high-mass X-ray binaries. Finally, we note the discovery of an interesting new transient X-ray source, which we are unable to classify.

Characterizing X-ray Sources in the Rich Open Cluster NGC 7789 Using XMM-Newton

NASA Astrophysics Data System (ADS)

Farner, William; Pooley, David

2018-01-01

It is well established that globular clusters exhibit a correlation between their population of exotic binaries and their rate of stellar encounters, but little work has been done to characterize this relationship in rich open clusters. X-ray observations are the most efficient means to find various types of close binaries, and optical (and radio) identifications can provide secure source classifications. We report on an observation of the rich open cluster NGC 7789 using the XMM-Newton observatory. We present the X-ray and optical imaging data, source lists, and preliminary characterization of the sources based on their X-ray and multiwavelength properties.

The XMM-Newton SSC survey of the Galactic plane

NASA Astrophysics Data System (ADS)

Nebot Gómez-Morán, A.; Motch, C.; Barcons, X.; Carrera, F. J.; Ceballos, M. T.; Cropper, M.; Grosso, N.; Guillout, P.; Hérent, O.; Mateos, S.; Michel, L.; Osborne, J. P.; Pakull, M.; Pineau, F.-X.; Pye, J. P.; Roberts, T. P.; Rosen, S. R.; Schwope, A. D.; Watson, M. G.; Webb, N.

2013-05-01

Many different classes of X-ray sources contribute to the Galactic landscape at high energies. Although the nature of the most luminous X-ray emitters is now fairly well understood, the population of low-to-medium X-ray luminosity (LX = 1027-34 erg s-1) sources remains much less studied, our knowledge being mostly based on the observation of local members. The advent of wide field and high sensitivity X-ray telescopes such as XMM-Newton now offers the opportunity to observe this low-to-medium LX population at large distances. We report on the results of a Galactic plane survey conducted by the XMM-Newton Survey Science Centre (SSC). Beyond its astrophysical goals, this survey aims at gathering a representative sample of identified X-ray sources at low latitude that can be used later on to statistically identify the rest of the serendipitous sources discovered in the Milky Way. The survey is based on 26 XMM-Newton observations, obtained at | b | < 20 deg, distributed over a large range in Galactic longitudes and covering a summed area of 4 deg2. The flux limit of our survey is 2 × 10-15 erg cm-2 s-1 in the soft (0.5-2 keV) band and 1 × 10-14 erg cm-2 s-1 in the hard (2-12 keV) band. We detect a total of 1319 individual X-ray sources. Using optical follow-up observations supplemented by cross-correlation with a large range of multi-wavelength archival catalogues we identify 316 X-ray sources. This constitutes the largest group of spectroscopically identified low latitude X-ray sources at this flux level. The majority of the identified X-ray sources are active coronae with spectral types in the range A-M at maximum distances of ~1 kpc. The number of identified active starsincreases towards late spectral types, reaching a maximum at K. Using infrared colours we classify 18% of the stars as giants. The observed distributions of FX/FV, X-ray and infrared colours indicates that our sample is dominated by a young (100 Myr) to intermediate (600 Myr) age population with a

XMM-Newton operations beyond the design lifetime

NASA Astrophysics Data System (ADS)

Parmar, Arvind N.; Kirsch, Marcus G. F.; Muñoz, J. Ramon; Santos-Lleo, Maria; Schartel, Norbert

2012-09-01

After more than twelve years in orbit and two years beyond the design lifetime, XMM-Newton continues its near faultless operations providing the worldwide astronomical community with an unprecedented combination of imaging and spectroscopic X-ray capabilities together with simultaneous optical and ultra-violet monitoring. The interest from the scientific community in observing with XMM-Newton remains extremely high with the last annual Announcement of Observing Opportunity (AO-11) attracting proposals requesting 6.7 times more observing time than was available. Following recovery from a communications problem in 2008, all elements of the mission are stable and largely trouble free. The operational lifetime if currently limited by the amount of available hydrazine fuel. XMM-Newton normally uses reaction wheels for attitude control and fuel is only used when offsetting reaction wheel speed away from limiting values and for emergency Sun acquisition following an anomaly. Currently, the hydrazine is predicted to last until around 2020. However, ESA is investigating the possibility of making changes to the operations concept and the onboard software that would enable lower fuel consumption. This could allow operations to well beyond 2026.

The XMM-Newton Science Archive and its integration into ESASky

NASA Astrophysics Data System (ADS)

Loiseau, N.; Baines, D.; Colomo, E.; Giordano, F.; Merín, B.; Racero, E.; Rodríguez, P.; Salgado, J.; Sarmiento, M.

2017-07-01

We describe the variety of functionalities of the XSA (XMM-Newton Science Archive) that allow to search and access the XMM-Newton data and catalogues. The web interface http://nxsa.esac.esa.int/ is very flexible allowing different kinds of searches by a single position or target name, or by a list of targets, with several selecting options (target type, text in the abstract, etc.), and with several display options. The resulting data can be easily broadcast to Virtual Observatory (VO) facilities for a first look analysis, or for cross-matching the results with info from other observatories. Direct access via URL or command line are also possible for scripts usage, or to link XMM-Newton data from other interfaces like Vizier, ADS, etc. The full metadata content of the XSA can be queried through the TAP (Table access Protocol) via ADQL (Astronomical Data Query Language). We present also the roadmap for future improvements of the XSA including the integration of the Upper Limit server, the on-the-fly data analysis, and the interactive visualization of EPIC sources spectra and light curves and RGS spectra, among other advanced features. Within this modern visualization philosophy XSA is also being integrated into ESASky (http://sky.esa.int). ESASky is the science-driven multi-wavelength discovery portal for all the ESA Astronomy Missions (Integral, HST, Herschel, Suzaku, Planck, etc.), and other space and ground telescope data. The system offers progressive multi-resolution all-sky projections of full mission datasets using HiPS, a new generation of HEALPix projections developed by CDS, precise footprints to connect to individual observations, and direct access to science-ready data from the underlying mission specific science archives. XMM-Newton EPIC and OM all-sky HiPS maps, catalogues and links to the observations are available through ESASky.

Turbulence in the Intracluster Medium: XMM-Newton legacy

NASA Astrophysics Data System (ADS)

Pinto, C.; Fabian, A.; Sanders, J.; De Plaa, J.

2017-10-01

The kinematics structure of the Intracluster Medium (ICM) in clusters of galaxies is heir of their past evolution. AGN feedback, sloshing of gas within the potential well, and galaxy mergers are thought to generate turbulence of several hundred km/s into the ICM. Accurate measurements of velocity widths provide the means to understand the effects of these energetic phenomena onto the evolution of the clusters. In this talk I will review our recent measurements of turbulence using the high-resolution grating and microcalorimeter spectrometers on board XMM-Newton and Hitomi, respectively. Most recently, we have produced the largest XMM-Newton/RGS grating catalogue totalling about a hundred objects, which merge the recent CHEERS campaign and the efforts of the last decade as well as the newest observations of clusters and groups of galaxies. This catalogue includes all high-quality grating spectra publicly available by January 2017 and provides the XMM-Newton legacy for the future work. In this talk, I will discuss the first results with particular focus on the measurements of velocity broadening and the new constraints on turbulence.

UNBIASED CORRECTION RELATIONS FOR GALAXY CLUSTER PROPERTIES DERIVED FROM CHANDRA AND XMM-NEWTON

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

Zhao, Hai-Hui; Li, Cheng-Kui; Chen, Yong

2015-01-20

We use a sample of 62 clusters of galaxies to investigate the discrepancies between the gas temperature and total mass within r {sub 500} from XMM-Newton and Chandra data. Comparisons of the properties show that (1) both the de-projected and projected temperatures determined by Chandra are higher than those of XMM-Newton and there is a good linear relationship for the de-projected temperatures: T {sub Chandra} = 1.25 × T {sub XMM}–0.13. (2) The Chandra mass is much higher than the XMM-Newton mass with a bias of 0.15 and our mass relation is log{sub 10} M {sub Chandra} = 1.02 × log{sub 10}more » M {sub XMM}+0.15. To explore the reasons for the discrepancy in mass, we recalculate the Chandra mass (expressed as M{sub Ch}{sup mo/d}) by modifying its temperature with the de-projected temperature relation. The results show that M{sub Ch}{sup mo/d} is closer to the XMM-Newton mass with the bias reducing to 0.02. Moreover, M{sub Ch}{sup mo/d} are corrected with the r {sub 500} measured by XMM-Newton and the intrinsic scatter is significantly improved with the value reducing from 0.20 to 0.12. These mean that the temperature bias may be the main factor causing the mass bias. Finally, we find that M{sub Ch}{sup mo/d} is consistent with the corresponding XMM-Newton mass derived directly from our mass relation at a given Chandra mass. Thus, the de-projected temperature and mass relations can provide unbiased corrections for galaxy cluster properties derived from Chandra and XMM-Newton.« less

Dark Matter Search Using XMM-Newton Observations of Willman 1

NASA Technical Reports Server (NTRS)

Lowenstein, Michael; Kusenko, Alexander

2012-01-01

We report the results of a search for an emission line from radiatively decaying dark matter in the ultra-faint dwarf spheroidal galaxy Willman 1 based on analysis of spectra extracted from XMM-Newton X-ray Observatory data. The observation follows up our analysis of Chandra data of Willman 1that resulted in line flux upper limits over the Chandra bandpass and evidence of a 2.5 keY feature at a significance below the 99% confidence threshold used to define the limits. The higher effective area of the XMM-Newton detectors, combined with application of recently developing methods for extended-source analysis, allow us to derive improved constraints on the combination of mass and mixing angle of the sterile neutrino dark matter candidate. We do not confirm the Chandra evidence for a 2.5 keV emission line.

Symbiotic Stars in X-rays. II. Faint Sources Detected with XMM-Newton and Chandra

NASA Technical Reports Server (NTRS)

Nunez, N. E.; Luna, G. J. M.; Pillitteri, I.; Mukai, K.

2014-01-01

We report the detection from four symbiotic stars that were not known to be X-ray sources. These four object show a ß-type X-ray spectrum, that is, their spectra can be modeled with an absorbed optically thin thermal emission with temperatures of a few million degrees. Photometric series obtained with the Optical Monitor on board XMM-Newton from V2416 Sgr and NSV 25735 support the proposed scenario where the X-ray emission is produced in a shock-heated region inside the symbiotic nebulae.

Galactic Sources Detected in the NuSTAR Serendipitous Survey

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

Tomsick, John A.; Clavel, Maïca; Chiu, Jeng-Lun

The Nuclear Spectroscopic Telescope Array (NuSTAR) provides an improvement in sensitivity at energies above 10 keV by two orders of magnitude over non-focusing satellites, making it possible to probe deeper into the Galaxy and universe. Lansbury and collaborators recently completed a catalog of 497 sources serendipitously detected in the 3–24 keV band using 13 deg{sup 2} of NuSTAR coverage. Here, we report on an optical and X-ray study of 16 Galactic sources in the catalog. We identify 8 of them as stars (but some or all could have binary companions), and use information from Gaia to report distances and X-ray luminositiesmore » for 3 of them. There are 4 CVs or CV candidates, and we argue that NuSTAR J233426–2343.9 is a relatively strong CV candidate based partly on an X-ray spectrum from XMM-Newton . NuSTAR J092418–3142.2, which is the brightest serendipitous source in the Lansbury catalog, and NuSTAR J073959–3147.8 are low-mass X-ray binary candidates, but it is also possible that these 2 sources are CVs. One of the sources is a known high-mass X-ray binary (HMXB), and NuSTAR J105008–5958.8 is a new HMXB candidate that has strong Balmer emission lines in its optical spectrum and a hard X-ray spectrum. We discuss the implications of finding these HMXBs for the surface density (log N –log S ) and luminosity function of Galactic HMXBs. We conclude that with the large fraction of unclassified sources in the Galactic plane detected by NuSTAR in the 8–24 keV band, there could be a significant population of low-luminosity HMXBs.« less

XMM-Newton Proposal 03033401

NASA Astrophysics Data System (ADS)

Ghosh, Kajal

2004-10-01

We have detected a highly blueshifted (7.6 keV at the source frame) emission feature in the ASCA spectra of the unusual Narrow-line Seyfert 1 galaxy RX J0136.9-3510. At ASCA resolution it is impossible to tell if the feature is a single line or a combination of lines nor if the feature is due to He-like or H-like Fe. The line profile can tell us where the bulk of the emission origin- ates: A low velocity dispersion would favor a wind/outflow origin, while a hi- gher dispersion may allow for an ionized disk reflection origin. Strong absor- ption and resonant scattering could also produce blueshifted line. To acquire better resolution spectrum to constrain the origin of the line via detailed physical modeling, we propose 50 ks XMM-Newton observations of RXJ0136.9-3510.

Seeing Red and Shooting Blanks: A Study of Red Quasars and Blank Field X-Ray Sources

NASA Technical Reports Server (NTRS)

Oliversen, Ronald J. (Technical Monitor); Elvis, Martin

2004-01-01

One type of "Blank Field X-ray Source" is now being seen in deep Chandra and XMM-Newton surveys. These are the newly dubbed "XBONGs" (X-ray Bright, Optically Normal Galaxies). The study of the brighter counterparts from ROSAT and XMM- Newton serendipitous surveys is therefore of renewed interest and topicality. We continue to define the properties of the ROSAT sample which is the basis of this grant. We expect to publish the SEDs of these sources soon.

Using XMM-Newton and Optical Photometry to Figure Out CVs

NASA Astrophysics Data System (ADS)

Szkody, P.; Homer, L.; Henden, A.

2006-06-01

X-ray light curves from XMM-Newton combined with optical data from the satellite and ground-based observers provide distinctive shapes and periodicities that give information on the correct classification of cataclysmic variables. Our recent data on three SDSS sources with strong helium emission are used to identify a highly magnetic system (a polar), the spin of the white dwarf in an intermediate polar, and a typical disk accreting system.

Has ESA's XMM-Newton cast doubt over dark energy?

NASA Astrophysics Data System (ADS)

2003-12-01

one knows what the dark energy might be. In the currently popular 'concordance model' of the Universe, 70% of the cosmos is thought to be dark energy, 25% dark matter and 5% normal matter. XMM-Newton XMM-Newton can detect more X-ray sources than any previous satellite and is helping to solve many cosmic mysteries of the violent Universe, from black holes to the formation of galaxies. It was launched on 10 December 1999, using an Ariane-5 rocket from French Guiana. It is expected to return data for a decade. XMM-Newton's high-tech design uses over 170 wafer-thin cylindrical mirrors spread over three telescopes. Its orbit takes it almost a third of the way to the Moon, so that astronomers can enjoy long, uninterrupted views of celestial objects. Image caption The fuzzy object at the centre of the frame is one of the galaxy clusters observed by XMM-Newton in its investigation of the distant Universe. The cluster, designated RXJ0847.2+3449, is about 7 000 million light years away, so we see it here as it was 7 000 million years ago, when the Universe was only about half of its present age. This cluster is made up of several dozen galaxies. Credits: ESA

An XMM-Newton Observation of 4U1755-33 in Quiescence: Evidence for a Fossil X-Ray Jet

NASA Technical Reports Server (NTRS)

Angelini, Lorella; White, Nicholas E.

2003-01-01

We report an XMM-Newton observation of the Low mass X-ray Binary (LMXB) and black hole candidate 4U1755-33. This source had been a bright persistent source for at least 25 yrs, but in 1995 entered an extended quiescent phase. 4U1755-33 was not detected with an upper limit to the 2-10 keV luminosity of 5 x 10(exp 31) d(sup 2) (sub 4kpc) ergs per second (where d(sub 4kpc) is the distance in units of 4 kpc) - consistent with the luminosity of other black hole candidates in a quiescent state. An unexpected result is the discovery of a narrow 7 arc min long X-ray jet centered on the position of 4Ul755-33. The spectrum of the jet is similar to that of jets observed from other galactic and extragalactic sources, and may have been ejected from 4Ul755-33 when it was bright. Jets are a feature of accreting black holes, and the detection of a fossil jet provides additional evidence supporting the black hole candidacy of 4U1755-33. The spectral properties of three bright serendipitous sources in the field are reported and it is suggested these are background active galactic nuclei sources.

XMM-Newton Observations of the Toothbrush and Sausage Clusters

NASA Astrophysics Data System (ADS)

Kara, S.; Mernier, F.; Ezer, C.; Akamatsu, H.; Ercan, E.

2017-10-01

Galaxy clusters are the largest gravitationally-bound objects in the universe. The member galaxies are embedded in a hot X-ray emitting Intra Cluster Medium (ICM) that has been enriched with metals produced by supernovae over the last billion years. Here we report new results from XMM-Newton archival observations of the merging clusters 1RXSJ0603.3+4213 and CIZA J2242.8+5301. These two clusters, also known as the Toothbrush and Sausage clusters, respectively, show a large radio relic associated with a merger shock North of their respective core. We show the distribution of the metal abundances with respect to the merger structures in these two clusters. The results are derived from spatially resolved X-ray spectra from the EPIC instrument on board XMM-Newton.

INTEGRAL and XMM-Newton Spectral Studies of NGC 4388

NASA Technical Reports Server (NTRS)

Beckmann, V.; Gehrels, N.; Favre, P.; Walter, R.; Courvoisier, T. J.-L.; Petrucci, P.-O.; Malzac, J.

2004-01-01

We present first INTEGRAL and XMM-Newton observations of a Seyfert galaxy, the type 2 AGN NGC 4388. Several INTEGRAL observations performed in 2003 allow us to study the spectrum in the 20 - 300 keV range. In addition two XMM-Newton observations give detailed insight into the 0.2 - 10 keV emission. Comparison with previous observations by BeppoSAX, SIGMA and CGRO/OSSE show that the overall spectrum for soft X-rays up to the gamma-rays can be described by a highly absorbed (N(sub H approx. = 2.7 x 10(exp 23)/sq cm) and variable non-thermal component in addition to constant non-absorbed thermal emission (T approx. = 0.8 keV) of low abundance (Z approx. 5% Z (solar)), plus a constant Fe K a line. The hard X-ray component is well described by a simple power law with a mean photon index of Gamma = 1.7. During the INTEGRAL observations the flux at 100 keV increased by a factor of 1.5. The analysis of XMM-Newton data implies that the emission below 3 keV is decoupled from the AGN and probably due to extended emission as seen in Chandra observations. The constant iron line emission is apparently also decoupled from the direct emission of the central engine and likely to be generated in the obscuring material, e.g. in the molecular torus.

XMM-Newton Detection of a Delayed X-ray Eruption from V838 Monocerotis

NASA Astrophysics Data System (ADS)

Antonini, Fabio; Montez, R., Jr.; Kastner, J.; Bond, H. E.; Soker, N.; Tylenda, R.; Starrfield, S.

2010-01-01

The star V838 Mon, discovered undergoing an outburst at the beginning of January 2002, is one of the most enigmatic objects observed in stellar astrophysics in recent decades. We report the XMM-Newton/EPIC detection in 2008 March of a pair of spatially confused X-ray sources in the vicinity of V838 Mon. Spectral/spatial analysis demonstrates the presence of a relatively hard, luminous source that is spatially coincident with V838 Mon itself, and a second, more luminous source located 8'' south of V838 Mon (projected separation 0.2pc if at the 6 kpc distance of V838 Mon). Neither source was detected in a Chandra/ACIS-S observation obtained about one year after outburst. The inferred X-ray luminosity and temperature of the hard source component at the position of V838 Mon, as well as its delayed appearance, appear consistent with a stellar merger scenario for the optical/IR outburst of V838 Mon. Further X-ray observations of V838 Mon are warranted, to confirm the position(s) of the source(s) in the vicinity of V838 Mon and to establish their long- and short-term temporal behavior.This research has been supported via NASA/GSFC XMM/Newton Guest Observer Facility grant NNX08AD91G to RIT (and associated subcontracts to STScI and the University of Arizona).

Nine Years of XMM-Newton Pipeline: Experience and Feedback

NASA Astrophysics Data System (ADS)

Michel, Laurent; Motch, Christian

2009-05-01

The Strasbourg Astronomical Observatory is member of the Survey Science Centre (SSC) of the XMM-Newton satellite. Among other responsibilities, we provide a database access to the 2XMMi catalogue and run the part of the data processing pipeline performing the cross-correlation of EPIC sources with archival catalogs. These tasks were all developed in Strasbourg. Pipeline processing is flawlessly in operation since 1999. We describe here the work load and infrastructure setup in Strasbourg to support SSC activities. Our nine year long SSC experience could be used in the framework of the Simbol-X ground segment.

Arakelian 564: An XMM-Newton View

NASA Technical Reports Server (NTRS)

Vignali, Cristian; Brandt, W. N.; Boller, Th.; Fabian, A. C.; Vaughan, Simon

2003-01-01

We report on two XMM-Newton observations of the bright narrow-line Seyfert 1 galaxy Ark 564 taken one year apart (2000 June and 2001 June). The 0.6-10 keV continuum is well described by a soft blackbody component (kTau approximately equal 140-150 eV) plus a steep power law (Tau approximately equal to 2.50-2.55). No significant spectral changes are observed between the two observations, although the X-ray flux in the second observation is approximately equal to 40-50 per cent lower. In both observations we detect a significant absorption edge at a rest-frame energy of approximately equal to 0.73 keV, corresponding to O VII. The presence of the absorption feature is confirmed by a simultaneous Chandra grating observation in 2000 June, although the best-fitting edge threshold is at a slightly lower energy in the Chandra data, possibly because of a different parameterization of the underlying X-ray continuum. We find tentative evidence for a broad iron emission line in the 2000 June observation. The results from an analysis of the power spectral density (PSD) function are also presented. The present XMM-Newton data support the idea that the PSD shown two breads, although the location of the high-frequency break requires further constraints.

XMM-NEWTON OBSERVATION OF THE {alpha} PERSEI CLUSTER

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

Pillitteri, Ignazio; Evans, Nancy Remage; Wolk, Scott J.

We report on the analysis of an archival observation of part of the {alpha} Persei cluster obtained with XMM-Newton. We detected 102 X-ray sources in the band 0.3-8.0 keV, of which 39 of them are associated with the cluster as evidenced by appropriate magnitudes and colors from Two Micron All Sky Survey photometry. We extend the X-ray luminosity distribution (XLD) for M dwarfs, to add to the XLD found for hotter dwarfs from spatially extensive surveys of the whole cluster by ROSAT. Some of the hotter stars are identified as a background, possible slightly older group of stars at amore » distance of approximately 500 pc.« less

VizieR Online Data Catalog: XMM-Newton point-source catalogue of the SMC (Sturm+, 2013)

NASA Astrophysics Data System (ADS)

Sturm, R.; Haberl, F.; Pietsch, W.; Ballet, J.; Hatzidimitriou, D.; Buckley, D. A. H.; Coe, M.; Ehle, M.; Filipovic, M. D.; La Palombara, N.; Tiengo, A.

2013-07-01

The XMM-Newton survey of the Small Magellanic Cloud (SMC) yields a complete coverage of the bar and eastern wing in the 0.2-12.0keV band. This catalogue comprises 3053 unique X-ray point sources and sources with moderate extent that have been reduced from 5236 individual detections found in observations between April 2000 and April 2010. Sources have a median position uncertainty of 1.3" (1σ) and limiting fluxes down to ~1*10-14erg/s/cm2 in the 0.2-4.5keV band, corresponding to 5*1033erg/s for sources in the SMC. Sources have been classified using hardness ratios, X-ray variability, and their multi-wavelength properties. In addition to the main-field (5.58deg2) available outer fields have been included in the catalogue, yielding a total field area of 6.32deg2. X-ray sources with high extent (>40", e.g. supernova remnants and galaxy cluster) have been presented by Haberl et al. (2012, Cat. J/A+A/545/A128) (2 data files).

Discovery of the Candidate Off-nuclear Ultrasoft Hyper-luminous X-Ray Source 3XMM J141711.1+522541

NASA Astrophysics Data System (ADS)

Lin, Dacheng; Carrasco, Eleazar R.; Webb, Natalie A.; Irwin, Jimmy A.; Dupke, Renato; Romanowsky, Aaron J.; Ramirez-Ruiz, Enrico; Strader, Jay; Homan, Jeroen; Barret, Didier; Godet, Olivier

2016-04-01

We report the discovery of an off-nuclear ultrasoft hyper-luminous X-ray source candidate 3XMM J141711.1+522541 in the inactive S0 galaxy SDSS J141711.07+522540.8 (z = 0.41827, dL = 2.3 Gpc) in the Extended Groth Strip. It is located at a projected offset of ˜1.″0 (5.2 kpc) from the nucleus of the galaxy and was serendipitously detected in five XMM-Newton observations in 2000 July. Two observations have enough counts and can be fitted with a standard thermal disk with an apparent inner disk temperature {{kT}}{MCD}˜ 0.13 {{keV}} and a 0.28-14.2 keV unabsorbed luminosity LX ˜ 4 × 1043 erg s-1 in the source rest frame. The source was still detected in three Chandra observations in 2002 August, with similarly ultrasoft but fainter spectra (kTMCD ˜ 0.17 keV, LX ˜ 0.5 × 1043 erg s-1). It was not detected in later observations, including two by Chandra in 2005 October, one by XMM-Newton in 2014 January, and two by Chandra in 2014 September-October, implying a long-term flux variation factor of >14. Therefore the source could be a transient with an outburst in 2000-2002. It has a faint optical counterpart candidate, with apparent magnitudes of mF606W = 26.3 AB mag and mF814W = 25.5 AB mag in 2004 December (implying an absolute V-band magnitude of ˜-15.9 AB mag). We discuss various explanations for the source and find that it is best explained as a massive black hole (BH) embedded in the nucleus of a possibly stripped satellite galaxy, with the X-ray outburst due to tidal disruption of a surrounding star by the BH. The BH mass is ˜105 M⊙, assuming the peak X-ray luminosity at around the Eddington limit.

TESTING RELATIVISTIC REFLECTION AND RESOLVING OUTFLOWS IN PG 1211+143 WITH XMM-NEWTON AND NuSTAR

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

Lobban, A. P.; Pounds, K.; Vaughan, S.

We analyze the broad-band X-ray spectrum (0.3–50 keV) of the luminous Seyfert 1/quasar PG 1211+143—the archetypal source for high-velocity X-ray outflows—using near-simultaneous XMM-Newton and NuSTAR observations. We compare pure relativistic reflection models with a model including the strong imprint of photoionized emission and absorption from a high-velocity wind, finding a spectral fit that extrapolates well over the higher photon energies covered by NuSTAR . Inclusion of the high signal-to-noise ratio XMM-Newton spectrum provides much tighter constraints on the model parameters, with a much harder photon index/lower reflection fraction compared to that from the NuSTAR data alone. We show that puremore » relativistic reflection models are not able to account for the spectral complexity of PG 1211+143 and that wind absorption models are strongly required to match the data in both the soft X-ray and Fe K spectral regions. In confirming the significance of previously reported ionized absorption features, the new analysis provides a further demonstration of the power of combining the high throughput and resolution of long-look XMM-Newton observations with the unprecedented spectral coverage of NuSTAR .« less

XMM-Newton detects X-ray 'solar cycle' in distant star

NASA Astrophysics Data System (ADS)

2004-05-01

whether the Sun's X-ray cycle is common among other solar-type stars, and in particular among those hosting potential rocky planets, can give scientists much needed clues on whether and where other forms of life might exist outside the Solar System. At the same time, understanding how typical and long-lasting is the solar behaviour will tell us more about the evolution of the climate on Earth. Further observations of HD 81809 and other similar stars are already planned with XMM-Newton. They will allow astronomers to study whether the large modulations in X-ray brightness observed in the Sun are indeed the norm for stars of its type. Understanding how other solar-like stars behave in general will give scientists better insight into the past and future of our own Sun. Note to editors The results described here were published in the April issue of the scientific journal Astronomy and Astrophysics (Vol. 418, p. L13). The authors of the paper are F. Favata, G. Micela, S. Baliunas, J. Schmitt, M. Guedel, F. Harnden Jr., S. Sciortino and R. Stern. A reprint of the paper can be found at: http://arxiv.org/abs/astro-ph/0403142 More about XMM-Newton XMM-Newton can detect more X-ray sources than any previous satellite and is helping to solve many cosmic mysteries of the violent Universe, from black holes to the formation of galaxies. It was launched on 10 December 1999, using an Ariane-5 rocket from French Guiana. It is expected to return data for a decade. XMM-Newton's high-tech design uses over 170 wafer-thin cylindrical mirrors spread over three telescopes. Its orbit takes it almost a third of the way to the Moon, so that astronomers can enjoy long, uninterrupted views of celestial objects. More information on XMM-Newton can be found at: http://www.esa.int/esaSC/SEMM8IGHZTD_1_spk.html More about SOHO SOHO is a project of international cooperation between ESA and NASA to study the Sun, from its deep core to the outer corona, and the solar wind. Fourteen European countries, led by

EXTraS unveils a supernova shock break-out candidate in XMM-Newton archival data

NASA Astrophysics Data System (ADS)

Tiengo, A.; Novara, G.; Lisini, G.; De Luca, A.; Salvaterra, R.; Belfiore, A.; Marelli, M.; Salvetti, D.; Mereghetti, S.; Vianello, G.

2017-10-01

During the search for short X-ray transients within the Exploring the X-ray Transient and variable Sky (EXTraS) project, we discovered a new X-ray source that can be detected only in a ˜5 minutes interval of a ˜21 hours long XMM-Newton observation. Thanks to dedicated follow-up observations, we found that its position is consistent with a galaxy at redshift z=0.092. At this redshift, the transient released 2×10^{46} erg in the 0.3-10 keV energy band. Its luminosity and spectral and timing properties make it an analogue of the X-ray transient associated to SN2008, detected by Swift/XRT during an observation of the nearby supernova-rich galaxy NGC 2770. The discovery of this much more distant transient in a field galaxy during a systematic analysis of the full XMM-Newton archive allows us to better constrain the rate of these rare events.

XMM-Newton Proposal 03060602

NASA Astrophysics Data System (ADS)

Strickland, David

2004-10-01

We propose to observe 3 edge-on Milky-Way-like normal spiral galaxies in order to constrain the presence, properties and physical origin of hot gas in their halos, a topic about which relatively little is currently known. These observations will complete our sample of 8 edge-on normal spirals for which we have a wide range of existing observational data, so that all galaxies will have deep XMM-Newton and/or Chandra observations. With this sample we can assess the relative contribution to the halo X-ray emission of normal spirals from SNII-driven galactic fountains, accretion of primordial gas, and SNIa-driven outflows. The observations will robustly detect NGC 891-like hot halos, broadly quantify their properties, and can be used to constrain the efficiency of mechanical energy feedback.

NuSTAR and XMM-Newton Observations of the Hard X- Ray Spectrum of Centaurus A

NASA Technical Reports Server (NTRS)

Furst, F.; Muller, C.; Madsen, K. K.; Lanz, L.; Rivers, E.; Brightman, M.; Arevalo, P.; Balokovic, M.; Beuchert, T.; Zhang, W.

2016-01-01

We present simultaneous XMM-Newton and Nuclear Spectroscopic Telescope Array (NuSTAR) observations spanning 3-78 keV of the nearest radio galaxy, Centaurus A (Cen A). The accretion geometry around the central engine in Cen A is still debated, and we investigate possible configurations using detailed X-ray spectral modeling. NuSTAR imaged the central region of Cen A with subarcminute resolution at X-ray energies above 10 keV for the first time, but found no evidence for an extended source or other off-nuclear point sources. The XMM-Newton and NuSTAR spectra agree well and can be described with an absorbed power law with a photon index Gamma = 1.8150 +/- 0.005 and a fluorescent Fe Kaline in good agreement with literature values. The spectrum is greater than 1 MeV. A thermal Comptonization continuum describes the data well, with parameters that agree with values measured by INTEGRAL, in particular an electron temperature kTe between approximately 100-300 keV and seed photon input temperatures between 5 and 50 eV. We do not find evidence for reflection or a broad iron line and put stringent upper limits of R is less than 0.01 on the reflection fraction and accretion disk illumination. We use archival Chandra data to estimate the contribution from diffuse emission, extra-nuclear point sources, and the outer X-ray jet to the observed NuSTAR and XMM-Newton X-ray spectra and find the contribution to be negligible. We discuss different scenarios for the physical origin of the observed hard X-ray spectrum and conclude that the inner disk is replaced by an advection-dominated accretion flow or that the X-rays are dominated by synchrotron self-Compton emission from the inner regions of the radio jet or a combination thereof.

XMM-Newton study of the supersoft symbiotic system Draco C1

NASA Astrophysics Data System (ADS)

Saeedi, Sara; Sasaki, Manami; Ducci, Lorenzo

2018-01-01

We present the results of the analysis of thirty-one XMM-Newton observations of the symbiotic star Draco C1 located in the Draco dwarf spheroidal galaxy. This object had been identified as a supersoft source based on ROSAT data. We analysed X-ray, ultraviolet (UV) and optical data taken with XMM-Newton in order to obtain the physical parameters and the geometry of the system. We have also performed the first X-ray timing analysis of Draco C1. The X-ray spectrum is well fitted with a blackbody model with a temperature of (1.8 ± 0.3) × 105 K. We obtained a bolometric luminosity of ≳1038 erg s-1 for the white dwarf. The X-ray spectrum and luminosity suggest stable nuclear burning on the surface of the white dwarf. The low column density derived from the X-ray spectrum is consistent with the lack of nebular lines found in previous UV studies. The long-term variability in the optical and the UV suggests that the system is not observed face-on and that the variability is caused by the reflection effect. For the red giant companion, we estimate a radius of ∼110 R⊙ and an upper limit ≲1.5 M⊙ for its mass assuming Roche lobe overflow.

Using the XMM-Newton Optical Monitor to Study Cluster Galaxy Evolution

NASA Technical Reports Server (NTRS)

Miller, Neal A.; O'Steen, Richard; Yen, Steffi; Kuntz, K. D.; Hammer, Derek

2012-01-01

We explore the application of XMM Newton Optical Monitor (XMM-OM) ultraviolet (UV) data to study galaxy evolution. Our sample is constructed as the intersection of all Abell clusters with z < 0.05 and having archival XMM-OM data in either the UVM2 or UVW1 filters, plus optical and UV photometry from the Sloan Digital Sky Survey and GALEX, respectively. The 11 resulting clusters include 726 galaxies with measured redshifts, 520 of which have redshifts placing them within their parent Abell clusters. We develop procedures for manipulating the XMM-OM images and measuring galaxy photometry from them, and we confirm our results via comparison with published catalogs. Color-magnitude diagrams (CMDs) constructed using the XMM-OM data along with SDSS optical data show promise for evolutionary studies, with good separation between red and blue sequences and real variation in the width of the red sequence that is likely indicative of differences in star formation history. This is particularly true for UVW1 data, as the relative abundance of data collected using this filter and its depth make it an attractive choice. Available tools that use stellar synthesis libraries to fit the UV and optical photometric data may also be used, thereby better describing star formation history within the past billion years and providing estimates of total stellar mass that include contributions from young stars. Finally, color-color diagrams that include XMM-OM UV data appear useful to the photometric identification of both extragalactic and stellar sources.

Using the XMM-Newton Optical Monitor to Study Cluster Galaxy Evolution

NASA Astrophysics Data System (ADS)

Miller, Neal A.; O'Steen, Richard; Yen, Steffi; Kuntz, K. D.; Hammer, Derek

2012-02-01

We explore the application of XMM-Newton Optical Monitor (XMM-OM) ultraviolet (UV) data to study galaxy evolution. Our sample is constructed as the intersection of all Abell clusters with z < 0.05 and having archival XMM-OM data in either the UVM2 or UVW1 filters, plus optical and UV photometry from the Sloan Digital Sky Survey and GALEX, respectively. The 11 resulting clusters include 726 galaxies with measured redshifts, 520 of which have redshifts placing them within their parent Abell clusters. We develop procedures for manipulating the XMM-OM images and measuring galaxy photometry from them, and we confirm our results via comparison with published catalogs. Color-magnitude diagrams (CMDs) constructed using the XMM-OM data along with SDSS optical data show promise for evolutionary studies, with good separation between red and blue sequences and real variation in the width of the red sequence that is likely indicative of differences in star formation history. This is particularly true for UVW1 data, as the relative abundance of data collected using this filter and its depth make it an attractive choice. Available tools that use stellar synthesis libraries to fit the UV and optical photometric data may also be used, thereby better describing star formation history within the past billion years and providing estimates of total stellar mass that include contributions from young stars. Finally, color-color diagrams that include XMM-OM UV data appear useful to the photometric identification of both extragalactic and stellar sources.

Highly variable AGN from the XMM-Newton slew survey

NASA Astrophysics Data System (ADS)

Strotjohann, N. L.; Saxton, R. D.; Starling, R. L. C.; Esquej, P.; Read, A. M.; Evans, P. A.; Miniutti, G.

2016-07-01

Aims: We investigate the properties of a variability-selected complete sample of active galactic nuclei (AGN) in order to identify the mechanisms which cause large amplitude X-ray variability on timescales of years. Methods: A complete sample of 24 sources was constructed, from AGN which changed their soft X-ray luminosity by more than one order of magnitude over 5-20 years between ROSAT observations and the XMM-Newton slew survey. Follow-up observations were obtained with the Swift satellite. We analysed the spectra of these AGN at the Swift and XMM observation epochs, where six sources had continued to display extreme variability. Multiwavelength data are used to calculate black hole masses and the relative X-ray brightness αOX. Results: After removal of two probable spurious sources, we find that the sample has global properties which differ little from a non-varying control sample drawn from the wider XMM-slew/ROSAT/Veron sample of all secure AGN detections. A wide range of AGN types are represented in the varying sample. The black hole mass distributions for the varying and non-varying sample are not significantly different. This suggests that long timescale variability is not strongly affected by black hole mass. There is marginal evidence that the variable sources have a lower redshift (2σ) and X-ray luminosity (1.7σ). Apart from two radio-loud sources, the sample sources have normal optical-X-ray ratios (αOX) when at their peak but are X-ray weak during their lowest flux measurements. Conclusions: Drawing on our results and other studies, we are able to identify a variety of variability mechanisms at play: tidal disruption events, jet activity, changes in absorption, thermal emission from the inner accretion disc, and variable accretion disc reflection. Little evidence for strong absorption is seen in the majority of the sample and single-component absorption can be excluded as the mechanism for most sources.

Adaptation of XMM-Newton SAS to GRID and VO architectures via web

NASA Astrophysics Data System (ADS)

Ibarra, A.; de La Calle, I.; Gabriel, C.; Salgado, J.; Osuna, P.

2008-10-01

The XMM-Newton Scientific Analysis Software (SAS) is a robust software that has allowed users to produce good scientific results since the beginning of the mission. This has been possible given the SAS capability to evolve with the advent of new technologies and adapt to the needs of the scientific community. The prototype of the Remote Interface for Science Analysis (RISA) presented here, is one such example, which provides remote analysis of XMM-Newton data with access to all the existing SAS functionality, while making use of GRID computing technology. This new technology has recently emerged within the astrophysical community to tackle the ever lasting problem of computer power for the reduction of large amounts of data.

The peculiar isolated neutron star in the Carina Nebula. Deep XMM-Newton and ESO-VLT observations of 2XMM J104608.7-594306

NASA Astrophysics Data System (ADS)

Pires, A. M.; Motch, C.; Turolla, R.; Schwope, A.; Pilia, M.; Treves, A.; Popov, S. B.; Janot-Pacheco, E.

2012-08-01

While fewer in number than the dominant rotation-powered radio pulsar population, peculiar classes of isolated neutron stars (INSs) - which include magnetars, the ROSAT-discovered "Magnificent Seven" (M7), rotating radio transients (RRATs), and central compact objects in supernova remnants (CCOs) - represent a key element in understanding the neutron star phenomenology. We report the results of an observational campaign to study the properties of the source 2XMM J104608.7-594306, a newly discovered thermally emitting INS. The evolutionary state of the neutron star is investigated by means of deep dedicated observations obtained with the XMM-Newton Observatory, the ESO Very Large Telescope, as well as publicly available γ-ray data from the Fermi Space Telescope and the AGILE Mission. The observations confirm previous expectations and reveal a unique type of object. The source, which is likely within the Carina Nebula (NH = 2.6 × 1021 cm-2), has a spectrum that is both thermal and soft, with kT∞ = 135 eV. Non-thermal (magnetospheric) emission is not detected down to 1% (3σ, 0.1-12 keV) of the source luminosity. Significant deviations (absorption features) from a simple blackbody model are identified in the spectrum of the source around energies 0.6 keV and 1.35 keV. While the former deviation is likely related to a local oxygen overabundance in the Carina Nebula, the latter can only be accounted for by an additional spectral component, which is modelled as a Gaussian line in absorption with EW = 91 eV and σ = 0.14 keV (1σ). Furthermore, the optical counterpart is fainter than mV = 27 (2σ) and no γ-ray emission is significantly detected by either the Fermi or AGILE missions. Very interestingly, while these characteristics are remarkably similar to those of the M7 or the only RRAT so far detected in X-rays, which all have spin periods of a few seconds, we found intriguing evidence of very rapid rotation, P = 18.6 ms, at the 4σ confidence level. We interpret

Catalog of candidates for quasars at 3 < z < 5.5 selected among X-Ray sources from the 3XMM-DR4 survey of the XMM-Newton observatory

NASA Astrophysics Data System (ADS)

Khorunzhev, G. A.; Burenin, R. A.; Meshcheryakov, A. V.; Sazonov, S. Yu.

2016-05-01

We have compiled a catalog of 903 candidates for type 1 quasars at redshifts 3 < z < 5.5 selected among the X-ray sources of the "serendipitous" XMM-Newton survey presented in the 3XMMDR4 catalog (the median X-ray flux is ≈5 × 10-15 erg s-1 cm-2 in the 0.5-2 keV energy band) and located at high Galactic latitudes | b| > 20° in Sloan Digital Sky Survey (SDSS) fields with a total area of about 300 deg2. Photometric SDSS data as well infrared 2MASS and WISE data were used to select the objects. We selected the point sources from the photometric SDSS catalog with a magnitude error δ mz' < 0.2 and a color i' - z' < 0.6 (to first eliminate the M-type stars). For the selected sources, we have calculated the dependences χ2( z) for various spectral templates from the library that we compiled for these purposes using the EAZY software. Based on these data, we have rejected the objects whose spectral energy distributions are better described by the templates of stars at z = 0 and obtained a sample of quasars with photometric redshift estimates 2.75 < z phot < 5.5. The selection completeness of known quasars at z spec > 3 in the investigated fields is shown to be about 80%. The normalized median absolute deviation (Δ z = | z spec - z phot|) is σ Δ z /(1+ z spec) = 0.07, while the outlier fraction is η = 9% when Δ z/(1 + z cпek.) > 0.2. The number of objects per unit area in our sample exceeds the number of quasars in the spectroscopic SDSS sample at the same redshifts approximately by a factor of 1.5. The subsequent spectroscopic testing of the redshifts of our selected candidates for quasars at 3 < z < 5.5 will allow the purity of this sample to be estimated more accurately.

Identification of high-mass X-ray binaries selected from XMM-Newton observations of the LMC★

NASA Astrophysics Data System (ADS)

van Jaarsveld, N.; Buckley, D. A. H.; McBride, V. A.; Haberl, F.; Vasilopoulos, G.; Maitra, C.; Udalski, A.; Miszalski, B.

2018-04-01

The Large Magellanic Cloud (LMC) currently hosts around 23 high-mass X-ray binaries (HMXBs) of which most are Be/X-ray binaries. The LMC XMM-Newton survey provided follow-up observations of previously known X-ray sources that were likely HMXBs, as well as identifying new HMXB candidates. In total, 19 candidate HMXBs were selected based on their X-ray hardness ratios. In this paper we present red and blue optical spectroscopy, obtained with Southern African Large Telescope and the South African Astronomical Observatory 1.9-m telescope, plus a timing analysis of the long-term optical light curves from OGLE to confirm the nature of these candidates. We find that nine of the candidates are new Be/X-ray binaries, substantially increasing the LMC Be/X-ray binary population. Furthermore, we present the optical properties of these new systems, both individually and as a group of all the BeXBs identified by the XMM-Newton survey of the LMC.

How fast can an AGN shut down? XMM-Newton observation of IC 2497

NASA Astrophysics Data System (ADS)

Schawinski, Kevin

2008-10-01

We propose to observe IC 2497 with XMM-Newton to detect, or rule out, an obscured AGN that might account for the illumination of `Hanny's Voorwerp'. The Voorwerp is a highly ionised cloud of gas extended over 15-25 kpc next to the spiral galaxy IC 2497. There is no source of ionisation within the Voorwerp, implicating a luminous 1E44 erg/s AGN in IC 2497 as the source. Swift XRT observations do not yield a detection, allowing the presence of a highly obscured, sufficiently luminous AGN. With 34 ksec of XMM observations, we could detect an obscured AGN down to 1E42 erg/s. We can thus either locate an obscured AGN, or we can for the first time constrain the shutdown time scale for a powerful AGN, as it drops by a factor of 100 in luminosity in 1E5 years.

Analysis of Quasi-periodic Oscillations and Time Lag in Ultraluminous X-Ray Sources with XMM-Newton

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

Li, Zi-Jian; Xiao, Guang-Cheng; Zhang, Shu

We investigated the power density spectrum (PDS) and time lag of ultraluminous X-ray sources (ULXs) observed by XMM-Newton . We determined the PDSs for each ULX and found that five of them show intrinsic variability due to obvious quasi-periodic oscillations (QPOs) of mHz–1 Hz, consistent with previous reports. We further investigated these five ULXs to determine their possible time lag. The ULX QPOs exhibit a soft time lag that is linearly related to the QPO frequency. We discuss the likelihood of the ULX QPOs being type-C QPO analogs, and the time lag models. The ULXs might harbor intermediate-mass black holesmore » if their QPOs are type-C QPO analogs. We suggest that the soft lag and the linearity may be due to reverberation.« less

AG Draconis observed with XMM-Newton

NASA Astrophysics Data System (ADS)

González-Riestra, R.; Viotti, R. F.; Iijima, T.; Rossi, C.; Montagni, F.; Bernabei, S.; Frasca, A.; Skopal, A.

2008-04-01

Context: AG Draconis is the brightest symbiotic star in X-rays and one of the prototypes of the supersoft X-ray source class. Aims: Study of the X-ray spectrum of this peculiar binary system, covering both quiescence and activity periods, is necessary to investigate the physics of the high temperature spectral component, and to unveil the origin of the outbursts. Methods: X-ray and UV observations with XMM-Newton during 2003-2005 and coordinated optical spectrophotometric monitoring, together with archive data, are employed to derive the behaviour of the high energy source of the AG Dra system during different orbital and activity phases. Results: During quiescence the X-ray emission is very soft and is close in strength to the previous ROSAT observations, with an estimated luminosity of 2600 L_⊙ and a radius of 0.06 R_⊙. We also found a 20% flux decrease in June 2005 at the time when a U-band minimum coincided with a V-band maximum. The X-ray flux in the XMM range largely decreases, and even vanishes near the optical light maxima (bursts). The UV fluxes measured with the XMM Optical Monitor is close to the fluxes observed with the IUE satellite. There is a marked anticorrelation between X-ray fluxes, and ultraviolet and optical fluxes, indicating that during outburst the WD is mostly emitting below 0.1 keV. Conversely, the large strengthening of the He II 4686 Å emission during the October 2003 and July 2005 light maxima indicates a marked increase of the far-UV brightness especially during the early stages of the outbursts. A high energy 0.5-0.6 keV X-ray excess seems to be present both in quiescence and outburst. Conclusions: This is the first time that X-ray spectra of AG Draconis during an active phase are obtained. These data have allowed us to investigate the change of the energy distribution. The anti-correlation between X-ray and optical/ultraviolet emission appears to be a general feature of AG Dra independent of the type and strength of the outburst

An XMM-Newton Science Archive for next decade, and its integration into ESASky

NASA Astrophysics Data System (ADS)

Loiseau, N.; Baines, D.; Rodriguez, P.; Salgado, J.; Sarmiento, M.; Colomo, E.; Merin, B.; Giordano, F.; Racero, E.; Migliari, S.

2016-06-01

We will present a roadmap for the next decade improvements of the XMM-Newton Science Archive (XSA), as planned for an always faster and more user friendly access to all XMM-Newton data. This plan includes the integration of the Upper Limit server, an interactive visualization of EPIC and RGS spectra, on-the-fly data analysis, among other advanced features. Within this philosophy XSA is also being integrated into ESASky, the science-driven discovery portal for all the ESA Astronomy Missions. A first public beta release of the ESASky service has been already released at the end of 2015. It is currently featuring an interface for exploration of the multi-wavelength sky and for single and/or multiple target searches of science-ready data. The system offers progressive multi-resolution all-sky projections of full mission datasets using a new generation of HEALPix projections called HiPS, developed at the CDS; detailed geometrical footprints to connect the all-sky mosaics to individual observations; and direct access to science-ready data at the underlying mission-specific science archives. New XMM-Newton EPIC and OM all-sky HiPS maps, catalogues and links to the observations are available through ESASky, together with INTEGRAL, HST, Herschel, Planck and other future data.

XMM-Newton studies of the supernova remnant G350.0-2.0

NASA Astrophysics Data System (ADS)

Karpova, A.; Shternin, P.; Zyuzin, D.; Danilenko, A.; Shibanov, Yu.

2016-11-01

We report the results of XMM-Newton observations of the Galactic mixed-morphology supernova remnant G350.0-2.0. Diffuse thermal X-ray emission fills the north-western part of the remnant surrounded by radio shell-like structures. We did not detect any X-ray counterpart of the latter structures, but found several bright blobs within the diffuse emission. The X-ray spectrum of the most part of the remnant can be described by a collisionally ionized plasma model VAPEC with solar abundances and a temperature of ≈0.8 keV. The solar abundances of plasma indicate that the X-ray emission comes from the shocked interstellar material. The overabundance of Fe was found in some of the bright blobs. We also analysed the brightest point-like X-ray source 1RXS J172653.4-382157 projected on the extended emission. Its spectrum is well described by the two-temperature optically thin thermal plasma model MEKAL typical for cataclysmic variable stars. The cataclysmic variable source nature is supported by the presence of a faint (g ≈ 21) optical source with non-stellar spectral energy distribution at the X-ray position of 1RXS J172653.4-382157. It was detected with the XMM-Newton optical/UV monitor in the U filter and was also found in the archival Hα and optical/near-infrared broad-band sky survey images. On the other hand, the X-ray spectrum is also described by the power law plus thermal component model typical for a rotation powered pulsar. Therefore, the pulsar interpretation of the source cannot be excluded. For this source, we derived the upper limit for the pulsed fraction of 27 per cent.

XMM-Newton discovery of pulsations from IGR J21237+4218=V2069 Cyg

NASA Astrophysics Data System (ADS)

de Martino, D.; Bonnet-Bidaud, J. M.; Falanga, M.; Mouchet, M.; Motch, C.

2009-06-01

We report on a preliminary analysis of a XMM-Newton observation of the INTEGRAL source IGR J21237+4218 identified as the cataclysmic variable RXJ2123.7+4217=V2069 Cyg (Motch et al. 1996 A&A 307, 459; Barlow et al. 2006, MNRAS 372, 224). This observation was performed on April 30, 2009 (Start time: 2009-04-30T10:45:58.000) for a total of 28ksec (Observation ID: 0601270101). The source is detected in the EPIC cameras at an average net countrate of 1.05 cts/sec (EPIC-pn) and 0.65cts/sec (EPIC-MOS).

Investigating the galactic Supernova Remnant Kes 78 with XMM-Newton

NASA Astrophysics Data System (ADS)

Miceli, M.; Bamba, A.; Orlando, S.; Bocchino, F.

2016-06-01

The galactic supernova remnant Kes 78 is associated with a HESS gamma-ray source and its X-ray emission has been recently revealed by Suzaku observations which have found indications for a hard X-ray component in the spectra. We analyzed an XMM-Newton EPIC observation of Kes 78 and studied the spatial distribution of the physical and chemical properties of the X-ray emitting plasma. The EPIC data unveiled a very complex morphology for the soft X-ray emission. We performed image analysis and spatially resolved spectral analysis finding indications for the interaction of the remnant with a local molecular cloud. Finally, we investigated the origin of the hard X-ray emitting component.

Investigating the Galactic supernova remnant Kes 78 with XMM-Newton

NASA Astrophysics Data System (ADS)

Miceli, Marco; Bamba, Aya; Orlando, Salvatore; Bocchino, Fabrizio

2016-06-01

The galactic supernova remnant Kes 78 is associated with a HESS gamma-ray source and its X-ray emission has been recently revealed by Suzaku observations which have found indications for a hard X-ray component in the spectra. We analyzed an XMM-Newton EPIC observation of Kes 78 and studied the spatial distribution of the physical and chemical properties of the X-ray emitting plasma. The EPIC data unveiled a very complex morphology for the soft X-ray emission. We performed image analysis and spatially resolved spectral analysis finding indications for the interaction of the remnant with a local molecular cloud. Finally, we investigated the origin of the hard X-ray emitting component.

Insights on the X-ray weak quasar phenomenon from XMM-Newton monitoring of PHL 1092

NASA Astrophysics Data System (ADS)

Miniutti, Giovanni; Fabian, Andy; Gallo, Luigi; Brandt, Niel; Schneider, Donald

2012-09-01

PHL 1092 is a z~0.4 high-luminosity counterpart of the class of Narrow Line Seyfert 1 galaxies. In 2008, PHL 1092 was found to be in a remarkably low X-ray flux state during an XMM-Newton observation. Its 2 keV flux density had dropped by a factor of ~260 with respect to a previous observation performed 4.5 yr earlier. The UV flux remained almost constant, resulting in a significant steepening of the optical-to-X-ray slope alpha_ox from -1.57 to -2.51, making PHL 1092 one of the most extreme X-ray weak quasars with no observed broad absorption lines (BALs) in the UV. We have monitored the source since 2008 with XMM-Newton, producing a simultaneous UV and X-ray database spanning almost 10 yr in total in the activity of the source. We apply a series of physically motivated models to the data with the goal of explaining as self-consistently as possible the UV-to-X-ray spectral energy distribution (SED) and the extreme X-ray and alpha_ox variability. We discuss our results in the context of the class of non-BAL X-ray weak quasars and so-called PHL 1811 analogs.

A year after lift-off, XMM-Newton is impressing the X-ray astronomy community

NASA Astrophysics Data System (ADS)

2000-11-01

XMM-Newton was launched from Kourou on 10 December 1999 on the first Ariane-5 commercial flight. After in-orbit commissioning of the spacecraft, and calibration and performance verification of its science instruments, the observatory entered its routine operations phase on 1 July. At the press conference, ESA's Director of Science Prof. Roger-Maurice Bonnet and XMM-Newton Project Scientist Fred Jansen will present some of the many scientific results from the first eight months of the mission. Also present will be two of Europe's foremost X-ray astronomers, Prof. Johan Bleeker of the Space Research Organisation of the Netherlands, and Prof. Guenther Hasinger of the Astrophysikalisches Institut Potsdam, Germany. Amongst the topics to be illustrated with some remarkably vivid "colour" images of the X-ray Universe, will be XMM-Newton's first examination of a cataclysmic binary star, its first insights into some enigmatic black hole systems, analysis of the morphology of a few supernovae remnants, and evidence it has collected to end the long-standing mystery over X-ray cosmic background emission... The press conference will also recap on the spacecraft's operations, the performance of its science instruments, the issue of radiation constraints and future aspects of the mission. Media representatives wishing to attend the press event are kindly invited to complete the attached reply form and fax it back to ESA Media Relations Office +33(0)1.53.69.7690. Note to editors XMM-Newton is ESA's second Cornerstone Mission of the Horizon 2000 programme. The spacecraft was built by a European consortium of companies led by Astrium (formerly Dornier Satellitensysteme), Friedrichshafen, Germany. Its X-ray imaging and spectrographic instruments (EPIC and RGS) and its optical telescope (OM) were provided by large consortia, whose principal investigators are from, respectively, the University of Leicester, UK, SRON University of Utrecht Netherlands, and the Mullard Space Science

XMM-Newton study of the lensing cluster of galaxies CL 0024+17

NASA Astrophysics Data System (ADS)

Zhang, Y.-Y.; Böhringer, H.; Mellier, Y.; Soucail, G.; Forman, W.

2005-01-01

We present a detailed gravitational mass measurement based on the XMM-Newton imaging spectroscopy analysis of the lensing cluster of galaxies CL 0024+17 at z=0.395. The emission appears approximately symmetric. However, on the scale of r ˜ 3.3' some indication of elongation is visible in the northwest-southeast (NW-SE) direction from the hardness ratio map (HRM). Within 3', we measure a global gas temperature of 3.52 ± 0.17 keV, metallicity of 0.22 ± 0.07, and bolometric luminosity of 2.9 ± 0.1 × 1044 h-270 erg s-1. We derive a temperature distribution with an isothermal temperature of 3.9 keV to a radius of 1.5' and a temperature gradient in the outskirts (1.3'XMM-Newton X-ray observations and HST optical lensing measurements. This work is based on observations made with the XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA member states and the USA (NASA). Based on observations made with the European Southern Observatory telescopes obtained from the ESO/ST-ECF Science Archive Facility.

The XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST)

NASA Astrophysics Data System (ADS)

Feigelson, Eric; Guedel, M.

2007-12-01

The XMM-Newton Extended Survey of the Taurus Molecular Cloud is an exceptionally large and growing X-ray survey of the Taurus Molecular Cloud (TMC). Now comprising 31 1/2-degree diameter fields, observed with the three XMM-Newton EPIC cameras. High-resolution spectroscopy has been obtained for about ten T Tauri stars (TTS) with the RGS instruments, and the Optical Monitor secured an optical/UV survey. XEST detects essentially the entire surveyed TTS population of the TMC in X-rays including about half of the observed (8/16) brown dwarfs and Class I protostars (8/20). Several new candidate members are identified. The X-ray luminosity (LX) of TTS shows related correlations with both stellar bolometric luminosity and mass. Classical TTS show suppressed X-ray output in the CCD band by a factor of about 2. These statistical results confirm results from other star formation regions. Different from previous reports on TMC, XEST identifies no activity-rotation relation. Brown dwarfs are found to follow trends set by TTS, both for accreting and non-accreting objects. But a decrease of the fractional luminosity, LX/Lbol, is seen with decreasing mass indicating weakened heating efficiency in the substellar domain. XEST reports five members of the class of "Two-Absorber X-Ray" (TAX) sources which reveal a double-peaked spectrum originating from two unrelated sources with different absorption column densities. The softer emission is thought to be related to jets, as explicitly seen in DG Tau. RGS spectroscopy shows a systematic "X-ray soft excess" in classical TTS, suggesting excessive cool (1-2 MK) plasma due to accretion, although the excess seems to correlate with magnetic activity as well. XEST has been supported by the Space Science Institute (Bern/Switz.).

Joint XMM-Newton, Chandra, and RXTE Observations of Cyg X-1 at Phase Zero

NASA Technical Reports Server (NTRS)

Pottschmidt, Katja

2008-01-01

We present first results of simultaneous observations of the high mass X-ray binary Cyg X-1 for 50 ks with XMM-Newton, Chandra-HETGS and RXTE in 2008 April. The observations are centered on phase 0 of the 5.6 d orbit when pronounced dips in the X-ray emission from the black hole are known to occur. The dips are due to highly variable absorption in the accretion stream from the O-star companion to the black hole. Compared to previous high resolution spectroscopy studies of the dip and non-dip emission with Chandra, the addition of XMM-Newton data allows for a better determination of the continuum, especially through the broad iron line region (with RXTE constraining the greater than 10 keV continuum).

XMM-Newton and INTEGRAL view of the hard state of EXO 1745-248 during its 2015 outburst

NASA Astrophysics Data System (ADS)

Matranga, M.; Papitto, A.; Di Salvo, T.; Bozzo, E.; Torres, D. F.; Iaria, R.; Burderi, L.; Rea, N.; de Martino, D.; Sanchez-Fernandez, C.; Gambino, A. F.; Ferrigno, C.; Stella, L.

2017-07-01

Context. Transient low-mass X-ray binaries (LMXBs) often show outbursts that typically last a few weeks and are characterized by a high X-ray luminosity (Lx ≈ 1036-1038 erg s-1), while most of the time they are found in X-ray quiescence (LX ≈ 1031-1033 erg s-1). The source EXO 1745-248 is one of them. Aims: The broad-band coverage and sensitivity of the instrument on board XMM-Newton and INTEGRAL offers the opportunity of characterizing the hard X-ray spectrum during the outburst of EXO 1745-248. Methods: We report on quasi-simultaneous XMM-Newton and INTEGRAL observations of the X-ray transient EXO 1745-248 located in the globular cluster Terzan 5, performed ten days after the beginning of the outburst (on 2015 March 16) of the source between March and June 2015. The source was caught in a hard state, emitting a 0.8-100 keV luminosity of ≃ 1037 erg s-1. Results: The spectral continuum was dominated by thermal Comptonization of seed photons with temperature kTin ≃ 1.3 keV, by a cloud with a moderate optical depth τ ≃ 2, and with an electron temperature of kTe ≃ 40 keV. A weaker soft thermal component at temperature kTth ≃ 0.6-0.7 keV and compatible with a fraction of the neutron star radius was also detected. A rich emission line spectrum was observed by the EPIC-pn on board XMM-Newton; features at energies compatible with K-α transitions of ionized sulfur, argon, calcium, and iron were detected, with a broadness compatible with either thermal Compton broadening or Doppler broadening in the inner parts of an accretion disk truncated at 20 ± 6 gravitational radii from the neutron star. Strikingly, at least one narrow emission line ascribed to neutral or mildly ionized iron is needed to model the prominent emission complex detected between 5.5 and 7.5 keV. The different ionization state and broadness suggest an origin in a region located farther from the neutron star than where the other emission lines are produced. Seven consecutive type I bursts

XMM-Newton X-ray spectra of V407 Lup (Nova Lup 2016)

NASA Astrophysics Data System (ADS)

Ness, Jan-Uwe; Starrfield, Sumner; Woodward, Chick E.; Kuin, Paul; Page, Kim; Beardmore, Andy; Osborne, Julian; Sala, Gloria; Hernanz, Margarita; Orio, Marina; Williams, Bob

2017-09-01

Nova Lup 2016 (V407 Lup) was observed by XMM-Newton from 11 March 2017, 11:45 to 17:08 UT, 168 days after outburst (ATel #9538) with an exposure duration of 23,000 s. The EPIC pn was operated in Timing Mode with Medium filter.

XMM-Newton observations of the non-thermal supernova remnant HESS J1731-347 (G353.6-0.7)

NASA Astrophysics Data System (ADS)

Doroshenko, V.; Pühlhofer, G.; Bamba, A.; Acero, F.; Tian, W. W.; Klochkov, D.; Santangelo, A.

2017-12-01

We report on the analysis of XMM-Newton observations of the non-thermal shell-type supernova remnant HESS J1731-347 (G353.6-0.7). For the first time the complete remnant shell has been covered in X-rays, which allowed direct comparison with radio and TeV observations. We carried out a spatially resolved spectral analysis of XMM-Newton data and confirmed the previously reported non-thermal power-law X-ray spectrum of the source with negligible variations of spectral index across the shell. On the other hand, the X-ray absorption column is strongly variable and correlates with the CO emission thus confirming that the absorbing material must be in the foreground and reinforcing the previously suggested lower limit on distance. Finally, we find that the X-ray emission of the remnant is suppressed towards the Galactic plane, which points to lower shock velocities in this region, likely due to the interaction of the shock with the nearby molecular cloud.

The XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST)

NASA Technical Reports Server (NTRS)

Guedel, M.; Briggs, K. R.; Arzner, K.; Audard, M.; Bouvier, J.; Feigelson, E. D.; Franciosini, E.; Glauser, A.; Grosso, N.; Micela, G.;

X-ray Observations of Binary and Single Wolf-Rayet Stars with XMM-Newton and Chandra

NASA Technical Reports Server (NTRS)

Skinner, Stephen; Gudel, Manuel; Schmutz, Werner; Zhekov, Svetozar

2006-01-01

We present an overview of recent X-ray observations of Wolf-Rayet (WR) stars with XMM-Newton and Chandra. These observations are aimed at determining the differences in X-ray properties between massive WR + OB binary systems and putatively single WR stars. A new XMM spectrum of the nearby WN8 + OB binary WR 147 shows hard absorbed X-ray emission (including the Fe Ka line complex), characteristic of colliding wind shock sources. In contrast, sensitive observations of four of the closest known single WC (carbon-rich) WR stars have yielded only nondetections. These results tentatively suggest that single WC stars are X-ray quiet. The presence of a companion may thus be an essential factor in elevating the X-ray emission of WC + OB stars to detectable levels.

A systematic analysis of the XMM-Newton background: III. Impact of the magnetospheric environment

NASA Astrophysics Data System (ADS)

Ghizzardi, Simona; Marelli, Martino; Salvetti, David; Gastaldello, Fabio; Molendi, Silvano; De Luca, Andrea; Moretti, Alberto; Rossetti, Mariachiara; Tiengo, Andrea

2017-12-01

A detailed characterization of the particle induced background is fundamental for many of the scientific objectives of the Athena X-ray telescope, thus an adequate knowledge of the background that will be encountered by Athena is desirable. Current X-ray telescopes have shown that the intensity of the particle induced background can be highly variable. Different regions of the magnetosphere can have very different environmental conditions, which can, in principle, differently affect the particle induced background detected by the instruments. We present results concerning the influence of the magnetospheric environment on the background detected by EPIC instrument onboard XMM-Newton through the estimate of the variation of the in-Field-of-View background excess along the XMM-Newton orbit. An important contribution to the XMM background, which may affect the Athena background as well, comes from soft proton flares. Along with the flaring component a low-intensity component is also present. We find that both show modest variations in the different magnetozones and that the soft proton component shows a strong trend with the distance from Earth.

The XMM Cluster Survey: X-ray analysis methodology

NASA Astrophysics Data System (ADS)

Lloyd-Davies, E. J.; Romer, A. Kathy; Mehrtens, Nicola; Hosmer, Mark; Davidson, Michael; Sabirli, Kivanc; Mann, Robert G.; Hilton, Matt; Liddle, Andrew R.; Viana, Pedro T. P.; Campbell, Heather C.; Collins, Chris A.; Dubois, E. Naomi; Freeman, Peter; Harrison, Craig D.; Hoyle, Ben; Kay, Scott T.; Kuwertz, Emma; Miller, Christopher J.; Nichol, Robert C.; Sahlén, Martin; Stanford, S. A.; Stott, John P.

2011-11-01

The XMM Cluster Survey (XCS) is a serendipitous search for galaxy clusters using all publicly available data in the XMM-Newton Science Archive. Its main aims are to measure cosmological parameters and trace the evolution of X-ray scaling relations. In this paper we describe the data processing methodology applied to the 5776 XMM observations used to construct the current XCS source catalogue. A total of 3675 > 4σ cluster candidates with >50 background-subtracted X-ray counts are extracted from a total non-overlapping area suitable for cluster searching of 410 deg2. Of these, 993 candidates are detected with >300 background-subtracted X-ray photon counts, and we demonstrate that robust temperature measurements can be obtained down to this count limit. We describe in detail the automated pipelines used to perform the spectral and surface brightness fitting for these candidates, as well as to estimate redshifts from the X-ray data alone. A total of 587 (122) X-ray temperatures to a typical accuracy of <40 (<10) per cent have been measured to date. We also present the methodology adopted for determining the selection function of the survey, and show that the extended source detection algorithm is robust to a range of cluster morphologies by inserting mock clusters derived from hydrodynamical simulations into real XMMimages. These tests show that the simple isothermal β-profiles is sufficient to capture the essential details of the cluster population detected in the archival XMM observations. The redshift follow-up of the XCS cluster sample is presented in a companion paper, together with a first data release of 503 optically confirmed clusters.

Automated source classification of new transient sources

NASA Astrophysics Data System (ADS)

Oertel, M.; Kreikenbohm, A.; Wilms, J.; DeLuca, A.

2017-10-01

The EXTraS project harvests the hitherto unexplored temporal domain information buried in the serendipitous data collected by the European Photon Imaging Camera (EPIC) onboard the ESA XMM-Newton mission since its launch. This includes a search for fast transients, missed by standard image analysis, and a search and characterization of variability in hundreds of thousands of sources. We present an automated classification scheme for new transient sources in the EXTraS project. The method is as follows: source classification features of a training sample are used to train machine learning algorithms (performed in R; randomForest (Breiman, 2001) in supervised mode) which are then tested on a sample of known source classes and used for classification.

Exospheric Neutral Density at the Earth's subsolar magnetopause deduced from the XMM-Newton X-ray observations

NASA Astrophysics Data System (ADS)

Connor, H. K.; Carter, J. A.

2017-12-01

Soft X-rays can be emitted when highly charged solar wind ions and exospheric neutrals exchange electrons. Astrophysics missions, such as XMM-Newton and ROSAT X-ray telescopes, have found that such solar wind charge exchange happens at the Earth's exosphere. The Earth's magnetosphere can be imaged via soft X-rays in order to understand its interaction with solar wind. Consequently, two soft X-ray telescope missions (CuPID and SMILE) are scheduled to launch in 2019 and 2021. They will provide wide field-of-view soft X-ray images of the Earth's dayside magnetosphere. The imagers will track the location and movement of the cusps, magnetopause, and bow shock in response to solar wind variations. To support these missions, an understanding of exospheric neutral density profile is needed. The neutral density is one of the controlling factors of soft X-ray signals. Strong neutral density can help to obtain high-resolution and high-cadence of soft X-ray images. In this study, we estimate the exospheric neutral density at 10 RE subsolar point using XMM X-ray observations, Cluster plasma observations, and OpenGGCM global magnetosphere - ionosphere MHD model. XMM-Newton observes line-of-sight, narrow field-of-view, integrated soft X-ray emissions when it looks through the dayside magnetosphere. OpenGGCM reproduces soft X-ray signals seen by the XMM spacecraft, assuming exospheric neutral density as a function of the neutral density at the 10RE subsolar point and the radial distance. Cluster observations are used to confirm OpenGGCM plasma results. Finally, we deduce the neutral density at 10 RE subsolar point by adjusting the model results to the XMM-Newton soft X-ray observations.

Processing challenges in the XMM-Newton slew survey

NASA Astrophysics Data System (ADS)

Saxton, Richard D.; Altieri, Bruno; Read, Andrew M.; Freyberg, Michael J.; Esquej, M. P.; Bermejo, Diego

2005-08-01

The great collecting area of the mirrors coupled with the high quantum efficiency of the EPIC detectors have made XMM-Newton the most sensitive X-ray observatory flown to date. This is particularly evident during slew exposures which, while giving only 15 seconds of on-source time, actually constitute a 2-10 keV survey ten times deeper than current "all-sky" catalogues. Here we report on progress towards making a catalogue of slew detections constructed from the full, 0.2-12 keV energy band and discuss the challenges associated with processing the slew data. The fast (90 degrees per hour) slew speed results in images which are smeared, by different amounts depending on the readout mode, effectively changing the form of the point spread function. The extremely low background in slew images changes the optimum source searching criteria such that searching a single image using the full energy band is seen to be more sensitive than splitting the data into discrete energy bands. False detections due to optical loading by bright stars, the wings of the PSF in very bright sources and single-frame detector flashes are considered and techniques for identifying and removing these spurious sources from the final catalogue are outlined. Finally, the attitude reconstruction of the satellite during the slewing maneuver is complex. We discuss the implications of this on the positional accuracy of the catalogue.

The XXL Survey. I. Scientific motivations - XMM-Newton observing plan - Follow-up observations and simulation programme

NASA Astrophysics Data System (ADS)

Pierre, M.; Pacaud, F.; Adami, C.; Alis, S.; Altieri, B.; Baran, N.; Benoist, C.; Birkinshaw, M.; Bongiorno, A.; Bremer, M. N.; Brusa, M.; Butler, A.; Ciliegi, P.; Chiappetti, L.; Clerc, N.; Corasaniti, P. S.; Coupon, J.; De Breuck, C.; Democles, J.; Desai, S.; Delhaize, J.; Devriendt, J.; Dubois, Y.; Eckert, D.; Elyiv, A.; Ettori, S.; Evrard, A.; Faccioli, L.; Farahi, A.; Ferrari, C.; Finet, F.; Fotopoulou, S.; Fourmanoit, N.; Gandhi, P.; Gastaldello, F.; Gastaud, R.; Georgantopoulos, I.; Giles, P.; Guennou, L.; Guglielmo, V.; Horellou, C.; Husband, K.; Huynh, M.; Iovino, A.; Kilbinger, M.; Koulouridis, E.; Lavoie, S.; Le Brun, A. M. C.; Le Fevre, J. P.; Lidman, C.; Lieu, M.; Lin, C. A.; Mantz, A.; Maughan, B. J.; Maurogordato, S.; McCarthy, I. G.; McGee, S.; Melin, J. B.; Melnyk, O.; Menanteau, F.; Novak, M.; Paltani, S.; Plionis, M.; Poggianti, B. M.; Pomarede, D.; Pompei, E.; Ponman, T. J.; Ramos-Ceja, M. E.; Ranalli, P.; Rapetti, D.; Raychaudury, S.; Reiprich, T. H.; Rottgering, H.; Rozo, E.; Rykoff, E.; Sadibekova, T.; Santos, J.; Sauvageot, J. L.; Schimd, C.; Sereno, M.; Smith, G. P.; Smolčić, V.; Snowden, S.; Spergel, D.; Stanford, S.; Surdej, J.; Valageas, P.; Valotti, A.; Valtchanov, I.; Vignali, C.; Willis, J.; Ziparo, F.

2016-06-01

Context. The quest for the cosmological parameters that describe our universe continues to motivate the scientific community to undertake very large survey initiatives across the electromagnetic spectrum. Over the past two decades, the Chandra and XMM-Newton observatories have supported numerous studies of X-ray-selected clusters of galaxies, active galactic nuclei (AGNs), and the X-ray background. The present paper is the first in a series reporting results of the XXL-XMM survey; it comes at a time when the Planck mission results are being finalised. Aims: We present the XXL Survey, the largest XMM programme totaling some 6.9 Ms to date and involving an international consortium of roughly 100 members. The XXL Survey covers two extragalactic areas of 25 deg2 each at a point-source sensitivity of ~5 × 10-15 erg s-1 cm-2 in the [0.5-2] keV band (completeness limit). The survey's main goals are to provide constraints on the dark energy equation of state from the space-time distribution of clusters of galaxies and to serve as a pathfinder for future, wide-area X-ray missions. We review science objectives, including cluster studies, AGN evolution, and large-scale structure, that are being conducted with the support of approximately 30 follow-up programmes. Methods: We describe the 542 XMM observations along with the associated multi-λ and numerical simulation programmes. We give a detailed account of the X-ray processing steps and describe innovative tools being developed for the cosmological analysis. Results: The paper provides a thorough evaluation of the X-ray data, including quality controls, photon statistics, exposure and background maps, and sky coverage. Source catalogue construction and multi-λ associations are briefly described. This material will be the basis for the calculation of the cluster and AGN selection functions, critical elements of the cosmological and science analyses. Conclusions: The XXL multi-λ data set will have a unique lasting legacy

Observations of MCG-5-23-16 with Suzaku, XMM-Newton and NuSTAR: Disk Tomography and Compton Hump Reverberation

NASA Technical Reports Server (NTRS)

Zoghbi, A.; Cackett, E. M.; Reynolds, C.; Kara, E.; Harrison, F. A.; Fabian, A. C.; Lohfink, A.; Matt, G.; Stern, D.; Zhang, W. W.

2014-01-01

MCG-5-23-16 is one of the first active galactic nuclei (AGNs) where relativistic reverberation in the iron K line originating in the vicinity of the supermassive black hole was found, based on a short XMM-Newton observation. In this work, we present the results from long X-ray observations using Suzaku, XMM-Newton, and NuSTAR designed to map the emission region using X-ray reverberation. A relativistic iron line is detected in the lag spectra on three different timescales, allowing the emission from different regions around the black hole to be separated. Using NuSTAR coverage of energies above 10 keV reveals a lag between these energies and the primary continuum, which is detected for the first time in an AGN. This lag is a result of the Compton reflection hump responding to changes in the primary source in a manner similar to the response of the relativistic iron K line.

Observations of MCG-5-23-16 with Suzaku, XMM-Newton and NuSTAR: Disk tomography and compton hump reverberation

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

Zoghbi, A.; Reynolds, C.; Lohfink, A.

2014-07-01

MCG-5-23-16 is one of the first active galactic nuclei (AGNs) where relativistic reverberation in the iron K line originating in the vicinity of the supermassive black hole was found, based on a short XMM-Newton observation. In this work, we present the results from long X-ray observations using Suzaku, XMM-Newton, and NuSTAR designed to map the emission region using X-ray reverberation. A relativistic iron line is detected in the lag spectra on three different timescales, allowing the emission from different regions around the black hole to be separated. Using NuSTAR coverage of energies above 10 keV reveals a lag between thesemore » energies and the primary continuum, which is detected for the first time in an AGN. This lag is a result of the Compton reflection hump responding to changes in the primary source in a manner similar to the response of the relativistic iron K line.« less

VizieR Online Data Catalog: Classification of 2XMM variable sources (Lo+, 2014)

NASA Astrophysics Data System (ADS)

Lo, K. K.; Farrell, S.; Murphy, T.; Gaensler, B. M.

2017-06-01

The 2XMMi-DR2 catalog (Cat. IX/40) consists of observations made with the XMM-Newton satellite between 2000 and 2008 and covers a sky area of about 420 deg2. The observations were made using the European Photon Imaging Camera (EPIC) that consists of three CCD cameras - pn, MOS1, and MOS2 - and covers the energy range from 0.2 keV to 12 keV. There are 221012 unique sources in 2XMM-DR2, of which 2267 were flagged as variable by the XMM processing pipeline (Watson et al. 2009, J/A+A/493/339). The variability test used by the pipeline is a {Chi}2 test against the null hypothesis that the source flux is constant, with the probability threshold set at 10-5. (1 data file).

The XMM-SERVS Survey: first results in the 5 deg^2 XMM-LSS region

NASA Astrophysics Data System (ADS)

Chen, Chien-Ting; Brandt, William; Luo, Bin; X-SERVS team

2018-01-01

We present an X-ray source catalog obtained with XMM-Newton in the XMM-LSS region as part of the X-SERVS survey (XMM-SERVS-LSS), which aims to expand the parameter space of current X-ray surveys with medium-deep X-ray observations in multiple large fields with superb multiwavelength coverage. Within the 5 deg$^2$ XMM-SERVS-LSS field, we combine the 1.3 Ms XMM observations allocated at XMM AO-15 with archival data, and identified 5218 X-ray sources of which 2400 are new sources. We reach $1.2\\times10^{-15}$ erg s$^{-1} cm$^{-1}$ for 50\\% of the area, which is comparable to the XMM-COSMOS survey but with 2.5 times more sources. We also present multiwavelength identifications, basic photometric properties, and spectroscopic redshifts obtained from the literature. These data, combined with the existing data from COSMOS, will enable a wide range of science on AGN evolution, including studying SMBH growth across the full range of cosmic environments and minimizing cosmic variance.

XMM-Newton X-ray Observatory Guest Observer program (AO-1) at CASA

NASA Technical Reports Server (NTRS)

Skinner, Stephen L.

2003-01-01

In this research program, we obtained and analyzed X-ray observations of the Wolf-Rayet (WR) star WR 110 (HD 165688) using the XMM-Newton space-based observatory. Radio observations were also obtained using the Very Large Array (VLA) radio telescope located in New Mexico and operated by the Natl. Radio Astronomy Observatory (NRAO). This star was targeted for observations primarily because it is believed to be a single WR star without a companion. Single WR stars are thought to emit X-rays from cool plasma in shocks distributed throughout their powerful stellar winds. However, there has been little observational work done to test this idea since single WR stars are relatively weak X-ray sources and have been difficult to detect with previous generation telescopes. The launch of XMM-Newton provides a new telescope that is much more sensitive than its predecessors, allowing single WR stars to be studied in detail for the first time. X-ray emission was clearly detected from WR 110. Analysis of its spectrum yields a surprising result. Its X-ray emitting plasma is distributed over a range of temperatures and is dominated by relatively cool plasma with a characteristic temperature T is approximately 6 million K. Such plasma can be explained by existing theoretical wind shock models. However, the spectrum also shows hotter plasma whose temperature is uncertain but is thought to be in excess of T approximately 30 million K. The origin of this hotter plasma is yet unknown, but possible mechanisms are identified

The Soft-X-Ray Emission of Ark 120. XMM-Newton, NuSTAR, and the Importance of Taking the Broad View

NASA Technical Reports Server (NTRS)

Matt, G.; Marinucci, A.; Guainazzi, M.; Brenneman, L. W.; Elvis, M.; Lohfink, A.; Arevalo, P.; Boggs, S. E.; Cappi, M.; Stern, D.;

XMM-Newton Observations of NGC 253: Resolving the Emission Components in the Disk and Nuclear Area

NASA Technical Reports Server (NTRS)

Pietsch, W.; Borozdin, K. N.; Branduardi-Raymont, G.; Cappi, M.; Ehle, M.; Ferrando, P.; Freyberg, M. J.; Kahn, S. M.; Ponman, T. J.; Ptak, A.

2000-01-01

We describe the first XMM-Newton observations of the starburst galaxy NGC 253. As known from previous X-ray observations, NGC 253 shows a mixture of extended (disk and halo) and point-source emission. The high XMM-Newton throughput allows for the first time a detailed investigation of the spatial, spectral and variability properties of these components simultaneously. We detect a bright X-ray transient approx. 70 sec SSW of the nucleus and show the spectrum and light curve of the brightest point source (approx. 30 sec S of the nucleus, most likely a black-hole X-ray binary, BHXRB). The unprecedented combination of RGS and EPIC also sheds new light on the emission of the complex nuclear region, the X-ray plume and the disk diffuse emission. In particular, EPIC images reveal that the limb-brightening of the plume is mostly seen in higher ionization emission lines, while in the lower ionization lines, and below 0.5 keV, the plume is more homo- geneously structured, pointing to new interpretations as to the make up of the starburst-driven outflow. Assuming that type IIa supernova remnants (SNRs) are mostly responsible for the E greater than 4 keV emission, the detection with EPIC of the 6.7 keV line allows us to estimate a supernova rate within the nuclear starburst of 0.2 /yr.

Extreme AGN Captured in a Low State by XMM-Newton and NuSTAR

NASA Astrophysics Data System (ADS)

Frederick, Sara; Kara, Erin; Reynolds, Christopher S.

2018-01-01

The most variable active galactic nuclei (AGN), taken together, are a compelling wellspring of interesting accretion-related phenomena and can exhibit dramatic variability in the X-ray band down to timescales of a few minutes. We present the exemplifying case study of 1H 1934-063 (z = 0.0102), a narrow-line Seyfert I (NLS1) that is among the most variable AGN ever observed with XMM-Newton. We present spectroscopic and temporal analyses of a concurrent XMM-Newton and NuSTAR 120 ks observation, during which the source exhibited a steep (factor of 1.5) plummet and subsequent full recovery of flux that we explore in detail. Combined spectral and timing results point to a dramatic change in the continuum on timescales as short as a few ks. Similar to other highly variable Seyfert 1s, this AGN is X-ray bright and displays strong reflection spectral features. We find agreement with a change in the continuum, and we rule out absorption as the cause for this dramatic variability that is observed even at NuSTAR energies. We compare measurements from detailed time-resolved spectral fitting with Fourier-based timing results to constrain coronal geometry, dynamics, and emission/absorption processes dictating the nature of this variability. We also announce the discovery of a Fe-K time lag between the hard X-ray continuum emission (1-4 keV) and relativistically-blurred reprocessing by the inner accretion flow (0.3-1 keV).

XMM-Newton Observations of MBM 12: More Constraints on the Solar Wind Charge Exchange and Local Bubble Emissions

NASA Technical Reports Server (NTRS)

Koutroumpa, Dimitra; Smith, Randall K.; Edgar, Richard J.; Kuntz, Kip D.; Plucinsky, Paul P.; Snowden, Steven L.

2010-01-01

We present the first analysis of an XMM-Newton observation of the nearby molecular cloud MBM 12. We find that in the direction of MBM 12 the total O VII (0.57 keV) triplet emission is 1.8(+0.5/-0.6) photons/sq cm/s/sr (or Line Units - LU) while for the O VIII (0.65 keV) line emission we find a 3(sigma) upper limit of <1 LU. We also use a heliospheric model to calculate the O VII and O VIII emission generated by Solar Wind Charge-eXchange (SWCX) which we compare to the XMM-Newton observations. This comparison provides new constraints on the relative heliospheric and Local Bubble contributions to the local diffuse X-ray background. The heliospheric SWCX model predicts 0.82 LU for O VII, which accounts for approx. 46+/-15% of the observed value, and 0.33 LU for the O VIII line emission consistent with the XMM-Newton observed value. We discuss our results in combination with previous observations of the MBM 12 with CHANDRA and Suzaku.

XMM-Newton spectroscopy of the accreting magnetar candidate 4U0114+65

NASA Astrophysics Data System (ADS)

Sanjurjo-Ferrrín, G.; Torrejón, J. M.; Postnov, K.; Oskinova, L.; Rodes-Roca, J. J.; Bernabeu, G.

2017-10-01

Aims: 4U0114+65 is one of the slowest known X-ray pulsars. We present an analysis of a pointed observation by the XMM-Newton X-ray telescope in order to study the nature of the X-ray pulsations and the accretion process, and to diagnose the physical properties of the donor's stellar wind. Methods: We analysed the energy-resolved light curve and the time-resolved X-ray spectra provided by the EPIC cameras on board XMM-Newton. We also analysed the first high-resolution spectrum of this source provided by the Reflection Grating Spectrometer. Results: An X-ray pulse of 9350 ± 160 s was measured. Comparison with previous measurements confirms the secular spin up of this source. We successfully fit the pulse-phase-resolved spectra with Comptonisation models. These models imply a very small (r 3 km) and hot (kT 2 - 3 keV) emitting region and therefore point to a hot spot over the neutron star (NS) surface as the most reliable explanation for the X-ray pulse. The long NS spin period, the spin-up rate, and persistent X-ray emission can be explained within the theory of quasi-spherical settling accretion, which may indicate that the magnetic field is in the magnetar range. Thus, 4U 0114+65 could be a wind-accreting magnetar. We also observed two episodes of low luminosity. The first was only observed in the low-energy light curve and can be explained as an absorption by a large over-dense structure in the wind of the B1 supergiant donor. The second episode, which was deeper and affected all energies, may be due to temporal cessation of accretion onto one magnetic pole caused by non-spherical matter capture from the structured stellar wind. The light curve displays two types of dips that are clearly seen during the high-flux intervals. The short dips, with durations of tens of seconds, are produced through absorption by wind clumps. The long dips, in turn, seem to be associated with the rarefied interclump medium. From the analysis of the X-ray spectra, we found evidence of

XMM-NEWTON SLEW SURVEY OBSERVATIONS OF THE GRAVITATIONAL WAVE EVENT GW150914

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

Troja, E.; Read, A. M.; Tiengo, A.

The detection of the first gravitational wave (GW) transient GW150914 prompted an extensive campaign of follow-up observations at all wavelengths. Although no dedicated XMM-Newton observations have been performed, the satellite passed through the GW150914 error region during normal operations. Here we report the analysis of the data taken during these satellite slews performed two hours and two weeks after the GW event. Our data cover 1.1 and 4.8 deg{sup 2} of the final GW localization region. No X-ray counterpart to GW150914 is found down to a sensitivity of 6 × 10{sup −13} erg cm{sup −2} s{sup −1} in the 0.2–2more » keV band. Nevertheless, these observations show the great potential of XMM-Newton slew observations for searching for the electromagnetic counterparts of GW events. A series of adjacent slews performed in response to a GW trigger would take ≲1.5 days to cover most of the typical GW credible region. We discuss this scenario and its prospects for detecting the X-ray counterpart of future GW detections.« less

An XMM-Newton Study of 9SGR and the Lagoon Nebula

NASA Technical Reports Server (NTRS)

Rauw, G.; Blomme, R.; Waldron, W. L.; Naze, Y.; Harries, T. J.; Chapman, J. M.; Corcoran, M. F.; Detal, A.; Gosset, E.

2001-01-01

We report preliminary results of an XMM-Newton observation of the 04 V star 9 Sgr (= HD 164794). 9 Sgr is one of a few single OB stars that display a non-thermal radio emission attributed to synchrotron emission by relativistic electrons. Inverse Compton scattering of photospheric UV photons by these relativistic electrons is a priori expected to generate a non-thermal power-law tail in the X-ray spectrum. Our EPIC and RGS spectra of 9 Sgr suggest a more complex situation than expected from this 'simple' theoretical picture. Furthermore, soft-band EPIC images of the region around 9 Sgr reveal a number of point sources inside the Lagoon Nebula (M8). Most of these sources have optical counterparts inside the very young open cluster NGC 6530 and several X-ray sources are associated with low and intermediate mass pre-main sequence stars. Finally, we also detect (probably) diffuse X-ray emission from the Hourglass Region that might reveal a hot bubble blown by the stellar wind of Herschel 36, the ionizing star of the HG region.

The XMM-Newton view of the non-thermal supernova remnant HESS J1731-347

NASA Astrophysics Data System (ADS)

Puehlhofer, G.; Doroshenko, V.; Acero, F.; Bamba, A.; Klochkov, D.; Tian, W.

2017-10-01

HESS J1731-347 belongs to a small group of supernova remnants that are characterized by a spatially-resolved shell-type TeV morphology and strong synchrotron X-ray emission. We report on XMM-Newton observations of the source that provide for the first time a complete X-ray view of the remnant. The data show an emissivity gradient across the source, which is not observed in the TeV gamma-ray and radio bands. While the broadband spectral analysis is compatible with a pure leptonic emission scenario up to TeV energies, the morphological analysis could be indicative of a blend of hadronic and leptonic TeV emission. We discuss the possibility of an interaction of the supernova remnant with nearby molecular clouds.

X-Ray Spectral Study of AGN Sources Content in Some Deep Extragalactic XMM-Newton Fields

NASA Astrophysics Data System (ADS)

Hassan, M. A.; Korany, B. A.; Misra, R.; Issa, I. A. M.; Ahmed, M. K.; Abdel-Salam, F. A.

2012-06-01

We undertake a spectral study of a sample of bright X-ray sources taken from six XMM-Newton fields at high galactic latitudes, where AGN are the most populous class. These six fields were chosen such that the observation had an exposure time more than 60 ksec, had data from the EPIC-pn detector in the full-Frame mode and lying at high galactic latitude | b|>25°. The analysis started by fitting the spectra of all sources with an absorbed power-law model, and then we fitted all the spectra with an absorbed power-law with a low energy black-body component model.The sources for which we added a black body gave an F-test probability of 0.01 or less (i.e. at 99% confidence level), were recognized as sources that display soft excess. We perform a comparative analysis of soft excess spectral parameters with respect to the underlying power-law one for sources that satisfy this criterion. Those sources, that do not show evidence for a soft excess, based on the F-test probability at a 99% confidence level, were also fitted with the absorbed power-law with a low energy black-body component model with the black-body temperature fixed at 0.1 and 0.2 keV. We establish upper limits on the soft excess flux for those sources at these two temperatures. Finally we have made use of Aladdin interactive sky atlas and matching with NASA/IPAC Extragalactic Database (NED) to identify the X-ray sources in our sample. For those sources which are identified in the NED catalogue, we make a comparative study of the soft excess phenomenon for different types of systems.

NuSTAR and XMM-Newton Observations of 1E1743.1-2843: Indications of a Neutron Star LMXB Nature of the Compact Object

NASA Technical Reports Server (NTRS)

Lotti, Simone; Natalucci, Lorenzo; Mori, Kaya; Baganoff, Frederick K.; Boggs, Steven E.; Christensen, Finn E.; Craig, William W.; Hailey, Charles J.; Harrison, Fiona A.; Hong, Jaesub;

The enigma of the magnetic pulsar SXP1062: a new look with XMM-Newton

NASA Astrophysics Data System (ADS)

Oskinova, Lidia

2012-10-01

SXP 1062 is an exceptional case of a young neutron star with known age in a wind-fed HMXB. A unique combination of measured spin period, its derivative, luminosity and young age makes this source a key probe for the physics of accretion and neutron star evolution. All current accretion scenarios encounter major difficulties explaining the spin-down rate of this accretion-powered pulsar. This study will allow us to construct a spin period-luminosity relation as a powerful tool for distinguishing between different accretion and evolution scenarios. The XMM-Newton observations of SXP 1062 will thus shed new light on the physics of accreting neutron stars.

XMM-Newton Observation of IGR J18538-0102 and an Optical/IR Candidate

NASA Astrophysics Data System (ADS)

Halpern, J. P.; Gotthelf, E. V.

2010-02-01

We observed the X-ray counterpart of IGR J18538-0102 (Stephen et al., ATel #2441) in a pointed observation with XMM-Newton on 2004 October 8. This apparently steady source (in an 8 ks exposure) can be fitted with a power-law model of photon index 1.7+/-0.1, NH = (1.5+/-0.2)e22 cm-2, and unabsorbed 1-10 keV flux 5.6e-12 erg cm-2 s-1. Its coordinates 18h53m48.50s, -01d02'30.0" (J2000), with 90% confidence error radius of 3.2", coincide with an object in the 2MASS Point Source Catalog at 18h53m48.48s, -01d02'29.6" of magnitudes H=14.00+/-0.05 and K=12.50+/-0.05.

The Broad Iron K-alpha line of Cygnus X-1 as Seen by XMM-Newton in the EPIC-pn Modified Timing Mode

NASA Technical Reports Server (NTRS)

Duro, Refiz; Dauser, Thomas; Wilms, Jorn; Pottschmidt, Katja; Nowak, Michael A.; Fritz, Sonja; Kendziorra, Eckhard; Kirsch, Marcus G. F.; Reynolds, Christopher S.; Staubert, Rudiger

2011-01-01

We present the analysis of the broadened, flourescent iron K(alpha) line in simultaneous XMM-Newton and RXTE data from the black hole Cygnus X-I. The XMM-Newton data were taken in a modified version of the Timing Mode of the EPIC-pn camera. In this mode the lower energy threshold of the instrument is increased to 2.8 keV to avoid telemetry drop outs due to the brightness of the source, while at the same time preserving the signal to noise ratio in the Fe K(alpha) band. We find that the best-fit spectrum consists of the sum of an exponentially cut-off power-law and relativistically smeared, ionized reflection. The shape of the broadened Fe K(alpha) feature is due to strong Compton broadening combined with relativistic broadening. Assuming a standard, thin accretion disk, the black hole is close to maximally rotating. Key words. X-rays: binaries - black hole physics - gravitation

Observaciones combinadas XMM-Newton/Chandra del remanente de supernova G306.3-0.9

NASA Astrophysics Data System (ADS)

Filócomo, A.; Combi, J. A.; García, F.; Suárez, A. E.; Luque-Escamilla, P. L.; Parón, S.

2016-08-01

In this paper we study the spatial and spectral distribution of the physical and chemical properties of the supernova remnant G306.3-0.9 by using data of the X-rays telescopes XMM-Newton and Chandra, which we complement with radio and infrared information in order to study the morphology of the source and the effect of the shock wave in the interestelar medium. The results show a non-uniform morphology of the emission, dominated by thermal radiation with high values of Ne, Mg, S, Ca, Ar and Fe in the central region, typical of ejecta material. Also, using an infrared flux distribution, we could restrict the type of the progenitor responsible of the supernova phenomena.

A XMM-Newton Observation of Nova LMC 1995, a Bright Supersoft X-ray Source

NASA Technical Reports Server (NTRS)

Orio, Marina; Hartmann, Wouter; Still, Martin; Greiner, Jochen

2003-01-01

Nova LMC 1995, previously detected during 1995-1998 with ROSAT, was observed again as a luminous supersoft X-ray source with XMM-Newton in December of 2000. This nova offers the possibility to observe the spectrum of a hot white dwarf, burning hydrogen in a shell and not obscured by a wind or by nebular emission like in other supersoft X-ray sources. Notwithstanding uncertainties in the calibration of the EPIC instruments at energy E<0.5 keV, using atmospheric models in Non Local Thermonuclear Equilibrium we derived an effective temperature in the range 400,000-450,000 K, a bolometric luminosity Lbolabout equal to 2.3 times 10 sup37 erg s sup-l, and we verified that the abundance of carbon is not significantly enhanced in the X-rays emitting shell. The RGS grating spectra do not show emission lines (originated in a nebula or a wind) observed for some other supersoft X-ray sources. The crowded atmospheric absorption lines of the white dwarf cannot be not resolved. There is no hard component (expected from a wind, a surrounding nebula or an accretion disk), with no counts above the background at E>0.6 keV, and an upper limit Fx,hard = 10 sup-14 erg s sup-l cm sup-2 to the X-ray flux above this energy. The background corrected count rate measured by the EPIC instruments was variable on time scales of minutes and hours, but without the flares or sudden obscuration observed for other novae. The power spectrum shows a peak at 5.25 hours, possibly due to a modulation with the orbital period. We also briefly discuss the scenarios in which this nova may become a type Ia supernova progenitor.

Contributions of the "Great" X-Ray Observatories (XMM-Newton and Chandra) to Astronomy and Astrophysics

NASA Technical Reports Server (NTRS)

Weisskopf, Martin

2011-01-01

NASA s Chandra X-ray Observatory and ESA s XMM-Newton made their first observations over a decade ago. The unprecedented and complementary capabilities of these observatories to detect, image, and measure the energy of cosmic X-rays, achieved less than 50 years after the first detection of an extra-solar X-ray source, represent an increase in sensitivity comparable in going from naked-eye observations to the most powerful optical telescopes over the past 400 years. In this presentation we highlight some of the many discoveries made using these powerful X-ray observatories that have transformed 21st century astronomy. We briefly discuss future prospects for this truly exciting field.

First XMM-Newton Observations of an Isolated Neutron Star: RXJ0720.4-3125

NASA Technical Reports Server (NTRS)

Paerels, Frits; Mori, Kaya; Motch, Christian; Haberl, Frank; Zavlin, Vyacheslav E.; Zane, Silvia; Ramsay, Gavin; Cropper, Mark

2000-01-01

We present the high resolution spectrum of the isolated neutron star RXJ0720.4-3125, obtained with the Reflection Grating Spectrometer on XMM-Newton, complemented with the broad band spectrum observed with the EPIC PN camera. The spectrum appears smooth, with no evidence for strong photospheric absorption or emission features. We briefly discuss the implications of our failure to detect structure in the spectrum.

A High Resolution Spectroscopic Observation of CAL 83 with XMM-Newton/RGS

NASA Technical Reports Server (NTRS)

Paerels, Frits; Rasmussen, Andrew P.; Hartmann, H. W.; Heise, J.; Brinkman, A. C.; deVries, C. P.; denHerder, J.-W.

2000-01-01

We present the first high resolution photospheric X-ray spectrum of a Supersoft X-ray Source, the famous CAL 83 in the Large Magellanic Cloud. The spectrum was obtained with the Reflection Grating Spectrometer on XMM-Newton during the Calibration/Performance Verification phase of the observatory. The spectrum covers the range 20-40 A at an approximately constant resolution of 0.05 A, and shows very significant, intricate detail, that is very sensitive to the physical properties of the object. We present the results of an initial investigation of the spectrum, from which we draw the conclusion that the spectral structure is probably dominated by numerous absorption features due to transitions in the Gshells of the mid-2 elements and the M-shell of Fe, in addition to a few strong K-shell features due to CNO.

XMM-Newton observations of NGC 3268 in the Antlia Galaxy Cluster: characterization of a hidden group of galaxies at z ≈ 0.41

NASA Astrophysics Data System (ADS)

Gargiulo, I. D.; García, F.; Combi, J. A.; Caso, J. P.; Bassino, L. P.

2018-05-01

We report on a detailed X-ray study of the extended emission of the intracluster medium (ICM) around NGC 3268, in the Antlia cluster of galaxies, together with a characterization of an extended source in the field, namely a background cluster of galaxies at z ≈ 0.41, which was previously accounted as an X-ray point source. The spectral properties of the extended emission of the gas present in Antlia were studied using data from the XMM-Newton satellite complemented with optical images of CTIO-Blanco telescope, to attain for associations of the optical sources with the X-ray emission. The XMM-Newton observations show that the intracluster gas is concentrated in a region centred in one of the main galaxies of the cluster, NGC 3268. By means of a spatially-resolved spectral analysis we derived the abundances of the ICM plasma. We found a wall-like feature in the northeast direction where the gas is characterized by a lower temperature with respect to the rest of the ICM. Furthermore, using combined optical observations we inferred the presence of an elliptical galaxy in the centre of the extended X-ray source considered as a background cluster, which favours this interpretation.

ESA's XMM-Newton sees matter speed-racing around a black hole

NASA Astrophysics Data System (ADS)

2005-01-01

hi-res Size hi-res: 715 Kb Credits: NASA/Dana Berry, SkyWorks Digital ESA’s XMM-Newton sees matter speed-racing around a black hole Click here for animation in MOV format Movie still in TIFF format (9761 Kb) Movie still in JPG format (715 Kb) This animation depicts three hot chunks of matter orbiting a black hole. If placed in our Solar System, this black hole would appear like a dark abyss spread out nearly as wide as Mercury's orbit. And the three chunks (each as large as the Sun) would be as far out as Jupiter. They orbit the black hole in a lightning-quick 30 000 kilometres per second, over a tenth of the speed of light. hi-res Size hi-res: 220 Kb Credits: NASA/Dana Berry, SkyWorks Digital ESA’s XMM-Newton sees matter speed-racing around a black hole Click here for animation in MPG format Movie still in TIFF format (2553 Kb) Movie still in JPG format (220 Kb) This is a simplified illustration of two hot chunks of matter orbiting a black hole, showing how scientists tracked the blobs by observing their Doppler shift. First, we see one blob. Note how the energy emitted from this orbiting material rises to about 6.5 kilo-electron volt (an energy unit) as it moves towards us, and then falls to about 5.8 kilo-electron volt as it moves away. This is the 'Doppler effect' and a similar phenomenon happens with the changing pitch of a police siren. If it is approaching, the frequency of the sound is higher, but if it is receding the frequency is lower. Matter goes round and round; energy goes up and down. About 14 seconds into the animation, a second blob is added, which also displays a rise and fall in energy during its orbit. The observation, made with ESA’s XMM-Newton observatory, marks the first time scientists could trace individual blobs of shredded matter on a complete journey around a black hole. This provides a crucial measurement that has long been missing from black hole studies: an orbital period. Knowing this, scientists can measure black hole mass and

Evidence of Spin and Energy Extraction in a Galactic Black Hole Candidate: The XMM-NEWTON/EPIC SPECTRUM of XTE 11650-500

NASA Technical Reports Server (NTRS)

Miller, J. M.; Fabian, A. C.; Wunands, R.; Reynolds, C. S.; Ehle, M.; Freyberg, M. J.; VanDerKlis, M.; Lewin, W. H. G.; Sanchez-Fernandez, C.; Castro-Tirado, A. J.

2002-01-01

We observed the Galactic black hole candidate XTE J1650-500 early in its fall of 2001 outburst with the XMM-Newton European Photon Imaging pn Camera (EPIC-pn). The observed spectrum is consistent with the source having been in the very high state. We h d a broad, skewed Fe Kar emission line that suggests the primary in this system may be a Kerr black hole and that indicates a steep disk emissivity profile that is hard to explain in terms of a standard accretion disk model. These results are quantitatively and qualitatively similar to those from an XMM-Newton observation of the Seyfert galaxy MCG -6-30-15. The steep emissivity in MCG -6-30-15 may be explained by the extraction and dissipation of rotational energy from a black hole with nearly maximal angular momentum or from material in the plunging region via magnetic connections to the inner accretion disk. If this process is at work in both sources, an exotic but fundamental general relativistic prediction may be confirmed across a factor of l0(exp 6) in black hole mass. We discuss these results in terms of the accretion flow geometry in stellar-mass black holes and the variety of enigmatic phenomena often observed in the very high state.

THE XMM-NEWTON WIDE-FIELD SURVEY IN THE COSMOS FIELD (XMM-COSMOS): DEMOGRAPHY AND MULTIWAVELENGTH PROPERTIES OF OBSCURED AND UNOBSCURED LUMINOUS ACTIVE GALACTIC NUCLEI

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

Brusa, M.; Cappelluti, N.; Merloni, A.

2010-06-10

We report the final optical identifications of the medium-depth ({approx}60 ks), contiguous (2 deg{sup 2}) XMM-Newton survey of the COSMOS field. XMM-Newton has detected {approx}1800 X-ray sources down to limiting fluxes of {approx}5 x 10{sup -16}, {approx}3 x 10{sup -15}, and {approx}7 x 10{sup -15} erg cm{sup -2} s{sup -1} in the 0.5-2 keV, 2-10 keV, and 5-10 keV bands, respectively ({approx}1 x 10{sup -15}, {approx}6 x 10{sup -15}, and {approx}1 x 10{sup -14} erg cm{sup -2} s{sup -1}, in the three bands, respectively, over 50% of the area). The work is complemented by an extensive collection of multiwavelength datamore » from 24 {mu}m to UV, available from the COSMOS survey, for each of the X-ray sources, including spectroscopic redshifts for {approx}>50% of the sample, and high-quality photometric redshifts for the rest. The XMM and multiwavelength flux limits are well matched: 1760 (98%) of the X-ray sources have optical counterparts, 1711 ({approx}95%) have IRAC counterparts, and 1394 ({approx}78%) have MIPS 24 {mu}m detections. Thanks to the redshift completeness (almost 100%) we were able to constrain the high-luminosity tail of the X-ray luminosity function confirming that the peak of the number density of log L{sub X} > 44.5 active galactic nuclei (AGNs) is at z {approx} 2. Spectroscopically identified obscured and unobscured AGNs, as well as normal and star-forming galaxies, present well-defined optical and infrared properties. We devised a robust method to identify a sample of {approx}150 high-redshift (z > 1), obscured AGN candidates for which optical spectroscopy is not available. We were able to determine that the fraction of the obscured AGN population at the highest (L{sub X} > 10{sup 44} erg s{sup -1}) X-ray luminosity is {approx}15%-30% when selection effects are taken into account, providing an important observational constraint for X-ray background synthesis. We studied in detail the optical spectrum and the overall spectral energy

The Reflection Grating Spectrometer on Board XMM-Newton

NASA Technical Reports Server (NTRS)

denHerder, J. W.; Brinkman, A. C.; Kahn, S. M.; Branduardi-Raymont, G.; Thomsen, K.; Aarts, H.; Audard, M.; Bixler, J. V.; denBoggende, A. J.

2000-01-01

The ESA X-ray Multi Mirror mission, XMM-Newton, carries two identical Reflection Grating Spectrometers (RGS) behind two of its three nested sets of Wolter I type mirrors. The instrument allows high-resolution (E/(Delta)E = 100 to 500) measurements in the soft X-ray range (6 to 38 A or 2.1 to 0.3 keV) with a maximum effective area of about 140 sq cm at 15 A. Its design is optimized for the detection of the K-shell transitions of carbon, nitrogen, oxygen, neon, magnesium, and silicon. as well as the L shell transitions of iron. The present paper gives a full description of the design of the RGS and its operational modes. We also review details of the calibrations and in-orbit performance including the line spread function, the wavelength calibration, the effective area, and the instrumental background.

Non-thermal emission in the core of Perseus: results from a long XMM-Newton observation

NASA Astrophysics Data System (ADS)

Molendi, S.; Gastaldello, F.

2009-01-01

We employ a long XMM-Newton observation of the core of the Perseus cluster to validate claims of a non-thermal component discovered with Chandra. From a meticulous analysis of our dataset, which includes a detailed treatment of systematic errors, we find the 2-10 keV surface brightness of the non-thermal component to be less than about 5 × 10-16 erg~cm-2 s-1 arcsec-2. The most likely explanation for the discrepancy between the XMM-Newton and Chandra estimates is a problem in the effective area calibration of the latter. Our EPIC-based magnetic field lower limits do not disagree with Faraday rotation measure estimates on a few cool cores and with a minimum energy estimate on Perseus. In the not too distant future Simbol-X may allow detection of non-thermal components with intensities more than 10 times lower than those that can be measured with EPIC; nonetheless even the exquisite sensitivity within reach for Simbol-X might be insufficient to detect the IC emission from Perseus.

The XXL Survey I. Scientific Motivations - Xmm-Newton Observing Plan - Follow-up Observations and Simulation Programme

NASA Technical Reports Server (NTRS)

Pierre, M.; Pacaud, F.; Adami, C.; Alis, S.; Altieri, B.; Baran, N.; Benoist, C.; Birkinshaw, M.; Bongiorno, A.; Bremer, M. N.;

Physics and evolution of obscured X-ray sources: a multiwavelength approach

NASA Astrophysics Data System (ADS)

Brusa, Marcella

2004-06-01

Observations at high energies yield important information on the structure and nature of AGN; when coupled with deep optical and near-infrared (photometric and spectroscopic) follow-up, they provide constraints on the mass of the growing black holes and, therefore, are essential to better understand the nature of the various components of the X-ray background light and can be used as test for the accretion paradigm. Conversely, optical and near-infrared surveys of galaxies are crucial to discriminate between different cosmological scenarios (e.g. hierarchical or monolithic growth of the structures) and, thus, to recover the galaxy evolution path. In this framework, in the first part of the thesis, I will discuss the main results from an extensive program of multiwavelength observations of hard X-ray selected sources serendipitously discovered in XMM-Newton fields over ~1 deg^2 (the HELLAS2XMM survey). With a complementary approach to that of hard X-ray surveys, in order to investigate the link between nuclear activity and the galaxy formation, in the second part of the thesis I will present XMM-Newton and Chandra observations of photometric and spectroscopically selected Extremely Red Objects (EROs).

The Jet/Disk Connection in AGN: Chandra and XMM-Newton Observations of Three Powerful Radio-Loud Quasars

NASA Technical Reports Server (NTRS)

Sambruna, Rita; Gliozzi, Mario; Tavecchio, F.; Maraschi, L.; Foschini, Luigi

2007-01-01

The connection between the accretion process that powers AGN and the formation of jets is still poorly understood. Here we tackle this issue using new, deep Chandra and XMM-Newton observations of tlie cores of three powerful radio loud quasars: 1136-135, 1150+497 (Chandra), and 0723+679 (XMM-Newton), in the redshift range z=0.3-0.8. These sources are known from our previous Chandra siiapsliot survey to liave kpc-scale X-ray jets. In 1136-135 and 1150-1+497; evidence is found for the presence of diffuse thermal X-ray emission around the cores; on scales of 40-50 kpc and with luminosity L(sub 0.3-2 kev approx. 10(sup 43) erg per second, suggesting thermal emission from the host galaxy or a galaxy group. The X-ray continua of the cores in the three sources are described by an upward-curved (concave) broken power law, with photon indices GAMMA (sub soft) approx. 1.8 - 2.1 and GAMMA (sub hard) approx. 1.7 below and above approx. equal to 2 keV, respectively. There is evidence for an uiiresolved Fe K alpha line with EW approx. 70 eV in the three quasars. The Spectral Energy Distributions of the sources can be well described by a mix of jet and disk emission, with the jet dominating the radio and hard X-rays (via synchrotron and external Compton) and the disk dominating the optical/UV through soft X-rays. The ratio of the jet-to-disk powers is approx. 1, consistent with those derived for a number of gamma ray emitting blazars. This indicates that near equality of accretion and jet power may be common in powerful radio-loud AGN.

An XMM-Newton view of the radio galaxy 3C 411

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

Bostrom, Allison; Reynolds, Christopher S.; Tombesi, Francesco

We present the first high signal-to-noise XMM-Newton observations of the broad-line radio galaxy 3C 411. After fitting various spectral models, an absorbed double power-law (PL) continuum and a blurred relativistic disk reflection model (kdblur) are found to be equally plausible descriptions of the data. While the softer PL component (Γ = 2.11) of the double PL model is entirely consistent with that found in Seyfert galaxies (and hence likely originates from a disk corona), the additional PL component is very hard (Γ = 1.05); amongst the active galactic nucleus zoo, only flat-spectrum radio quasars (FSRQ) have such hard spectra. Togethermore » with the flat radio-spectrum displayed by this source, we suggest that it should instead be classified as an FSRQ. This leads to potential discrepancies regarding the jet inclination angle, with the radio morphology suggesting a large jet inclination but the FSRQ classification suggesting small inclinations. The kdblur model predicts an inner disk radius of at most 20 r {sub g} and relativistic reflection.« less

An XMM-Newton Study of the Bright Narrow-Line Seyfert 1 Galaxy Arakelian 564

NASA Technical Reports Server (NTRS)

Brandt, Niel

2004-01-01

We report on two XMM-Newton observations of the bright Narrow-Line Seyfert 1 galaxy Ark 564 taken one year apart (2000 June and 2001 June). The 0.6-10 keV continuum is well described by a soft blackbody component (kT - 140-150 eV) plus a steep power law (Gamma - 2.50-2.55). No significant spectral changes are observed between the two observations, although the X-ray flux in the second observation is - 40-50 per cent lower. In both observations we detect a significant absorption edge at a rest-frame energy of - 0.73 keV, corresponding to 0 VII. The presence of the absorption feature is confirmed by a simultaneous Chandra grating observation in 2000 June, although the best-fitting edge threshold is at a slightly lower energy in the Chandra data, possibly because of a different parameterization of the underlying X-ray continuum. We find tentative evidence for a broad iron emission line in the 2000 June observation. The results from an analysis of the power spectral density (PSD) function are also presented. The present XMM-Newton data support the idea that the PSD shows two breaks, although the location of the high-frequency break requires further constraints.

A cluster in a crowded environment: XMM-Newton and Chandra observations of A3558

NASA Astrophysics Data System (ADS)

Rossetti, M.; Ghizzardi, S.; Molendi, S.; Finoguenov, A.

2007-03-01

Combining XMM-Newton and Chandra data, we have performed a detailed study of Abell 3558. Our analysis shows that its dynamical history is more complicated than previously thought. We have found some traits typical of cool core clusters (surface brightness peaked at the center, peaked metal abundance profile) and others that are more common in merging clusters, like deviations from spherical symmetry in the thermodynamic quantities of the ICM. This last result has been achieved with a new technique for deriving temperature maps from images. We have also detected a cold front and, with the combined use of XMM-Newton and Chandra, we have characterized its properties, such as the speed and the metal abundance profile across the edge. This cold front is probably due to the sloshing of the core, induced by the perturbation of the gravitational potential associated with a past merger. The hydrodynamic processes related to this perturbation have presumably produced a tail of lower entropy, higher pressure and metal rich ICM, which extends behind the cold front for~500 kpc. The unique characteristics of A3558 are probably due to the very peculiar environment in which it is located: the core of the Shapley supercluster. Appendices A and B are only available in electronic form at http://www.aanda.org

Nature of the Unidentified TeV Source HESS J1614-518 Revealed by Suzaku and XMM-Newton Observations

NASA Astrophysics Data System (ADS)

Sakai, M.; Yajima, Y.; Matsumoto, H.

2013-03-01

We report new results concerning HESS J1614-518, which exhibits two regions with intense γ-ray emission. The south and center regions of HESS J1614-518 were observed with Suzaku in 2008, while the north region with the 1st brightest peak was observed in 2006. No X-ray counterpart is found at the 2nd brightest peak; the upper limit of the X-ray flux is estimated as 1.6 × 10-13 erg cm-2 s-1 in the 2-10 keV band. A previously-known soft X-ray source, Suzaku J1614-5152, is detected at the center of HESS J1614-518. Analyzing the XMM-Newton archival data, we reveal that Suzaku J1614-5152 consists of multiple point sources. The X-ray spectrum of the brightest point source, XMMU J161406.0-515225, could be described by a power-law model with the photon index Γ = 5.2+0.6-0.5 or a blackbody model with the temperature kT = 0.38+0.04-0.04 {keV}. In the blackbody model, the estimated column density N H = 1.1+0.3-0.2 × 1022 {cm}-2 is almost the same as that of the hard extended X-ray emission in Suzaku J1614-5141, spatially coincident with the 1st peak position. In this case, XMMU J161406.0-515225 may be physically related to Suzaku J1614-5141 and HESS J1614-518.

The XMM-Newton View of Wolf-Rayet Bubbles

NASA Astrophysics Data System (ADS)

Guerrero, M.; Toala, J.

2017-10-01

The powerful stellar winds of Wolf-Rayet (WR) stars blow large bubble into the circumstellar material ejected in previous phases of stellar evolution. The shock of those stellar winds produces X-ray-emitting hot plasmas which tells us about the diffusion of processed material onto the interstellar medium, about processes of heat conduction and turbulent mixing at the interface, about the late stages of stellar evolution, and about the shaping of the circumstellar environment, just before supernova explosions. The unique sensitivity of XMM-Newton has been key for the detection, mapping and spectral analysis of the X-ray emission from the hot bubbles around WR stars. These observations underscore the importance of the structure of the interstellar medium around massive stars, but they have also unveiled unknown phenomena, such as blowouts of hot gas into the interstellar medium or spatially-resolved spectral properties of the hot gas, which disclose inhomogeneous chemical abundances and physical properties across these bubbles.

Exploring the Diffuse X-ray Emission of Supernova Remnant Kesteven 69 with XMM-Newton

NASA Astrophysics Data System (ADS)

Seo, Kyoung-Ae; Hui, Chung Yue

2013-06-01

We have investigated the X-ray emission from the shock-heated plasma of the Galactic supernova remnant Kesteven 69 with XMM-Newton. Assuming the plasma is at collisional ionization equilibrium, a plasma temperature and a column absorption are found to be kT ~ 0.62 keV and NH ~ 2.85 ×10^22 cm-2 respectively by imaging spectroscopy. Together with the deduced emission measure, we place constraints on its Sedov parameters.

XMM-Newton Science Analysis Software: How to Bring New Technologies to Long-life Satellite Missions

NASA Astrophysics Data System (ADS)

Ibarra, A.; Calle, I.; Gabriel, C.; Salgado, J.; Osuna, P.

2009-09-01

We present here the beta version of the Remote Interface to SAS Analysis (RISA), a web service-based system that allows users the analysis of XMM-Newton data making use of all of the existing SAS functionalities. RISA takes advantage of GRID architecture to run SAS, achieving high performance in resource management. We are also making the SAS remote analysis compatible with present and future VO standards.

XMM-Newton Archival Study of the ULX Population in Nearby Galaxies

NASA Technical Reports Server (NTRS)

Winter, Lisa M.; Mushotzky, Richard; Reynolds, Christopher S.

2005-01-01

We have conducted an archival XMM-Newton study of the bright X-ray point sources in 32 nearby galaxies. From our list of approximately 100 point sources, we attempt to determine if there is a low-state counterpart to the Ultraluminous X-ray (ULX) population. Indeed, 16 sources in our sample match the criteria we set for a low-state ULX, namely, L(sub X) greater than 10(exp 38 ergs per second) and a spectrum best fit with an absorbed power law. Further, we find evidence for 26 high-state ULXs which are best fit by a combined blackbody and a power law. As in Galactic black hole systems, the spectral indices, GAMMA, of the low-state objects, as well a s the luminosities, tend to be lower than those of the high-state objects. The observed range of blackbody temperatures is 0.1-1 keV with the most luminous systems tending toward the lowest temperatures. We also find a class of object whose properties (luminosity, blackbody temperature, and power law slopes) are very similar to those of galactic stellar mass black holes. In addition, we find a subset of these objects that can be best fit by a Comptonized spectrum similar to that used for Galactic black holes in the very high state, when they are radiating near the Eddington limit.

A Potential Cyclotron Resonant Scattering Feature in the Ultraluminous X-Ray Source Pulsar NGC 300 ULX1 Seen by NuSTAR and XMM-Newton

NASA Astrophysics Data System (ADS)

Walton, D. J.; Bachetti, M.; Fürst, F.; Barret, D.; Brightman, M.; Fabian, A. C.; Grefenstette, B. W.; Harrison, F. A.; Heida, M.; Kennea, J.; Kosec, P.; Lau, R. M.; Madsen, K. K.; Middleton, M. J.; Pinto, C.; Steiner, J. F.; Webb, N.

2018-04-01

Based on phase-resolved broadband spectroscopy using XMM-Newton and NuSTAR, we report on a potential cyclotron resonant scattering feature (CRSF) at E ∼ 13 keV in the pulsed spectrum of the recently discovered ultraluminous X-ray source (ULX) pulsar NGC 300 ULX1. If this interpretation is correct, the implied magnetic field of the central neutron star is B ∼ 1012 G (assuming scattering by electrons), similar to that estimated from the observed spin-up of the star, and also similar to known Galactic X-ray pulsars. We discuss the implications of this result for the connection between NGC 300 ULX1 and the other known ULX pulsars, particularly in light of the recent discovery of a likely proton cyclotron line in another ULX, M51 ULX-8.

XMM-Newton mission operations - ready for its third decade

NASA Astrophysics Data System (ADS)

Kirsch, M.; Finn, T.; Godard, T.; v. Krusenstiern, N.; Pfeil, N.; Salt, D.; Toma, L.; Webert, D.; Weissmann, U.

2017-10-01

The XMM-Newton X-ray space observatory is approaching its third decade of operations. The spacecraft and payload are operating without major degradation and scientific demand is continuously very high. With the change to a new way of using the Attitude and Orbit control System in 2013 the fuel consumption was reduced by a factor of two, additionally this has reduced stress on the reaction wheels. The challenge for the next decade is now to ensure that the saved fuel is available for continuous usage. We will describe the process of the so called 'fuel migration and replenishment' activities needed to keep the spacecraft operational potentially up to 2029+. We provide as well an overall health status of the mission, the evolution of the ground segment and concepts on streamlining mission operations with continued high safety requirements using automation tools.

The NGC 4839 group falling into the Coma cluster observed by XMM-Newton

NASA Astrophysics Data System (ADS)

Neumann, D. M.; Arnaud, M.; Gastaud, R.; Aghanim, N.; Lumb, D.; Briel, U. G.; Vestrand, W. T.; Stewart, G. C.; Molendi, S.; Mittaz, J. P. D.

2001-01-01

We present here the first analysis of the XMM-Newton EPIC-MOS data of the galaxy group around NGC 4839, which lies at a projected distance to the Coma cluster center of 1.6h50-1 Mpc. In our analysis, which includes imaging, spectro-imaging and spectroscopy we find compelling evidence for the sub group being on its first infall onto the Coma cluster. The complex temperature structure around NGC 4839 is consistent with simulations of galaxies falling into a cluster environment. We see indications of a bow shock and of ram pressure stripping around NGC 4839. Furthermore our data reveal a displacement between NGC 4839 and the center of the hot gas in the group of about 300h50-1 kpc. With a simple approximation we can explain this displacement by the pressure force originating from the infall, which acts much stronger on the group gas than on the galaxies. 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). EPIC was developed by the EPIC Consortium led by the Principal Investigator, Dr. M. J. L. Turner. The consortium comprises the following Institutes: University of Leicester, University of Birmingham, (UK); CEA/Saclay, IAS Orsay, CESR Toulouse, (France); IAAP Tuebingen, MPE Garching, (Germany); IFC Milan, ITESRE Bologna, IAUP Palermo, Italy. EPIC is funded by: PPARC, CEA, CNES, DLR and ASI.

XMM-Newton Observations of Four Millisecond Pulsars

NASA Technical Reports Server (NTRS)

Zavlin, Vyacheslav E.

2005-01-01

I present an analysis of the XMM-Newton observations of four millisecond pulsars, J0437-4715, J2124-3358, J1024-0719, and J0034-0534. The new data provide strong evidence of thermal emission in the X-ray flux detected from the first three objects. This thermal component is best interpreted as radiation from pulsar polar caps covered with a nonmagnetic hydrogen atmosphere. A nonthermal power-law component, dominating at energies E greater than or equal to 3 keV, can also be present in the detected X-ray emission. For PSR J0437-4715, the timing analysis reveals that the shape and pulsed fraction of the pulsar light curves are energy dependent. This, together with the results obtained from the phase-resolved spectroscopy, supports the two-component (thermal plus nonthermal) interpretation of the pulsar's X-ray radiation. Highly significant pulsations have been found in the X-ray flux of PSRs 52124-3358 and 51024-0719. For PSR 50034-0534, a possible X-ray counterpart of the radio pulsar has been suggested. The inferred properties of the detected thermal emission are compared with predictions of radio pulsar models.

An XMM-Newton Observation of the Seyfert Galaxy 1H0419-577 in an Extreme Low State

NASA Technical Reports Server (NTRS)

Pounds, K. A.; Reeves, J. N.; Page, K. L.; O'Brien, P. T.

2003-01-01

Previous observations of the luminous Seyfert galaxy 1H 0419-577 have found its X-ray spectrum to range from that of a typical Seyfert 1 with 2-10 keV power law index Gamma approx. 1.9 to a much flatter power law of Gamma approx. 1.5 or less. We report here a new XMM-Newton observation which allows the low state spectrum to be studied in much greater detail than hitherto. We find a very hard spectrum (Gamma approx. 1.0) which exhibits broad features that can be modelled with the addition of an extreme relativistic Fe K emission line or with partial covering of the underlying continuum by a substantial column density of near-neutral gas. Both the EPIC and RGS data show evidence for strong line emission of OVII and OVIII requiring an extended region of low density photoionised gas in 1H 0419- 577. Comparison with an earlier XMM-Newton observation when 1H 0419-577 was X-ray bright indicates the dominant spectral variability occurs via a steep power law component.

On-the-fly Data Reprocessing and Analysis Capabilities from the XMM-Newton Archive

NASA Astrophysics Data System (ADS)

Ibarra, A.; Sarmiento, M.; Colomo, E.; Loiseau, N.; Salgado, J.; Gabriel, C.

2017-10-01

The XMM-Newton Science Archive (XSA) includes since last release the possibility to perform on-the-fly data processing with SAS through the Remote Interface for Science Analysis (RISA) server. It enables scientists to analyse data without any download and installation of data and software. The analysis options presently available include extraction of spectra and light curves of user-defined EPIC source regions and full reprocessing of data for which currently archived pipeline products were processed with older SAS versions or calibration files. The current pipeline is fully aligned with the most recent SAS and calibration, while the last full reprocessing of the archive was performed in 2013. The on-the-fly data processing functionality in this release is an experimental version and we invite the community to test and let us know their results. Known issues and workarounds are described in the 'Watchouts' section of the XSA web page. Feedback on how this functionality should evolve will be highly appreciated.

Swift, XMM-Newton, and NuSTAR Observations of PSR J2032+4127/MT91 213

NASA Astrophysics Data System (ADS)

Li, K. L.; Kong, A. K. H.; Tam, P. H. T.; Hou, X.; Takata, J.; Hui, C. Y.

2017-07-01

We report our recent Swift, NuSTAR, and XMM-Newton X-ray and Lijiang optical observations on PSR J2032+4127/MT91 213, the γ-ray binary candidate with a period of 45-50 years. The coming periastron of the system was predicted to be in 2017 November, around which high-energy flares from keV to TeV are expected. Recent studies with Chandra and Swift X-ray observations taken in 2015/2016 showed that its X-ray emission has been brighter by a factors of ˜10 than that before 2013, probably revealing some ongoing activities between the pulsar wind and the stellar wind. Our new Swift/XRT lightcurve shows no strong evidence of a single vigorous brightening trend, but rather several strong X-ray flares on weekly to monthly timescales with a slowly brightening baseline, namely the low state. The NuSTAR and XMM-Newton observations taken during the flaring and the low states, respectively, show a denser environment and a softer power-law index during the flaring state, implying that the pulsar wind interacted with the stronger stellar winds of the companion to produce the flares. These precursors would be crucial in studying the predicted giant outburst from this extreme γ-ray binary during the periastron passage in late 2017.

Automatic Classification of Time-variable X-Ray Sources

NASA Astrophysics Data System (ADS)

Lo, Kitty K.; Farrell, Sean; Murphy, Tara; Gaensler, B. M.

2014-05-01

To maximize the discovery potential of future synoptic surveys, especially in the field of transient science, it will be necessary to use automatic classification to identify some of the astronomical sources. The data mining technique of supervised classification is suitable for this problem. Here, we present a supervised learning method to automatically classify variable X-ray sources in the Second XMM-Newton Serendipitous Source Catalog (2XMMi-DR2). Random Forest is our classifier of choice since it is one of the most accurate learning algorithms available. Our training set consists of 873 variable sources and their features are derived from time series, spectra, and other multi-wavelength contextual information. The 10 fold cross validation accuracy of the training data is ~97% on a 7 class data set. We applied the trained classification model to 411 unknown variable 2XMM sources to produce a probabilistically classified catalog. Using the classification margin and the Random Forest derived outlier measure, we identified 12 anomalous sources, of which 2XMM J180658.7-500250 appears to be the most unusual source in the sample. Its X-ray spectra is suggestive of a ultraluminous X-ray source but its variability makes it highly unusual. Machine-learned classification and anomaly detection will facilitate scientific discoveries in the era of all-sky surveys.

Automatic classification of time-variable X-ray sources

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

Lo, Kitty K.; Farrell, Sean; Murphy, Tara

2014-05-01

To maximize the discovery potential of future synoptic surveys, especially in the field of transient science, it will be necessary to use automatic classification to identify some of the astronomical sources. The data mining technique of supervised classification is suitable for this problem. Here, we present a supervised learning method to automatically classify variable X-ray sources in the Second XMM-Newton Serendipitous Source Catalog (2XMMi-DR2). Random Forest is our classifier of choice since it is one of the most accurate learning algorithms available. Our training set consists of 873 variable sources and their features are derived from time series, spectra, andmore » other multi-wavelength contextual information. The 10 fold cross validation accuracy of the training data is ∼97% on a 7 class data set. We applied the trained classification model to 411 unknown variable 2XMM sources to produce a probabilistically classified catalog. Using the classification margin and the Random Forest derived outlier measure, we identified 12 anomalous sources, of which 2XMM J180658.7–500250 appears to be the most unusual source in the sample. Its X-ray spectra is suggestive of a ultraluminous X-ray source but its variability makes it highly unusual. Machine-learned classification and anomaly detection will facilitate scientific discoveries in the era of all-sky surveys.« less

The NuSTAR Serendipitous Survey: Hunting for the Most Extreme Obscured AGN at >10 keV

NASA Astrophysics Data System (ADS)

Lansbury, G. B.; Alexander, D. M.; Aird, J.; Gandhi, P.; Stern, D.; Koss, M.; Lamperti, I.; Ajello, M.; Annuar, A.; Assef, R. J.; Ballantyne, D. R.; Baloković, M.; Bauer, F. E.; Brandt, W. N.; Brightman, M.; Chen, C.-T. J.; Civano, F.; Comastri, A.; Del Moro, A.; Fuentes, C.; Harrison, F. A.; Marchesi, S.; Masini, A.; Mullaney, J. R.; Ricci, C.; Saez, C.; Tomsick, J. A.; Treister, E.; Walton, D. J.; Zappacosta, L.

2017-09-01

We identify sources with extremely hard X-ray spectra (I.e., with photon indices of {{Γ }}≲ 0.6) in the 13 deg2 NuSTAR serendipitous survey, to search for the most highly obscured active galactic nuclei (AGNs) detected at > 10 {keV}. Eight extreme NuSTAR sources are identified, and we use the NuSTAR data in combination with lower-energy X-ray observations (from Chandra, Swift XRT, and XMM-Newton) to characterize the broadband (0.5-24 keV) X-ray spectra. We find that all of the extreme sources are highly obscured AGNs, including three robust Compton-thick (CT; {N}{{H}}> 1.5× {10}24 cm-2) AGNs at low redshift (z< 0.1) and a likely CT AGN at higher redshift (z = 0.16). Most of the extreme sources would not have been identified as highly obscured based on the low-energy (< 10 keV) X-ray coverage alone. The multiwavelength properties (e.g., optical spectra and X-ray-mid-IR luminosity ratios) provide further support for the eight sources being significantly obscured. Correcting for absorption, the intrinsic rest-frame 10-40 keV luminosities of the extreme sources cover a broad range, from ≈ 5× {10}42 to 1045 erg s-1. The estimated number counts of CT AGNs in the NuSTAR serendipitous survey are in broad agreement with model expectations based on previous X-ray surveys, except for the lowest redshifts (z< 0.07), where we measure a high CT fraction of {f}{CT}{obs}={30}-12+16 % . For the small sample of CT AGNs, we find a high fraction of galaxy major mergers (50% ± 33%) compared to control samples of “normal” AGNs.

The NuSTAR Serendipitous Survey: The 40-month Catalog and the Properties of the Distant High-Energy X-Ray Source Population

NASA Technical Reports Server (NTRS)

Lansbury, G. B.; Stern, D.; Aird, J.; Alexander, D. M.; Fuentes, C.; Harrison, F. A.; Treister, E.; Bauer, F. E.; Tomsick, J. A.; Balokovic, M.;

A Search for Hyperluminous X-Ray Sources in the XMM-Newton Source Catalog

NASA Astrophysics Data System (ADS)

Zolotukhin, I.; Webb, N. A.; Godet, O.; Bachetti, M.; Barret, D.

2016-02-01

We present a new method to identify luminous off-nuclear X-ray sources in the outskirts of galaxies from large public redshift surveys, distinguishing them from foreground and background interlopers. Using the 3XMM-DR5 catalog of X-ray sources and the SDSS DR12 spectroscopic sample of galaxies, with the help of this off-nuclear cross-matching technique, we selected 98 sources with inferred X-ray luminosities in the range 1041 < LX < 1044 erg s-1, compatible with hyperluminous X-ray objects (HLX). To validate the method, we verify that it allowed us to recover known HLX candidates such as ESO 243-49 HLX-1 and M82 X-1. From a statistical study, we conservatively estimate that up to 71 ± 11 of these sources may be foreground- or background sources, statistically leaving at least 16 that are likely to be HLXs, thus providing support for the existence of the HLX population. We identify two good HLX candidates and using other publicly available data sets, in particular the VLA FIRST in radio, UKIRT Infrared Deep Sky Survey in the near-infrared, GALEX in the ultraviolet and Canada-France-Hawaii Telescope Megacam archive in the optical, we present evidence that these objects are unlikely to be foreground or background X-ray objects of conventional types, e.g., active galactic nuclei, BL Lac objects, Galactic X-ray binaries, or nearby stars. However, additional dedicated X-ray and optical observations are needed to confirm their association with the assumed host galaxies and thus secure their HLX classification.

An XMM-Newton Observation of the Seyfert 1 Galaxy 1H 0419-577 in an Extreme Low State

NASA Technical Reports Server (NTRS)

Pounds, K. A.; Reeves, J. N.; Page, K. L.; OBrien, P. T.

2004-01-01

Previous observations of the luminous Seyfert 1 galaxy 1H 0419-577 have found its X-ray spectrum to range from that of a typical Seyfert 1 with 2-10 keV power law index Gamma approx. 1.9 to a much flatter power law of Gamma approx. 1.5 or less. We report here a new XMM-Newton observation which allows the low state spectrum to be studied in much greater detail than hitherto. We find a very hard spectrum (Gamma approx. 1.0), which exhibits broad features that can be modelled myth the addition of an extreme relativistic Fe K emission line or with partial covering of the underlying continuum by a substantial column density of near-neutral gas. Both the EPIC and RGS data show evidence for strong line emission of OVII and OVIII requiring an extended region of low density photoionised gas in 1H 0419-577. Comparison with an earlier XMM-Newton observation when 1H 0419-577 was 'X-ray bright' indicates the dominant spectral variability occurs via a steep power law component.

Swift , XMM - Newton , and NuSTAR Observations of PSR J2032+4127/MT91 213

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

Li, K. L.; Kong, A. K. H.; Tam, P. H. T.

2017-07-10

We report our recent Swift , NuSTAR , and XMM - Newton X-ray and Lijiang optical observations on PSR J2032+4127/MT91 213, the γ -ray binary candidate with a period of 45–50 years. The coming periastron of the system was predicted to be in 2017 November, around which high-energy flares from keV to TeV are expected. Recent studies with Chandra and Swift X-ray observations taken in 2015/2016 showed that its X-ray emission has been brighter by a factors of ∼10 than that before 2013, probably revealing some ongoing activities between the pulsar wind and the stellar wind. Our new Swift /XRTmore » lightcurve shows no strong evidence of a single vigorous brightening trend, but rather several strong X-ray flares on weekly to monthly timescales with a slowly brightening baseline, namely the low state. The NuSTAR and XMM - Newton observations taken during the flaring and the low states, respectively, show a denser environment and a softer power-law index during the flaring state, implying that the pulsar wind interacted with the stronger stellar winds of the companion to produce the flares. These precursors would be crucial in studying the predicted giant outburst from this extreme γ -ray binary during the periastron passage in late 2017.« less

Insights on the X-ray weak quasar phenomenon from XMM-Newton monitoring of PHL 1092

NASA Astrophysics Data System (ADS)

Miniutti, G.; Brandt, W. N.; Schneider, D. P.; Fabian, A. C.; Gallo, L. C.; Boller, Th.

2012-09-01

PHL 1092 is a z ˜ 0.4 high-luminosity counterpart of the class of Narrow-Line Seyfert 1 galaxies. In 2008, PHL 1092 was found to be in a remarkably low X-ray flux state during an XMM-Newton observation. Its 2 keV flux density had dropped by a factor of ˜260 with respect to a previous observation performed 4.5 yr earlier. The ultraviolet (UV) flux remained almost constant, resulting in a significant steepening of the optical-to-X-ray slope αox from -1.57 to -2.51, making PHL 1092 one of the most extreme X-ray weak quasars with no observed broad absorption lines (BALs) in the UV. We have monitored the source since 2008 with three further XMM-Newton observations, producing a simultaneous UV and X-ray data base spanning almost 10 yr in total in the activity of the source. Our monitoring programme demonstrates that the αox variability in PHL 1092 is entirely driven by long-term X-ray flux changes. We apply a series of physically motivated models with the goal of explaining the UV-to-X-ray spectral energy distribution and the extreme X-ray and αox variability. We consider three possible models. (i) A breathing corona scenario in which the size of the X-ray-emitting corona is correlated with the X-ray flux. In this case, the lowest X-ray flux states of PHL 1092 are associated with an almost complete collapse of the X-ray corona down to the marginal stable orbit. (ii) An absorption scenario in which the X-ray flux variability is entirely due to intervening absorption. If so, PHL 1092 is a quasar with standard X-ray output for its optical luminosity, appearing as X-ray weak at times due to absorption. (iii) A disc-reflection-dominated scenario in which the X-ray-emitting corona is confined within a few gravitational radii from the black hole at all times. In this case, the intrinsic variability of PHL 1092 only needs to be a factor of ˜10 rather than the observed factor of ˜260. We discuss these scenarios in the context of non-BAL X-ray weak quasars.

Supernova remnants in M33: X-ray properties as observed by XMM-Newton

NASA Astrophysics Data System (ADS)

Garofali, Kristen; Williams, Benjamin F.; Plucinsky, Paul P.; Gaetz, Terrance J.; Wold, Brian; Haberl, Frank; Long, Knox S.; Blair, William P.; Pannuti, Thomas G.; Winkler, P. Frank; Gross, Jacob

2017-11-01

We have carried out a study of the X-ray properties of the supernova remnant (SNR) population in M33 with XMM-Newton, comprising deep observations of eight fields in M33 covering all of the area within the D25 contours, and with a typical luminosity of 7.1 × 1034 erg s-1 (0.2-2.0 keV). Here, we report our work to characterize the X-ray properties of the previously identified SNRs in M33, as well as our search for new X-ray detected SNRs. With our deep observations and large field of view we have detected 105 SNRs at the 3σ level, of which 54 SNRs are newly detected in X-rays, and three are newly discovered SNRs. Combining XMM-Newton data with deep Chandra survey data allows detailed spectral fitting of 15 SNRs, for which we have measured temperatures, ionization time-scales and individual abundances. This large sample of SNRs allows us to construct an X-ray luminosity function, and compare its shape to luminosity functions from host galaxies of differing metallicities and star formation rates to look for environmental effects on SNR properties. We conclude that while metallicity may play a role in SNR population characteristics, differing star formation histories on short time-scales, and small-scale environmental effects appear to cause more significant differences between X-ray luminosity distributions. In addition, we analyse the X-ray detectability of SNRs, and find that in M33 SNRs with higher [S II]/H α ratios, as well as those with smaller galactocentric distances, are more detectable in X-rays.

A Survey of X-Ray Variability in Seyfert 1 Galaxies with XMM-Newton to study the soft excess and the broad Fe lines

NASA Astrophysics Data System (ADS)

Ponti, Gabriele

The nature of the soft excess and the presence of the broad Fe lines is still nowadays highly debated because the different absorption/emission models are degenerate. Spectral variability studies have the potential to break this degeneracy. I will present the results of a spectral variability RMS survey of the 36 brightest type 1 Seyfert galaxies observed by XMM-Newton for more than 30 ks. More than 80 as already measured, on longer timescales, with RXTE (Markowitz et al. 2004). About half of the sample show lower variability in the soft energy band, indicating that the emission from the soft excess is more stable than the one of the continuum. While the other sources show a soft excess that is as variable as the continuum. About half of the sample do not show an excess of variability where the warm absorber component imprints its stronger features, suggesting that for these sources the soft excess is not produced by a relativistic absorbing wind. In a few bright and well exposed sources it has been possible to measure an excess of variability at the energy of the broad component of the Fe K line, in agreement with the broad emission line interpretation. For the sources where more than one observation was available the stability of the shape of the RMS spectrum has been investigated. Moreover, it will be presented the results of the computation of the excess variance of all the radio quiet type 1 AGN of the XMM-Newton database. The relations between variability, black hole mass, accretion rate and luminosity are investigated and their scatter measured.

The HELLAS2XMM survey. IV. Optical identifications and the evolution of the accretion luminosity in the Universe

NASA Astrophysics Data System (ADS)

Fiore, F.; Brusa, M.; Cocchia, F.; Baldi, A.; Carangelo, N.; Ciliegi, P.; Comastri, A.; La Franca, F.; Maiolino, R.; Matt, G.; Molendi, S.; Mignoli, M.; Perola, G. C.; Severgnini, P.; Vignali, C.

2003-10-01

We present results from the photometric and spectroscopic identification of 122 X-ray sources recently discovered by XMM-Newton in the 2-10 keV band (the HELLAS2XMM 1dF sample). Their flux cover the range 8*E-15-4*E-13 erg cm-2 s-1 and the total area surveyed is 0.9 square degrees. One of the most interesting results (which is found also in deeper sourveys) is that about 20% of the hard X-ray selected sources have an X-ray to optical flux ratio (X/O) ten times or more higher than that of optically selected AGN. Unlike the faint sources found in the ultra-deep Chandra and XMM-Newton surveys, which reach X-ray (and optical) fluxes more than one order of magnitude lower than the HELLAS2XMM survey sources, many of the extreme X/O sources in our sample have Rprotect la25 and are therefore accessible to optical spectroscopy. We report the identification of 13 sources with X/Oprotect ga10 (to be compared with 9 sources known from the deeper, pencil-beam surveys). Eight of them are narrow line QSO (seemingly the extension to very high luminosity of the type 2 Seyfert galaxies), four are broad line QSO. The results from our survey are also used to make reliable predictions about the luminosity of the sources not yet spectroscopically identified, both in our sample and in deeper Chandra and XMM-Newton samples. We then use a combined sample of 317 hard X-ray selected sources (HELLAS2XMM 1dF, Chandra Deep Field North 1Msec, Chandra SSA13 and XMM-Newton Lockman Hole flux limited samples), 221 with measured redshifts, to evaluate the cosmological evolution of the hard X-ray source's number and luminosity densities. Looking backward in time, the low luminosity sources (log L2-10 keV=43-44 erg s-1) increase in number at a much slower rate than the very high luminosity sources (log L2-10 keV >44.5 erg s-1), reaching a maximum around z=1 and then levelling off beyond z=2. This translates into an accretion driven luminosity density which is dominated by sources with log L2-10 keV <44

XMM-Newton observations of the Lockman Hole IV: spectra of the brightest AGN

NASA Astrophysics Data System (ADS)

Mateos, S.; Barcons, X.; Carrera, F. J.; Ceballos, M. T.; Hasinger, G.; Lehmann, I.; Fabian, A. C.; Streblyanska, A.

2005-12-01

This paper presents the results of a detailed X-ray spectral analysis of a sample of 123 X-ray sources detected with XMM-Newton in the Lockman Hole field. This is the deepest observation carried out with XMM-Newton with more that 600 ks of good EPIC-pn data. We have spectra with good signal to noise (>500 source counts) for all objects down to 0.2-12 keV fluxes of 5×10-15 erg cm-2 s-1 (flux limit of 6×10-16 erg cm-2 s-1 in the 0.5-2 and 2-10 keV bands). At the time of the analysis, we had optical spectroscopic identifications for 60% of the sources, 46 being optical type-1 AGN and 28 optical type-2 AGN. Using a single power law model our sources' average spectral slope hardens at faint 0.5-2 keV fluxes but not at faint 2-10 keV fluxes. We have been able to explain this effect in terms of an increase in X-ray absorption at faint fluxes. We did not find in our data any evidence for the existence of a population of faint intrinsically harder sources. The average spectral slope of our sources is 1.9, with an intrinsic dispersion of 0.28. We detected X-ray absorption (F-test significance ≥95%) in 37% of the sources, 10% in type-1 AGN (rest-frame {NH ˜ 1.6 × 1021{-}1.2 × 1022 cm-2}) and 77% (rest-frame {NH ˜ 1.5 ×1021{-}4× 1023 cm-2}) in type-2 AGN. Using X-ray fluxes corrected for absorption, the fraction of absorbed objects and the absorbing column density distribution did not vary with X-ray flux. Our type-1 and type-2 AGN do not appear to have different continuum shapes, but the distribution of intrinsic (rest-frame) absorbing column densities is different among both classes. A significant fraction of our type-2 AGN (5 out of 28) were found to display no substantial absorption ({NH<1021 cm-2}). We discuss possible interpretations to this in terms of Compton-thick AGN and intrinsic Broad Line Region properties. An emission line compatible with Fe Kα was detected in 8 sources (1 type-1 AGN, 5 type-2 AGN and 2 unidentified) with rest frame equivalent widths

A medium-deep Chandra and Subaru survey of the 13-h XMM/ROSAT deep survey area

NASA Astrophysics Data System (ADS)

McHardy, I. M.; Gunn, K. F.; Newsam, A. M.; Mason, K. O.; Page, M. J.; Takata, T.; Sekiguchi, K.; Sasseen, T.; Cordova, F.; Jones, L. R.; Loaring, N.

2003-07-01

We present the results of a Chandra ACIS-I survey of a high-latitude region at 13 h +38° which was earlier observed with ROSAT and which has recently been observed by XMM-Newton for 200 ks. XMM-Newton will provide good-quality X-ray spectra for over 200 sources with fluxes around the knee of the log N/ log S, which are responsible for the bulk of the X-ray background. The main aim of the Chandra observations is to provide arcsecond, or better, positions, and hence reliable identifications, for the XMM-Newton sources. The ACIS-I observations were arranged in a mosaic of four 30-ks pointings, covering almost all of the 15-arcmin radius XMM-Newton/ROSAT field. We detect 214 Chandra sources above a Cash likelihood statistic of 25, which approximates to 5σ significance, to a limiting flux of ~1.3 × 10-15 erg cm-2 s-1 (0.5-7 keV). Optical counterparts are derived from a Subaru SuprimeCam image reaching to R~ 27. The very large majority of the Chandra sources have an optical counterpart, with the distribution peaking at 23 < R < 24, although 14 have no counterpart to R= 27. The fraction of X-ray sources with no identification brighter than R= 27 is similar to that found in deeper Chandra surveys. The majority of the identifications are with galaxies. As found in other Chandra surveys, there is a very wide range of optical magnitudes for a given X-ray flux, implying a range of emission mechanisms, and many sources have high LX/Lopt ratios, implying absorption at moderate redshift. Comparison with the earlier ROSAT survey shows that the accuracy of the ROSAT positions agrees very well with the predictions from simulations by McHardy et al. and that the large majority of the identifications were correct.

XMM-Newton Archival Study of the ULX Population in Nearby Galaxies

NASA Technical Reports Server (NTRS)

Winter, Lisa M.; Mushotzky, Richard F.; Reynolds, christopher S.

2006-01-01

We present the results of an archival XMM-Newton study of the bright X-ray point sources (L(sub X) greater than 10(exp 38 erg per second)) in 32 nearby galaxies. From our list of approximately 100 point sources, we attempt to determine if there is a low-state counterpart to the Ultraluminous X-ray (ULX) population, searching for a soft-hard state dichotomy similar to that known for Galactic X-ray binaries and testing the specific predictions of the IMBH hypothesis. To this end, we searched for low-state objects, which we defined as objects within our sample which had a spectrum well fit by a simple absorbed power law, and high-state objects, which we defined as objects better fit by a combined blackbody and a power law. Assuming that low-state)) objects accrete at approximately 10% of the Eddington luminosity (Done & Gierlinski 2003) and that high-state objects accrete near the Eddington luminosity we further divided our sample of sources into low and high state ULX sources. We classify 16 sources as low-state ULXs and 26 objects as high-state ULXs. As in Galactic black hole systems, the spectral indices, GAMMA, of the lowstate objects, as well as the luminosities, tend to be lower than those of the high-state objects. The observed range of blackbody temperatures for the high state is 0.1-1 keV, with the most luminous systems tending toward the lowest temperatures. We therefore divide our high-state ULXs into candidate IMBHs (with blackbody temperatures of approximately 0.1 keV) and candidate stellar mass BHs (with blackbody temperatures of approximately 1.0 keV). A subset of the candidate stellar mass BHs have spectra that are well-fit by a Comptonization model, a property similar of Galactic BHs radiating in the very-high state near the Eddington limit.

XMM-NEWTON MEASUREMENT OF THE GALACTIC HALO X-RAY EMISSION USING A COMPACT SHADOWING CLOUD

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

Henley, David B.; Shelton, Robin L.; Cumbee, Renata S.

2015-02-01

Observations of interstellar clouds that cast shadows in the soft X-ray background can be used to separate the background Galactic halo emission from the local emission due to solar wind charge exchange (SWCX) and/or the Local Bubble (LB). We present an XMM-Newton observation of a shadowing cloud, G225.60–66.40, that is sufficiently compact that the on- and off-shadow spectra can be extracted from a single field of view (unlike previous shadowing observations of the halo with CCD-resolution spectrometers, which consisted of separate on- and off-shadow pointings). We analyzed the spectra using a variety of foreground models: one representing LB emission, andmore » two representing SWCX emission. We found that the resulting halo model parameters (temperature T {sub h} ≈ 2 × 10{sup 6} K, emission measure E{sub h}≈4×10{sup −3} cm{sup −6} pc) were not sensitive to the foreground model used. This is likely due to the relative faintness of the foreground emission in this observation. However, the data do favor the existence of a foreground. The halo parameters derived from this observation are in good agreement with those from previous shadowing observations, and from an XMM-Newton survey of the Galactic halo emission. This supports the conclusion that the latter results are not subject to systematic errors, and can confidently be used to test models of the halo emission.« less

NuSTAR and XMM-Newton Observations of the 2015 Outburst Decay of GX 339-4

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

Stiele, H.; Kong, A. K. H., E-mail: hstiele@mx.nthu.edu.tw

The extent of the accretion disk in the low/hard state of stellar mass black hole X-ray binaries remains an open question. There is some evidence suggesting that the inner accretion disk is truncated and replaced by a hot flow, while the detection of relativistic broadened iron emission lines seems to require an accretion disk extending fully to the innermost stable circular orbit. We present comprehensive spectral and timing analyses of six Nuclear Spectroscopic Telescope Array and XMM-Newton observations of GX 339–4 taken during outburst decay in the autumn of 2015. Using a spectral model consisting of a thermal accretion disk,more » Comptonized emission, and a relativistic reflection component, we obtain a decreasing photon index, consistent with an X-ray binary during outburst decay. Although we observe a discrepancy in the inner radius of the accretion disk and that of the reflector, which can be attributed to the different underlying assumptions in each model, both model components indicate a truncated accretion disk that resiles with decreasing luminosity. The evolution of the characteristic frequency in Fourier power spectra and their missing energy dependence support the interpretation of a truncated and evolving disk in the hard state. The XMM-Newton data set allowed us to study, for the first time, the evolution of the covariance spectra and ratio during outburst decay. The covariance ratio increases and steeps during outburst decay, consistent with increased disk instabilities.« less

VizieR Online Data Catalog: XMM-Newton and Chandra monitoring of Sgr A* (Ponti+, 2015)

NASA Astrophysics Data System (ADS)

Ponti, G.; de, Marco B.; Morris, M. R.; Merloni, A.; Munoz-Darias, T.; Clavel, M.; Haggard, D.; Zhang, S.; Nandra, K.; Gillessen, S.; Mori, K.; Neilsen, J.; Rea, N.; Degenaar, N.; Terrier, R.; Goldwurm, A.

2018-01-01

As of 2014 November 11 the XMM-Newton archive contains 37 public observations that can be used for our analysis of Sgr A*. In addition, we consider four new observations aimed at monitoring the interaction between the G2 object and Sgr A*, performed in fall 2014 (see Table A4). A total of 41 XMM-Newton data sets are considered in this work. All the 46 Chandra observations accumulated between 1999 and 2011 and analysed here are obtained with the ACIS-I camera without any gratings on (see Table A1). From 2012 onwards, data from the ACIS-S camera were also employed. The 2012 Chandra "X-ray Visionary Project" (XVP) is composed of 38 High-Energy Transmission Grating (HETG) observations with the ACIS-S camera at the focus (Nowak et al. 2012ApJ...759...95N; Neilsen et al. 2013ApJ...774...42N; 2015ApJ...799..199N; Wang et al. 2013Sci...341..981W; see Table A2). The first two observations of the 2013 monitoring campaign were performed with the ACIS-I instrument, while the ACIS-S camera was employed in all the remaining observations, after the outburst of SGR J1745-2900 on 2013 April 25. Three observations between 2013 May and July were performed with the HETG on, while all the remaining ones do not employ any gratings (see Table A2). (4 data files).

A Catalog of Galaxy Clusters Observed by XMM-Newton

NASA Technical Reports Server (NTRS)

Snowden, S. L.; Mushotzky, R. M.; Kuntz, K. D.; Davis, David S.

2007-01-01

Images and the radial profiles of the temperature, abundance, and brightness for 70 clusters of galaxies observed by XMM-Newton are presented along with a detailed discussion of the data reduction and analysis methods, including background modeling, which were used in the processing. Proper consideration of the various background components is vital to extend the reliable determination of cluster parameters to the largest possible cluster radii. The various components of the background including the quiescent particle background, cosmic diffuse emission, soft proton contamination, and solar wind charge exchange emission are discussed along with suggested means of their identification, filtering, and/or their modeling and subtraction. Every component is spectrally variable, sometimes significantly so, and all components except the cosmic background are temporally variable as well. The distributions of the events over the FOV vary between the components, and some distributions vary with energy. The scientific results from observations of low surface brightness objects and the diffuse background itself can be strongly affected by these background components and therefore great care should be taken in their consideration.

XMM-Newton RGS observations of the Cat's Eye Nebula

NASA Astrophysics Data System (ADS)

Guerrero, M. A.; Toalá, J. A.; Chu, Y.-H.; Gruendl, R. A.

2015-02-01

We present an analysis of XMM-Newton Reflection Grating Spectrometer (RGS) observations of the planetary nebula (PN) NGC 6543. These observations render it the second PN with high-resolution X-ray spectroscopic observations after BD +30°3639. The observations consist of 26 pointings, 14 of which included RGS observations for a total integration time of 435 ks. Many of these observations, however, were severely affected by high-background levels, and the net useful exposure time is drastically reduced to 25 ks. Only the O vii triplet at 22 Å is unambiguously detected in the RGS spectrum of NGC 6543. We find this spectrum consistent with an optically thin plasma at 0.147 keV (1.7 MK) and nebular abundances. Unlike BD +30°3639, the X-ray emission from NGC 6543 does not reveal overabundances of C and Ne. The results suggest that the N/O ratio of the hot plasma is consistent with that of the stellar wind, that is, it is lower than the nebular N/O ratio, but this result is not conclusive.

Simultaneous NuSTAR and XMM-Newton 0.5-80 KeV Spectroscopy of the Narrow-Line Seyfert 1 Galaxy SWIFT J2127.4+5654

NASA Technical Reports Server (NTRS)

Marinucci, A.; Matt, G.; Kara, E.; Miniutti, G.; Elvis, M.; Arevalo, P.; Ballantyne, D. R.; Balokovic, M.; Bauer, F.; Brenneman, L.;

On the origin of the broad, relativistic iron line of MCG-6-30-15 observed by XMM-Newton

NASA Astrophysics Data System (ADS)

Martocchia, A.; Matt, G.; Karas, V.

2002-03-01

The relativistic iron line profile recently observed by XMM-Newton in the spectrum of the Seyfert 1 galaxy MCG-6-30-15 (Wilms et al. \\cite{Wilms01}) is discussed in the framework of the lamp-post model. It is shown that the steep disc emissivity, the large line equivalent width and the amount of Compton reflection can be self-consistently reproduced in this scenario.

X-rays from young stars: A summary of highlights from the XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST)

NASA Astrophysics Data System (ADS)

Güdel, M.

2008-02-01

The XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST) is a survey of the nearest large star-forming region, the Taurus Molecular Cloud (TMC), making use of all instruments on board the XMM-Newton X-ray observatory. The survey, presently still growing, has provided unprecedented spectroscopic results from nearly every observed T Tauri star, and from ≈50% of the studied brown dwarfs and protostars. The survey includes the first coherent statistical sample of high-resolution spectra of T Tauri stars, and is accompanied by an U-band/ultraviolet imaging photometric survey of the TMC. XEST led to the discovery of new, systematic X-ray features not possible before with smaller samples, in particular the X-ray soft excess in classical T Tauri stars and the Two-Absorber X-ray (TAX) spectra of jet-driving T Tauri stars. This paper summarizes highlights from XEST and reviews the key role of this large project.

Tidal disruption events seen in the XMM-Newton slew survey

NASA Astrophysics Data System (ADS)

Saxton, Richard; Komossa, S.; Read, Andrew; Lira, Paulina; Alexander, Kate D.; Steele, Iain

XMM-Newton performs a survey of the sky in the 0.2-12 keV X-ray band while slewing between observation targets. The sensitivity in the soft X-ray band is comparable with that of the ROSAT all-sky survey, allowing bright transients to be identified in near real-time by a comparison of the flux in both surveys. Several of the soft X-ray flares are coincident with galaxy nuclei and five of these have been interpreted as candidate tidal disruption events (TDE). The first three discovered had a soft X-ray spectrum, consistent with the classical model of TDE, where radiation is released during the accretion phase by thermal processes. The remaining two have an additional hard, power-law component, which in only one case was accompanied by radio emission. Overall the flares decay with the classical index of t -5/3 but vary greatly in the early phase.

A good mass proxy for galaxy clusters with XMM-Newton

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

Zhao, Hai-Hui; Jia, Shu-Mei; Chen, Yong

2013-12-01

We use a sample of 39 galaxy clusters at redshift z < 0.1 observed by XMM-Newton to investigate the relations between X-ray observables and total mass. Based on central cooling time and central temperature drop, the clusters in this sample are divided into two groups: 25 cool core clusters and 14 non-cool core clusters, respectively. We study the scaling relations of L {sub bol}-M {sub 500}, M {sub 500}-T, M {sub 500}-M {sub g}, and M {sub 500}-Y {sub X}, and also the influences of cool core on these relations. The results show that the M {sub 500}-Y {sub X}more » relation has a slope close to the standard self-similar value, has the smallest scatter and does not vary with the cluster sample. Moreover, the M {sub 500}-Y {sub X} relation is not affected by the cool core. Thus, the parameter of Y{sub X} may be the best mass indicator.« less

Observing the Fast X-ray Spectral Variability of NLS1 1H1934-063 with XMM-Newton and NuSTAR

NASA Astrophysics Data System (ADS)

Frederick, Sara; Kara, Erin; Reynolds, Christopher S.

2017-08-01

The most variable active galactic nuclei (AGN), taken together, are a compelling wellspring of interesting accretion-related phenomena. They can exhibit dramatic variability in the X-ray band on a range of timescales down to a few minutes. We present the exemplifying case study of 1H1934-063 (z = 0.0102), a narrow-line Seyfert I (NLS1) that is among the most variable AGN ever observed with XMM-Newton. We present spectral and temporal analyses of a concurrent XMM-Newton and NuSTAR observation taken in 2015 and lasting 120 ks, during which the source exhibited a steep (factor of 1.5) plummet and subsequent full recovery of flux that we explore in detail here. Combined spectral and timing results point to a dramatic change in the continuum on timescales as short as a few ks. Similar to other highly variable Seyfert 1s, this AGN is quite X-ray bright and displays strong reflection spectral features. We find agreement with a change in the continuum, and we rule out absorption as the cause for this dramatic variability observed even at NuSTAR energies. We compare detailed time-resolved spectral fitting with Fourier-based timing analysis in order to constrain coronal geometry, dynamics, and emission/absorption processes dictating the nature of this variability. We also announce the discovery of a Fe-K time lag between the hard X-ray continuum emission (1 - 4 keV) and its relativistically-blurred reflection off the inner accretion flow (0.3 - 1 keV).

Modeling the Magnetospheric X-ray Emission from Solar Wind Charge Exchange with Verification from XMM-Newton Observations

DTIC Science & Technology

2016-08-26

Journal of Geophysical Research: Space Physics Modeling the magnetospheric X-ray emission from solar wind charge exchange with verification from XMM...Newton observations Ian C. Whittaker1, Steve Sembay1, Jennifer A. Carter1, AndrewM. Read1, Steve E. Milan1, andMinna Palmroth2 1Department of Physics ...observations, J. Geophys. Res. Space Physics , 121, 4158–4179, doi:10.1002/2015JA022292. Received 21 DEC 2015 Accepted 26 FEB 2016 Accepted article online 29

Radial distribution of metals in the hot intra-cluster medium as observed by XMM-Newton

NASA Astrophysics Data System (ADS)

Mernier, F.; de Plaa, J.; Kaastra, J.; Zhang, Y.; Akamatsu, H.; Gu, L.; Mao, J.; Pinto, C.; Reiprich, T.; Sanders, J.

2017-10-01

The hot intra-cluster medium (ICM), which accounts for ˜80% of the baryonic content in galaxy clusters, is rich in heavy elements. Since these metals have been produced by stars and supernovae before enriching the ICM, measuring metal abundance distributions in galaxy clusters and groups provides essential clues to determine the main astrophysical source(s) and epoch(s) of the ICM enrichment. In this work, we present radial abundance profiles averaged over 44 nearby cool-core galaxy clusters, groups, and massive ellipticals (the CHEERS sample) measured with XMM-Newton EPIC. While most of the Fe of the Universe is thought to be synthesised by Type Ia supernovae (SNIa), lighter elements, such as O, Mg, Si or S, are mostly produced by core-collapse supernovae (SNcc). The derived average radial profiles of the O, Mg, Si, S, Ar, Ca, Fe, and Ni abundances out to ˜ 0.5 r_{500} allows us to accurately compare the distributions of SNIa and SNcc products in clusters and groups. By comparing our results with recent chemo-dynamical simulations, we discuss the interpretation of the profiles in the context of early and late ICM enrichments.

XMM-Newton Proposal 03001001

NASA Astrophysics Data System (ADS)

Barrado Y Navascues, David

2004-10-01

We propose observations with XMM-EPIC/MOS in five distinct sibling associations belonging to the Lambda Orionis Star Forming Region (2-5 Myr, 340 pc). We have already optical and IR photometry and spectroscopy for objects down to 0.015 M(sun). The goals are: i) Assess the membership of our candidates and detect new members. ii) Derive accurate IMFs for each association, checking the universality of the IMF. iii) Study the properties and evolution of the X-ray Luminosity Functions.

Searching for Decaying Dark Matter in Deep XMM-Newton Observation of the Draco Dwarf Spheroidal

NASA Technical Reports Server (NTRS)

Ruchayskiy, Oleg; Boyardsky, Alex; Iakbovskyi, Dmytro; Bulbul, Esra; Eckert, Domique; Franse, Jeron; Malyshev, Denys; Markevitch, Maxim; Neronov, Andrii

2016-01-01

We present results of a search for the 3.5 keV emission line in our recent very long (approx. 1.4 Ms) XMM-Newton observation of the Draco dwarf spheroidal galaxy. The astrophysical X-ray emission from such dark matter-dominated galaxies is faint, thus they provide a test for the dark matter origin of the 3.5 keV line previously detected in other massive, but X-ray bright objects, such as galaxies and galaxy clusters. We do not detect a statistically significant emission line from Draco; this constrains the lifetime of a decaying dark matter particle to tau >(7-9) × 10(exp 27) s at 95% CL (combining all three XMM-Newton cameras; the interval corresponds to the uncertainty of the dark matter column density in the direction of Draco). The PN camera, which has the highest sensitivity of the three, does show a positive spectral residual (above the carefully modeled continuum) at E = 3.54 +/- 0.06 keV with a 2.3(sigma) significance. The two MOS cameras show less-significant or no positive deviations, consistently within 1(sigma) with PN. Our Draco limit on tau is consistent with previous detections in the stacked galaxy clusters, M31 and the Galactic Centre within their 1 - 2(sigma) uncertainties, but is inconsistent with the high signal from the core of the Perseus cluster (which has itself been inconsistent with the rest of the detections). We conclude that this Draco observation does not exclude the dark matter interpretation of the 3.5 keV line in those objects.

A (likely) X-ray jet from NGC6217 observed by XMM-Newton

NASA Astrophysics Data System (ADS)

Falocco, Serena; Larsson, Josefin; Nandi, Sumana

2017-12-01

NGC6217 is a nearby spiral galaxy with a starburst region near its centre. Evidence for a low-luminosity Active Galactic Nucleus (AGN) in its core has also been found in optical spectra. Intriguingly, X-ray observations by ROSAT revealed three knots aligned with the galaxy centre, resembling a jet structure. This paper presents a study of XMM-Newton observations made to assess the hypothesis of a jet emitted from the centre of NGC6217. The XMM data confirm the knots found with ROSAT and our spectral analysis shows that they have similar spectral properties with a hard photon index Γ ∼ 1.7. The core of NGC6217 is well fitted by a model with an AGN and a starburst component, where the AGN contributes at most 46 per cent of the total flux. The candidate jet has an apparent length ∼15 kpc and a luminosity of ∼5 × 1038 erg s- 1. It stands out by being hosted by a spiral galaxy, since jets are more widely associated with ellipticals. To explain the jet launching mechanism we consider the hypothesis of an advection dominated accretion flow with a low accretion rate. The candidate jet emitted from NGC6217 is intriguing since it represents a challenge to the current knowledge of the connection between AGN, jets and host galaxies.

Monte Carlo simulations of soft proton flares: testing the physics with XMM-Newton

NASA Astrophysics Data System (ADS)

Fioretti, Valentina; Bulgarelli, Andrea; Malaguti, Giuseppe; Spiga, Daniele; Tiengo, Andrea

2016-07-01

Low energy protons (< 100 - 300 keV) in the Van Allen belt and the outer regions can enter the field of view of X-ray focusing telescopes, interact with the Wolter-I optics, and reach the focal plane. The funneling of soft protons was discovered after the damaging of the Chandra/ACIS Front-Illuminated CCDs in September 1999 after the first passages through the radiation belt. The use of special filters protects the XMM-Newton focal plane below an altitude of 70000 km, but above this limit the effect of soft protons is still present in the form of sudden ares in the count rate of the EPIC instruments that can last from hundreds of seconds to hours and can hardly be disentangled from X-ray photons, causing the loss of large amounts of observing time. The accurate characterization of (i) the distribution of the soft proton population, (ii) the physics interaction at play, and (iii) the effect on the focal plane, are mandatory to evaluate the background and design the proton magnetic diverter on board future X-ray focusing telescopes (e.g. ATHENA). Several solutions have been proposed so far for the primary population and the physics interaction, however the difficulty in precise angle and energy measurements in laboratory makes the smoking gun still unclear. Since the only real data available is the XMM-Newton spectrum of soft proton flares in orbit, we try to characterize the input proton population and the physics interaction by simulating, using the BoGEMMS framework, the proton interaction with a simplified model of the X-ray mirror module and the focal plane, and comparing the result with a real observation. The analysis of ten orbits of observations of the EPIC/pn instrument show that the detection of flares in regions far outside the radiation belt is largely influenced by the different orientation of the Earth's magnetosphere respect with XMM-Newton'os orbit, confirming the solar origin of the soft proton population. The Equator-S proton spectrum at 70000 km

An Archival Chandra and XMM-Newton Survey of Type 2 Quasars

NASA Technical Reports Server (NTRS)

Jia, Jianjun; Ptak, Andrew Francis; Heckman, Timothy; Zakamska, Nadia L.

2013-01-01

In order to investigate obscuration in high-luminosity type 2 active galactic nuclei (AGNs), we analyzed Chandra and XMM-Newton archival observations for 71 type 2 quasars detected at 0.05 < z < 0.73, which were selected based on their [O III] lambda5007 emission lines. For 54 objects with good spectral fits, the observed hard X-ray luminosity ranges from 2 × 10(exp 41) to 5.3 × 10(exp 44) erg s(exp -1), with a median of 1.1 × 10(exp 43) erg s(exp -1). We find that the means of the column density and photon index of our sample are log N(sub H) = 22.9 cm(exp -2) and gamma = 1.87, respectively. From simulations using a more physically realistic model, we find that the absorbing column density estimates based on simple power-law models significantly underestimate the actual absorption in approximately half of the sources. Eleven sources show a prominent Fe K alpha emission line (EW>100 eV in the rest frame) and we detect this line in the other sources through a joint fit (spectral stacking). The correlation between the Fe K alpha and [O III] fluxes and the inverse correlation of the equivalent width of the Fe Ka line with the ratio of hard X-ray and [O III] fluxes is consistent with previous results for lower luminosity Seyfert 2 galaxies. We conclude that obscuration is the cause of the weak hard X-ray emission rather than intrinsically low X-ray luminosities. We find that about half of the population of optically selected type 2 quasars are likely to be Compton thick. We also find no evidence that the amount of X-ray obscuration depends on the AGN luminosity (over a range of more than three orders of magnitude in luminosity).

Uncovering extreme AGN variability in serendipitous X-ray source surveys

NASA Astrophysics Data System (ADS)

Moran, Edward C.; Garcia Soto, Aylin; LaMassa, Stephanie; Urry, Meg

2018-01-01

Constraints on the duty cycle and duration of accretion episodes in active galactic nuclei (AGNs) are vital for establishing how most AGNs are fueled, which is essential for a complete picture of black hole/galaxy co-evolution. Perhaps the best handle we have on these activity parameters is provided by AGNs that have displayed dramatic changes in their bolometric luminosities and, in some cases, spectroscopic classifications. Given that X-ray emission is directly linked to black-hole accretion, X-ray surveys should provide a straightforward means of identifying AGNs that have undergone dramatic changes in their accretion states. However, it appears that such events are very rare, so wide-area surveys separated in time by many years are needed to maximize discovery rates. We have cross-correlated the Einstein IPC Two-Sigma Catalog with the ROSAT All-Sky Survey Faint Source Catalog to identify a sample of soft X-ray sources that varied by factors ranging from 7 to more than 100 over a ten year timescale. When possible, we have constructed long-term X-ray light curves for the sources by combining the Einstein and RASS fluxes with those obtained from serendipitous pointed observations by ROSAT, Chandra,XMM, and Swift. Optical follow-up observations indicate that many of the extremely variable sources in our sample are indeed radio-quiet AGNs. Interestingly, the majority of objects that dimmed between ~1980 and ~1990 are still (or are again) broad-line AGNs rather than“changing-look” candidates that have more subtle AGN signatures in their spectra — despite the fact that none of the sources examined thus far has returned to its highest observed luminosity. Future X-ray observations will provide the opportunity to characterize the X-ray behavior of these anonymous, extreme AGNs over a four decade span.

ESA study of XEUS, a potential follow-on to XMM-Newton

NASA Astrophysics Data System (ADS)

Rando, N.; Lyngvi, A.; Gondoin, P.; Lumb, D.; Bavdaz, M.; Verhoeve, P.; de Wilde, D.; Parmar, A.; Peacock, A.

2017-11-01

In October 2005, based on a massive response by the Science Community to ESA's call for themes in space science, a large aperture X-ray Observatory (XRO) was identified as a candidate project for Europe within the frame of the 2015-2025 Cosmic Vision program. Such a mission would represent the natural follow-on to XMM Newton, providing a large aperture X-ray telescope combined with high spectral and time resolution instruments, capable of investigating matter under extreme conditions and the evolution of the early universe. The paper summarises the results of the most recent ESA internal study activities, leading to an updated mission configuration, with a mirror and a detector spacecraft flying in formation around L2 and a consolidated scientific payload design. The paper also describes the ongoing technology development activities for the payload and for the spacecraft that will play a crucial role in case ESA would decide to develop such a mission.

XMM-Newton Observations of the Cluster of Galaxies Sersic 159-03

NASA Technical Reports Server (NTRS)

Kaastra, J. S.; Ferrigno, C.; Tamura, T.; Paerels, F. B. S.; Peterson, J. R.; Mittaz, J. P. D.

2000-01-01

The cluster of galaxies Sersic 159-03 was observed with the XMM-Newton X-ray observatory as part of the Guaranteed Time program. X-ray spectra taken with the EPIC and RGS instruments show no evidence for the strong cooling flow derived from previous X-ray observations. There is a significant lack of cool gas below 1.5 keV as compared to standard isobaric cooling flow models. While the oxygen is distributed more or less uniformly over the cluster, iron shows a strong concentration in the center of the cluster, slightly offset from the brightness center but within the central cD galaxy. This points to enhanced type Ia supernova activity in the center of the cluster. There is also an elongated iron-rich structure ex- tending to the east of the cluster, showing the inhomogeneity of the iron distribution. Finally, the temperature drops rapidly beyond 4' from the cluster center.

First XMM-Newton Observations of a Cataclysmic Variable II: Spectral Studies of OY Car

NASA Technical Reports Server (NTRS)

Ramsay, Gavin; Cordova, France; Cottam, Jean; Mason, Keith; Much, Rudu; Osborne, Julian; Pandel, Dirk; Poole, Tracey; Wheatley, Peter

2000-01-01

We present XMM-Newton X-ray spectra of the disc accreting cataclysmic variable OY Car, which were obtained during the performance verification phase of the mission. These data were taken 4 days after a short outburst. In the EPIC spectra we find strong Iron K(beta) emission with weaker Iron K(alpha) emission together with Silicon and Sulphur lines. The spectra are best fitted with a three temperature plasma model with a partial covering absorber. Multiple temperature emission is confirmed by the emission lines seen in the RGS spectrum and the H/He like intensity ratio for Iron and Sulphur which imply temperatures of approx. 7keV and approx. 3keV respectively.

An XMM-Newton Monitoring Campaign of the Accretion Flow in IGRJ16318-4848

NASA Technical Reports Server (NTRS)

Mushotzky, Richard (Technical Monitor); Nicastro, Fabrizio

2005-01-01

This grant is associated to a successful XMM-Newton-AO3 observational proposal to monitor the spectrum of the X-ray loud component of the recently discovered binary system IGR J16138-4848, to study the conditions of the accretion flows (and their evolution) in binary system. All four EPIC-PN and MOS observations of the target have now been performed (the last one of the 4, only 3 months ago). The four observations were logarithmically spaced, so to cover timescales from days to months. Data from all four pointings have now been reduced, using the XMM-Newton data reduction pipeline, and spectra and lightcurves from the target have been extracted. For the first three observations we have already performed the observation-by-observation data analysis, by fitting the single EPIC spectra with spectral models that include an intrinsic continuum power law (reduced at low energy by neutral absorption), a 6.4 keV iron emission line (detected in all spectra with varying intensity) and a Compton-reflection component. A Compton reflection component is also detected in all spectra, although at lower significance. The analysis of the fourth and last observation of our monitoring campaign has just recently begun. Next, we will (1) stack together the four observations of IGR J16138-4848, to obtain high-accuracy estimates of the average spectral parameters of this object; and then (2) proceed to the time-evolving analysis, of the three spectral parameters: (a) Gamma (the slope of the intrinsic continuum), (b) W(FeK), the equivalent width of the 6.4 keV Iron emission line, and (c) R, the relative amount of Compton reflection. Through this time-resolved spectroscopic analysis we hope to constrain (a) the physical state of the accreting matter and its relation with the X-ray output, and (b) the evolution of the accretion flow geometry, distribution and covering factor.

SPIDERS: selection of spectroscopic targets using AGN candidates detected in all-sky X-ray surveys

NASA Astrophysics Data System (ADS)

Dwelly, T.; Salvato, M.; Merloni, A.; Brusa, M.; Buchner, J.; Anderson, S. F.; Boller, Th.; Brandt, W. N.; Budavári, T.; Clerc, N.; Coffey, D.; Del Moro, A.; Georgakakis, A.; Green, P. J.; Jin, C.; Menzel, M.-L.; Myers, A. D.; Nandra, K.; Nichol, R. C.; Ridl, J.; Schwope, A. D.; Simm, T.

2017-07-01

SPIDERS (SPectroscopic IDentification of eROSITA Sources) is a Sloan Digital Sky Survey IV (SDSS-IV) survey running in parallel to the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) cosmology project. SPIDERS will obtain optical spectroscopy for large numbers of X-ray-selected active galactic nuclei (AGN) and galaxy cluster members detected in wide-area eROSITA, XMM-Newton and ROSAT surveys. We describe the methods used to choose spectroscopic targets for two sub-programmes of SPIDERS X-ray selected AGN candidates detected in the ROSAT All Sky and the XMM-Newton Slew surveys. We have exploited a Bayesian cross-matching algorithm, guided by priors based on mid-IR colour-magnitude information from the Wide-field Infrared Survey Explorer survey, to select the most probable optical counterpart to each X-ray detection. We empirically demonstrate the high fidelity of our counterpart selection method using a reference sample of bright well-localized X-ray sources collated from XMM-Newton, Chandra and Swift-XRT serendipitous catalogues, and also by examining blank-sky locations. We describe the down-selection steps which resulted in the final set of SPIDERS-AGN targets put forward for spectroscopy within the eBOSS/TDSS/SPIDERS survey, and present catalogues of these targets. We also present catalogues of ˜12 000 ROSAT and ˜1500 XMM-Newton Slew survey sources that have existing optical spectroscopy from SDSS-DR12, including the results of our visual inspections. On completion of the SPIDERS programme, we expect to have collected homogeneous spectroscopic redshift information over a footprint of ˜7500 deg2 for >85 per cent of the ROSAT and XMM-Newton Slew survey sources having optical counterparts in the magnitude range 17 < r < 22.5, producing a large and highly complete sample of bright X-ray-selected AGN suitable for statistical studies of AGN evolution and clustering.

Radio-loud AGN through the eyes of 3XMM, WISE and FIRST/NVSS

NASA Astrophysics Data System (ADS)

Mingo, B.

2014-07-01

We present the results from a new radio-loud AGN sample, obtained through the cross-correlation between the 3XMM, WISE and FIRST/NVSS catalogues. The radio selection allows us to eliminate the restrictions traditionally associated with mid-IR and X-ray sample selections, and to explore the population of lower luminosity AGN, in which the host galaxy contribution is substantial. We investigate the correlations between radio, mid-IR and X-ray emission associated to both stellar and AGN activity, and whether they can be disentangled. This work has been carried out as part of the ARCHES project. ARCHES (Astronomical Resource Cross-matching for High Energy Studies), funded within the EU/FP7-Cooperation Space framework, is a project which aims to produce well-characterised multi-wavelength data for large samples of sources drawn from the 3XMM serendipitous source catalogue.

The NuSTAR Serendipitous Survey: The 40-month Catalog and the Properties of the Distant High-energy X-Ray Source Population

NASA Astrophysics Data System (ADS)

Lansbury, G. B.; Stern, D.; Aird, J.; Alexander, D. M.; Fuentes, C.; Harrison, F. A.; Treister, E.; Bauer, F. E.; Tomsick, J. A.; Baloković, M.; Del Moro, A.; Gandhi, P.; Ajello, M.; Annuar, A.; Ballantyne, D. R.; Boggs, S. E.; Brandt, W. N.; Brightman, M.; Chen, C.-T. J.; Christensen, F. E.; Civano, F.; Comastri, A.; Craig, W. W.; Forster, K.; Grefenstette, B. W.; Hailey, C. J.; Hickox, R. C.; Jiang, B.; Jun, H. D.; Koss, M.; Marchesi, S.; Melo, A. D.; Mullaney, J. R.; Noirot, G.; Schulze, S.; Walton, D. J.; Zappacosta, L.; Zhang, W. W.

2017-02-01

We present the first full catalog and science results for the Nuclear Spectroscopic Telescope Array (NuSTAR) serendipitous survey. The catalog incorporates data taken during the first 40 months of NuSTAR operation, which provide ≈20 Ms of effective exposure time over 331 fields, with an areal coverage of 13 deg2, and 497 sources detected in total over the 3-24 keV energy range. There are 276 sources with spectroscopic redshifts and classifications, largely resulting from our extensive campaign of ground-based spectroscopic follow-up. We characterize the overall sample in terms of the X-ray, optical, and infrared source properties. The sample is primarily composed of active galactic nuclei (AGNs), detected over a large range in redshift from z = 0.002 to 3.4 (median of < z> =0.56), but also includes 16 spectroscopically confirmed Galactic sources. There is a large range in X-ray flux, from {log}({f}3-24{keV}/{erg} {{{s}}}-1 {{cm}}-2)≈ -14 to -11, and in rest-frame 10-40 keV luminosity, from {log}({L}10-40{keV}/{erg} {{{s}}}-1)≈ 39 to 46, with a median of 44.1. Approximately 79% of the NuSTAR sources have lower-energy (<10 keV) X-ray counterparts from XMM-Newton, Chandra, and Swift XRT. The mid-infrared (MIR) analysis, using WISE all-sky survey data, shows that MIR AGN color selections miss a large fraction of the NuSTAR-selected AGN population, from ≈15% at the highest luminosities ({L}{{X}}> {10}44 erg s-1) to ≈80% at the lowest luminosities ({L}{{X}}< {10}43 erg s-1). Our optical spectroscopic analysis finds that the observed fraction of optically obscured AGNs (I.e., the type 2 fraction) is {F}{Type2}={53}-15+14 % , for a well-defined subset of the 8-24 keV selected sample. This is higher, albeit at a low significance level, than the type 2 fraction measured for redshift- and luminosity-matched AGNs selected by <10 keV X-ray missions.

Spectral and Temporal Analysis of 1H1934-0617: Observing an “Eclipsed” AGN with XMM-Newton and NuSTAR

NASA Astrophysics Data System (ADS)

Frederick, Sara; Kara, Erin; Reynolds, Christopher S.

2017-01-01

1H1934-0617 is a low-mass (3×106 M⊙) NLS1 which was ranked as 7th in excess variance among AGN comprising the CAIXA catalogue (Ponti 2012). Similar to its high-ranking and oft-studied counterparts, this AGN is extremely time-variable, luminous, and displays strong reflection features. We present spectral and temporal analyses of concurrent XMM-Newton and NuSTAR observations (120 ks), during which we explore a dramatic dip in flux, similar to that of Fairall 9 (Lohfink 2012, 2016). The transit-like dip appears in the NuSTAR band, and the spectral shape of the 0.3-2 keV band remains constant throughout the flux varied observation, ruling out a strong absorber. XMM-Newton’s large effective area and NuSTAR’s constraints on the 10-79 keV band combine to inform us about the source geometry, black hole spin, and emission/absorption processes as we speculate on the nature of the variability of this scarcely-studied AGN. Preliminary spectral modeling indicates that the dip in flux can be understood as a decrease in the height of the corona, and preliminary timing analysis shows hints of an iron K reverberation lag.

Chemical Evolution in Sersic 159-03 Observed with Xmm-Newton

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

de Plaa, Jelle; Werner, N.; Bykov, A.M.

2006-03-10

Using a new long X-ray observation of the cluster of galaxies Sersic 159-03 with XMM-Newton, we derive radial temperature and abundance profiles using single- and multi-temperature models. The fits to the EPIC and RGS spectra prefer multi-temperature models especially in the core. The radial profiles of oxygen and iron measured with EPIC/RGS and the line profiles in RGS suggest that there is a dip in the O/Fe ratio in the centre of the cluster compared to its immediate surroundings. A possible explanation for the large scale metallicity distribution is that SNIa and SNII products are released in the ICM throughmore » ram-pressure stripping of in-falling galaxies. This causes a peaked metallicity distribution. In addition, SNIa in the central cD galaxy enrich mainly the centre of the cluster with iron. This excess of SNIa products is consistent with the low O/Fe ratio we detect in the centre of the cluster. We fit the abundances we obtain with yields from SNIa, SNII and Population-III stars to derive the clusters chemical evolution. We find that the measured abundance pattern does not require a Population-III star contribution. The relative contribution of the number of SNIa with respect to the total number of SNe which enrich the ICM is about 25-50%. Furthermore, we discuss the possible presence of a non-thermal component in the EPIC spectra. A potential source of this non-thermal emission can be inverse-Compton scattering between Cosmic Microwave Background (CMB) photons and relativistic electrons, which are accelerated in bow shocks associated with ram-pressure stripping of in-falling galaxies.« less

A Novel Approach to model EPIC variable background

NASA Astrophysics Data System (ADS)

Marelli, M.; De Luca, A.; Salvetti, D.; Belfiore, A.

2017-10-01

One of the main aim of the EXTraS (Exploring the X-ray Transient and variable Sky) project is to characterise the variability of serendipitous XMM-Newton sources within each single observation. Unfortunately, 164 Ms out of the 774 Ms of cumulative exposure considered (21%) are badly affected by soft proton flares, hampering any classical analysis of field sources. De facto, the latest releases of the 3XMM catalog, as well as most of the analysis in literature, simply exclude these 'high background' periods from analysis. We implemented a novel SAS-indipendent approach to produce background-subtracted light curves, which allows to treat the case of very faint sources and very bright proton flares. EXTraS light curves of 3XMM-DR5 sources will be soon released to the community, together with new tools we are developing.

NuSTAR + XMM-Newton monitoring of the neutron star transient AX J1745.6-2901

NASA Astrophysics Data System (ADS)

Ponti, G.; Bianchi, S.; Muñoz-Darias, T.; Mori, K.; De, K.; Rau, A.; De Marco, B.; Hailey, C.; Tomsick, J.; Madsen, K. K.; Clavel, M.; Rahoui, F.; Lal, D. V.; Roy, S.; Stern, D.

2018-01-01

AX J1745.6-2901 is a high-inclination (eclipsing) transient neutron star (NS) low-mass X-ray binary showcasing intense ionized Fe K absorption. We present here the analysis of 11 XMM-Newton and 15 NuSTAR new data sets (obtained between 2013 and 2016), therefore tripling the number of observations of AX J1745.6-2901 in outburst. Thanks to simultaneous XMM-Newton and NuSTAR spectra, we greatly improve on the fitting of the X-ray continuum. During the soft state, the emission can be described by a disc blackbody (kT ∼ 1.1-1.2 keV and inner disc radius rDBB ∼ 14 km), plus hot (kT ∼ 2.2-3.0 keV) blackbody radiation with a small emitting radius (rBB ∼ 0.5 - 0.8 km) likely associated with the boundary layer or NS surface, plus a faint Comptonization component. Imprinted on the spectra are clear absorption features created by both neutral and ionized matter. Additionally, positive residuals suggestive of an emission Fe K α disc line and consistent with relativistic ionized reflection are present during the soft state, while such residuals are not significant during the hard state. The hard-state spectra are characterized by a hard (Γ ∼ 1.9-2.1) power law, showing no evidence for a high energy cut-off (kTe > 60-140 keV) and implying a small optical depth (τ < 1.6). The new observations confirm the previously witnessed trend of exhibiting strong Fe K absorption in the soft state that significantly weakens during the hard state. Optical (GROND) and radio (GMRT) observations suggest for AX J1745.6-2901 a standard broad-band spectral energy distribution as typically observed in accreting NSs.

The XMM-Newton Wide-Field Survey in the COSMOS Field. II. X-Ray Data and the logN-logS Relations

NASA Astrophysics Data System (ADS)

Cappelluti, N.; Hasinger, G.; Brusa, M.; Comastri, A.; Zamorani, G.; Böhringer, H.; Brunner, H.; Civano, F.; Finoguenov, A.; Fiore, F.; Gilli, R.; Griffiths, R. E.; Mainieri, V.; Matute, I.; Miyaji, T.; Silverman, J.

2007-09-01

We present data analysis and X-ray source counts for the first season of XMM-Newton observations in the COSMOS field. The survey covers ~2 deg2 within the region of sky bounded by 09h57m30ssource detection was performed in the 0.5-2, 2-4.5, and 4.5-10 keV energy bands, and 1390 pointlike sources were detected in at least one band. Detailed Monte Carlo simulations were performed to fully test the source-detection method and to derive the sky coverage to be used in the computation of the logN-logS relations. These relations were then derived in the 0.5-2, 2-10, and 5-10 keV energy bands, down to flux limits of 7.2×10-16 ergs cm-2 s-1, 4.0×10-15 ergs cm-2 s-1, and 9.7×10-15 ergs cm-2 s-1, respectively. Thanks to the large number of sources detected in the COSMOS survey, the logN-logS curves are tightly constrained over a range of fluxes which were poorly covered by previous surveys, especially in the 2-10 and 5-10 keV bands. The 0.5-2 and 2-10 keV differential logN-logS relations were fitted with a broken power-law model which revealed a Euclidean slope at the bright end and a flatter slope (α~1.5) at faint fluxes. In the 5-10 keV energy band a single power law provides an acceptable fit to the observed source counts with a slope α~2.4. A comparison with the results of previous surveys shows good agreement in all the energy bands under investigation in the overlapping flux range. We also notice a remarkable agreement between our logN-logS relations and the most recent model of the X-ray background. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA; also based on data collected at the Canada-France-Hawaii Telescope operated by the National Research Council of Canada, the Centre National de la Recherche Scientifique de France, and the University of

Coronal Structures in Cool Stars: XMM-NEWTON Hybrid Stars and Coronal Evolution

NASA Technical Reports Server (NTRS)

Dupree, Andrea K.; Mushotzky, Richard (Technical Monitor)

2003-01-01

This program addresses the evolution of stellar coronas by comparing a solar-like corona in the supergiant Beta Dra (G2 Ib-IIa) to the corona in the allegedly more evolved state of a hybrid star, alpha TrA (K2 II-III). Because the hybrid star has a massive wind, it appears likely that the corona will be cooler and less dense as the magnetic loop structures are no longer closed. By analogy with solar coronal holes, when the topology of the magnetic field is configured with open magnetic structures, both the coronal temperature and density are lower than in atmospheres dominated by closed loops. The hybrid stars assume a pivotal role in the definition of coronal evolution, atmospheric heating processes and mechanisms to drive winds of cool stars. We are attempting to determine if this model of coronal evolution is correct by using XMM-NEWTON RGS spectra for the 2 targets we were allocated through the Guest Observer program.

XMM-Newton Observations of NGC 507: Supersolar Metal Abundances in the Hot Interstellar Medium

NASA Astrophysics Data System (ADS)

Kim, Dong-Woo; Fabbiano, Giuseppina

2004-10-01

We present the results of the X-ray XMM-Newton observations of NGC 507, a dominant elliptical galaxy in a small group of galaxies, and report supersolar metal abundances of both Fe and α-elements in the hot interstellar medium (ISM) of this galaxy. These results are robust in that we considered all possible systematic effects in our analysis. We find ZFe=2-3 times solar inside the D25 ellipse of NGC 507. This is the highest ZFe reported so far for the hot halo of an elliptical galaxy; this high iron abundance is fully consistent with the predictions of stellar evolution models, which include the yield of both Type II and Type Ia supernovae (SNe). Our analysis shows that abundance measurements are critically dependent on the selection of the proper emission model. The spatially resolved, high-quality XMM-Newton spectra provide enough statistics to formally require at least three emission components in each of four circumnuclear concentric shells (within 5' or 100 kpc): two soft thermal components indicating a range of temperatures in the hot ISM plus a harder component, consistent with the integrated output of low-mass X-ray binaries (LMXBs) in NGC 507. The two-component (thermal+LMXB) model customarily used in past studies yields a much lower ZFe, consistent with previous reports of subsolar metal abundances. This model, however, gives a significantly worse fit to the data (F-test probability<0.0001). The abundance of α-elements (most accurately determined by Si) is also found to be supersolar. The α-element-to-Fe abundance ratio is close to the solar ratio, suggesting that ~70% of the iron mass in the hot ISM originated from Type Ia SNe. The α-element-to-Fe abundance ratio remains constant out to at least 100 kpc, indicating that Types II and Ia SN ejecta are well mixed on a scale much larger than the extent of the stellar body.

The Multi-Layer Variable Absorbers in NGC 1365 Revealed by XMM-Newton and NuSTAR

NASA Technical Reports Server (NTRS)

Rivers, E.; Risaliti, G.; Walton, D. J.; Harrison, F.; Arevalo, P.; Baur, F. E.; Boggs, S. E.; Brenneman, L. W.; Brightman, M.; Zhang, W. W.

2015-01-01

Between 2012 July and 2013 February, NuSTAR and XMM-Newton performed four long-look joint observations of the type 1.8 Seyfert, NGC 1365. We have analyzed the variable absorption seen in these observations in order to characterize the geometry of the absorbing material. Two of the observations caught NGC 1365 in an unusually low absorption state, revealing complexity in the multi-layer absorber that had previously been hidden. We find the need for three distinct zones of neutral absorption in addition to the two zones of ionized absorption and the Compton-thick torus previously seen in this source. The most prominent absorber is likely associated with broad-line region clouds with column densities of around approximately 10 (sup 23) per square centimeter and a highly clumpy nature as evidenced by an occultation event in 2013 February. We also find evidence of a patchy absorber with a variable column around approximately 10 (sup 22) per square centimeter and a line-of-sight covering fraction of 0.3-0.9, which responds directly to the intrinsic source flux, possibly due to a wind geometry. A full-covering, constant absorber with a low column density of approximately 1 by 10 (sup 22) per square centimeter is also present, though the location of this low density haze is unknown.

XMM-Newton observation of the Coma Galaxy cluster. The temperature structure in the central region

NASA Astrophysics Data System (ADS)

Arnaud, M.; Aghanim, N.; Gastaud, R.; Neumann, D. M.; Lumb, D.; Briel, U.; Altieri, B.; Ghizzardi, S.; Mittaz, J.; Sasseen, T. P.; Vestrand, W. T.

2001-01-01

We present a temperature map and a temperature profile of the central part (r < 20' or 1/4 virial radius) of the Coma cluster. We combined 5 overlapping pointings made with XMM/EPIC/MOS and extracted spectra in boxes of 3.5'x3.5'. The temperature distribution around the two central galaxies is remarkably homogeneous (r<10'), contrary to previous ASCA results, suggesting that the core is actually in a relaxed state. At larger distance from the cluster center we do see evidence for recent matter accretion. We confirm the cool area in the direction of NGC 4921, probably due to gas stripped from an infalling group. We find indications of a hot front in the South West, in the direction of NGC 4839, probably due to an adiabatic compression. 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). EPIC was developed by the EPIC Consortium led by the Principal Investigator, Dr. M. J. L. Turner. The consortium comprises the following Institutes: University of Leicester, University of Birmingham, (UK); CEA/Saclay, IAS Orsay, CESR Toulouse, (France); IAAP Tuebingen, MPE Garching, (Germany); IFC Milan, ITESRE Bologna, IAUP Palermo, Italy. EPIC is funded by: PPARC, CEA, CNES, DLR and ASI.

XMM-Newton confirmation of a new intermediate polar: XMMU J185330.7-012815

NASA Astrophysics Data System (ADS)

Hui, C. Y.; Sriram, K.; Choi, C.-S.

2012-01-01

We report on the results of a detailed spectro-imaging and temporal analysis of an archival XMM-Newton observation of a new intermediate polar XMMU J185330.7-012815. Its X-ray spectrum can be well described by a multitemperature thermal plasma model with the K lines of heavy elements clearly detected. Possible counterparts of XMMU J185330.7-012815 have been identified in optical and ultraviolet (UV) bands. The low values of the inferred X-ray-to-UV and X-ray-to-optical flux ratios safely rule out the possibility of its being an isolated neutron star. We confirm the X-ray periodicity of ˜238 s but, differently from the previous preliminary results, we do not find any convincing evidence of phase shift in this observation. We further investigate its properties through an energy-resolved temporal analysis and find that the pulsed fraction monotonically increases with energy.

XMM Observations of Low Mass Groups

NASA Technical Reports Server (NTRS)

Davis, David S.

2005-01-01

The contents of this report contains discussion of the two-dimensional XMM-Newton group survey. The analysis of the NGC 2300 and Pavo observations indicated by the azimuthally averaged analysis that the temperature structure is minimal to the NGC2300 system; however, the Pavo system shows signs of a merger in progress. XMM data is used to generate two dimensional maps of the temperature and abundance used to generate maps of pressure and entropy.

Star Formation Rates in Cooling Flow Clusters: A UV Pilot Study with Archival XMM-Newton Optical Monitor Data

NASA Technical Reports Server (NTRS)

Hicks, A. K.; Mushotzky, R.

2006-01-01

We have analyzed XMM-Newton Optical Monitor (OM) UV (180-400 nm) data for a sample of 33 galaxies. 30 are cluster member galaxies, and nine of these are central cluster galaxies (CCGs) in cooling flow clusters having mass deposition rates which span a range of 8 - 525 Solar Mass/yr. By comparing the ratio of UV to 2MASS J band fluxes, we find a significant UV excess in many, but not all, cooling flow CCGs, a finding consistent with the outcome of previous studies based on optical imaging data (McNamara & O'Connell 1989; Cardiel, Gorgas, & Aragon-Salamanca 1998; Crawford et al. 1999). This UV excess is a direct indication of the presence of young massive stars, and therefore recent star formation, in these galaxies. Using the Starburst99 spectral energy distribution (SED) model of continuous star formation over a 900 Myr period, we derive star formation rates of 0.2 - 219 solar Mass/yr for the cooling flow sample. For 2/3 of this sample it is possible to equate Chandra/XMM cooling flow mass deposition rates with UV inferred star formation rates, for a combination of starburst lifetime and IMF slope. This is a pilot study of the well populated XMM UV cluster archive and a more extensive follow up study is currently underway.

Extremely Hard X-ray Emission from Eta Carinae observed with XMM-Newton and NuSTAR around Periastron in 2014.5

NASA Astrophysics Data System (ADS)

Hamaguchi, Kenji; Corcoran, Michael F.; Takahashi, Hiromitsu; Yuasa, Tadayuki; Groh, Jose H.; Russell, Christopher Michael Post; Pittard, Julian M.; Madura, Thomas; Owocki, Stanley P.; Grefenstette, Brian

2015-01-01

The super massive colliding wind binary system, Eta Carinae, experienced another periastron passage in the summer of 2014. We monitored this event using the multiple X-ray observatories, Chandra, XMM-Newton, NuSTAR, Suzaku and Swift. With a high eccentricity of its 5.5 year orbit, X-ray emission from the wind-wind collision (WWC) increases strongly toward periastron but then drops sharply by more than two orders of magnitude in two weeks around periastron due probably to an eclipse and an intrinsic activity decline of the WWC plasma. In this observing campaign, XMM-Newton and NuSTAR coordinated two simultaneous observations around the X-ray flux maximum on June 6 and just before the flux minimum on July 28. These two observations captured Eta Carinae with X-ray focusing telescopes in the extreme hard X-ray band above 10 keV for the first time.During the first observation, XMM and NuSTAR detected stable X-ray emission from the central binary system between 1 - 40 keV. A fit of a 1-temperature bremsstrahlung model to the high energy slope in the NuSTAR spectrum derives an electron temperature of ~6 keV, which is significantly higher than an ionization temperature at ~4.5 keV, measured from the Fe K emission lines resolved in the XMM spectrum.This result suggests the presence of very hot plasma and/or X-ray reflection at surrounding cold material. During the second observation, the X-ray flux between 5 - 10 keV declined steadily by a factor of ~2 in a day, while the other energy bands were rather stable. This variation may be explained by an increase of the line of sight absorption to emission from the plasma component that dominates above 5 keV. NuSTAR did not detect, in either observation, the very hard non-thermal component that dominated emission above 25 keV seen in earlier INTEGRAL and Suzaku observations. We discuss the plasma condition and the wind structure of Eta Carinae around periastron, and the nature of the non-thermal component.

Radial Profiles of PKS 0745-191 Galaxy Cluster with XMM-Newton X-Ray Observations

NASA Astrophysics Data System (ADS)

Tumer, A.; Ezer, C.; Ercan, E.

2017-10-01

Since clusters of galaxies are the largest comprehensive samples of the universe, they provide essential information on from the most basic to the most complex physical mechanisms such as nucleosynthesis and supernovae events. Some of these information are provided by the X-ray emission data from Intra Cluster Medium (ICM) which contains hot dilute gas. Recent archieved observation of the X-Ray spectrum of the cool core galaxy cluster PKS 0745-191 provided by XMM-Newton is subjected to data analysis using ESAS package. Followed by spectra analysis utilizing Xspec spectral fitting software, we present the radial profiles of temperature and abundance from the core to 0.5R_500 of brightest distant cluster (z ˜ 0.102) PKS 0745-191. Using the deprojected spectra, the radial distribution of pressure and entropy in the aforementioned region are also presented.

XMM-Newton Proposal 03039101

NASA Astrophysics Data System (ADS)

Hernanz, Margarita

2004-10-01

Two recent galactic novae, V2487 Oph 1998 and V4633 Sgr 1998, have been detec- ted in both soft and hard X-rays with XMM. V2487 Oph showed an iron fluores- cent line only 2.7 yrs after its explosion, a clear signature of the very fast recovery of accretion, and V4633 Sgr displayed hard X-ray emission not clearly attributable to shocked ejecta or accretion. Longer observations are needed to do accurate timing and high resolution spectroscopy, essential to determine the main properties of the underlying cataclysmic variable in V2487 Oph (first nova seen in X-rays prior and after exploding) and to disentangle the origin of the hard X-rays from V4633 Sgr, through an analysis of the chemical compo- sition of the emitting thermal plasma, solar if accretion, non solar if ejecta.

Spatially resolved spectroscopy analysis of the XMM-Newton large program on SN1006

NASA Astrophysics Data System (ADS)

Li, Jiang-Tao; Decourchelle, Anne; Miceli, Marco; Vink, Jacco; Bocchino, Fabrizio

2016-04-01

We perform analysis of the XMM-Newton large program on SN1006 based on our newly developed methods of spatially resolved spectroscopy analysis. We extract spectra from low and high resolution meshes. The former (3596 meshes) is used to roughly decompose the thermal and non-thermal components and characterize the spatial distributions of different parameters, such as temperature, abundances of different elements, ionization age, and electron density of the thermal component, as well as photon index and cutoff frequency of the non-thermal component. On the other hand, the low resolution meshes (583 meshes) focus on the interior region dominated by the thermal emission and have enough counts to well characterize the Si lines. We fit the spectra from the low resolution meshes with different models, in order to decompose the multiple plasma components at different thermal and ionization states and compare their spatial distributions. In this poster, we will present the initial results of this project.

X-Ray Spectroscopy of the Cluster of Galaxies Abell 1795 with XMM-Newton

NASA Technical Reports Server (NTRS)

Tamura, T.; Kaastra, J. S.; Peterson, J. R.; Paerels, F.; Mittaz, J. P. D.; Trudolyubov, S. P.; Stewart, G.; Fabian, A. C.; Mushotzky, R. F.; Lumb, D. H.

2000-01-01

The initial results from XMM-Newton observations of the rich cluster of galaxies Abell 1795 are presented. The spatially-resolved X-ray spectra taken by the European Photon Imaging Cameras (EPIC) show a temperature drop at a radius of - 200 kpc from the cluster center, indicating that the ICM is cooling. Both the EPIC and the Reflection Grating Spectrometers (RGS) spectra extracted from the cluster center can be described by an isothermal model with a temperature of approx. 4 keV. The volume emission measure of any cool component (less than 1 keV) is less than a few % of the hot component at the cluster center. A strong O VIII Lyman alpha line was detected with the RGS from the cluster core. The O abundance of the ICM is 0.2-0.5 times the solar value. The O to Fe ratio at the cluster center is 0.5 - 1.5 times the solar ratio.

A Search for New Galactic Magnetars in Archival Chandra and XMM-Newton Observations

NASA Astrophysics Data System (ADS)

Muno, M. P.; Gaensler, B. M.; Nechita, A.; Miller, J. M.; Slane, P. O.

2008-06-01

We present constraints on the number of Galactic magnetars, which we have established by searching for sources with periodic variability in 506 archival Chandra observations and 441 archival XMM-Newton observations of the Galactic plane (| b| < 5°). Our search revealed four sources with periodic variability on timescales of 200-5000 s, all of which are probably accreting white dwarfs. We identify 7 of 12 known Galactic magnetars, but find no new examples with periods between 5 and 20 s. We convert this nondetection into limits on the total number of Galactic magnetars by computing the fraction of the young Galactic stellar population that our survey covered. We find that easily detectable magnetars, modeled after persistent anomalous X-ray pulsars (e.g., with LX = 1035 ergs s-1 [0.5-10.0 keV] and Arms = 12% ), could have been identified in ≈5% of the Galactic spiral arms by mass. If we assume that three previously known examples randomly fall within our survey, then there are 59+ 92-32 in the Galaxy. Barely detectable magnetars (LX = 3 × 1033 ergs s-1 and Arms = 15% ) could have been identified throughout ≈0.4% of the spiral arms. The lack of new examples implies that <540 exist in the Galaxy (90% confidence). Similar constraints are found by considering the detectability of transient magnetars in outburst. For assumed lifetimes of 104 yr, the birth rate of magnetars is between 0.003 and 0.06 yr-1. Therefore, the birth rate of magnetars is at least 10% of that for normal radio pulsars, and could exceed that value, unless transient magnetars are active for gtrsim105 yr.

Unveiling the AGN activity in multiple SMBH systems observed with XMM-Newton

NASA Astrophysics Data System (ADS)

De Rosa, A.

2017-10-01

In this talk we will present results from the MAGNA (Multiple AGN Activity) project focused on the detection and study of multiple supermassive black hole systems. We investigate the physical properties (accretion rate and local environment) of multiple AGN candidates in interacting systems with respect to isolated sources with the goal to understand the mechanisms that trigger AGN activity in different stages of galaxy mergers. We present the study performed with SDSS and XMM data sets of 4 AGN pairs at separations of 20-70 kpc. XMM data allowed us to detect and characterize the AGN in all systems, by measuring the accretion and absorption properties of the sources. In each system at least one object is highly obscured, possibly Compton-thick, in agreement with the hypothesis that galaxy encounters are effective in driving gas inflow. One system however manifests the opposite behaviour showing a pair composed from an unobscured type 1 AGN and a Compton Thick AGN. The talk will reflect on broader implications of these findings.

Broadband X-ray spectra of the ultraluminous X-ray source Holmberg IX X-1 observed with NuSTAR, XMM-Newton, and Suzaku

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

Walton, D. J.; Harrison, F. A.; Grefenstette, B. W.

2014-09-20

We present results from the coordinated broadband X-ray observations of the extreme ultraluminous X-ray source Holmberg IX X-1 performed by NuSTAR, XMM-Newton, and Suzaku in late 2012. These observations provide the first high-quality spectra of Holmberg IX X-1 above 10 keV to date, extending the X-ray coverage of this remarkable source up to ∼30 keV. Broadband observations were undertaken at two epochs, between which Holmberg IX X-1 exhibited both flux and strong spectral variability, increasing in luminosity from L {sub X} = (1.90 ± 0.03) × 10{sup 40} erg s{sup –1} to L {sub X} = (3.35 ± 0.03) ×more » 10{sup 40} erg s{sup –1}. Neither epoch exhibits a spectrum consistent with emission from the standard low/hard accretion state seen in Galactic black hole binaries, which would have been expected if Holmberg IX X-1 harbors a truly massive black hole accreting at substantially sub-Eddington accretion rates. The NuSTAR data confirm that the curvature observed previously in the 3-10 keV bandpass does represent a true spectral cutoff. During each epoch, the spectrum appears to be dominated by two optically thick thermal components, likely associated with an accretion disk. The spectrum also shows some evidence for a nonthermal tail at the highest energies, which may further support this scenario. The available data allow for either of the two thermal components to dominate the spectral evolution, although both scenarios require highly nonstandard behavior for thermal accretion disk emission.« less

Black Holes in Bulgeless Galaxies: An XMM-Newton Investigation of NGC 3367 AND NGC 4536

NASA Technical Reports Server (NTRS)

McAlpine, W.; Satyapal, S.; Gliozzi, M.; Cheung, C. C.; Sambruna, R. M.; Eracleous, Michael

2012-01-01

The vast majority of optically identified active galactic nuclei (AGNs) in the local Universe reside in host galaxies with prominent bulges, supporting the hypothesis that black hole formation and growth is fundamentally connected to the build-up of galaxy bulges. However, recent mid-infrared spectroscopic studies with Spitzer of a sample of optically "normal" late-type galaxies reveal remarkably the presence of high-ionization [NeV] lines in several sources, providing strong evidence for AGNs in these galaxies. We present follow-up X-ray observations recently obtained with XMM-Newton of two such sources, the late-type optically normal galaxies NGC 3367 and NGC 4536. Both sources are detected in our observations. Detailed spectral analysis reveals that for both galaxies, the 2-10 keV emission is dominated by a power law with an X-ray luminosity in the L(sub 2- 10 keV) approximates 10(exp 39) - 10(exp 40) ergs/s range, consistent with low luminosity AGNs. While there is a possibility that X-ray binaries account for some fraction of the observed X-ray luminosity, we argue that this fraction is negligible. These observations therefore add to the growing evidence that the fraction of late-type galaxies hosting AGNs is significantly underestimated using optical observations alone. A comparison of the midinfrared [NeV] luminosity and the X-ray luminosities suggests the presence of an additional highly absorbed X-ray source in both galaxies, and that the black hole masses are in the range of 10(exp 5) - 10(exp 7) solar M for NGC 3367 and 10(exp 4) - (exp 10) solar M for NGC 4536

The Properties of the Diffuse X-ray Background from the DXL sounding rocket mission (plus ROSAT, XMM-Newton and Suzaku data)

NASA Astrophysics Data System (ADS)

Galeazzi, Massimiliano

2017-08-01

Understanding the properties of the different components of the Diffuse X-ray Background (DXB) is made particularly difficult by their similar spectral signature.The University of Miami has been working on disentangling the different DXB components for many years, using a combination of proprietary and archival data from XMM-Newton, Suzaku, and Chandra, and a sounding rocket mission (DXL) specifically designed to study the properties of Local Hot Bubble (LHB) and Solar Wind Charge eXchange (SWCX) using their spatial signature. In this talk we will present:(a) Results from the DXL mission, specifically launch #2, to study the properties of the SWCX and LHB (and GH) and their contribution to the ROSAT All Sky Survey Bands(b) Results from a Suzaku key project to characterize the SWCX and build a semi-empirical model to predict the SWCX line emission for any time, any direction. A publicly available web portal for the model will go online by the end of the year(c) Results from XMM-Newton deep surveys to study the angular correlation of the Warm-Hot Intergalactic Medium (WHIM) in the direction of the Chandra Deep Field South.DXL launch #3, schedule for January 2018 and the development of the DXG sounding rocket mission to characterize the GH-CGM emission using newly developed micropore optics will also be discussed.

NUSTAR AND XMM-Newton Observations of the Neutron Star X-Ray Binary 1RXS J180408.9-34205

NASA Astrophysics Data System (ADS)

Ludlam, Renee; Miller, Jon M.; Cackett, Edward; Fabian, Andrew C.; Bachetti, Matteo; Parker, Michael; Tomsick, John; Barret, Didier; Natalucci, Lorenzo; Rana, Vikram; Harrison, Fiona

2016-04-01

We report on observations of the neutron star (NS) residing in the low-mass X-ray binary 1RXS J180408.9-34205 taken 2015 March by NuSTAR and XMM-Newton while the source was in the hard spectral state. We findmultiple reflection features (Fe Kα detected with NuSTAR N VII, O VII, and O VIII detected in the RGS) fromdifferent ionization zones. Through joint fits using the self consistent relativistic reflection model RELXILL,we determine the inner radius to be 6.6(+13.2,-0.6) Rg. We find the inclination of the system to be between 18-29 degrees.If the disk is truncated at a radius greater than the innermost stable circular orbit (ISCO), then the position at which the inner disk terminates likely corresponds to the magnetospheric radius. For a spin parameter of a = 0, we estimate a conservative upper limit on the strength of the magnetic field to be B ≤ (0.9 - 3.0) × 109 G at the magnetic poles depending on the choice of conversion factor between spherical and disk accretion.

Hunting for swinging millisecond pulsars with XMM-Newton

NASA Astrophysics Data System (ADS)

Papitto, Alessandro

2013-10-01

The recent XMM discovery of a millisecond pulsar swinging between an accretion- powered (X-ray) and a rotation-powered (radio) pulsar state provided the final evidence of the evolutionary link between these two classes, demonstrating that transitions between the two states can be observed over of a few weeks. We propose a ToO program (made of 3 triggers of 60 ks, over a 3years timescale) aimed at detecting X-ray accretion powered pulsations in sources already known as ms radio pulsars. Candidates are restricted to black widows and redbacks, systems in an evolutionary phase that allows state transitions. Enlarging the number of systems in this transitional phase is crucial to test binary evolution theories, and to study the disk-field interaction over a large range of mass accretion rates.

An XMM-Newton Observation of the Lagoon Nebula and the Very Young Open Cluster NGC 6530

NASA Technical Reports Server (NTRS)

Rauw, G.; Naze, Y.; Gosset, E.; Stevens, I. R.; Blomme, R.; Corcoran, M. F.; Pittard, J. M.; Runacres, M. C.

2002-01-01

We report the results of an XMM-Newton observation of the Lagoon Nebula (M 8). Our EPIC images of this region reveal a cluster of point sources, most of which have optical counterparts inside the very young open cluster NGC 6530. The bulk of these X-ray sources are probably associated with low and intermediate mass pre-main sequence stars. One of the sources experiences a flare-like increase of its X-ray flux making it the second brightest source in M 8 after the O4 star 9 Sgr. The X-ray spectra of most of the brightest sources can be fitted with thermal plasma models with temperatures of kT approximately a few keV. Only a few of the X-ray selected PMS candidates are known to display H(alpha) emission and were previously classified as classical T Tauri stars. This suggests that most of the X-ray emitting PMS stars in NGC 6530 are weak line T Tauri stars. In addition to 9 Sgr, our EPIC field of view contains also a few early-type stars. The X-ray emission from HD 164816 is found to be typical for an O9.5III-IV star. At least one of the known Herbig Be stars in NGC 6530 (LkH(alpha) 115) exhibits a relatively strong X-ray emission, while most of the main sequence stars of spectral type B1 and later are not detected. We also detect (probably) diffuse X-ray emission from the Hourglass Region that might reveal a hot bubble blown by the stellar wind of Herschel 36, the ionizing star of the Hourglass Region.

Modeling the Oxygen K Absorption in the Interstellar Medium: An XMM-Newton View of Sco X-1

NASA Technical Reports Server (NTRS)

Garcia, J.; Ramirez, J. M.; Kallman, T. R.; Witthoeft, M.; Bautista, M. A.; Mendoza, C.; Palmeri, P.; Quinet, P.

2011-01-01

We investigate the absorption structure of the oxygen in the interstellar medium by analyzing XMM-Newton observations of the low mass X-ray binary Sco X-1. We use simple models based on the O I atomic cross section from different sources to fit the data and evaluate the impact of the atomic data in the interpretation of astrophysical observations. We show that relatively small differences in the atomic calculations can yield spurious results. We also show that the most complete and accurate set of atomic cross sections successfully reproduce the observed data in the 21 - 24.5 Angstrom wavelength region of the spectrum. Our fits indicate that the absorption is mainly due to neutral gas with an ionization parameter of Epsilon = 10(exp -4) erg/sq cm, and an oxygen column density of N(sub O) approx. = 8-10 x 10(exp 17)/sq cm. Our models are able to reproduce both the K edge and the K(alpha) absorption line from O I, which are the two main features in this region. We find no conclusive evidence for absorption by other than atomic oxygen.

VizieR Online Data Catalog: XCS-DR1 Cluster Catalogue (Mehrtens+, 2012)

NASA Astrophysics Data System (ADS)

Mehrtens, N.; Romer, A. K.; Hilton, M.; Lloyd-Davies, E. J.; Miller, C. J.; Stanford, S. A.; Hosmer, M.; Hoyle, B.; Collins, C. A.; Liddle, A. R.; Viana, P. T. P.; Nichol, R. C.; Stott, J. P.; Dubois, E. N.; Kay, S. T.; Sahlen, M.; Young, O.; Short, C. J.; Christodoulou, L.; Watson, W. A.; Davidson, M.; Harrison, C. D.; Baruah, L.; Smith, M.; Burke, C.; Mayers, J. A.; Deadman, P.-J.; Rooney, P. J.; Edmondson, E. M.; West, M.; Campbell, H. C.; Edge, A. C.; Mann, R. G.; Sabirli, K.; Wake, D.; Benoist, C.; da Costa, L.; Maia, M. A. G.; Ogando, R.

2013-04-01

The XMM Cluster Survey (XCS) is a serendipitous search for galaxy clusters using all publicly available data in the XMM-Newton Science Archive. Its main aims are to measure cosmological parameters and trace the evolution of X-ray scaling relations. In this paper we present the first data release from the XMM Cluster Survey (XCS-DR1). This consists of 503 optically confirmed, serendipitously detected, X-ray clusters. Of these clusters, 256 are new to the literature and 357 are new X-ray discoveries. We present 463 clusters with a redshift estimate (0.06

New Gener. High-Energy Spectra of the Blazar 3C 279 with XMM-Newton and GLAST

NASA Astrophysics Data System (ADS)

Collmar, Werner

2007-10-01

We propose two 20 ksec XMM-Newton observations of the X-ray bright gamma-ray blazar 3C~279 simultaneous with GLAST/LAT. The main goal is to measure its X-ray properties (spectrum, variability) in order to (1) improve our knowledge on the X-ray emission of the blazar, and (2) to supplement and correlate them to simultaneous GLAST/LAT Gamma-ray observations (30 MeV-300 GeV). Simultaneous GLAST observations of 3C 279 are guaranteed (assuming proper operation then). The high-energy data will be supplemented by ground-based measurements, adding finally up to multifrequency spectra which have unprecedented accuracy and will extend up to high-energy gamma-rays. Such high-quality SEDs will provide severe constraints on their modeling and have the potential to discriminate among models.

Detection of a 9.4 min periodicity in the XMM-Newton and Chandra X-ray light curves of V407 Lup (Nova Lup 2016)

NASA Astrophysics Data System (ADS)

Beardmore, Andy; Dobrotka, Andrej; Ness, Jan-Uwe; Orio, Marina; Osborne, Julian; Page, Kim

2017-09-01

We report on the timing analysis of two long, uninterrupted X-ray observations of V407 Lup (also know as ASASSN-16kt and Nova Lup 2016; see ATel #9538, #9539, #9550, #9554, #9587, #9594 and #9644, #10632, #10722) performed with XMM-Newton for 22,000 s on 2017 March 11 and with the Chandra HRC_s and Low Energy Transmission Grating on 2017 August 30 for 34,000 s.

Spectral and Temporal Characteristics of LS PEG and TW PIC Using XMM-NEWTON Data

NASA Astrophysics Data System (ADS)

Talebpour Sheshvan, Nasrin; Balman, Solen

2016-07-01

We report the analysis of archival XMM-Newton X-ray observations of LS Peg and TW Pic. These are Cataclysmic Variables (CVs) suggested as Intermediate Polars (IPs), but unconfirmed in the X-rays. Identification of several periodic oscillations in the optical band hint them as IPs. Unlike the previous spectral analysis on the EPIC-MOS data by fitting a hot optically thin plasma emission model with a single temperature for LS Peg, we simultaneously fitted all EPIC spectrum (pn+MOS) using a composite model of absorption for interstellar medium (tbabs) with two different partial covering absorbers (pcfabs) including a multitemperature plasma emission component (cevmkl) and a Gaussian emission line at 6.4 keV. TW Pic is best modeled in a similar manner with only one partial covering absorber and an extra Gaussian emission line at 6.7 keV. LS Peg has a maximum plasma temperature of ˜14.8 keV with an X-ray luminosity of ˜5×10^{32}ergs ^{-1} translating to an accretion rate of ˜1.27×10^{-10}M _{⊙}yr ^{-1}. TW Pic shows kT _{max} ˜38.7 keV with an X-ray luminosity around 1.6×10^{33}ergs ^{-1} at an accretion rate of ˜4×10^{-10}M _{⊙}yr ^{-1}. In addition, we discuss orbital modulations in the X-rays and power spectral analysis, and derive the EPIC pn spectra for orbital minimum and orbital maximum phases for both sources. We elaborate on the geometry of accretion and absorption in the X-ray emitting regions of both sources with articulation on the magnetic nature.

Peering Through the Dust. II. XMM-Newton Observations of Two Additional FIRST-2MASS Red Quasars

NASA Astrophysics Data System (ADS)

Glikman, Eilat; LaMassa, Stephanie; Piconcelli, Enrico; Urry, Meg; Lacy, Mark

2017-10-01

We obtained XMM-Newton observations of two highly luminous dust-reddened quasars, F2M1113+1244 and F2M1656+3821, that appear to be in the early, transitional phase predicted by merger-driven models of quasar/galaxy co-evolution. These sources have been well studied at optical through mid-infrared wavelengths and are growing relatively rapidly, with Eddington ratios > 30 % . Their black hole masses are relatively small compared to their host galaxies, placing them below the {M}{BH}{--}{L}{bulge} relation. We find that for both sources, an absorbed power-law model with 1%-3% of the intrinsic continuum scattered or leaked back into the line of sight best fits their X-ray spectra. We measure the absorbing column density (N H ) and constrain the dust-to-gas ratios in these systems, finding that they lie well below the Galactic value. This, combined with the presence of broad emission lines in their optical and near-infrared spectra, suggests that the dust absorption occurs far from the nucleus and in the host galaxy, while the X-rays are mostly absorbed in the nuclear, dust-free region within the sublimation radius. We also compare the quasars’ absorption-corrected, rest-frame X-ray luminosities (2-10 keV) to their rest-frame infrared luminosities (6 μm) and find that red quasars, similar to other populations of luminous obscured quasars, are either underluminous in X-rays or overluminous in the infrared.

X-ray Spectral Analysis of the Cataclysmic Variable LS Peg using XMM-Newton Observatory Data

NASA Astrophysics Data System (ADS)

Talebpour Sheshvan, N.; Nabizadeh, A.; Balman, S.

2017-10-01

LS Peg is a Cataclysmic Variable (CV) suggested as Intermediate Polar (IP) because of similar properties to those observed in IP systems. We used archival XMM-Newton observation of LS Peg in order to study the X-ray characteristics of the system. We show LS Peg light curves in several different energy bands, and discuss about orbital modulations and power spectral analysis. Unlike the previous spectral analysis of the EPIC-MOS data by fitting a hot optically thin plasma emission model with a single temperature, we simultaneously fit EPIC spectrum (pn+MOS) using a composite model of absorption (tbabs) along with two different partial covering absorbers plus a multi-temperature plasma emission component in XSPEC. In addition, we find a Gaussian emission line at 6.4 keV. For LS Peg the maximum temperature of the plasma distribution is found to be ˜ 17.8 keV with a luminosity of ˜ 7.4×10^{32}erg s^{-1} translating to an accretion rate of ˜ 1.7×10 ^{-10} M_{⊙} yr^{-1}. We present spectra for orbital minimum and orbital maximum. In addition, we use SWIFT observations of the source in order to make a comparison. We elaborate on the geometry of accretion and absorption in the X-ray emitting region with articulation on the magnetic nature.

Deep X-ray and UV Surveys of Galaxies with Chandra, XMM-Newton, and GALEX

NASA Technical Reports Server (NTRS)

Hornschemeier, Ann

2006-01-01

Only with the deepest Chandra surveys has X-ray emission from normal and star forming galaxies (as opposed to AGN, which dominate the X-ray sky) been accessible at cosmologically interesting distances. The X-ray emission from accreting binaries provide a critical glimpse into the binary phase of stellar evolution and studies of the hot gas reservoir constrain past star formation. UV studies provide important, sensitive diagnostics of the young star forming populations and provide the most mature means for studying galaxies at 2 < zeta < 4. This talk will review current progress on studying X-ray emission in concert with UV emission from normal/star-forming galaxies at higher redshift. We will also report on our new, deep surveys with GALEX and XMM-Newton in the nearby Coma cluster. These studies are relevant to DEEP06 as Coma is the nearest rich cluster of galaxies and provides an important benchmark for high-redshift studies in the X-ray and UV wavebands. The 30 ks GALEX (note: similar depth to the GALEX Deep Imaging Survey) and the 110 ks XMM observations provide extremely deep coverage of a Coma outskirts field, allowing the construction of the UV and X-ray luminosity function of galaxies and important constraints on star formation scaling relations such as the X-ray-Star Formation Rate correlation and the X-ray/Stellar Mass correlation. We will discuss what we learn from these deep observations of Coma, including the recently established suppression of the X-ray emission from galaxies in the Coma outskirts that is likely associated with lower levels of past star formation and/or the results of tidal gas stripping.

XMM-Newton Observations of the Southeastern Radio Relic in Abell 3667

NASA Astrophysics Data System (ADS)

Storm, Emma; Vink, Jacco; Zandanel, Fabio; Akamatsu, Hiroki

2018-06-01

Radio relics, elongated, non-thermal, structures located at the edges of galaxy clusters, are the result of synchrotron radiation from cosmic-ray electrons accelerated by merger-driven shocks at the cluster outskirts. However, X-ray observations of such shocks in some clusters suggest that they are too weak to efficiently accelerate electrons via diffusive shock acceleration to energies required to produce the observed radio power. We examine this issue in the merging galaxy cluster Abell 3667 (A3667), which hosts a pair of radio relics. While the Northwest relic in A3667 has been well studied in the radio and X-ray by multiple instruments, the Southeast relic region has only been observed so far by Suzaku, which detected a temperature jump across the relic, suggesting the presence of a weak shock. We present observations of the Southeastern region of A3667 with XMM-Newton centered on the radio relic. We confirm the existence of an X-ray shock with Mach number of about 1.8 from a clear detection of temperature jump and a tentative detection of a density jump, consistent with previous measurements by Suzaku. We discuss the implications of this measurement for diffusive shock acceleration as the main mechanism for explaining the origin of radio relics. We then speculate on the plausibility of alternative scenarios, including re-acceleration and variations in the Mach number along shock fronts.

A deep X-ray view of the bare AGN Ark 120. IV. XMM-Newton and NuSTAR spectra dominated by two temperature (warm, hot) Comptonization processes

NASA Astrophysics Data System (ADS)

Porquet, D.; Reeves, J. N.; Matt, G.; Marinucci, A.; Nardini, E.; Braito, V.; Lobban, A.; Ballantyne, D. R.; Boggs, S. E.; Christensen, F. E.; Dauser, T.; Farrah, D.; Garcia, J.; Hailey, C. J.; Harrison, F.; Stern, D.; Tortosa, A.; Ursini, F.; Zhang, W. W.

2018-01-01

Context. The physical characteristics of the material closest to supermassive black holes (SMBHs) are primarily studied through X-ray observations. However, the origins of the main X-ray components such as the soft X-ray excess, the Fe Kα line complex, and the hard X-ray excess are still hotly debated. This is particularly problematic for active galactic nuclei (AGN) showing a significant intrinsic absorption, either warm or neutral, which can severely distort the observed continuum. Therefore, AGN with no (or very weak) intrinsic absorption along the line of sight, so-called "bare AGN", are the best targets to directly probe matter very close to the SMBH. Aims: We perform an X-ray spectral analysis of the brightest and cleanest bare AGN known so far, Ark 120, in order to determine the process(es) at work in the vicinity of the SMBH. Methods: We present spectral analyses of data from an extensive campaign observing Ark 120 in X-rays with XMM-Newton (4 × 120 ks, 2014 March 18-24), and NuSTAR (65.5 ks, 2014 March 22). Results: During this very deep X-ray campaign, the source was caught in a high-flux state similar to the earlier 2003 XMM-Newton observation, and about twice as bright as the lower-flux observation in 2013. The spectral analysis confirms the "softer when brighter" behavior of Ark 120. The four XMM-Newton/pn spectra are characterized by the presence of a prominent soft X-ray excess and a significant Fe Kα complex. The continuum is very similar above about 3 keV, while significant variability is present for the soft X-ray excess. We find that relativistic reflection from a constant-density, flat accretion disk cannot simultaneously produce the soft excess, broad Fe Kα complex, and hard X-ray excess. Instead, Comptonization reproduces the broadband (0.3-79 keV) continuum well, together with a contribution from a mildly relativistic disk reflection spectrum. Conclusions: During this 2014 observational campaign, the soft X-ray spectrum of Ark 120 below 0

VizieR Online Data Catalog: Catalog of XMM X-ray galaxy groups (Gozaliasl+, 2014)

NASA Astrophysics Data System (ADS)

Gozaliasl, G.; Finoguenov, A.; Khosroshahi, H. G.; Mirkazemi, M.; Salvato, M.; Jassur, D. M. Z.; Erfanianfar, G.; Popesso, P.; Tanaka, M.; Lerchster, M.; Kneib, J. P.; McCracken, H. J.; Mellier, Y.; Egami, E.; Pereira, M. J.; Brimioulle, F.; Erben, T.; Seitz, S.

2014-10-01

We analysed the XMM-Newton observations of the CFHTLS wide (W1) field as a part of the XMM-LSS survey (Pierre et al., 2007MNRAS.382..279P, Cat. J/MNRAS/382/279). The details of observations and data reduction are presented in Bielby et al. (2010A&A...523A..66B). We concentrate on the low-z counterparts of the X-ray sources and use all XMM observations performed till 2009, covering an area of 2.276°x2.276°. The CFHTLS wide observations have been carried out in the period between 2003 and 2008, covering an effective survey area of ~154 square degrees. The optical images and data of the CFHTLS were obtained with the MegaPrime instrument mounted on the CFHT in the five filters u*, g', r', i' and z'. (1 data file).

UV Observations of the Galaxy Cluster Abell 1795 with the Optical Monitor on XMM-Newton

NASA Technical Reports Server (NTRS)

Mittaz, J. P. D.; Kaastra, J. S.; Tamura, T.; Fabian, A. C.; Mushotzky, F.; Peterson, J. R.; Ikebe, Y.; Lumb, D. H.; Paerels, F.; Stewart, G.

2000-01-01

We present the results of an analysis of broad band UV observations of the central regions of Abell 1795 observed with the optical monitor on XMM-Newton. As have been found with other UV observations of the central regions of clusters of galaxies, we find evidence for star formation. However, we also find evidence for absorption in the cD galaxy on a more extended scale than has been seen with optical imaging. We also report the first UV observation of part of the filamentary structure seen in H-alpha, X-rays and very deep U band imaging. The part of the filament we see is very blue with UV colours consistent with a very early (O/B) stellar population. This is the first direct evidence of a dominant population of early type stars at the centre of Abell 1795 and implies very recent star formation. The relationship of this emission to emission at other wavebands is discussed.

Using XMM-OM UV Data to Study Cluster Galaxy Evolution

NASA Astrophysics Data System (ADS)

Miller, Neal A.; O'Steen, R.

2010-01-01

The XMM-Newton satellite includes an Optical Monitor (XMM-OM) for the simultaneous observation of its X-ray targets at UV and optical wavelengths. On account of XMM's excellent characteristics for the observation of the hot intracluster medium, a large number of galaxy clusters have been observed by XMM and there is consequently a large and virtually unused database of XMM-OM UV data for galaxies in the cores of these clusters. We have begun a program to capitalize on such data, and describe here our efforts on a subsample of ten nearby clusters having XMM-OM, GALEX, and SDSS data. We present our methods for photometry and calibration of the XMM-OM UV data, and briefly present some applications including galaxy color magnitude diagrams (and identification of the red sequence, blue cloud, and green valley) and SED fitting (and galaxy stellar masses and star formation histories). Support for this work is provided by NASA Award Number NNX09AC76G.

Eta Carinae's Thermal X-Ray Tail Measured with XMM-Newton and NuStar

NASA Technical Reports Server (NTRS)

Hamaguchi, Kenji; Corcoran, Michael F.; Gull, Theodore R.; Takahashi, Hiromitsu; Grefenstette, Brian; Yuasa, Takayuki; Stuhlinger, Martin; Russell, Christopher; Moffat, Anthony F. J.; Madura, Thomas

2016-01-01

The evolved, massive highly eccentric binary system, Car, underwent a periastron passage in the summer of 2014. We obtained two coordinated X-ray observations with XMM-Newton and NuSTAR during the elevated X-ray flux state and just before the X-ray minimum flux state around this passage. These NuSTAR observations clearly detected X-ray emission associated with eta Car extending up to approx. 50 keV for the first time. The NuSTAR spectrum above 10 keV can be fit with the bremsstrahlung tail from a kT approx. 6 keV plasma. This temperature is delta kT 2 keV higher than those measured from the iron K emission line complex, if the shocked gas is in collisional ionization equilibrium. This result may suggest that the companion star's pre-shock wind velocity is underestimated. The NuSTAR observation near the X-ray minimum state showed a gradual decline in the X-ray emission by 40% at energies above 5 keV in a day, the largest rate of change of the X-ray flux yet observed in individual eta Car observations. The column density to the hardest emission component, N(sub H) approx. 10(exp24) H cm(exp-2), marked one of the highest values ever observed for eta Car, strongly suggesting the increased obscuration of the wind-wind colliding X-ray emission by the thick primary stellar wind prior to superior conjunction. Neither observation detected the power-law component in the extremely hard band that INTEGRAL and Suzaku observed prior to 2011. The power-law source might have faded before these observations.

First stars of the ρ Ophiuchi dark cloud. XMM-Newton view of ρ Oph and its neighbors

NASA Astrophysics Data System (ADS)

Pillitteri, I.; Wolk, S. J.; Chen, H. H.; Goodman, A.

2016-08-01

Star formation in molecular clouds can be triggered by the dynamical action of winds from massive stars. Furthermore, X-ray and UV fluxes from massive stars can influence the life time of surrounding circumstellar disks. We present the results of a 53 ks XMM-Newton observation centered on the ρ Ophiuchi A+B binary system. ρ Ophiuchi lies in the center of a ring of dust, likely formed by the action of its winds. This region is different from the dense core of the cloud (L1688 Core F) where star formation is at work. X-rays are detected from ρ Ophiuchi as well as a group of surrounding X-ray sources. We detected 89 X-ray sources, 47 of them have at least one counterpart in 2MASS+All-WISE catalogs. Based on IR and X-ray properties, we can distinguish between young stellar objects (YSOs) belonging to the cloud and background objects. Among the cloud members, we detect three debris-disk objects and 22 disk-less - Class III young stars.We show that these stars have ages in 5-10 Myr, and are significantly older than the YSOs in L1688. We speculate that they are the result of an early burst of star formation in the cloud. An X-ray energy of ≥5 × 1044 erg has been injected into the surrounding mediumover the past 5 Myr, we discuss the effects of such energy budget in relation to the cloud properties and dynamics.

INTEGRAL and XMM-Newton observations of the puzzling binary system LSI +61 303

NASA Astrophysics Data System (ADS)

Chernyakova, Masha; Neronov, A.; Walter, R.

LSI +61° 303 is one of the few X-ray binaries with Be star companion from which both radio and high-energy gamma-ray emission have been observed. We present XMM-Newton and INTE- GRAL observations which reveal variability of the X-ray spectral index of the system. The X-ray spectrum is hard (photon index Γ ≃ 1.5) during the orbital phases of both high and low X-ray flux. However, the spectrum softens at the moment of transition from high to low X-ray state. The spectrum of the system in the hard X-ray band does not reveal the presence of a cut-off (or, at least a spectral break) at 10-60 keV energies, expected if the compact object is an accreting neu- tron star. The observed spectrum and spectral variability can be explained if the compact object in the system is a rotation powered pulsar. In this case the recently found X-ray spectral variability of the system on the several kiloseconds time scale can be explained by the clumpy structure of the Be star disk.

XMM-Newton and NuSTAR Simultaneous X-Ray Observations of IGR J11215-5952

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

Sidoli, L.; Tiengo, A.; Paizis, A.

2017-04-01

We report the results of an XMM - Newton and NuSTAR coordinated observation of the Supergiant Fast X-ray Transient (SFXT) IGR J11215–5952, performed on 2016 February 14, during the expected peak of its brief outburst, which repeats every ∼165 days. Timing and spectral analysis were performed simultaneously in the energy band 0.4–78 keV. A spin period of 187.0 (±0.4) s was measured, consistent with previous observations performed in 2007. The X-ray intensity shows a large variability (more than one order of magnitude) on timescales longer than the spin period, with several luminous X-ray flares that repeat every 2–2.5 ks, somemore » of which simultaneously observed by both satellites. The broadband (0.4–78 keV) time-averaged spectrum was well deconvolved with a double-component model (a blackbody plus a power law with a high energy cutoff) together with a weak iron line in emission at 6.4 keV (equivalent width, EW, of 40 ± 10 eV). Alternatively, a partial covering model also resulted in an adequate description of the data. The source time-averaged X-ray luminosity was 10{sup 36} erg s{sup −1} (0.1–100 keV; assuming 7 kpc). We discuss the results of these observations in the framework of the different models proposed to explain SFXTs, supporting a quasi-spherical settling accretion regime, although alternative possibilities (e.g., centrifugal barrier) cannot be ruled out.« less

Re-examining the XMM-Newton spectrum of the black hole candidate XTE J1652-453

NASA Astrophysics Data System (ADS)

Chiang, Chia-Ying; Reis, R. C.; Walton, D. J.; Fabian, A. C.

2012-10-01

The XMM-Newton spectrum of the black hole candidate XTE J1652-453 shows a broad and strong Fe Kα emission line, generally believed to originate from reflection of the inner accretion disc. These data have been analysed by Hiemstra et al. using a variety of phenomenological models. We re-examine the spectrum with a self-consistent relativistic reflection model. A narrow absorption line near 7.2 keV may be present, which if real is likely the Fe XXVI absorption line arising from highly ionized, rapidly outflowing disc wind. The blueshift of this feature corresponds to a velocity of about 11 100 km s-1, which is much larger than the typical values seen in stellar mass black holes. Given that we also find the source to have a low inclination (i ≲ 32°; close to face-on), we would therefore be seeing through the very base of outflow. This could be a possible explanation for the unusually high velocity. We use a reflection model combined with a relativistic convolution kernel which allows for both prograde and retrograde black hole spin, and treat the potential absorption feature with a physical model for a photoionized plasma. In this manner, assuming the disc is not truncated, we could only constrain the spin of the black hole in XTE J1652-453 to be less than ˜0.5 Jc/GM2 at the 90 per cent confidence limit.

The XMM-Newton Iron Line Profile of NGC 3783

NASA Technical Reports Server (NTRS)

Reeves, J. N.; Nandra, K.; George, I. M.; Pounds, K. A.; Turner, T. J.; Yaqoob, T.

2003-01-01

We report on observations of the iron K line in the nearby Seyfert 1 galaxy, NGC 3783, obtained in a long, 2 orbit (approx. 240 ks) XMM-Newton observation. The line profile obtained exhibits two strong narrow peaks at 6.4 keV and at 7.0 keV, with measured line equivalent widths of 120 and 35 eV respectively. The 6.4 keV emission is the K(alpha) line from near neutral Fe, whilst the 7.0 keV feature probably originates from a blend of the neutral Fe K(beta) line and the Hydrogen-like line of Fe at 6.97 keV. The relatively narrow velocity width of the K(alpha) line (approx. less than 5000 km/s), its lack of response to the continuum emission on short timescales and the detection of a neutral Compton reflection component are all consistent with a distant origin in Compton-thick matter such as the putative molecular torus. A strong absorption line from highly ionized iron (at 6.67 keV) is detected in the time-averaged iron line profile, whilst the depth of the feature appears to vary with time, being strongest when the continuum flux is higher. The iron absorption line probably arises from the highest ionization component of the known warm absorber in NGC 3783, with an ionization of log xi approx 3 and column density of N(sub H) approx. 5 x 10(exp 22)/sq cm and may originate from within 0.1 pc of the nucleus. A weak red-wing to the iron K line profile is also detected below 6.4 keV. However when the effect of the highly ionized warm absorber on the underlying continuum is taken into account, the requirement for a relativistic iron line component from the inner disk is reduced.

Screening and validation of EXTraS data products

NASA Astrophysics Data System (ADS)

Carpano, Stefania; Haberl, F.; De Luca, A.; Tiengo, A.: Israel, G.; Rodriguez, G.; Belfiore, A.; Rosen, S.; Read, A.; Wilms, J.; Kreikenbohm, A.; Law-Green, D.

2015-09-01

The EXTraS project (Exploring the X-ray Transient and variable Sky) is aimed at fullyexploring the serendipitous content of the XMM-Newton EPIC database in the timedomain. The project is funded within the EU/FP7-Cooperation Space framework and is carried out by a collaboration including INAF (Italy), IUSS (Italy), CNR/IMATI (Italy), University of Leicester (UK), MPE (Germany) and ECAP (Germany). The several tasks consist in characterise aperiodicvariability for all 3XMM sources, search for short-term periodic variability on hundreds of thousands sources, detect new transient sources that are missed by standard source detection and hence not belonging to the 3XMM catalogue, search for long term variability by measuring fluxes or upper limits for both pointed and slew observations, and finally perform multiwavelength characterisation andclassification. Screening and validation of the different products is essentially in order to reject flawed results, generated by the automatic pipelines. We present here the screening tool we developed in the form of a Graphical User Interface and our plans for a systematic screening of the different catalogues.

ETA CARINAE’S THERMAL X-RAY TAIL MEASURED WITH XMM-NEWTON AND NuSTAR

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

Hamaguchi, Kenji; Corcoran, Michael F.; Gull, Theodore R.

The evolved, massive highly eccentric binary system, η Car, underwent a periastron passage in the summer of 2014. We obtained two coordinated X-ray observations with XMM-Newton and NuSTAR during the elevated X-ray flux state and just before the X-ray minimum flux state around this passage. These NuSTAR observations clearly detected X-ray emission associated with η Car extending up to ∼50 keV for the first time. The NuSTAR spectrum above 10 keV can be fit with the bremsstrahlung tail from a kT ∼ 6 keV plasma. This temperature is ΔkT ∼ 2 keV higher than those measured from the iron K emission line complex, if the shockedmore » gas is in collisional ionization equilibrium. This result may suggest that the companion star's pre-shock wind velocity is underestimated. The NuSTAR observation near the X-ray minimum state showed a gradual decline in the X-ray emission by 40% at energies above 5 keV in a day, the largest rate of change of the X-ray flux yet observed in individual η Car observations. The column density to the hardest emission component, N{sub H} ∼ 10{sup 24} H cm{sup −2}, marked one of the highest values ever observed for η Car, strongly suggesting increased obscuration of the wind–wind colliding X-ray emission by the thick primary stellar wind prior to superior conjunction. Neither observation detected the power-law component in the extremely hard band that INTEGRAL and Suzaku observed prior to 2011. If the non-detection by NuSTAR is caused by absorption, the power-law source must be small and located very near the wind–wind collision apex. Alternatively, it may be that the power-law source is not related to either η Car or the GeV γ-ray source.« less

High-Resolution X-Ray Spectroscopy of the Galactic Supernova Remnant Puppis A with the XMM-Newton RGS

NASA Technical Reports Server (NTRS)

Katsuda, Satoru; Tsunemi, Hiroshi; Mori, Koji; Uchida, Hiroyuki; Petre, Robert; Yamada, Shinya; Akamatsu, Hiroki; Konami, Saori; Tamagawa, Toru

2012-01-01

We present high-resolution X-ray spectra of cloud-shock interaction regions in the eastern and northern rims of the Galactic supernova remnant Puppis A, using the Reflection Grating Spectrometer onboard the XMM-Newton satellite. A number of emission lines including K(alpha) triplets of He-like N, O , and Ne are clearly resolved for the first time. Intensity ratios of forbidden to resonance lines in the triplets are found to be higher than predictions by thermal emission models having plausible plasma parameters. The anomalous line ratios cannot be reproduced by effects of resonance scattering, recombination, or inner-shell ionization processes, but could be explained by charge-exchange emission that should arise at interfaces between the cold/warm clouds and the hot plasma. Our observations thus provide observational support for charge-exchange X-ray emission in supernova remnants.

Flares from small to large: X-ray spectroscopy of Proxima Centauri with XMM-Newton

NASA Astrophysics Data System (ADS)

Güdel, M.; Audard, M.; Reale, F.; Skinner, S. L.; Linsky, J. L.

2004-03-01

We report results from a comprehensive study of the nearby M dwarf Proxima Centauri with the XMM-Newton satellite, using simultaneously its X-ray detectors and the Optical Monitor with its U band filter. We find strongly variable coronal X-ray emission, with flares ranging over a factor of 100 in peak flux. The low-level emission is found to be continuously variable on at least three time scales (a slow decay of several hours, modulation on a time scale of 1 hr, and weak flares with time scales of a few minutes). Several weak flares are characteristically preceded by an optical burst, compatible with predictions from standard solar flare models. We propose that the U band bursts are proxies for the elusive stellar non-thermal hard X-ray bursts suggested from solar observations. In the course of the observation, a very large X-ray flare started and was observed essentially in its entirety. Its peak luminosity reached 3.9× 1028 erg s-1 [0.15-10 keV], and the total X-ray energy released in the same band is derived to be 1.5× 1032 ergs. This flare has for the first time allowed to measure significant density variations across several phases of the flare from X-ray spectroscopy of the O VII He-like triplet; we find peak densities reaching up to 4× 1011 cm-3 for plasma of about 1-5 MK. Abundance ratios show little variability in time, with a tendency of elements with a high first ionization potential to be overabundant relative to solar photospheric values. Using Fe XVII lines with different oscillator strengths, we do not find significant effects due to opacity during the flare, indicating that large opacity increases are not the rule even in extreme flares. We model the large flare in terms of an analytic 2-Ribbon flare model and find that the flaring loop system should have large characteristic sizes (≈ 1R*) within the framework of this simplistic model. These results are supported by full hydrodynamic simulations. Comparing the large flare to flares of similar

X-Ray Spectroscopy of AS1101 with Chandra, XMM-Newton, and ROSAT: Bandpass Dependence of the Temperature Profile and Soft Excess Emission

NASA Astrophysics Data System (ADS)

Bonamente, Massimiliano; Nevalainen, Jukka

2011-09-01

We present spatially resolved spectroscopy of the galaxy cluster AS1101, also known as Sèrsic 159-03, with Chandra, XMM-Newton, and ROSAT, and investigate the presence of soft X-ray excess emission above the contribution from the hot intracluster medium. In earlier papers we reported an extremely bright soft excess component that reached 100% of the thermal radiation in the R2 ROSAT band (0.2-0.4 keV), using the H I column density measurement by Dickey and Lockman. In this paper we use the newer Leiden-Argentine-Bonn survey measurements of the H I column density toward AS1101, significantly lower than the previous value, and show that the soft excess emission in AS1101 is now at the level of 10%-20% of the hot gas emission, in line with those of a large sample of clusters analyzed by Bonamente et al. in 2002. The ROSAT soft excess emission is detected regardless of calibration uncertainties between Chandra and XMM-Newton. This new analysis of AS1101 indicates that the 1/4 keV band emission is compatible with the presence of warm-hot intergalactic medium (WHIM) filaments connected to the cluster and extending outward into the intergalactic medium; the temperatures we find in this study are typically lower than those of the WHIM probed in other X-ray studies. We also show that the soft excess emission is compatible with a non-thermal origin as the inverse Compton scattering of relativistic electrons off the cosmic microwave background, with pressure less than 1% of the thermal electrons.

A new ultraluminous X-ray source in the galaxy NGC 5907

NASA Astrophysics Data System (ADS)

Pintore, F.; Belfiore, A.; Novara, G.; Salvaterra, R.; Marelli, M.; De Luca, A.; Rigoselli, M.; Israel, G.; Rodriguez, G.; Mereghetti, S.; Wolter, A.; Walton, D. J.; Fuerst, F.; Ambrosi, E.; Zampieri, L.; Tiengo, A.; Salvaggio, C.

2018-06-01

We report on the serendipitous discovery of a new transient in NGC 5907, at a peak luminosity of 6.4 × 1039 erg s-1. The source was undetected in previous 2012 Chandra observations with a 3σ upper limit on the luminosity of 1.5 × 1038 erg s-1, implying a flux increase of a factor of >35. We analysed three recent 60 ks/50 ks Chandra and 50 ks XMM-Newton observations, as well as all the available Swift/XRT observations performed between 2017 August and 2018 March. Until the first half of 2017 October, Swift/XRT observations did not show any emission from the source. The transient entered the ultraluminous X-ray source (ULX) regime in less than two weeks and its outburst was still on-going at the end of 2018 February. The 0.3-10 keV spectrum is consistent with a single multicolour blackbody disc (kT ˜ 1.5 keV). The source might be an ˜30 M⊙ black hole accreting at the Eddington limit. However, although we did not find evidence of pulsations, we cannot rule out the possibility that this ULX hosts an accreting NS.

Chandra and XMM-Newton Observations of the Abell 3395/Abell 3391 Intercluster Filament

NASA Astrophysics Data System (ADS)

Alvarez, Gabriella E.; Randall, Scott W.; Bourdin, Hervé; Jones, Christine; Holley-Bockelmann, Kelly

2018-05-01

We present Chandra and XMM-Newton X-ray observations of the Abell 3391/Abell 3395 intercluster filament. It has been suggested that the galaxy clusters Abell 3395, Abell 3391, and the galaxy group ESO-161 -IG 006 located between the two clusters, are in alignment along a large-scale intercluster filament. We find that the filament is aligned close to the plane of the sky, in contrast to previous results. We find a global projected filament temperature kT = {4.45}-0.55+0.89 keV, electron density {n}e={1.08}-0.05+0.06× {10}-4 cm‑3, and {M}gas}={2.7}-0.1+0.2 × {10}13 M ⊙. The thermodynamic properties of the filament are consistent with that of the intracluster medium (ICM) of Abell 3395 and Abell 3391, suggesting that the filament emission is dominated by ICM gas that has been tidally disrupted during an early stage merger between these two clusters. We present temperature, density, entropy, and abundance profiles across the filament. We find that the galaxy group ESO-161 may be undergoing ram-pressure-stripping in the low-density environment at or near the virial radius of both clusters, due to its rapid motion through the filament.

A sensitive search for unknown spectral emission lines in the diffuse X-ray background with XMM-Newton

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

Gewering-Peine, A.; Horns, D.; Schmitt, J.H.M.M., E-mail: alexander.gewering-peine@desy.de, E-mail: dieter.horns@desy.de, E-mail: jschmitt@hs.uni-hamburg.de

The Standard Model of particle physics can be extended to include sterile (right-handed) neutrinos or axions to solve the dark matter problem. Depending upon the mixing angle between active and sterile neutrinos, the latter have the possibility to decay into monoenergetic active neutrinos and photons in the keV-range while axions can couple to two photons. We have used data taken with the X-ray telescope XMM-Newton for the search of line emissions. We used pointings with high exposures and expected dark matter column densities with respect to the dark matter halo of the Milky Way. The posterior predictive p-value analysis hasmore » been applied to locate parameter space regions which favour additional emission lines. In addition, upper limits of the parameter space of the models have been generated such that the preexisting limits have been significantly improved.« less

CHEERS: Chemical enrichment of clusters of galaxies measured using a large XMM-Newton sample

NASA Astrophysics Data System (ADS)

de Plaa, J.; Mernier, F.; Kaastra, J.; Pinto, C.

2017-10-01

The Chemical Enrichment RGS Sample (CHEERS) is aimed to be a sample of the most optimal clusters of galaxies for observation with the Reflection Grating Spectrometer (RGS) aboard XMM-Newton. It consists of 5 Ms of deep cluster observations of 44 objects obtained through a very large program and archival observations. The main goal is to measure chemical abundances in the hot Intra-Cluster Medium (ICM) of clusters to provide constraints on chemical evolution models. Especially the origin and evolution of type Ia supernovae is still poorly known and X-ray observations could contribute to constrain models regarding the SNIa explosion mechanism. Due to the high quality of the data, the uncertainties on the abundances are dominated by systematic effects. By carefully treating each systematic effect, we increase the accuracy or estimate the remaining uncertainty on the measurement. The resulting abundances are then compared to supernova models. In addition, also radial abundance profiles are derived. In the talk, we present an overview of the results that the CHEERS collaboration obtained based on the CHEERS data. We focus on the abundance measurements. The other topics range from turbulence measurements through line broadening to cool gas in groups.

Thermal and Non-thermal Nature of the Soft Excess Emission from Sersic 159-03 observed with XMM-Newton

NASA Technical Reports Server (NTRS)

Bonamente, Massimiliano; Lieu, Richard; Mittaz, Jonathan P. D.; Kaastra, Jelle S.; Nevalainen, Jukka

2005-01-01

Several nearby clusters exhibit an excess of soft X-ray radiation which cannot be attributed to the hot virialized intra-cluster medium. There is no consensus to date on the origin of the excess emission: it could be either of thermal origin, or due to an inverse Compton scattering of the cosmic microwave background. Using high resolution XMM-Newton data of Sersic 159-03 we first show that strong soft excess emission is detected out to a radial distance of 0.9 Mpc. The data are interpreted using the two viable models available, i.e., by invoking a warm reservoir of thermal gas, or relativistic electrons which are part of a cosmic ray population. The thermal model leads to a better goodness-of-fit, and the emitting warm gas must be high in mass and low in metallicity.

XMM-Newton Observations of Solar Wind Charge Exchange Emission

NASA Technical Reports Server (NTRS)

Snowden, S. L.; Collier, M. R.; Kuntz, K. D.

2004-01-01

We present an XMM-Newton spectrum of diffuse X-ray emission from within the solar system. The spectrum is dominated by O VII and O VIII lines at 0.57 keV and 0.65 keV, O VIII (and possibly Fe XVII) lines at approximately 0.8 keV, Ne IX lines at approximately 0.92 keV, and Mg XI lines at approximately 1.35 keV. This spectrum is consistent with what is expected from charge exchange emission between the highly ionized solar wind and either interstellar neutrals in the heliosphere or material from Earth's exosphere. The emission is clearly seen as a low-energy ( E less than 1.5 keV) spectral enhancement in one of a series of observations of the Hubble Deep Field North. The X-ray enhancement is concurrent with an enhancement in the solar wind measured by the ACE satellite. The solar wind enhancement reaches a flux level an order of magnitude more intense than typical fluxes at 1 AU, and has ion ratios with significantly enhanced higher ionization states. Whereas observations of the solar wind plasma made at a single point reflect only local conditions which may only be representative of solar wind properties with spatial scales ranging from less than half of an Earth radii (approximately 10 s) to 100 Earth radii, X-ray observations of solar wind charge exchange are remote sensing measurements which may provide observations which are significantly more global in character. Besides being of interest in its own right for studies of the solar system, this emission can have significant consequences for observations of more cosmological objects. It can provide emission lines at zero redshift which are of particular interest (e.g., O VII and O VIII) in studies of diffuse thermal emission, and which can therefore act as contamination in objects which cover the entire detector field of view. We propose the use of solar wind monitoring data, such as from the ACE and Wind spacecraft, as a diagnostic to screen for such possibilities.

Using XMM-Newton to study the energy-dependent variability of H 1743-322 during its 2014 outburst

NASA Astrophysics Data System (ADS)

Stiele, H.; Yu, W.

2016-08-01

Black hole transients evolve during bright outbursts, showing distinct changes in their spectral and variability properties. These changes are interpreted as evidence for changes in the accretion flow and in the X-ray-emitting regions. We obtained an anticipated XMM-Newton Target of Opportunity observation of H 1743-322 during its outburst in 2014 September. Based on data from eight outbursts observed in the last 10 yr, we expected to catch the start of the hard-to-soft state transition. The fact that neither the general shape of the observed power density spectrum nor the characteristic frequency shows an energy dependence implies that the source remained in the low-hard state at the time of our observation near outburst peak. The spectral properties agree with the source being in the low-hard state, and a Swift/XRT monitoring of the outburst revealed that H 1743-322 stayed in the low-hard state during the entire outburst (known as a `failed outburst'). Here we derive the averaged QPO waveform and obtain phase-resolved spectra. A comparison of the phase-resolved spectra with the phase-averaged energy spectrum reveals spectral pivoting. We compare variability on long and short time-scales using covariance spectra and find that the covariance ratio does not show an increase towards lower energies. In other binaries an increase has been found. There are two possible explanations: either the absence of additional disc variability on longer time-scales is related to the high inclination of H 1743-322 compared with other black hole X-ray binaries, or it is the reason why we observe H 1743-322 during a failed outburst. More data on failed outbursts and on high-inclination sources will be needed in order to investigate these two possibilities further.

3XMM J185246.6+003317: Another Low Magnetic Field Magnetar

NASA Astrophysics Data System (ADS)

Rea, N.; Viganò, D.; Israel, G. L.; Pons, J. A.; Torres, D. F.

2014-01-01

We study the outburst of the newly discovered X-ray transient 3XMM J185246.6+003317, re-analyzing all available XMM-Newton observations of the source to perform a phase-coherent timing analysis, and derive updated values of the period and period derivative. We find the source rotating at P = 11.55871346(6) s (90% confidence level; at epoch MJD 54728.7) but no evidence for a period derivative in the seven months of outburst decay spanned by the observations. This translates to a 3σ upper limit for the period derivative of \\dot{P}< 1.4\\times 10^{-13} s s-1, which, assuming the classical magneto-dipolar braking model, gives a limit on the dipolar magnetic field of B dip < 4.1 × 1013 G. The X-ray outburst and spectral characteristics of 3XMM J185246.6+003317 confirm its identification as a magnetar, but the magnetic field upper limit we derive defines it as the third "low-B" magnetar discovered in the past 3 yr, after SGR 0418+5729 and Swift J1822.3-1606. We have also obtained an upper limit to the quiescent luminosity (<4 × 1033 erg s-1), in line with the expectations for an old magnetar. The discovery of this new low field magnetar reaffirms the prediction of about one outburst per year from the hidden population of aged magnetars.

GRS 1739-278 Observed at Very Low Luminosity with XMM-Newton and NuSTAR

NASA Astrophysics Data System (ADS)

Fürst, F.; Tomsick, J. A.; Yamaoka, K.; Dauser, T.; Miller, J. M.; Clavel, M.; Corbel, S.; Fabian, A.; García, J.; Harrison, F. A.; Loh, A.; Kaaret, P.; Kalemci, E.; Migliari, S.; Miller-Jones, J. C. A.; Pottschmidt, K.; Rahoui, F.; Rodriguez, J.; Stern, D.; Stuhlinger, M.; Walton, D. J.; Wilms, J.

2016-12-01

We present a detailed spectral analysis of XMM-Newton and NuSTAR observations of the accreting transient black hole GRS 1739-278 during a very faint low hard state at ˜0.02% of the Eddington luminosity (for a distance of 8.5 kpc and a mass of 10 {M}⊙ ). The broadband X-ray spectrum between 0.5 and 60 keV can be well-described by a power-law continuum with an exponential cutoff. The continuum is unusually hard for such a low luminosity, with a photon index of Γ = 1.39 ± 0.04. We find evidence for an additional reflection component from an optically thick accretion disk at the 98% likelihood level. The reflection fraction is low, with {{ R }}{refl}={0.043}-0.023+0.033. In combination with measurements of the spin and inclination parameters made with NuSTAR during a brighter hard state by Miller et al., we seek to constrain the accretion disk geometry. Depending on the assumed emissivity profile of the accretion disk, we find a truncation radius of 15-35 {R}{{g}} (5-12 {R}{ISCO}) at the 90% confidence limit. These values depend strongly on the assumptions and we discuss possible systematic uncertainties.

X-ray emission from the Wolf-Rayet bubble NGC 6888 - II. XMM-Newton EPIC observations

NASA Astrophysics Data System (ADS)

Toalá, J. A.; Guerrero, M. A.; Chu, Y.-H.; Arthur, S. J.; Tafoya, D.; Gruendl, R. A.

2016-03-01

We present deep XMM-Newton European Photon Imaging Camera observations of the Wolf-Rayet (WR) bubble NGC 6888 around the star WR 136. The complete X-ray mapping of the nebula confirms the distribution of the hot gas in three maxima spatially associated with the caps and north-west blowout hinted at by previous Chandra observations. The global X-ray emission is well described by a two-temperature optically thin plasma model (T1 = 1.4 × 106 K, T2 = 8.2 × 106 K) with a luminosity of LX = 7.8 × 1033 erg s-1 in the 0.3-1.5 keV energy range. The rms electron density of the X-ray-emitting gas is estimated to be ne = 0.4 cm-3. The high-quality observations presented here reveal spectral variations within different regions in NGC 6888, which allowed us for the first time to detect temperature and/or nitrogen abundance inhomogeneities in the hot gas inside a WR nebula. One possible explanation for such spectral variations is that the mixing of material from the outer nebula into the hot bubble is less efficient around the caps than in other nebular regions.

High Resolution X-Ray Spectroscopy of zeta Puppis with the XMM-Newton Reflection Grating Spectrometer

NASA Technical Reports Server (NTRS)

Kahn, S. M.; Leutenegger, M. A.; Cottam, J.; Rauw, G.; Vreux, J.-M.; denBoggende, A. J. F.; Mewe, R.; Guedel, M.

2000-01-01

We present the first high resolution X-ray spectrum of the bright O4Ief supergiant star Puppis, obtained with the Reflection Grating Spectrometer on- board XMM-Newton. The spectrum exhibits bright emission lines of hydrogen-like and helium-like ions of nitrogen, oxygen, neon, magnesium, and silicon, as well as neon-like ions of iron. The lines are all significantly resolved, with characteristic velocity widths of order 1000 - 1500 km/ s. The nitrogen lines are especially strong, and indicate that the shocked gas in the wind is mixed with CNO-burned material, as has been previously inferred for the atmosphere of this star from ultraviolet spectra. We find that the forbidden to intercombination line ratios within the helium-like triplets are anomalously low for N VI, O VII, and Ne IX. While this is sometimes indicative of high electron density, we show that in this case, it is instead caused by the intense ultraviolet radiation field of the star. We use this interpretation to derive constraints on the location of the X-ray emitting shocks within the wind that agree remarkably well with current theoretical models for this system.

An XMM-Newton Study of the Mixed-morphology Supernova Remnant G346.6-0.2

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

Auchettl, Katie; Lopez, Laura; Ng, C-Y.

We present an X-ray imaging and spectroscopic study of the molecular cloud interacting mixed-morphology supernova remnant G346.6–0.2 using XMM-Newton . The X-ray spectrum of the remnant is well described by a recombining plasma that most likely arises from adiabatic cooling and has subsolar abundances of Mg, Si, and S. Our fits also suggest the presence of either an additional power-law component with a photon index of ∼2 or an additional thermal component with a temperature of ∼2.0 keV. We investigate the possible origin of this component and suggest that it could arise from either the Galactic ridge X-ray emission, anmore » unidentified pulsar wind nebula, or X-ray synchrotron emission from high-energy particles accelerated at the shock. However, deeper, high-resolution observations of this object are needed to shed light on the presence and origin of this feature. Based on its morphology, its Galactic latitude, the density of the surrounding environment, and its association with a dense molecular cloud, G346.6–0.2 most likely arises from a massive progenitor that underwent core collapse.« less

XMM-Newton X-ray and HST weak gravitational lensing study of the extremely X-ray luminous galaxy cluster Cl J120958.9+495352 (z = 0.902)

NASA Astrophysics Data System (ADS)

Thölken, Sophia; Schrabback, Tim; Reiprich, Thomas H.; Lovisari, Lorenzo; Allen, Steven W.; Hoekstra, Henk; Applegate, Douglas; Buddendiek, Axel; Hicks, Amalia

2018-03-01

Context. Observations of relaxed, massive, and distant clusters can provide important tests of standard cosmological models, for example by using the gas mass fraction. To perform this test, the dynamical state of the cluster and its gas properties have to be investigated. X-ray analyses provide one of the best opportunities to access this information and to determine important properties such as temperature profiles, gas mass, and the total X-ray hydrostatic mass. For the last of these, weak gravitational lensing analyses are complementary independent probes that are essential in order to test whether X-ray masses could be biased. Aims: We study the very luminous, high redshift (z = 0.902) galaxy cluster Cl J120958.9+495352 using XMM-Newton data. We measure global cluster properties and study the temperature profile and the cooling time to investigate the dynamical status with respect to the presence of a cool core. We use Hubble Space Telescope (HST) weak lensing data to estimate its total mass and determine the gas mass fraction. Methods: We perform a spectral analysis using an XMM-Newton observation of 15 ks cleaned exposure time. As the treatment of the background is crucial, we use two different approaches to account for the background emission to verify our results. We account for point spread function effects and deproject our results to estimate the gas mass fraction of the cluster. We measure weak lensing galaxy shapes from mosaic HST imaging and select background galaxies photometrically in combination with imaging data from the William Herschel Telescope. Results: The X-ray luminosity of Cl J120958.9+495352 in the 0.1-2.4 keV band estimated from our XMM-Newton data is LX = (13.4+1.2-1.0) × 1044 erg/s and thus it is one of the most X-ray luminous clusters known at similarly high redshift. We find clear indications for the presence of a cool core from the temperature profile and the central cooling time, which is very rare at such high redshifts. Based

Recurrent Outbursts Revealed in 3XMM J031820.8-663034

NASA Astrophysics Data System (ADS)

Zhao, Hai-Hui; Weng, Shan-Shan; Wang, Jun-Xian

2018-06-01

3XMM J031820.8-663034, first detected by ROSAT in NGC 1313, is one of a few known transient ultraluminous X-ray sources (ULXs). In this paper, we present decades of X-ray data of this source from ROSAT, XMM-Newton, Chandra, and the Neil Gehrels Swift Observatory. We find that its X-ray emission experienced four outbursts since 1992, with a typical recurrent time ∼1800 days, an outburst duration ∼240–300 days, and a nearly constant peak X-ray luminosity ∼1.5 × 1039 erg s‑1. The upper limit of X-ray luminosity at the quiescent state is ∼5.6 × 1036 erg s‑1, and the total energy radiated during one outburst is ∼1046 erg. The spectra at the high luminosity states can be described with an absorbed disk blackbody, and the disk temperature increases with the X-ray luminosity. We compare its outburst properties with other known transient ULXs including ESO 243-49 HLX-1. As its peak luminosity only marginally puts it in the category of ULXs, we also compare it with normal transient black hole binaries. Our results suggest that the source is powered by an accreting massive stellar-mass black hole, and the outbursts are triggered by the thermal-viscous instability.

INTEGRAL, XMM-Newton and ESO/NTT identification of AX J1749.1-2733: an obscured and probably distant Be/X-ray binary

NASA Astrophysics Data System (ADS)

Zurita Heras, J. A.; Chaty, S.

2008-10-01

Context: AX J1749.1-2733 is an unclassified transient X-ray source discovered during surveys by ASCA in 1993-1999. The transient behaviour and the short and bright flares of the source have led to the idea that it is part of the recently revealed subclass of supergiant fast X-ray transients. Aims: A multi-wavelength study in NIR, optical, X-rays, and hard X-rays of AX J1749.1-2733 is undertaken in order to determine its nature. Methods: Public INTEGRAL data and our target of opportunity observation with XMM-Newton were used to study the high-energy source through timing and spectral analysis. Multi-wavelength observations in optical and NIR with the ESO/NTT telescope were also performed to search for the counterpart. Results: AX J1749.1-2733 is a new high-mass X-ray binary pulsar with an orbital period of 185.5±1.1 days (or 185.5/f with f=2,3 or 4) and a spin period of 66 s, parameters typical of a Be/X-ray binary. The outbursts last 12 d. A spin-down of dot{P}=0.08 ± 0.02 s yr -1 is also observed, very likely due to the propeller effect. The most accurate X-ray position is RA (2000) =17h49m06.8s and Dec =-27°32 arcmin32.5 arcsec (uncertainty 2 arcsec). The high-energy broad-band spectrum is well-fitted with an absorbed powerlaw and a high-energy cutoff with values NH=20.1-1.3+1.5×1022 cm-2, Γ=1.0-0.3+0.1, and Ecut=21-3+5 keV. The only optical/NIR candidate counterpart within the X-ray error circle has magnitudes of R=21.9±0.1, I=20.92±0.09, J=17.42±0.03, H=16.71±0.02, and Ks=15.75±0.07, which points towards a Be star located far away (>8.5 kpc) and highly absorbed (NH˜ 1.7×1022 cm-2). The average 22-50 keV luminosity is 0.4-0.9×1036 erg s-1 during the long outbursts and 3×1036 erg s-1 during the bright flare that occurred on MJD 52891 for an assumed distance of 8.5 kpc. Based on observations made with 1) INTEGRAL, an ESA project with instruments and science data centre funded by ESA member states (especially the PI countries: Denmark, France, Germany

A Multi-Epoch Timing and Spectral Study of the ULX NGC 5408 X-1 with XMM-Newton

NASA Technical Reports Server (NTRS)

Strohmayer, Tod E.; Dheeraj, Pasham R.

2012-01-01

We report results from extensive new XMM- Newton observations of the ultraluminous X-ray source (ULX) NGC 5408 X-1, one of the few ULXs to show quasi-periodic X-ray variability. We detect quasi-periodic oscillations (QPOs) in each of four new (approximately equal 100 ks each) pointings, expanding the range of frequencies and rms amplitudes observed from the source to 10-40 mHz and 10-45 %, respectively. However, similarly significant variations in the power-law photon spectral index, Gamma, are not observed. We use the results of timing and energy spectral modeling to compare with the timing and spectral correlations seen in stellar-mass systems. We find that the qualitative nature of the timing and energy spectra of NGC 5408 X-1 are very similar to stellar-mass black holes in the steep power-law state exhibiting Type-C QPOs. However, in order for this analogy to quantitatively hold we must only be seeing the so-called saturated portion of the QPO frequency - photon index (or disk flux) relation. Assuming this to be the case, we place a lower limit on the mass of NGC 5408 X-1 of approx greater than 800 Solar Mass. Alternatively, the QPO centroid frequency is largely independent of the spectral parameters, in which case a close analogy of NGC 5408 X-1's mHz QPOs with Type-C QPOs in stellar systems is problematic. Measurement of the source's timing properties over a greater range of spectral parameters (in particular the spectral index) is needed in order to definitively resolve this ambiguity. We searched all the available data for both a broad Fe emission line as well as high frequency QPO analogs (0.1 - 1 Hz), but detected neither. We place upper limits on the equivalent width of any Fe emission feature in the 6 - 7 keY band, and of the amplitude (rms) of a high frequency QPO analog of approx equal 10 eV and approx equal 4%, respectively.

A long XMM-Newton campaign on the mode-switching radio pulsar PSR B0943+10

NASA Astrophysics Data System (ADS)

Mereghetti, S.

2017-10-01

Observations obtained in the last years challenged the widespread notion that rotation-powered neutron stars are steady X-ray emitters. Besides the few pulsars showing "magnetar-like" activity, in at least one remarkable object, PSR B0943+10, significant variations, correlated to radio-mode switching have been discovered. Their study opens a new window to investigate the processes responsible for the pulsar radio and high-energy emission. An XMM-Newton Large Program, with simultaneous radio observations with LOFAR, LWA and Arecibo, allowed us to detect X-ray pulsations also during the fainter state and to better constrain the spectral and variability properties of PSR B0943+10. In both radio states the pulsed emission can be described by a thermal blackbody with temperature of a few 10^6 K and the unpulsed emission by a power-law. We discuss a scenario in which both unpulsed non-thermal emission, likely of magnetospheric origin, and pulsed thermal emission from a small polar cap (˜1500 m^2) with a strong non-dipolar field (˜10^{14} G), are present during both modes and vary in intensity in a correlated way. This is broadly consistent with the predictions of the partially screened gap model and does not necessarily imply global magnetospheric rearrangements to explain the mode switching.

Star formation history of Canis Major OB1. II. A bimodal X-ray population revealed by XMM-Newton

NASA Astrophysics Data System (ADS)

Santos-Silva, T.; Gregorio-Hetem, J.; Montmerle, T.; Fernandes, B.; Stelzer, B.

2018-02-01

Aims: The Canis Major OB1 Association has an intriguing scenario of star formation, especially in the region called Canis Major R1 (CMa R1) traditionally assigned to a reflection nebula, but in reality an ionized region. This work is focussed on the young stellar population associated with CMa R1, for which our previous results from ROSAT, optical, and near-infrared data had revealed two stellar groups with different ages, suggesting a possible mixing of populations originated from distinct star formation episodes. Methods: The X-ray data allow the detected sources to be characterized according to hardness ratios, light curves, and spectra. Estimates of mass and age were obtained from the 2MASS catalogue and used to define a complete subsample of stellar counterparts for statistical purposes. Results: A catalogue of 387 XMM-Newton sources is provided, of which 78% are confirmed as members or probable members of the CMa R1 association. Flares (or similar events) were observed for 13 sources and the spectra of 21 bright sources could be fitted by a thermal plasma model. Mean values of fits parameters were used to estimate X-ray luminosities. We found a minimum value of log(LX [erg/s] ) = 29.43, indicating that our sample of low-mass stars (M⋆ ≤ 0.5 M⊙), which are faint X-ray emitters, is incomplete. Among the 250 objects selected as our complete subsample (defining our "best sample"), 171 are found to the east of the cloud, near Z CMa and dense molecular gas, of which 50% of them are young (<5 Myr) and 30% are older (>10 Myr). The opposite happens to the west, near GU CMa, in areas lacking molecular gas: among 79 objects, 30% are young and 50% are older. These findings confirm that a first episode of distributed star formation occurred in the whole studied region 10 Myr ago and dispersed the molecular gas, while a second, localized episode (<5 Myr) took place in the regions where molecular gas is still present.

The 3XMM spectral fit database

NASA Astrophysics Data System (ADS)

Georgantopoulos, I.; Corral, A.; Watson, M.; Carrera, F.; Webb, N.; Rosen, S.

2016-06-01

I will present the XMMFITCAT database which is a spectral fit inventory of the sources in the 3XMM catalogue. Spectra are available by the XMM/SSC for all 3XMM sources which have more than 50 background subtracted counts per module. This work is funded in the framework of the ESA Prodex project. The 3XMM catalog currently covers 877 sq. degrees and contains about 400,000 unique sources. Spectra are available for over 120,000 sources. Spectral fist have been performed with various spectral models. The results are available in the web page http://xraygroup.astro.noa.gr/ and also at the University of Leicester LEDAS database webpage ledas-www.star.le.ac.uk/. The database description as well as some science results in the joint area with SDSS are presented in two recent papers: Corral et al. 2015, A&A, 576, 61 and Corral et al. 2014, A&A, 569, 71. At least for extragalactic sources, the spectral fits will acquire added value when photometric redshifts become available. In the framework of a new Prodex project we have been funded to derive photometric redshifts for the 3XMM sources using machine learning techniques. I will present the techniques as well as the optical near-IR databases that will be used.

Buoyancy, Uplift, and AGN Feedback - Deep Chandra and XMM-Newton Observations of the Radio Outbursts in NGC 4472 and NGC 1399

NASA Astrophysics Data System (ADS)

Kraft, R.; Su, Y.; Gendron Marsolais, M.; Roediger, E.; Nulsen, P.; Hlavacek-Larrondo, J.; Forman, W.; Jones, C.; Randall, S.; Machacek, M.

2017-10-01

We present results from deep Chandra and XMM-Newton observations of the AGN outbursts in the nearby early-type galaxies NGC 4472 and NGC 1399. Both pairs of radio bubbles are surrounded by rims of enhanced X-ray emission. Spectral analysis shows that the temperatures of these rims are less than that of the surrounding medium, suggesting that they are gas uplifted from the group center by the buoyant rise of the radio bubbles and not shocks due to the supersonic inflation of the lobes. The energy required to uplift these shells can be a significant fraction of the total outburst energy, and thus may play an important role in the thermodynamic evolution of the galaxy core. Buoyant uplift could also be a very efficient means of transporting metals from the galaxy core to the halo.

The Subaru/XMM-Newton Deep Survey (SXDS). V. Optically Faint Variable Object Survey

NASA Astrophysics Data System (ADS)

Morokuma, Tomoki; Doi, Mamoru; Yasuda, Naoki; Akiyama, Masayuki; Sekiguchi, Kazuhiro; Furusawa, Hisanori; Ueda, Yoshihiro; Totani, Tomonori; Oda, Takeshi; Nagao, Tohru; Kashikawa, Nobunari; Murayama, Takashi; Ouchi, Masami; Watson, Mike G.; Richmond, Michael W.; Lidman, Christopher; Perlmutter, Saul; Spadafora, Anthony L.; Aldering, Greg; Wang, Lifan; Hook, Isobel M.; Knop, Rob A.

2008-03-01

We present our survey for optically faint variable objects using multiepoch (8-10 epochs over 2-4 years) i'-band imaging data obtained with Subaru Suprime-Cam over 0.918 deg2 in the Subaru/XMM-Newton Deep Field (SXDF). We found 1040 optically variable objects by image subtraction for all the combinations of images at different epochs. This is the first statistical sample of variable objects at depths achieved with 8-10 m class telescopes or the Hubble Space Telescope. The detection limit for variable components is i'vari ~ 25.5 mag. These variable objects were classified into variable stars, supernovae (SNe), and active galactic nuclei (AGNs), based on the optical morphologies, magnitudes, colors, and optical-mid-infrared colors of the host objects, spatial offsets of variable components from the host objects, and light curves. Detection completeness was examined by simulating light curves for periodic and irregular variability. We detected optical variability for 36% +/- 2% (51% +/- 3% for a bright sample with i' < 24.4 mag) of X-ray sources in the field. Number densities of variable objects as functions of time intervals Δ t and variable component magnitudes i'vari are obtained. Number densities of variable stars, SNe, and AGNs are 120, 489, and 579 objects deg-2, respectively. Bimodal distributions of variable stars in the color-magnitude diagrams indicate that the variable star sample consists of bright (V ~ 22 mag) blue variable stars of the halo population and faint (V ~ 23.5 mag) red variable stars of the disk population. There are a few candidates of RR Lyrae providing a possible number density of ~10-2 kpc-3 at a distance of >150 kpc from the Galactic center. Based in part on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. Based on observations (program GN-2002B-Q-30) obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a

X-ray spectroscopy of the mixed morphology supernova remnant W 28 with XMM-Newton

NASA Astrophysics Data System (ADS)

Nakamura, Ryoko; Bamba, Aya; Ishida, Manabu; Yamazaki, Ryo; Tatematsu, Ken'ichi; Kohri, Kazunori; Pühlhofer, Gerd; Wagner, Stefan J.; Sawada, Makoto

2014-06-01

We report on spatially resolved X-ray spectroscopy of the north-eastern part of the mixed morphology supernova remnant (SNR) W 28 with XMM-Newton. The observed field of view includes a prominent and twisted shell emission forming the edge of this SNR as well as part of the center-filled X-ray emission brightening toward the south-west edge of the field of view. The shell region spectra are in general represented by an optically thin thermal plasma emission in collisional ionization equilibrium with a temperature of ˜ 0.3 keV and a density of ˜ 10 cm-3, which is much higher than the density obtained for inner parts. In contrast, we detected no significant X-ray flux from one of the TeV γ-ray peaks with an upper-limit flux of 2.1 × 10-14 erg cm-2 s-1 in the 2-10 keV band. The large flux ratio of TeV to X-ray, larger than 16, and the spatial coincidence of the molecular cloud and the TeV γ-ray emission site indicate that the TeV γ-ray of W 28 is π0-decay emission originating from collisions between accelerated protons and molecular cloud protons. Comparing the spectrum in the TeV band and the X-ray upper limit, we obtained a weak upper limit on the magnetic field strength B ≲ 1500 μG.

The XMM-Newton View of Stellar Coronae: High-Resolution X-Ray Spectroscopy of Capella

NASA Technical Reports Server (NTRS)

Audard, M.; Behar, E.; Guedel, M.; Raassen, A. J. J.; Porquet, D.; Mewe, R.; Foley, C. A.; Bromage, G. E.

2000-01-01

We present the high-resolution RGS spectrum of the bright stellar binary Capella observed by the XMM-Newton satellite. A multi-thermal approach has been applied to fit the data and derive elemental abundances. The differential emission measure distribution is reconstructed using a Chebychev polynomial fit. The DEM shape is found to display a sharp peak around 7 MK, consistent with previous EUVE and ASCA results. A small but significant amount of emission measure is required around 1.8 MK in order to explain the O VII He-like triplet and the C VI Ly(alpha) line. Using the sensitivity to temperature of dielectronic recombination lines from O VI around 22 A, we confirm that the cool plasma temperature needs to be higher than 1.2 MK. In the approximation of a cool plasma described by one temperature, we used line ratios from the forbidden, intercombination, and resonance lines of the O VII triplet and derived an average density for the cool coronal plasma at the low density limit. A tentative study of line ratios from the M XI triplet gives an average temperature close to the sharp peak in emission measure and an average density of the order of 10(exp 12)cu cm, three orders of magnitude higher than for O VII. Implications for the coronal physics of Capella are discussed. We complement this paper with a discussion of the importance of the atomic code uncertainties on the spectral fitting procedure.

The changing source of X-ray reflection in the radio-intermediate Seyfert 1 galaxy III Zw 2

NASA Astrophysics Data System (ADS)

Gonzalez, A. G.; Waddell, S. G. H.; Gallo, L. C.

2018-03-01

We report on X-ray observations of the radio-intermediate, X-ray bright Seyfert 1 galaxy, III Zw 2, obtained with XMM-Newton, Suzaku, and Swift over the past 17 yr. The source brightness varies significantly over yearly time-scales, but more modestly over periods of days. Pointed observations with XMM-Newton in 2000 and Suzaku in 2011 show spectral differences despite comparable X-ray fluxes. The Suzaku spectra are consistent with a power-law continuum and a narrow Gaussian emission feature at ˜6.4 keV, whereas the earlier XMM-Newton spectrum requires a broader Gaussian profile and soft-excess below ˜2 keV. A potential interpretation is that the primary power-law emission, perhaps from a jet base, preferentially illuminates the inner accretion disc in 2000, but the distant torus in 2011. The interpretation could be consistent with the hypothesized precessing radio jet in III Zw 2 that may have originated from disc instabilities due to an ongoing merging event.

XMM-NEWTON DETECTS A HOT GASEOUS HALO IN THE FASTEST ROTATING SPIRAL GALAXY UGC 12591

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

Dai Xinyu; Anderson, Michael E.; Bregman, Joel N.

2012-08-20

We present our XMM-Newton observation of the fastest rotating spiral galaxy UGC 12591. We detect hot gas halo emission out to 80 kpc from the galaxy center, and constrain the halo gas mass to be smaller than 4.5 Multiplication-Sign 10{sup 11} M{sub Sun }. We also measure the temperature of the hot gas as T = 0.64 {+-} 0.03 keV. Combining our x-ray constraints and the near-infrared and radio measurements in the literature, we find a baryon mass fraction of 0.03-0.05 in UGC 12591, suggesting a missing baryon mass of 70% compared with the cosmological mean value. Combined with anothermore » recent measurement in NGC 1961, the result strongly argues that the majority of missing baryons in spiral galaxies do not reside in their hot halos. We also find that UGC 12591 lies significantly below the baryonic Tully-Fisher relationship. Finally, we find that the baryon fractions of massive spiral galaxies are similar to those of galaxy groups with similar masses, indicating that the baryon loss is ultimately controlled by the gravitational potential well. The cooling radius of this gas halo is small, similar to NGC 1961, which argues that the majority of the stellar mass of this galaxy is not assembled as a result of cooling of this gas halo.« less

Groups and the Entropy Floor: XMM-Newton Observations of Two Groups

NASA Technical Reports Server (NTRS)

Mushotzky, R. F.; Figueroa-Feliciano, E.; Loewenstein, M.; Snowden, S. L.

2002-01-01

Using XMM-Newton spatially resolved X-ray imaging spectroscopy we obtain the temperature, density, entropy, gas mass, and total mass profiles for two groups of galaxies out to approximately 0.3 R(sub vir)(R(sub vir), the virial radius). Our density profiles agree well with those derived previously, and the temperature data are broadly consistent with previous results but are considerably more precise. Both of these groups are at the mass scale of 2x10(exp 13) M(solar mass), but have rather different properties. Both have considerably lower gas mass fractions at r < 0.3 R(sub vir), than the rich clusters. NGC2563, one of the least luminous groups for its X-ray temperature, has a very low gas mass fraction of approximately 0.004 inside 0.1 R(sub vir), which increases with radius. NGC4325, one of the most luminous groups at the same average temperature, has a higher gas mass fraction of 0.02. The entropy profiles and the absolute values of the entropy as a function of virial radius also differ, with NGC4325 having a value of approximately 100 keV cm(exp -2) and NGC2563 a value of approximately 300 keV cm(exp -2) at r approximately 0.1 R(sub vir). For both groups the profiles rise monotonically with radius and there is no sign of an entropy 'floor'. These results are inconsistent with pre-heating scenarios that have been developed to explain a possible entropy floor in groups, but are broadly consistent with models of structure formation that include the effects of heating and/or the cooling of the gas. The total entropy in these systems provides a strong constraint on all models of galaxy and group formation, and on the poorly defined feedback process that controls the transformation of gas into stars and thus the formation of structure in the universe.

A Multi-Epoch Timing and Spectral Study of the Ultraluminous X-Ray NGC 5408 X-1 with XMM-Newton

NASA Technical Reports Server (NTRS)

Dheeraj, Pasham; Strohmayer, Tod E.

2012-01-01

We present results of new XMM-Newton observations of the ultraluminous X-ray source (ULX) NGC 5408 X-1, one of the few ULXs to show quasi-periodic oscillations (QPOs). We detect QPOs in each of four new (approximately equal to 100 ks) pointings, expanding the range of frequencies observed from 10 to 40 mHz. We compare our results with the timing and spectral correlations seen in stellar-mass black hole systems, and find that the qualitative nature of the timing and spectral behavior of NGC 5408 X-1 is similar to systems in the steep power-law state exhibiting Type-C QPOs. However, in order for this analogy to quantitatively hold we must only be seeing the so-called saturated portion of the QPO frequency-photon index (or disk flux) relation. Assuming this to be the case, we place a lower limit on the mass of NGC 5408 X-1 of greater than or equal to 800 solar mass. Alternatively, the QPO frequency is largely independent of the spectral parameters, in which case a close analogy with the Type-C QPOs in stellar system is problematic. Measurement of the source's timing properties over a wider range of energy spectral index is needed to definitively resolve this ambiguity. We searched all the available data for both a broad Fe emission line as well as high-frequency QPO analogs (0.1- 1 Hz), but detected neither. We place upper limits on the equivalent width of any Fe emission feature in the 6-7 keV band and of the amplitude (rms) of a high-frequency QPO analog of approximately equal to 10 eV and approximately equal to 4%, respectively.

Study of the Many Fluorescent Lines and the Absorption Variability in GX 301-2 with XMM-Newton

NASA Technical Reports Server (NTRS)

Fuerst, F.; Suchy, S.; Kreykenbohm, I.; Barragan, L.; Wilms, J.; Pottschmidt, K.; Caballero, I.; Kretschmar, P.; Ferrigno, C.; Rothschild, R. E.

2011-01-01

We present an in-depth study of the High Mass X-ray Binary (HMXB) GX 301-2 during its pre-periastron flare using data from the XMM-Newton satellite. The energy spectrum shows a power law continuum absorbed by a large equivalent hydrogen column on the order of 10(exp 24)/ sq cm and a prominent Fe K-alpha fluorescent emission line. Besides the Fe K-alpha line, evidence for Fe K-Beta, Ni K-alpha, Ni K-Beta, S K-alpha, Ar K-alpha, Ca K-alpha, and Cr K-alpha fluorescent lines is found. The observed line strengths are consistent with fluorescence in a cold absorber. This is the first time that Cr K-alpha is seen in emission in the X-ray spectrum of a HMXB. In addition to the modulation by the strong pulse period of approx 685 sec the source is highly variable and shows different states of activity. We perform time-resolved as well as pulse-to-pulse resolved spectroscopy to investigate differences between these states of activity. We find that fluorescent line fluxes are strongly variable and generally follow the overall flux. The N-H value is variable by a factor of 2, but not correlated to continuum normalization. We find an interval of low flux in the light curve in which the pulsations cease almost completely, without any indication of an increasing absorption column. We investigate this dip in detail and argue that it is most likely that during the dip the accretion ceased and the afterglow of the fluorescent iron accounted for the main portion of the X-ray flux. A similar dip was found earlier in RXTE data, and we compare our findings to these results.

Cosmology with XMM galaxy clusters: the X-CLASS/GROND catalogue and photometric redshifts

NASA Astrophysics Data System (ADS)

Ridl, J.; Clerc, N.; Sadibekova, T.; Faccioli, L.; Pacaud, F.; Greiner, J.; Krühler, T.; Rau, A.; Salvato, M.; Menzel, M.-L.; Steinle, H.; Wiseman, P.; Nandra, K.; Sanders, J.

2017-06-01

The XMM Cluster Archive Super Survey (X-CLASS) is a serendipitously detected X-ray-selected sample of 845 galaxy clusters based on 2774 XMM archival observations and covering an approximately 90 deg2 spread across the high-Galactic latitude (|b| > 20°) sky. The primary goal of this survey is to produce a well-selected sample of galaxy clusters on which cosmological analyses can be performed. This paper presents the photometric redshift follow-up of a high signal-to-noise ratio subset of 265 of these clusters with declination δ < +20° with Gamma-Ray Burst Optical and Near-Infrared Detector (GROND), a 7-channel (grizJHK) simultaneous imager on the MPG 2.2-m telescope at the ESO La Silla Observatory. We use a newly developed technique based on the red sequence colour-redshift relation, enhanced with information coming from the X-ray detection to provide photometric redshifts for this sample. We determine photometric redshifts for 232 clusters, finding a median redshift of z = 0.39 with an accuracy of Δz = 0.02(1 + z) when compared to a sample of 76 spectroscopically confirmed clusters. We also compute X-ray luminosities for the entire sample and find a median bolometric luminosity of 7.2 × 1043 erg s-1 and a median temperature of 2.9 keV. We compare our results to those of the XMM-XCS and XMM-XXL surveys, finding good agreement in both samples. The X-CLASS catalogue is available online at http://xmm-lss.in2p3.fr:8080/l4sdb/.

Suzaku and XMM-Newton observations of the North Polar Spur: Charge exchange or ISM absorption?

NASA Astrophysics Data System (ADS)

Gu, Liyi; Mao, Junjie; Costantini, Elisa; Kaastra, Jelle

2016-10-01

By revisiting the Suzaku and XMM-Newton data of the North Polar Spur, we discovered that the spectra are inconsistent with the traditional model consisting of pure thermal emission and neutral absorption. The most prominent discrepancies are the enhanced O vii and Ne ix forbidden-to-resonance ratios, and a high O viii Lyβ line relative to other Lyman series. A collisionally ionized absorption model can naturally explain both features, while a charge exchange component can only account for the former. By including the additional ionized absorption, the plasma in the North Polar Spur can be described by a single-phase collisional ionization equilibrium (CIE) component with a temperature of 0.25 keV, and nitrogen, oxygen, neon, magnesium, and iron abundances of 0.4-0.8 solar. The abundance pattern of the North Polar Spur is well in line with those of the Galactic halo stars. The high nitrogen-to-oxygen ratio reported in previous studies can be migrated to the large transmission of the O viii Lyα line. The ionized absorber is characterized by a balance temperature of 0.17-0.20 keV and a column density of 3-5 × 1019 cm-2. Based on the derived abundances and absorption, we speculate that the North Polar Spur is a structure in the Galactic halo, so that the emission is mostly absorbed by the Galactic interstellar medium in the line of sight.

XMM flying beautifully

NASA Astrophysics Data System (ADS)

1999-12-01

the flux of cosmic particles and radiations was switched on. Mission controllers have now placed XMM in a quiescent mode for the Christmas and New Year period. Full operations will resume on 4 January with the start of the spacecraft commissioning phase due to last until 15 February. ESA's XMM Science Operations Centre at Villafranca will be brought online early January allowing the start of the exhaustive calibration and performance verification phase of XMM's science instruments. Progress on this calibration should allow the telescope to target and take "firstlight pictures" of its first X-ray sources next March.

UV, X-ray, and Optical Variability of the Young Star T Cha Produced by Inner Disk Obscuration: Results from a Coordinated HST, XMM-Newton, LCOGT, and SMARTS Observing Campaign

NASA Astrophysics Data System (ADS)

Brown, Alexander; France, Kevin; Walter, Frederick M.; Schneider, P. Christian; Brown, Timothy M.; Andrews, Sean M.; Wilner, David J.

2018-06-01

The young (7 Myr) 1.5 solar mass T Tauri star T Chamaeleontis shows dramatic variability. The optical extinction varies by at least 3 magnitudes on few hour time-scales with no obvious periodicity. The obscuration is produced by material at the inner edge of the circumstellar disk and therefore characterizing the absorbing material can reveal important clues regarding the transport of gas and dust within such disks. The inner disk of T Cha is particularly interesting, because T Cha has a transitional disk with a large gap at 0.2-15 AU in the dust disk and allows study of the gas and dust structure in the terrestrial planet formation zone during this important rapid phase of protoplanetary disk evolution. For this reason we have conducted a major multi-spectral-region observing campaign to study the UV/X-ray/optical variability of T Cha. During 2018 February/March we monitored the optical photometric and spectral variability using LCOGT (Chile/South Africa/Australia) and the SMARTS telescopes in Chile. These optical data provide a broad context within which to interpret our shorter UV and X-ray observations. We observed T Cha during 3 coordinated observations (each 5 HST orbits + 25 ksec XMM; on 2018 Feb 22, Feb 26, Mar 2) using the HST COS/STIS spectrographs to measure the FUV/NUV spectra and XMM-Newton to measure the corresponding X-ray energy distribution. The observed spectral changes are well correlated and demonstrate the influence of the same absorbing material in all the spectral regions observed. By examining which spectral features change and by how much we can determine the location of different emitting regions relative to the absorbers along the line-of-sight to the star. In this poster we provide an overview of the variability seen in the different spectral regions and quantify the dust and gas content of T Cha's inner disk edge.(This work is supported by grant HST-GO-15128 and time awarded by HST, XMM-Newton, LCOGT, and SMARTS. We acknowledge the

Discovery of Periodic Dips in the Brightest Hard X-Ray Source of M31 with EXTraS

NASA Astrophysics Data System (ADS)

Marelli, Martino; Tiengo, Andrea; De Luca, Andrea; Salvetti, David; Saronni, Luca; Sidoli, Lara; Paizis, Adamantia; Salvaterra, Ruben; Belfiore, Andrea; Israel, Gianluca; Haberl, Frank; D’Agostino, Daniele

2017-12-01

We performed a search for eclipsing and dipping sources in the archive of the EXTraS project—a systematic characterization of the temporal behavior of XMM-Newton point sources. We discovered dips in the X-ray light curve of 3XMM J004232.1+411314, which has been recently associated with the hard X-ray source dominating the emission of M31. A systematic analysis of XMM-Newton observations revealed 13 dips in 40 observations (total exposure time of ∼0.8 Ms). Among them, four observations show two dips, separated by ∼4.01 hr. Dip depths and durations are variable. The dips occur only during low-luminosity states ({L}0.2{--12}< 1× {10}38 erg s‑1), while the source reaches {L}0.2{--12}∼ 2.8× {10}38 erg s‑1. We propose that this system is a new dipping low-mass X-ray binary in M31 seen at high inclination (60°–80°) the observed dipping periodicity is the orbital period of the system. A blue HST source within the Chandra error circle is the most likely optical counterpart of the accretion disk. The high luminosity of the system makes it the most luminous (not ULX) dipper known to date.

Applications for edge detection techniques using Chandra and XMM-Newton data: galaxy clusters and beyond

NASA Astrophysics Data System (ADS)

Walker, S. A.; Sanders, J. S.; Fabian, A. C.

2016-09-01

The unrivalled spatial resolution of the Chandra X-ray observatory has allowed many breakthroughs to be made in high-energy astrophysics. Here we explore applications of Gaussian gradient magnitude (GGM) filtering to X-ray data, which dramatically improves the clarity of surface brightness edges in X-ray observations, and maps gradients in X-ray surface brightness over a range of spatial scales. In galaxy clusters, we find that this method is able to reveal remarkable substructure behind the cold fronts in Abell 2142 and Abell 496, possibly the result of Kelvin-Helmholtz instabilities. In Abell 2319 and Abell 3667, we demonstrate that the GGM filter can provide a straightforward way of mapping variations in the widths and jump ratios along the lengths of cold fronts. We present results from our ongoing programme of analysing the Chandra and XMM-Newton archives with the GGM filter. In the Perseus cluster, we identify a previously unseen edge around 850 kpc from the core to the east, lying outside a known large-scale cold front, which is possibly a bow shock. In MKW 3s we find an unusual `V' shape surface brightness enhancement starting at the cluster core, which may be linked to the AGN jet. In the Crab nebula a new, moving feature in the outer part of the torus is identified which moves across the plane of the sky at a speed of ˜0.1c, and lies much further from the central pulsar than the previous motions seen by Chandra.

XMM-Newton observations of the supernova remnant IC 443. II. Evidence of stellar ejecta in the inner regions

NASA Astrophysics Data System (ADS)

Troja, E.; Bocchino, F.; Miceli, M.; Reale, F.

2008-07-01

Aims: We investigate the spatial distribution of the physical and chemical properties of the hot X-ray emitting plasma of the supernova remnant IC 443, to derive important constraints on its ionization stage, on the progenitor supernova explosion, on the age of the remnant, and its physical association with a close pulsar wind nebula. Methods: We present XMM-Newton images of IC 443, a median photon energy map, silicon and sulfur equivalent width maps, and a spatially resolved spectral analysis of a set of homogeneous regions. Results: The hard X-ray thermal emission (1.4-5.0 keV) of IC 443 displays a centrally-peaked morphology, its brightness peaks being associated with hot (kT > 1 keV) X-ray emitting plasma. A ring-shaped structure, characterized by high values of equivalent widths and median photon energy, encloses the PWN. Its hard X-ray emission is spectrally characterized by a collisional ionization equilibrium model, and strong emission lines of Mg, Si, and S, requiring oversolar metal abundances. Dynamically, the location of the ejecta ring suggests an SNR age of ~4000 yr. The presence of overionized plasma in the inner regions of IC 443, addressed in previous works, is much less evident in our observations.

Optical, Near-IR, and X-Ray Observations of SN 2015J and Its Host Galaxy

NASA Astrophysics Data System (ADS)

Nucita, A. A.; De Paolis, F.; Saxton, R.; Testa, V.; Strafella, F.; Read, A.; Licchelli, D.; Ingrosso, G.; Convenga, F.; Boutsia, K.

2017-12-01

SN 2015J was discovered on 2015 April 27th and is classified as an SN IIn. At first, it appeared to be an orphan SN candidate, I.e., without any clear identification of its host galaxy. Here, we present an analysis of the observations carried out by the VLT 8 m class telescope with the FORS2 camera in the R band and the Magellan telescope (6.5 m) equipped with the IMACS Short-Camera (V and I filters) and the FourStar camera (Ks filter). We show that SN 2015J resides in what appears to be a very compact galaxy, establishing a relation between the SN event and its natural host. We also present and discuss archival and new X-ray data centered on SN 2015J. At the time of the supernova explosion, Swift/XRT observations were made and a weak X-ray source was detected at the location of SN 2015J. Almost one year later, the same source was unambiguously identified during serendipitous observations by Swift/XRT and XMM-Newton, clearly showing an enhancement of the 0.3-10 keV band flux by a factor ≃ 30 with respect to the initial state. Swift/XRT observations show that the source is still active in the X-rays at a level of ≃ 0.05 counts s-1. The unabsorbed X-ray luminosity derived from the XMM-Newton slew and SWIFT observations, {L}x≃ 5× {10}41 erg s-1, places SN 2015J among the brightest young supernovae in X-rays. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA, with ESO Telescopes at the La Silla-Paranal Observatory under program ID 298.D-5016(A), and with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile. We also acknowledge the use of public data from the Swift data archive.

Serendipitous EUV sources detected during the first year of the Extreme Ultraviolet Explorer right angle program

NASA Technical Reports Server (NTRS)

Mcdonald, K.; Craig, N.; Sirk, M. M.; Drake, J. J.; Fruscione, A.; Vallerga, J. V.; Malina, R. F.

1994-01-01

We report the detection of 114 extreme ultraviolet (EUV; 58 - 740 A) sources, of which 99 are new serendipitous sources, based on observations made with the imaging telescopes on board the Extreme Ultraviolet Explorer (EUVE) during the Right Angle Program (RAP). These data were obtained using the survey scanners and the Deep Survey instrument during the first year of the spectroscopic guest observer phase of the mission, from January 1993 to January 1994. The data set consists of 162 discrete pointings whose exposure times are typically two orders of magnitude longer than the average exposure times during the EUVE all-sky survey. Based on these results, we can expect that EUVE will serendipitously detect approximately 100 new EUV sources per year, or about one new EUV source per 10 sq deg, during the guest observer phase of the EUVE mission. New EUVE sources of note include one B star and three extragalactic objects. The B star (HR 2875, EUVE J0729 - 38.7) is detected in both the Lexan/B (approximately 100 A) and Al/Ti/C (approximately 200 A) bandpasses, and the detection is shown not to be a result of UV leaks. We suggest that we are detecting EUV and/or soft x rays from a companion to the B star. Three sources, EUVE J2132+10.1, EUVE J2343-14.9, and EUVE J2359-30.6 are identified as the active galactic nuclei MKN 1513, MS2340.9-1511, and 1H2354-315, respectively.

3XMM J181923.7-170616: An X-Ray Binary with a 408 s Pulsar

NASA Astrophysics Data System (ADS)

Qiu, Hao; Zhou, Ping; Yu, Wenfei; Li, Xiangdong; Xu, Xiaojie

2017-09-01

We carry out a dedicated study of 3XMM J181923.7-170616 with an approximate pulsation period of 400 s using the XMM-Newton and Swift observations spanning across nine years. We have refined the period of the source to 407.904(7) s (at epoch MJD 57142) and constrained the 1σ upper limit on the period derivative \\dot{P}≤slant 1.1× {10}-8 {{s}} {{{s}}}-1. The source radiates hard, persistent X-ray emission during the observation epochs, which is best described by an absorbed power-law model (Γ ˜ 0.2-0.8) plus faint Fe lines at 6.4 and 6.7 keV. The X-ray flux revealed a variation within a factor of 2, along with a spectral hardening as the flux increased. The pulse shape is sinusoid-like and the spectral properties of different phases do not present significant variation. The absorption {N}{{H}} (˜ 1.3× {10}22 {{cm}}-2) is similar to the total Galactic hydrogen column density along the direction, indicating that it is a distant source. A search for the counterpart in optical and near-infrared surveys reveals a low-mass K-type giant, while the existence of a Galactic OB supergiant is excluded. A symbiotic X-ray binary (SyXB) is the favored nature of 3XMM J181923.7-170616 and can essentially explain the low luminosity of 2.78× {10}34{d}102 {erg} {{{s}}}-1, slow pulsation, hard X-ray spectrum, and possible K3 III companion. An alternative explanation of the source is a persistent Be X-ray binary (BeXB) with a companion star no earlier than B3-type.

Fifteen years in the high-energy life of the solar-type star HD 81809. XMM-Newton observations of a stellar activity cycle

NASA Astrophysics Data System (ADS)

Orlando, S.; Favata, F.; Micela, G.; Sciortino, S.; Maggio, A.; Schmitt, J. H. M. M.; Robrade, J.; Mittag, M.

2017-09-01

Context. The modulation of the activity level of solar-like stars is commonly revealed by cyclic variations in their chromospheric indicators, such as the Ca II H&K S-index, similarly to what is observed in our Sun. However, while the variation of solar activity is also reflected in the cyclical modulation of its coronal X-ray emission, similar behavior has only been discovered in a few stars other than the Sun. Aims: The data set of the long-term XMM-Newton monitoring program of HD 81809 is analyzed to study its X-ray cycle, investigate if the latter is related to the chromospheric cycle, infer the structure of the corona of HD 81809, and explore if the coronal activity of HD 81809 can be ascribed to phenomena similar to solar activity and, therefore, considered an extension of the solar case. Methods: We analyzed the observations of HD 81809 performed with XMM-Newton with a regular cadence of six months from 2001 to 2016, which represents one of the longest available observational baseline ( 15 yr) for a solar-like star with a well-studied chromospheric cycle (with a period of 8 yr). We investigated the modulation of coronal luminosity and temperature and its relation with the chromospheric cycle. We interpreted the data in terms of a mixture of solar-like coronal regions, adopting a method originally proposed to study the Sun as an X-ray star. Results: The observations show a well-defined regular cyclic modulation of the X-ray luminosity that reflects the activity level of HD 81809. The data covers approximately two cycles of coronal activity; the modulation has an amplitude of a factor of 5 (excluding evident flares, as in the June 2002 observation) and a period of 7.3 ± 1.5 yr, which is consistent with that of the chromospheric cycle. We demonstrate that the corona of HD 81809 can be interpreted as an extension of the solar case and can be modeled with a mixture of solar-like coronal regions along the whole cycle. The activity level is mainly determined by

XMM-Newton observation of the supernova remnant Kes 78 (G32.8-0.1): Evidence of shock-cloud interaction

NASA Astrophysics Data System (ADS)

Miceli, M.; Bamba, A.; Orlando, S.; Zhou, P.; Safi-Harb, S.; Chen, Y.; Bocchino, F.

2017-03-01

Context. The Galactic supernova remnant Kes 78 is surrounded by dense molecular clouds, whose projected position overlaps with the extended HESS γ-ray source HESS J1852-000. The X-ray emission from the remnant has recently been revealed by Suzaku observations, which have shown indications for a hard X-ray component in the spectra that might be associated with synchrotron radiation. Aims: We describe the spatial distribution of the physical properties of the X-ray emitting plasma and reveal the effects of the interaction of the remnant with the inhomogeneous ambient medium. We also investigate the origin of the γ-ray emission, which may be inverse-Compton radiation associated with X-ray synchrotron-emitting electrons or hadronic emission originating from the impact of high-energy protons on the nearby clouds. Methods: We analyzed an XMM-Newton EPIC observation of Kes 78 by performing image analysis and spatially resolved spectral analysis on a set of three regions. We tested our findings against the observations of the 12CO and 13CO emission in the environment of the remnant. Results: We reveal the complex X-ray morphology of Kes 78 and find variations in the spectral properties of the plasma, with significantly denser and cooler material at the eastern edge of the remnant, which we interpret as a signature of interaction with a molecular cloud. We also exclude that narrow filaments emit the X-ray synchrotron radiation. Conclusions: Assuming that the very high energy γ-ray emission is associated with Kes 78, the lack of synchrotron emission rules out a leptonic origin. A hadronic origin is further supported by evidence of interaction of the remnant with a dense molecular cloud in its eastern limb.

Joint XMM-Newton and Chandra observations of the NGC 1407/1400 complex: A tail of an early-type galaxy and a tale of a nearby merging group

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

Su, Yuanyuan; Gu, Liyi; White III, Raymond E.

2014-05-10

The nearby group centered on its bright central galaxy NGC 1407 has been suggested by previous kinematic studies to be an unusually dark system. It is also known for hosting a bright galaxy, NGC 1400, with a large radial velocity (1200 km s{sup –1}) with respect to the group center. Previous ROSAT X-ray observations revealed an extended region of enhanced surface brightness just eastward of NGC 1400. We investigate the NGC 1407/1400 complex with XMM-Newton and Chandra observations. We find that the temperature and metallicity of the enhanced region are different (cooler and more metal rich) than those of themore » surrounding group gas but are consistent with those of the interstellar medium (ISM) in NGC 1400. The relative velocity of NGC 1400 is large enough that much of its ISM could have been ram pressure stripped while plunging through the group atmosphere. We conclude that the enhanced region is likely to be hot gas stripped from the ISM of NGC 1400. We constrain the motion of NGC 1400 using the pressure jump at its associated stagnation front and the total mass profile of the NGC 1407 group. We conclude that NGC 1400 is moving within ∼30° of the line of sight with Mach number M≲3. We do not detect any obvious shock features in this complex, perhaps because of the high line-of-sight motion of NGC 1400. With an XMM-Newton pointing on the relatively relaxed eastern side of NGC 1407, we derive a hydrostatic mass for this group of ∼1 × 10{sup 13} M {sub ☉} within 100 kpc. The total mass extrapolated to the virial radius (681 kpc) is 3.8 × 10{sup 13} M {sub ☉}, which puts an upper limit of ∼300 M{sub ⊙}/L{sub B{sub ⊙}} on the mass-to-light ratio of this group. This suggests that the NGC 1407 group is not an unusually dark group.« less

NR TrA (Nova TrA 2008) monitoring in support of XMM observations

NASA Astrophysics Data System (ADS)

Waagen, Elizabeth O.

2017-03-01

Dr. Fred Walter (Stony Brook University) has requested AAVSO observers' assistance in monitoring NR TrA (Nova TrA 2008) in support of upcoming XMM Newton observations. The XMM observations will take place 2017 March 13 06:21 through March 14 10:34 UT. Walter writes: "NR TrA (Nova TrA 2008) is a compact eclipsing system with a 5.5 hour period. It was a normal Fe II nova that, upon reaching quiescence, took on the appearance of a super-soft source in the optical high state, which suggests an extremely high mass accretion rate. The optical spectrum is dominated by hot permitted lines of O VI, N V, C IV, and He II. Some nova-like variables have similar spectra, though generally without the hot emission lines. Primary eclipse is broad - nearly 40% of the orbit - and deeper at shorter wavelengths, which suggests the eclipse of a hot accretion disk. Primary eclipse depth is about 1 mag at V. There appears to be a shallow secondary eclipse.The primary aim [of the XMM observations] is to detect and characterize the eclipse at X-ray and UV wavelengths. We will obtain low cadence BVRI/JHK observations with SMARTS/Andicam. We request AAVSO support to obtain continuous photometric time series simultaneous with the XMM observation. Any filters are acceptable, but standard Johnson B, V or Cousins R, I are preferred. Clear filters are acceptable. Time resolution better than 5 minutes and uncertainties (outside of eclipse) <0.02 mag are preferred. The best ephemeris I have is: minimum light at JD 55956.822 + 0.219109E. This is based on data from 2013-2015." Finder charts with sequence may be created using the AAVSO Variable Star Plotter (https://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details.

The evolution of the X-ray afterglow emission of GW 170817/ GRB 170817A in XMM-Newton observations

NASA Astrophysics Data System (ADS)

D'Avanzo, P.; Campana, S.; Salafia, O. S.; Ghirlanda, G.; Ghisellini, G.; Melandri, A.; Bernardini, M. G.; Branchesi, M.; Chassande-Mottin, E.; Covino, S.; D'Elia, V.; Nava, L.; Salvaterra, R.; Tagliaferri, G.; Vergani, S. D.

2018-05-01

We report our observation of the short gamma-ray burst (GRB) GRB 170817A, associated to the binary neutron star merger gravitational wave (GW) event GW 170817, performed in the X-ray band with XMM-Newton 135 d after the event (on 29 December, 2017). We find evidence for a flattening of the X-ray light curve with respect to the previously observed brightening. This is also supported by a nearly simultaneous optical Hubble Space Telescope observation and successive X-ray Chandra and low-frequency radio observations recently reported in the literature. Since the optical-to-X-ray spectral slope did not change with respect to previous observations, we exclude that the change in the temporal evolution of the light curve is due to the passage of the cooling frequency: its origin must be geometric or dynamical. We interpret all the existing afterglow data with two models: i) a structured jet and ii) a jet-less isotropic fireball with some stratification in its radial velocity structure. Both models fit the data and predict that the radio flux must decrease simultaneously with the optical and X-ray emission, making it difficult to distinguish between them at the present stage. Polarimetric measurements and the rate of short GRB-GW associations in future LIGO/Virgo runs will be key to disentangle these two geometrically different scenarios.

An XMM-Newton and NuSTAR Study of IGR J18214-1318: A Non-pulsating High-mass X-Ray Binary with a Neutron Star

NASA Astrophysics Data System (ADS)

Fornasini, Francesca M.; Tomsick, John A.; Bachetti, Matteo; Krivonos, Roman A.; Fürst, Felix; Natalucci, Lorenzo; Pottschmidt, Katja; Wilms, Jörn

2017-05-01

IGR J18214-1318, a Galactic source discovered by the International Gamma-Ray Astrophysics Laboratory, is a high-mass X-ray binary (HMXB) with a supergiant O-type stellar donor. We report on the XMM-Newton and NuSTAR observations that were undertaken to determine the nature of the compact object in this system. This source exhibits high levels of aperiodic variability, but no periodic pulsations are detected with a 90% confidence upper limit of 2% fractional rms between 0.00003-88 Hz, a frequency range that includes the typical pulse periods of neutron stars (NSs) in HMXBs (0.1-103 s). Although the lack of pulsations prevents us from definitively identifying the compact object in IGR J18214-1318, the presence of an exponential cutoff with e-folding energy ≲ 30 {keV} in its 0.3-79 keV spectrum strongly suggests that the compact object is an NS. The X-ray spectrum also shows a Fe Kα emission line and a soft excess, which can be accounted for by either a partial-covering absorber with {N}{{H}}≈ {10}23 cm-2, which could be due to the inhomogeneous supergiant wind, or a blackbody component with {kT}={1.74}-0.05+0.04 keV and {R}{BB}≈ 0.3 km, which may originate from NS hot spots. Although neither explanation for the soft excess can be excluded, the former is more consistent with the properties observed in other supergiant HMXBs. We compare IGR J18214-1318 to other HMXBs that lack pulsations or have long pulsation periods beyond the range covered by our observations.

The XMM-Newton Wide Angle Survey (XWAS): the X-ray spectrum of type-1 AGN

NASA Astrophysics Data System (ADS)

Mateos, S.; Carrera, F. J.; Page, M. J.; Watson, M. G.; Corral, A.; Tedds, J. A.; Ebrero, J.; Krumpe, M.; Schwope, A.; Ceballos, M. T.

2010-02-01

Aims: We discuss the broad band X-ray properties of one of the largest samples of X-ray selected type-1 AGN to date (487 objects in total), drawn from the XMM-Newton Wide Angle Survey (XWAS). The objects presented in this work cover 2-10 keV (rest-frame) luminosities from 1042-1045 erg s-1 and are detected up to redshift 4. We constrain the overall properties of the broad band continuum, soft excess and X-ray absorption, along with their dependence on the X-ray luminosity and redshift. We discuss the implications for models of AGN emission. Methods: We fitted the observed 0.2-12 keV broad band spectra with various models to search for X-ray absorption and soft excess. The F-test was used with a significance threshold of 99% to statistically accept the detection of additional spectral components. Results: We constrained the mean spectral index of the broad band X-ray continuum to <Γ> = 1.96 ± 0.02 with intrinsic dispersion {σ< Γ >} = 0.27-0.02+0.01. The continuum becomes harder at faint fluxes and at higher redshifts and hard (2-10 keV) luminosities. The dependence of Γ with flux is likely due to undetected absorption rather than to spectral variation. We found a strong dependence of the detection efficiency of objects on the spectral shape. We expect this effect to have an impact on the measured mean continuum shapes of sources at different redshifts and luminosities. We detected excess absorption in ⪆3% of our objects, with rest-frame column densities a few ×1022 cm-2. The apparent mismatch between the optical classification and X-ray properties of these objects is a challenge for the standard orientation-based AGN unification model. We found that the fraction of objects with detected soft excess is 36%. Using a thermal model, we constrained the soft excess mean rest-frame temperature and intrinsic dispersion to kT 100 eV and σkT 34 eV. The origin of the soft excess as thermal emission from the accretion disk or Compton scattered disk emission is ruled

ESA unveils its big XMM spacecraft

NASA Astrophysics Data System (ADS)

1998-02-01

XMM, the X-ray Multi-Mirror mission, is due do be lanched in 1999. It is a European conception with innovative telescopes. XMM will revolutionize the study of X-rays coming from the Universe, by harvesting far more X-rays per hour than any previous mission. Its enormous capacity will enable astronomers to analyse many strong sources of cosmic X-rays very quickly, and to discover and characterize many faint sources previously beyond their reach. As the most popular and competitive branch of space astronomy, X-ray astronomy reveals special places in the Universe where very high temperatures or violent forces generate energetic radiation. These sources include black holes, exploding stars, paris of stars orbiting very close together, and the central region of clusters of galaxies. XMM's optical monitor, viewing the scenes by visible light, will help in the interpretations. The combination of X-ray telescopes and optical monitoring should be well-suited to tracking down gamma-ray bursters - extraordinary explosions in space that mystify the astronomers. Full descriptions of the X-ray sources will depend on precise spectral analysis of the relative intensities of X-rays of different energies, including the signatures of identifiable chemical elements. Such spectral analysis is XMM's task, using instruments of the highest quality fed by the remarkable telescopes. As seen at ESTEC today, the spacecraft stands upside down. Its front end, where the mirror modules of the X-ray telescopes pass through the satellite's service module, is closest to the ground. At the top is the section containing detectors at the focus of the X-ray telescopes. Surmounting the assembly, a pair of cones will carry heat away from the detectors. XMM's appearance is, though, dominated by the long tube that spans the telescope's focal length, and by the black thermal blanket that will protect the spacecraft from unequal heating on the sunny and shaded sides. A miracle of telescope engineering « You

CAVITIES AND SHOCKS IN THE GALAXY GROUP HCG 62 AS REVEALED BY CHANDRA, XMM-NEWTON, AND GIANT METREWAVE RADIO TELESCOPE DATA

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

Gitti, Myriam; O'Sullivan, Ewan; Giacintucci, Simona

2010-05-01

We report on the results of an analysis of Chandra, XMM-Newton, and new Giant Metrewave Radio Telescope (GMRT) data of the X-ray bright compact group of galaxies HCG 62, which is one of the few groups known to possess clear, small X-ray cavities in the inner regions. This is part of an ongoing X-ray/low-frequency radio study of 18 groups, initially chosen for the availability of good-quality X-ray data and evidence for active galactic nucleus/hot gas interaction. At higher frequency (1.4 GHz), the HCG 62 cavity system shows minimal if any radio emission, but the new GMRT observations at 235 MHzmore » and 610 MHz clearly detect extended low-frequency emission from radio lobes corresponding to the cavities. By means of the synergy of X-ray and low-frequency radio observations, we compare and discuss the morphology, luminosity, and pressure of the gas and of the radio source. We find that the radio source is radiatively inefficient, with a ratio of radio luminosity to mechanical cavity power of {approx}10{sup -4}, and that the radio pressure of the lobes is about 1 order of magnitude lower than the X-ray pressure of the surrounding thermal gas. Thanks to the high spatial resolution of the Chandra surface brightness and temperature profiles, we also identify a shock front located at 36 kpc to the southwest of the group center, close to the southern radio lobe, with a Mach number {approx}1.5 and a total power which is about 1 order of magnitude higher than the cavity power. Such a shock may have heated the gas in the southern region, as indicated by the temperature map. The shock may also explain the arc-like region of enriched gas seen in the iron abundance map, as this may be produced by a non-Maxwellian electron distribution near its front.« less

The AGN activity in a sample of IR Luminous Major Mergers

NASA Astrophysics Data System (ADS)

Loiseau, N.; de Rosa, A.; Bianchi, S.; Bogdanovich, T.

2017-10-01

As part of our study of the nuclear activity in a sample of 70 IR luminous major mergers we obtained XMM-Newton data of 4 more pairs of these galaxies. This is part of our multiwavelength study of the nuclear activity in mergers and groups of galaxies (MAGNA collaboration). Our purpose is to understand in which cases one or both of the galaxies of the major merger would have a massive black hole, and if the interaction stage, or the mass/type of the galaxies have role in the enhanced AGN and/or Starburst activity. X-rays can be the best tool to detect hidden AGN. At present very few mergers of AGN simultaneously active have been detected, most of them serendipitously. We present here the X-ray data of these 4 pairs, which have been selected using their WISE colors as a diagnostic tool. We compare the results for these 8 galaxies with the data of the 33 merging galaxies of this sample previously detected with XMM-Newton or Chandra.

An XMM-Newton Study of the Mixed-morphology Supernova Remnant W28 (G6.4-0.1)

NASA Astrophysics Data System (ADS)

Zhou, Ping; Safi-Harb, Samar; Chen, Yang; Zhang, Xiao; Jiang, Bing; Ferrand, Gilles

2014-08-01

We have performed an XMM-Newton imaging and spectroscopic study of supernova remnant (SNR) W28, a prototype mixed-morphology or thermal composite SNR believed to be interacting with a molecular cloud. The observed hot X-ray emitting plasma is characterized by low metal abundances, showing no evidence of ejecta. The X-rays arising from the deformed northeastern shell consist of a thermal component with a temperature of ~0.3 keV plus a hard component of either thermal (temperature ~0.6 keV) or non-thermal (photon index = 0.9-2.4) origin. The X-ray emission in the SNR interior is blobby and the corresponding spectra are best described as the emission from a cold (~0.4 keV) plasma in non-equilibrium ionization with an ionization timescale of ~4.3 × 1011 cm-3 s plus a hot (~0.8 keV) gas in collisional ionization equilibrium. Applying the two-temperature model to the smaller central regions, we find non-uniform interstellar absorption, temperature, and density distribution, which indicates that the remnant is evolving in a non-uniform environment with denser material in the east and north. The cloudlet evaporation mechanism can essentially explain the properties of the X-ray emission in the center, and thermal conduction may also play a role for length scales comparable to the remnant radius. A recombining plasma model with an electron temperature of ~0.6 keV is also feasible for describing the hot central gas with the recombination age of the gas estimated at ~2.9 × 104 yr.

The HELLAS2XMM survey. XI. Unveiling the nature of X-ray bright optically normal galaxies

NASA Astrophysics Data System (ADS)

Civano, F.; Mignoli, M.; Comastri, A.; Vignali, C.; Fiore, F.; Pozzetti, L.; Brusa, M.; La Franca, F.; Matt, G.; Puccetti, S.; Cocchia, F.

2007-12-01

Aims:X-ray bright optically normal galaxies (XBONGs) constitute a small but significant fraction of hard X-ray selected sources in recent Chandra and XMM-Newton surveys. Even though several possibilities were proposed to explain why a relatively luminous hard X-ray source does not leave any significant signature of its presence in terms of optical emission lines, the nature of XBONGs is still subject of debate. We aim to better understand their nature by means of a multiwavelength and morphological analysis of a small sample of these sources. Methods: Good-quality photometric near-infrared data (ISAAC/VLT) of four low-redshift (z = 0.1{-}0.3) XBONGs, selected from the HELLAS2XMM survey, have been used to search for the presence of the putative nucleus, applying the surface-brightness decomposition technique through the least-squares fitting program GALFIT. Results: The surface brightness decomposition allows us to reveal a nuclear point-like source, likely to be responsible for the X-ray emission, in two out of the four sources. The results indicate that moderate amounts of gas and dust, covering a large solid angle (possibly 4π) at the nuclear source, combined with the low nuclear activity, may explain the lack of optical emission lines. The third XBONG is associated with an X-ray extended source and no nuclear excess is detected in the near infrared at the limits of our observations. The last source is associated to a close (d≤ 1 arcsec) double system and the fitting procedure cannot achieve a firm conclusion. Based on observations made at the European Southern Observatory, Paranal, Chile (ESO Programme ID 69.A-0554).

The Swift-XRT imaging Performances and Serendipitous Survey

NASA Technical Reports Server (NTRS)

Moretti, A.; Perri, M.; Capalbi, M.; Abbey, A.F.; Angelini, L.; Beardmore, A.; Burrows, D.N.; Campana, S.; Chincaini, G.; Citterio, O.;

NuSTAR view of the central region of M31

NASA Astrophysics Data System (ADS)

Stiele, H.; Kong, A. K. H.

2018-04-01

Our neighbouring large spiral galaxy, the Andromeda galaxy (M31 or NGC 224), is an ideal target to study the X-ray source population of a nearby galaxy. NuSTAR observed the central region of M31 in 2015 and allows studying the population of X-ray point sources at energies higher than 10 keV. Based on the source catalogue of the large XMM-Newton survey of M31, we identified counterparts to the XMM-Newton sources in the NuSTAR data. The NuSTAR data only contain sources of a brightness comparable (or even brighter) than the selected sources that have been detected in XMM-Newton data. We investigate hardness ratios, spectra, and long-term light curves of individual sources obtained from NuSTAR data. Based on our spectral studies, we suggest four sources as possible X-ray binary candidates. The long-term light curves of seven sources that have been observed more than once show low (but significant) variability.

Evidence of Black Hole Spin in GX 339-4: XMM-Newton/EPIC-pn and RXTE Spectroscopy of the Very High State

NASA Astrophysics Data System (ADS)

Miller, J. M.; Fabian, A. C.; Reynolds, C. S.; Nowak, M. A.; Homan, J.; Freyberg, M. J.; Ehle, M.; Belloni, T.; Wijnands, R.; van der Klis, M.; Charles, P. A.; Lewin, W. H. G.

2004-05-01

We have analyzed spectra of the Galactic black hole GX 339-4 obtained through simultaneous 76 ks XMM-Newton/EPIC-pn and 10 ks Rossi X-Ray Timing Explorer observations during a bright phase of its 2002-2003 outburst. An extremely skewed, relativistic Fe Kα emission line and ionized disk reflection spectrum are revealed in these spectra. Self-consistent models for the Fe Kα emission-line profile and disk reflection spectrum rule out an inner disk radius compatible with a Schwarzschild black hole at more than the 8 σ level of confidence. The best-fit inner disk radius of (2-3)rg suggests that GX 339-4 harbors a black hole with a>=0.8-0.9 (where rg=GM/c2 and a=cJ/GM2, and assuming that reflection in the plunging region is relatively small). This confirms indications for black hole spin based on a Chandra spectrum obtained later in the outburst. The emission line and reflection spectrum also rule out a standard power-law disk emissivity in GX 339-4 a broken power-law form with enhanced emissivity inside ~6rg gives improved fits at more than the 8 σ level of confidence. The extreme red wing of the line and the steep emissivity require a centrally concentrated source of hard X-rays that can strongly illuminate the inner disk. Hard X-ray emission from the base of a jet-enhanced by gravitational light-bending effects-could create the concentrated hard X-ray emission; this process may be related to magnetic connections between the black hole and the inner disk. We discuss these results within the context of recent results from analyses of XTE J1650-500 and MCG -6-30-15, and of models for the inner accretion flow environment around black holes.

45 CFR 674.7 - Exception for serendipitous finds.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 3 2011-10-01 2011-10-01 false Exception for serendipitous finds. 674.7 Section 674.7 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION ANTARCTIC METEORITES § 674.7 Exception for serendipitous finds. A person who makes a serendipitous discovery...

A combined HST and XMM-Newton campaign for the magnetic O9.7 V star HD 54879. Constraining the weak-wind problem of massive stars

NASA Astrophysics Data System (ADS)

Shenar, T.; Oskinova, L. M.; Järvinen, S. P.; Luckas, P.; Hainich, R.; Todt, H.; Hubrig, S.; Sander, A. A. C.; Ilyin, I.; Hamann, W.-R.

2017-10-01

Context. HD 54879 (O9.7 V) is one of a dozen O-stars for which an organized atmospheric magnetic field has been detected. Despite their importance, little is known about the winds and evolution of magnetized massive stars. Aims: To gain insights into the interplay between atmospheres, winds, and magnetic fields of massive stars, we acquired UV and X-ray data of HD 54879 using the Hubble Space Telescope and the XMM-Newton satellite. In addition, 35 optical amateur spectra were secured to study the variability of HD 54879. Methods: A multiwavelength (X-ray to optical) spectral analysis is performed using the Potsdam Wolf-Rayet (PoWR) model atmosphere code and the xspec software. Results: The photospheric parameters (T∗ = 30.5 kK, log g = 4.0 [cm s-2], log L = 4.45 [L⊙]) are typical for an O9.7 V star. The microturbulent, macroturbulent, and projected rotational velocities are lower than previously suggested (ξph,vmac,vsini ≤ 4 km s-1). An initial mass of 16 M⊙ and an age of 5 Myr are inferred from evolutionary tracks. We derive a mean X-ray emitting temperature of log TX = 6.7 [K] and an X-ray luminosity of LX = 1 × 1032 erg s-1. Short- and long-scale variability is seen in the Hα line, but only a very long period of P ≈ 5 yr could be estimated. Assessing the circumstellar density of HD 54879 using UV spectra, we can roughly estimate the mass-loss rate HD 54879 would have in the absence of a magnetic field as log ṀB = 0 ≈ -9.0 [M⊙ yr-1]. The magnetic field traps the stellar wind up to the Alfvén radius rA ≳ 12 R∗, implying that its true mass-loss rate is log Ṁ ≲ -10.2 [M⊙ yr-1]. Hence, density enhancements around magnetic stars can be exploited to estimate mass-loss rates of non-magnetic stars of similar spectral types, essential for resolving the weak wind problem. Conclusions: Our study confirms that strongly magnetized stars lose little or no mass, and supplies important constraints on the weak-wind problem of massive main sequence

The XMM deep survey in the CDF-S. X. X-ray variability of bright sources

NASA Astrophysics Data System (ADS)

Falocco, S.; Paolillo, M.; Comastri, A.; Carrera, F. J.; Ranalli, P.; Iwasawa, K.; Georgantopoulos, I.; Vignali, C.; Gilli, R.

2017-12-01

Aims: We aim to study the variability properties of bright hard X-ray selected active galactic nuclei (AGN) in the redshift range between 0.3 and 1.6 detected in the Chandra Deep Field South (XMM-CDFS) by a long ( 3 Ms) XMM observation. Methods: Taking advantage of the good count statistics in the XMM CDFS, we search for flux and spectral variability using the hardness ratio (HR) techniques. We also investigate the spectral variability of different spectral components (photon index of the power law, column density of the local absorber, and reflection intensity). The spectra were merged in six epochs (defined as adjacent observations) and in high and low flux states to understand whether the flux transitions are accompanied by spectral changes. Results: The flux variability is significant in all the sources investigated. The HRs in general are not as variable as the fluxes, in line with previous results on deep fields. Only one source displays a variable HR, anti-correlated with the flux (source 337). The spectral analysis in the available epochs confirms the steeper when brighter trend consistent with Comptonisation models only in this source at 99% confidence level. Finding this trend in one out of seven unabsorbed sources is consistent, within the statistical limits, with the 15% of unabsorbed AGN in previous deep surveys. No significant variability in the column densities, nor in the Compton reflection component, has been detected across the epochs considered. The high and low states display in general different normalisations but consistent spectral properties. Conclusions: X-ray flux fluctuations are ubiquitous in AGN, though in some cases the data quality does not allow for their detection. In general, the significant flux variations are not associated with spectral variability: photon index and column densities are not significantly variable in nine out of the ten AGN over long timescales (from three to six and a half years). Photon index variability is

Exploring the galaxy cluster-group transition regime at high redshifts. Physical properties of two newly detected z > 1 systems

NASA Astrophysics Data System (ADS)

Šuhada, R.; Fassbender, R.; Nastasi, A.; Böhringer, H.; de Hoon, A.; Pierini, D.; Santos, J. S.; Rosati, P.; Mühlegger, M.; Quintana, H.; Schwope, A. D.; Lamer, G.; Kohnert, J.; Pratt, G. W.

2011-06-01

Context. Multi-wavelength surveys for clusters of galaxies are opening a window on the elusive high-redshift (z > 1) cluster population. Well controlled statistical samples of distant clusters will enable us to answer questions about their cosmological context, early assembly phases and the thermodynamical evolution of the intracluster medium. Aims: We report on the detection of two z > 1 systems, XMMU J0302.2-0001 and XMMU J1532.2-0836, as part of the XMM-Newton Distant Cluster Project (XDCP) sample. We investigate the nature of the sources, measure their spectroscopic redshift and determine their basic physical parameters. Methods: The results of the present paper are based on the analysis of XMM-Newton archival data, optical/near-infrared imaging and deep optical follow-up spectroscopy of the clusters. Results: We confirm the X-ray source XMMU J0302.2-0001 as a gravitationally bound, bona fide cluster of galaxies at spectroscopic redshift z = 1.185. We estimate its M500 mass to (1.6 ± 0.3) × 1014 M⊙ from its measured X-ray luminosity. This ranks the cluster among intermediate mass system. In the case of XMMU J1532.2-0836 we find the X-ray detection to be coincident with a dynamically bound system of galaxies at z = 1.358. Optical spectroscopy reveals the presence of a central active galactic nucleus, which can be a dominant source of the detected X-ray emission from this system. We provide upper limits of X-ray parameters for the system and discuss cluster identification challenges in the high-redshift low-mass cluster regime. A third, intermediate redshift (z = 0.647) cluster, XMMU J0302.1-0000, is serendipitously detected in the same field as XMMU J0302.2-0001. We provide its analysis as well. Based on observations obtained with ESO Telescopes at the Paranal Observatory under program ID 080.A-0659 and 081.A-0312, observations collected at the Centro Astrnómico Hispano Alemán (CAHA) at Calar Alto, Spain operated jointly by the Max-Planck Institut f

Estimating photometric redshifts for X-ray sources in the X-ATLAS field using machine-learning techniques

NASA Astrophysics Data System (ADS)

Mountrichas, G.; Corral, A.; Masoura, V. A.; Georgantopoulos, I.; Ruiz, A.; Georgakakis, A.; Carrera, F. J.; Fotopoulou, S.

2017-12-01

We present photometric redshifts for 1031 X-ray sources in the X-ATLAS field using the machine-learning technique TPZ. X-ATLAS covers 7.1 deg2 observed with XMM-Newton within the Science Demonstration Phase of the H-ATLAS field, making it one of the largest contiguous areas of the sky with both XMM-Newton and Herschel coverage. All of the sources have available SDSS photometry, while 810 additionally have mid-IR and/or near-IR photometry. A spectroscopic sample of 5157 sources primarily in the XMM/XXL field, but also from several X-ray surveys and the SDSS DR13 redshift catalogue, was used to train the algorithm. Our analysis reveals that the algorithm performs best when the sources are split, based on their optical morphology, into point-like and extended sources. Optical photometry alone is not enough to estimate accurate photometric redshifts, but the results greatly improve when at least mid-IR photometry is added in the training process. In particular, our measurements show that the estimated photometric redshifts for the X-ray sources of the training sample have a normalized absolute median deviation, nmad ≈ 0.06, and a percentage of outliers, η = 10-14%, depending upon whether the sources are extended or point like. Our final catalogue contains photometric redshifts for 933 out of the 1031 X-ray sources with a median redshift of 0.9. The table of the photometric redshifts is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/608/A39

Finding X-ray counterparts for unidentified sources in the 105 months BAT survey - 1

NASA Astrophysics Data System (ADS)

Stephen, J. B.; Bassani, L.; Malizia, A.; Masetti, N.; Ubertini, P.

2018-02-01

We provide X-ray counterparts for the unidentified Swift/BAT sources listed in the 105 month catalogue (Oh et al. 2018, ApJS in press). These associations were found by cross-correlating the list of U1,U2 and U3 sources with the ROSAT Bright (RASSBSC, Voges et al. 1999, A & A, 349, 389) and the XMM-Newton Slew (XMMSlew, Saxton et al. 2008, A & A, 480, 611) catalogues.

Representation of Serendipitous Scientific Data

NASA Technical Reports Server (NTRS)

James, Mark

2006-01-01

A computer program defines and implements an innovative kind of data structure than can be used for representing information derived from serendipitous discoveries made via collection of scientific data on long exploratory spacecraft missions. Data structures capable of collecting any kind of data can easily be implemented in advance, but the task of designing a fixed and efficient data structure suitable for processing raw data into useful information and taking advantage of serendipitous scientific discovery is becoming increasingly difficult as missions go deeper into space. The present software eases the task by enabling definition of arbitrarily complex data structures that can adapt at run time as raw data are transformed into other types of information. This software runs on a variety of computers, and can be distributed in either source code or binary code form. It must be run in conjunction with any one of a number of Lisp compilers that are available commercially or as shareware. It has no specific memory requirements and depends upon the other software with which it is used. This program is implemented as a library that is called by, and becomes folded into, the other software with which it is used.

45 CFR 674.7 - Exception for serendipitous finds.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 3 2014-10-01 2014-10-01 false Exception for serendipitous finds. 674.7 Section 674.7 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION ANTARCTIC METEORITES § 674.7 Exception for serendipitous finds. A person who makes a serendipitous discovery of a meteorite in Antarctica which could...

45 CFR 674.7 - Exception for serendipitous finds.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 3 2012-10-01 2012-10-01 false Exception for serendipitous finds. 674.7 Section 674.7 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION ANTARCTIC METEORITES § 674.7 Exception for serendipitous finds. A person who makes a serendipitous discovery of a meteorite in Antarctica which could...

45 CFR 674.7 - Exception for serendipitous finds.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 3 2013-10-01 2013-10-01 false Exception for serendipitous finds. 674.7 Section 674.7 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION ANTARCTIC METEORITES § 674.7 Exception for serendipitous finds. A person who makes a serendipitous discovery of a meteorite in Antarctica which could...

Application of a XMM-Newton EPIC Monte Carlo to Analysis And Interpretation of Data for Abell 1689, RXJ0658-55 And the Centaurus Clusters of Galaxies

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

Andersson, Karl E.; /Stockholm U. /SLAC; Peterson, J.R.

2007-04-17

We propose a new Monte Carlo method to study extended X-ray sources with the European Photon Imaging Camera (EPIC) aboard XMM Newton. The Smoothed Particle Inference (SPI) technique, described in a companion paper, is applied here to the EPIC data for the clusters of galaxies Abell 1689, Centaurus and RXJ 0658-55 (the ''bullet cluster''). We aim to show the advantages of this method of simultaneous spectral-spatial modeling over traditional X-ray spectral analysis. In Abell 1689 we confirm our earlier findings about structure in temperature distribution and produce a high resolution temperature map. We also confirm our findings about velocity structuremore » within the gas. In the bullet cluster, RXJ 0658-55, we produce the highest resolution temperature map ever to be published of this cluster allowing us to trace what looks like the motion of the bullet in the cluster. We even detect a south to north temperature gradient within the bullet itself. In the Centaurus cluster we detect, by dividing up the luminosity of the cluster in bands of gas temperatures, a striking feature to the north-east of the cluster core. We hypothesize that this feature is caused by a subcluster left over from a substantial merger that slightly displaced the core. We conclude that our method is very powerful in determining the spatial distributions of plasma temperatures and very useful for systematic studies in cluster structure.« less

Novae as a Class of Transient X-ray Sources

NASA Technical Reports Server (NTRS)

Mukai, K.; Orio, M.; Valle, M. Della

2007-01-01

Motivated by the recently discovered class of faint (10(exp 34)-10(exp 35) ergs/s) X-ray transients in the Galactic Center region, we investigate the 2-10 keV properties of classical and recurrent novae. Existing data are consistent with the idea that all classical novae are transient X-ray sources with durations of months to years and peak luminosities in the 10(exp 34)-10(exp 35)ergs/s range. This makes classical novae a viable candidate class for the faint Galactic Center transients. We estimate the rate of classical novae within a 15 arcmin radius region centered on the Galactic Center (roughly the field of view of XMM-Newton observations centered on Sgr A*) to be approx.0.1 per year. Therefore, it is plausible that some of the Galactic Center transients that have been announced to date are unrecognized classical novae. The continuing monitoring of the Galactic Center region carried out by Chandra and XMM-Newton may therefore provide a new method to detect classical novae in this crowded and obscured region, an

XMM Observations of X-Ray Emission from Supernovae

NASA Technical Reports Server (NTRS)

Immler, Stefan; Lewin, Walter

2003-01-01

Of the six proposed targets, only one observation was performed. The observation resulted in a 28ks observation of SN 1998S. At the time of writing the proposal, our target list only contained previously unknown X-ray supernovae. Between submission of the proposal and the actual observation, a Chandra DDT observation resulted in the detection of SN 1998S. Since SN 1998S was observed with Chandra five times before the XMM-Newton observation was made, the data did not yield enough new information to warrant a separate SN 1998S publication. The key science results of that observation were presented in a review article (by Immler and Lewin); the results were also presented at two conferences.

X-Ray Temperatures, Luminosities, and Masses from XMM-Newton Follow-up of the First Shear-selected Galaxy Cluster Sample

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

Deshpande, Amruta J.; Hughes, John P.; Wittman, David, E-mail: amrejd@physics.rutgers.edu, E-mail: jph@physics.rutgers.edu, E-mail: dwittman@physics.ucdavis.edu

We continue the study of the first sample of shear-selected clusters from the initial 8.6 square degrees of the Deep Lens Survey (DLS); a sample with well-defined selection criteria corresponding to the highest ranked shear peaks in the survey area. We aim to characterize the weak lensing selection by examining the sample’s X-ray properties. There are multiple X-ray clusters associated with nearly all the shear peaks: 14 X-ray clusters corresponding to seven DLS shear peaks. An additional three X-ray clusters cannot be definitively associated with shear peaks, mainly due to large positional offsets between the X-ray centroid and the shearmore » peak. Here we report on the XMM-Newton properties of the 17 X-ray clusters. The X-ray clusters display a wide range of luminosities and temperatures; the L {sub X} − T {sub X} relation we determine for the shear-associated X-ray clusters is consistent with X-ray cluster samples selected without regard to dynamical state, while it is inconsistent with self-similarity. For a subset of the sample, we measure X-ray masses using temperature as a proxy, and compare to weak lensing masses determined by the DLS team. The resulting mass comparison is consistent with equality. The X-ray and weak lensing masses show considerable intrinsic scatter (∼48%), which is consistent with X-ray selected samples when their X-ray and weak lensing masses are independently determined.« less

Discovery of a 23.8 h QPO in the Swift light curve of XMMU J134736.6+173403

NASA Astrophysics Data System (ADS)

Carpano, S.; Jin, C.

2018-07-01

XMMU J134736.6+173403 is an X-ray source discovered serendipitously by XMM-Newton, which was found to be spatially coincident with a pair of galaxies, including a Seyfert 2 galaxy, but presented in 2003 a very sharp persistent flux drop of a factor of 6.5 within 1 h. From the analysis of a set of 29 Swift observations conducted from 2008 February 6 to 2008 May 23, we discovered twin-peak quasi-periodic oscillations (QPOs) with periods of 23.82 ± 0.07 h and 71.44 ± 0.57 h. Using a Chandra observation of 2008, we evaluate more accurately the position of the X-ray source and show that the new source coordinates coincide with the position of the Seyfert 2 galaxy. We provide a detailed spectral energy distribution (SED) of the active galactic nucleus (AGN) counterpart using multiwavelength observations. The AGN is radio-loud and the broad-band SED modelling indicates a black hole with a mass of 9.8 × 106 M⊙, which accretes at an Eddington ratio of 0.047. QPOs for active galaxies have been reported so far in only few cases, the most reliable one being from RE J1034+396 for which a 1 h periodicity has been discovered analysing a 91 ks XMM-Newton observation. Twin-peak QPOs with an observed frequency ratio of 3:1 have not been reported so far for any AGN. From resonance models of the epicyclic frequencies, we evaluate the different possible mass-spin relations. It's still not clear what could have been the origin of the high flux and sharp drop only observed in 2003.

Finding X-ray counterparts for unidentified sources in the 105 months BAT survey - 2

NASA Astrophysics Data System (ADS)

Stephen, J. B.; Bassani, L.; Malizia, A.; Masetti, N.; Ubertini, P.

2018-02-01

We provide X-ray counterparts for unidentified Swift/BAT sources in the 105 month catalogue (Oh et al. 2018, ApJS in press). They were found by cross-correlating the list of U1,U2 and U3 sources with the ROSAT Bright (RASSBSC, Voges et al. 1999, A & A, 349, 389) and XMM-Newton Slew (XMMSlew, Saxton et al. 2008, A & A, 480, 611) catalogues and optically identified as reported in Atel #11340.

VizieR Online Data Catalog: X-ATLAS X-ray sources photometric redshifts (Mountrichas+, 2017)

NASA Astrophysics Data System (ADS)

Mountrichas, G.; Corral, A.; Masoura, V. A.; Georgantopoulos, I.; Ruiz, A.; Georgakakis, A.; Carrera, F. J.; Fotopoulou, S.

2017-10-01

The Herschel Terahertz Large Area survey (H-ATLAS) is the largest Open Time Key Project carried out with the Herschel Space Observatory (Eales et al., 2010PASP..122..499E), covering an area of 550 deg2 in five far-infrared and sub-millimeter (submm) bands (100, 160, 250, 350, and 500um). 16 deg2 have been presented in the Science Demonstration Phase (SDP) catalogue (Rigby et al., 2011, Cat. J/MNRAS/415/2336) and lie within one of the regions observed by the Galaxy And Mass Assembly (GAMA) survey (Driver et al. 2011, Cat. J/MNRAS/413/971; Baldry et al. 2010MNRAS.404...86B). XMM-Newton observed 7.1 deg2 with a total exposure time of 336ks (in the MOS1 camera) within the H-ATLAS SDP area, making the XMM-ATLAS one of the largest contiguous areas of the sky with both XMM-Newton and Herschel coverage. The catalogue contains 1816 unique sources (Ranalli et al. 2015, Cat. J/A+A/577/A121). To obtain optical, mid-IR, and far-IR photometry for the XMM-ATLAS sources, we cross-matched the X-ray catalogue with the SDSS-DR13 (Albareti et al., 2015, Cat. J/MNRAS/452/4153), the WISE (Wright et al. 2010AJ....140.1868W, See Cat. II/311 and II/328), and the VISTA-VIKING catalogues (Emerson et al. 2006, Msngr, 126, 41; Dalton et al. 2006, SPIE, 6269, see Cat. II/343/) with the ARCHES cross-correlation tool xmatch, which symmetrically matches an arbitrary number of catalogues providing a Bayesian Probability of association or non-association (Pineau, 2016, eprint arXiv:1609.03457). (1 data file).

Probing the nature of AX J0043-737: Not an 87 ms pulsar in the Small Magellanic Cloud

NASA Astrophysics Data System (ADS)

Maitra, C.; Ballet, J.; Esposito, P.; Haberl, F.; Tiengo, A.; Filipović, M. D.; Acero, F.

2018-05-01

Aims: AX J0043-737 is a source in the ASCA catalogue whose nature is uncertain. It is most commonly classified as a Crab-like pulsar in the Small Magellanic Cloud (SMC) following apparent detection of pulsations at 87 ms from a single ASCA observation. A follow-up ASCA observation was not able to confirm this, and the X-ray detection of the source has not been reported since. Methods: We studied the nature of the source with a dedicated XMM-Newton observation. We ascertained the source position, searched for the most probable counterpart, and studied the X-ray spectrum. We also analysed other archival observations with the source in the field of view to study its long-term variability. Results: With the good position localisation capability of XMM-Newton, we identify the counterpart of the source as MQS J004241.66-734041.3, an active galactic nucleus (AGN) behind the SMC at a redshift of 0.95. The X-ray spectrum can be fitted with an absorbed power law with a photon-index of Γ = 1.7, which is consistent with that expected from AGNs. By comparing the current XMM-Newton observation with an archival XMM-Newton and two other ASCA observations of the source, we find signatures of long-term variability, another common phenomenon in AGNs. All of the above are consistent with AX J0043-737 being an AGN behind the SMC.

Revival of the Magnetar PSR J1622–4950: Observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR

NASA Astrophysics Data System (ADS)

Camilo, F.; Scholz, P.; Serylak, M.; Buchner, S.; Merryfield, M.; Kaspi, V. M.; Archibald, R. F.; Bailes, M.; Jameson, A.; van Straten, W.; Sarkissian, J.; Reynolds, J. E.; Johnston, S.; Hobbs, G.; Abbott, T. D.; Adam, R. M.; Adams, G. B.; Alberts, T.; Andreas, R.; Asad, K. M. B.; Baker, D. E.; Baloyi, T.; Bauermeister, E. F.; Baxana, T.; Bennett, T. G. H.; Bernardi, G.; Booisen, D.; Booth, R. S.; Botha, D. H.; Boyana, L.; Brederode, L. R. S.; Burger, J. P.; Cheetham, T.; Conradie, J.; Conradie, J. P.; Davidson, D. B.; De Bruin, G.; de Swardt, B.; de Villiers, C.; de Villiers, D. I. L.; de Villiers, M. S.; de Villiers, W.; De Waal, C.; Dikgale, M. A.; du Toit, G.; du Toit, L. J.; Esterhuyse, S. W. P.; Fanaroff, B.; Fataar, S.; Foley, A. R.; Foster, G.; Fourie, D.; Gamatham, R.; Gatsi, T.; Geschke, R.; Goedhart, S.; Grobler, T. L.; Gumede, S. C.; Hlakola, M. J.; Hokwana, A.; Hoorn, D. H.; Horn, D.; Horrell, J.; Hugo, B.; Isaacson, A.; Jacobs, O.; Jansen van Rensburg, J. P.; Jonas, J. L.; Jordaan, B.; Joubert, A.; Joubert, F.; Józsa, G. I. G.; Julie, R.; Julius, C. C.; Kapp, F.; Karastergiou, A.; Karels, F.; Kariseb, M.; Karuppusamy, R.; Kasper, V.; Knox-Davies, E. C.; Koch, D.; Kotzé, P. P. A.; Krebs, A.; Kriek, N.; Kriel, H.; Kusel, T.; Lamoor, S.; Lehmensiek, R.; Liebenberg, D.; Liebenberg, I.; Lord, R. T.; Lunsky, B.; Mabombo, N.; Macdonald, T.; Macfarlane, P.; Madisa, K.; Mafhungo, L.; Magnus, L. G.; Magozore, C.; Mahgoub, O.; Main, J. P. L.; Makhathini, S.; Malan, J. A.; Malgas, P.; Manley, J. R.; Manzini, M.; Marais, L.; Marais, N.; Marais, S. J.; Maree, M.; Martens, A.; Matshawule, S. D.; Matthysen, N.; Mauch, T.; McNally, L. D.; Merry, B.; Millenaar, R. P.; Mjikelo, C.; Mkhabela, N.; Mnyandu, N.; Moeng, I. T.; Mokone, O. J.; Monama, T. E.; Montshiwa, K.; Moss, V.; Mphego, M.; New, W.; Ngcebetsha, B.; Ngoasheng, K.; Niehaus, H.; Ntuli, P.; Nzama, A.; Obies, F.; Obrocka, M.; Ockards, M. T.; Olyn, C.; Oozeer, N.; Otto, A. J.; Padayachee, Y.; Passmoor, S.; Patel, A. A.; Paula, S.; Peens-Hough, A.; Pholoholo, B.; Prozesky, P.; Rakoma, S.; Ramaila, A. J. T.; Rammala, I.; Ramudzuli, Z. R.; Rasivhaga, M.; Ratcliffe, S.; Reader, H. C.; Renil, R.; Richter, L.; Robyntjies, A.; Rosekrans, D.; Rust, A.; Salie, S.; Sambu, N.; Schollar, C. T. G.; Schwardt, L.; Seranyane, S.; Sethosa, G.; Sharpe, C.; Siebrits, R.; Sirothia, S. K.; Slabber, M. J.; Smirnov, O.; Smith, S.; Sofeya, L.; Songqumase, N.; Spann, R.; Stappers, B.; Steyn, D.; Steyn, T. J.; Strong, R.; Struthers, A.; Stuart, C.; Sunnylall, P.; Swart, P. S.; Taljaard, B.; Tasse, C.; Taylor, G.; Theron, I. P.; Thondikulam, V.; Thorat, K.; Tiplady, A.; Toruvanda, O.; van Aardt, J.; van Balla, T.; van den Heever, L.; van der Byl, A.; van der Merwe, C.; van der Merwe, P.; van Niekerk, P. C.; van Rooyen, R.; van Staden, J. P.; van Tonder, V.; van Wyk, R.; Wait, I.; Walker, A. L.; Wallace, B.; Welz, M.; Williams, L. P.; Xaia, B.; Young, N.; Zitha, S.

2018-04-01

New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and NuSTAR) observations of PSR J1622–4950 indicate that the magnetar, in a quiescent state since at least early 2015, reactivated between 2017 March 19 and April 5. The radio flux density, while variable, is approximately 100× larger than during its dormant state. The X-ray flux one month after reactivation was at least 800× larger than during quiescence, and has been decaying exponentially on a 111 ± 19 day timescale. This high-flux state, together with a radio-derived rotational ephemeris, enabled for the first time the detection of X-ray pulsations for this magnetar. At 5%, the 0.3–6 keV pulsed fraction is comparable to the smallest observed for magnetars. The overall pulsar geometry inferred from polarized radio emission appears to be broadly consistent with that determined 6–8 years earlier. However, rotating vector model fits suggest that we are now seeing radio emission from a different location in the magnetosphere than previously. This indicates a novel way in which radio emission from magnetars can differ from that of ordinary pulsars. The torque on the neutron star is varying rapidly and unsteadily, as is common for magnetars following outburst, having changed by a factor of 7 within six months of reactivation.

Infrared properties of serendipitous X-ray quasars

NASA Technical Reports Server (NTRS)

Neugebauer, G.; Soifer, B. T.; Matthews, K.; Margon, B.; Chanan, G. A.

1982-01-01

Near infrared measurements were obtained of 30 quasars originally found serendipitously as X-ray sources in fields of other objects. The observations show that the infrared characteristics of these quasars do not differ significantly from those of quasars selected by other criteria. Because this X-ray selected sample is subject to different selection biases than previous radio and optical surveys, this conclusion is useful in validating previous inferences regarding the infrared colors of 'typical' quasars.

The x-ray luminous galaxy cluster population at 0.9 < z ≲ 1.6 as revealed by the XMM-Newton Distant Cluster Project

NASA Astrophysics Data System (ADS)

Fassbender, R.; Böhringer, H.; Nastasi, A.; Šuhada, R.; Mühlegger, M.; de Hoon, A.; Kohnert, J.; Lamer, G.; Mohr, J. J.; Pierini, D.; Pratt, G. W.; Quintana, H.; Rosati, P.; Santos, J. S.; Schwope, A. D.

2011-12-01

We present the largest sample to date of spectroscopically confirmed x-ray luminous high-redshift galaxy clusters comprising 22 systems in the range 0.9 as part of the XMM-Newton Distant Cluster Project (XDCP). All systems were initially selected as extended x-ray sources over 76.1 deg2 of non-contiguous deep archival XMM-Newton coverage, of which 49.4 deg2 are part of the core survey with a quantifiable selection function and 17.7 deg2 are classified as ‘gold’ coverage as the starting point for upcoming cosmological applications. Distant cluster candidates were followed up with moderately deep optical and near-infrared imaging in at least two bands to photometrically identify the cluster galaxy populations and obtain redshift estimates based on the colors of simple stellar population models. We test and calibrate the most promising redshift estimation techniques based on the R-z and z-H colors for efficient distant cluster identifications and find a good redshift accuracy performance of the z-H color out to at least z ˜ 1.5, while the redshift evolution of the R-z color leads to increasingly large uncertainties at z ≳ 0.9. Photometrically identified high-z systems are spectroscopically confirmed with VLT/FORS 2 with a minimum of three concordant cluster member redshifts. We present first details of two newly identified clusters, XDCP J0338.5+0029 at z = 0.916 and XDCP J0027.2+1714 at z = 0.959, and investigate the x-ray properties of SpARCS J003550-431224 at z = 1.335, which shows evidence for ongoing major merger activity along the line-of-sight. We provide x-ray properties and luminosity-based total mass estimates for the full sample of 22 high-z clusters, of which 17 are at z ⩾ 1.0 and seven populate the highest redshift bin at z > 1.3. The median system mass of the sample is M200 ≃ 2 × 1014 M⊙, while the probed mass range for the distant clusters spans approximately (0.7-7) × 1014 M⊙. The majority (>70%) of the x-ray selected clusters

Serendipitous observations of asteroids in Herschel PACS and SPIRE maps

NASA Astrophysics Data System (ADS)

Szakáts, R.; Kiss, Cs.; Marton, G.; Varga-Verebélyi, E.; Müller, T.; Pál, A.

2017-09-01

We present our methods and results in finding serendipitous solar system objects on Herschel PACS and SPIRE maps. We can use this data to supplement the Herschel PACS and SPIRE point source catalogs with flags of possible contamination and to obtain thermal infrared fluxes for these asteroids.

Centaurus A: Source Populations in the Nearest Bright Elliptical

NASA Technical Reports Server (NTRS)

Mushotzky, Richard (Technical Monitor); Murray, Stephen S.

2003-01-01

The XMM/Newton observations of the nearby radio galaxy, Centaurus A, have proven to be a rich data set and has given us new insights into several important processes present in Centaurus A. A list of publications, conference proceedings, and conference abstracts related to these data are attached at the end of this document. We have used the XMM/Newton observations to study the interaction between the relativistic, radio emitting plasma emitted from active nuclei with the hot interstellar medium. Centaurus A is the nearest radio galaxy, so that we have been able to study these features at a linear resolution unattainable for any similar object.

Multiwavelength Properties of the X-Ray Sources in the Groth-Westphal Strip Field

NASA Astrophysics Data System (ADS)

Miyaji, Takamitsu; Sarajedini, Vicki; Griffiths, Richard E.; Yamada, Toru; Schurch, Matthew; Cristóbal-Hornillos, David; Motohara, Kentaro

2004-06-01

We summarize the multiwavelength properties of X-ray sources detected in the 80 ks XMM-Newton observation of the Groth-Westphal strip, a contiguous strip of 28 Hubble Space Telescope Wide Field Planetary Camera 2 (WFPC2) images. Among the ~150 X-ray sources detected in the XMM-Newton field of view, 23 are within the WFPC2 fields. Ten spectroscopic redshifts are available from the Deep Extragalactic Evolutionary Probe and Canada-France Redshift Survey projects. Four of these show broad Mg II emission and can be classified as type 1 active galactic nuclei (AGNs). Two of those without any broad lines, nevertheless, have [Ne V] emission, which is an unambiguous signature of AGN activity. One is a narrow-line Seyfert 1 and the other a type 2 AGN. As a follow-up, we have made near-infrared spectroscopic observations using the OHS/CISCO spectrometer for five of the X-ray sources for which we found no indication of AGN activity in the optical spectrum. We have detected Hα+[N II] emission in four of them. A broad Hα component and/or a large [N II]/Hα ratio is seen, suggestive of AGN activity. Nineteen sources have been detected in the Ks band, and four of these are extremely red objects (EROs) (I814-Ks>4). The optical counterparts for the majority of the X-ray sources are bulge-dominated. The I814-Ks color of these bulge-dominated hosts are indeed consistent with evolving elliptical galaxies, while contaminations from star formation/AGNs seems to be present in their V606-I814 color. Assuming that the known local relations among the bulge luminosity, central velocity dispersion, and the mass of the central blackhole still hold at z~1, we compare the AGN luminosity with the Eddington luminosity of the central blackhole mass. The AGN bolometric luminosity to Eddington luminosity ratio ranges from 0.3% to 10%. Based on observations from the XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA member states and NASA. Also based on data

XMM-Newton X-ray spectroscopy of the high-mass X-ray binary 4U 1700-37 at low flux

NASA Astrophysics Data System (ADS)

van der Meer, A.; Kaper, L.; di Salvo, T.; Méndez, M.; van der Klis, M.; Barr, P.; Trams, N. R.

2005-03-01

We present results of a monitoring campaign of the high-mass X-ray binary system 4U 1700-37/HD 153919, carried out with XMM-Newton in February 2001. The system was observed at four orbital phase intervals, covering 37% of one 3.41-day orbit. The lightcurve includes strong flares, commonly observed in this source. We focus on three epochs in which the data are not affected by photon pile up: the eclipse, the eclipse egress and a low-flux interval in the lightcurve around orbital phase φ ˜ 0.25. The high-energy part of the continuum is modelled as a direct plus a scattered component, each represented by a power law with identical photon index (α ˜ 1.4), but with different absorption columns. We show that during the low-flux interval the continuum is strongly reduced, probably due to a reduction of the accretion rate onto the compact object. A soft excess is detected in all spectra, consistent with either another continuum component originating in the outskirts of the system or a blend of emission lines. Many fluorescence emission lines from near-neutral species and discrete recombination lines from He- and H-like species are detected during eclipse and egress. The fluorescence Fe Kα line at 6.4 keV is very prominent; a second Kα line is detected at slightly higher energies (up to 6.7 keV) and a Kβ line at 7.1 keV. In the low-flux interval the Fe Kα line at 6.4 keV is strongly (factor ˜ 30) reduced in strength. In eclipse, the Fe Kβ/Kα ratio is consistent with a value of 0.13. In egress we initially measure a higher ratio, which can be explained by a shift in energy of the Fe K-edge to ~ 7.15 keV, which is consistent with moderately ionised iron, rather than neutral iron, as expected for the stellar wind medium. The detection of recombination lines during eclipse indicates the presence of an extended ionised region surrounding the compact object. The observed increase in strength of some emission lines corresponding to higher values of the ionisation

Searching for X-ray emission from AGB stars

NASA Astrophysics Data System (ADS)

Ramstedt, S.; Montez, R.; Kastner, J.; Vlemmings, W. H. T.

2012-07-01

Context. Magnetic fields have been measured around asymptotic giant branch (AGB) stars of all chemical types using maser polarization observations. If present, a large-scale magnetic field would lead to X-ray emission, which should be observable using current X-ray observatories. Aims: The aim is to search the archival data for AGB stars that are intrinsic X-ray emitters. Methods: We have searched the ROSAT, CXO, and XMM-Newton archives for serendipitous X-ray observations of a sample of ~500 AGB stars. We specifically searched for the AGB stars detected with GALEX. The data is calibrated, analyzed and the X-ray luminosities and temperatures are estimated as functions of the circumstellar absorption. Results: We identify 13 AGB stars as having either serendipitous or targeted observations in the X-ray data archives, however for a majority of the sources the detailed analysis show that the detections are questionable. Two new sources are detected by ROSAT: T Dra and R UMa. The spectral analysis suggests that the emission associated with these sources could be due to coronal activity or interaction across a binary system. Conclusions: Further observations of the detected sources are necessary to clearly determine the origin of the X-ray emission. Moreover, additional objects should be subject to targeted X-ray observations in order to achieve better constraints for the magnetic fields around AGB stars. Appendices are available in electronic form at http://www.aanda.org

Chandra and XMM Observations of the ADC Source 0921-630

NASA Technical Reports Server (NTRS)

Kallman, T. R.; Angelini, L.; Boroson, B.; Cottam, J.; White, Nicholas E. (Technical Monitor)

2002-01-01

We analyze observations of the low mass X-ray binary 2S0921-63 obtained with the gratings and CCDs on Chandra and XMM. This object is a high inclination system showing evidence for an accretion disk corona (ADC). Such a corona has the potential to constrain the properties of the heated accretion disk in this system, and other LMXBs by extension. We find evidence for line emission which is generally consistent with that found by previous experiments, although we are able to detect more lines. For the first time in this source, we find that the iron K line has multiple components. We set limits on the line widths and velocity offsets, and we fit the spectra to photoionization models and discuss the implications for accretion disk corona models. For the first time in any ADC source we use these fits, together with density constraints based on the O VII line ratio, in order to constrain the flux in the medium-ionization region of the ADC. Under various assumptions about the source luminosity this constrains the location of the emitting region. These estimates, together with estimates for the emission measure, favor a scenario in which the intrinsic luminosity of the source is comparable to what we observe.

Detection of Nitrogen and Neon in the X-ray Spectrum of GP Com with XMM/Newton

NASA Technical Reports Server (NTRS)

Strohmayer, Tod E.

2004-01-01

We report on X-ray spectroscopic observations with XMM/Newton of the ultra-compact, double white dwarf binary, GP Com. With the Reflection Grating Spectrometers (RGS) we detect the L(alpha) and L(beta) lines of hydrogen-like nitrogen (N VII) and neon (Ne X), as well as the helium-like triplets (N VI and Ne IX) of these same elements. All the emission lines are unresolved. These are the first detections of X-ray emission lines from a double-degenerate, AM CVn system. We detect the resonance (r) and intercombination (i) lines of the N VI triplet, but not the forbidden (f) line. The implied line ratios for N VI, R = f/i less than 0.3, and G = (f + i ) / r approx. = 1, combined with the strong resonance line are consistent with a dense, collision-dominated plasma. Both the RGS and EPIC/MOS spectra are well fit by emission horn an optically thin thermal plasma with an emission measure (EM) is a member of (kT/6.5 keV)(sup 0.8) (model cevmkl in XSPEC). Helium, nitrogen, oxygen and neon are required to adequately model the spectrum, however, the inclusion of sulphur and iron further improves the fit, suggesting these elements may also be present at low abundance. We confirm in the X-rays the under- abundance of both carbon and oxygen relative to nitrogen, first deduced from optical spectroscopy by Marsh et al. The average X-ray luminosity of approx. = 3 x 10(exp 30) ergs/s implies a mass accretion rate dot-m approx. = 9 x 10(exp -13) solar mass/yr. The implied temperature and density of the emitting plasma, combined with the presence of narrow emission lines and the low dot-m value, are consistent with production of the X-ray emission in an optically thin boundary layer just above the surface of the white dwarf.

The SCUBA HAlf Degree Extragalactic Survey (SHADES) - V. Submillimetre properties of near-infrared-selected galaxies in the Subaru/XMM -Newton deep field

NASA Astrophysics Data System (ADS)

Takagi, T.; Mortier, A. M. J.; Shimasaku, K.; Coppin, K.; Pope, A.; Ivison, R. J.; Hanami, H.; Serjeant, S.; Clements, D. L.; Priddey, R. S.; Dunlop, J. S.; Takata, T.; Aretxaga, I.; Chapman, S. C.; Eales, S. A.; Farrah, D.; Granato, G. L.; Halpern, M.; Hughes, D. H.; van Kampen, E.; Scott, D.; Sekiguchi, K.; Smail, I.; Vaccari, M.

2007-11-01

We have studied the submillimetre (submm) properties of the following classes of near-infrared-selected (NIR-selected) massive galaxies at high redshifts: BzK-selected star-forming galaxies (BzKs); distant red galaxies (DRGs); and extremely red objects (EROs). We used the SCUBA HAlf Degree Extragalactic Survey (SHADES), the largest uniform submm survey to date. Partial overlap of SIRIUS/NIR images and SHADES in Subaru/XMM-Newton deep field has allowed us to identify four submm-bright NIR-selected galaxies, which are detected in the mid-IR, 24μ m, and the radio, 1.4GHz. We find that all of our submm-bright NIR-selected galaxies satisfy the BzK selection criteria, i.e. BzK ≡ (z - K)AB - (B - z)AB >= -0.2, except for one galaxy whose B - z and z - K colours are however close to the BzK colour boundary. Two of the submm-bright NIR-selected galaxies satisfy all of the selection criteria we considered, i.e. they belong to the BzK-DRG-ERO overlapping population, or `extremely red' BzKs. Although these extremely red BzKs are rare (0.25 arcmin-2), up to 20 per cent of this population could be submm galaxies. This fraction is significantly higher than that found for other galaxy populations studied here. Via a stacking analysis, we have detected the 850-μ m flux of submm-faint BzKs and EROs in our SCUBA maps. While the contribution of z ~ 2 BzKs to the submm background is about 10-15 per cent and similar to that from EROs typically at z ~ 1, BzKs have a higher fraction (~30 per cent) of submm flux in resolved sources compared with EROs and submm sources as a whole. From the spectral energy distribution (SED) fitting analysis for both submm-bright and submm-faint BzKs, we found no clear signature that submm-bright BzKs are experiencing a specifically luminous evolutionary phase, compared with submm-faint BzKs. An alternative explanation might be that submm-bright BzKs are more massive than submm-faint ones.

Distant clusters of galaxies in the 2XMM/SDSS footprint: follow-up observations with the LBT

NASA Astrophysics Data System (ADS)

Rabitz, A.; Lamer, G.; Schwope, A.; Takey, A.

2017-11-01

Context. Galaxy clusters at high redshift are important to test cosmological models and models for the growth of structure. They are difficult to find in wide-angle optical surveys, however, leaving dedicated follow-up of X-ray selected candidates as one promising identification route. Aims: We aim to increase the number of galaxy clusters beyond the SDSS-limit, z 0.75. Methods: We compiled a list of extended X-ray sources from the 2XMMp catalogue within the footprint of the Sloan Digital Sky Survey. Fields without optical counterpart were selected for further investigation. Deep optical imaging and follow-up spectroscopy were obtained with the Large Binocular Telescope, Arizona (LBT), of those candidates not known to the literature. Results: From initially 19 candidates, selected by visually screening X-ray images of 478 XMM-Newton observations and the corresponding SDSS images, 6 clusters were found in the literature. Imaging data through r,z filters were obtained for the remaining candidates, and 7 were chosen for multi-object (MOS) spectroscopy. Spectroscopic redshifts, optical magnitudes, and X-ray parameters (flux, temperature, and luminosity) are presented for the clusters with spectroscopic redshifts. The distant clusters studied here constitute one additional redshift bin for studies of the LX-T relation, which does not seem to evolve from high to low redshifts. Conclusions: The selection method of distant galaxy clusters presented here was highly successful. It is based solely on archival optical (SDSS) and X-ray (XMM-Newton) data. Out of 19 selected candidates, 6 of the 7 candidates selected for spectroscopic follow-up were verified as distant clusters, a further candidate is most likely a group of galaxies at z 1.21. Out of the remaining 12 candidates, 6 were known previously as galaxy clusters, one object is a likely X-ray emission from an AGN radio jet, and for 5 we see no clear evidence for them to be high-redshift galaxy clusters. Based on

Derivation of photometric redshifts for the 3XMM catalogue

NASA Astrophysics Data System (ADS)

Georgantopoulos, I.; Corral, A.; Mountrichas, G.; Ruiz, A.; Masoura, V.; Fotopoulou, S.; Watson, M.

2017-10-01

We present the results from our ESA Prodex project that aims to derive photometric redshifts for the 3XMM catalogue. The 3XMM DR-6 offers the largest X-ray survey, containing 470,000 unique sources over 1000 sq. degrees. We cross-correlate the X-ray positions with optical and near-IR catalogues using Bayesian statistics. The optical catalogue used so far is the SDSS while currently we are employing the recently released PANSTARRS catalogue. In the near IR we use the Viking, VHS, UKIDS surveys and also the WISE W1 and W2 filters. The estimation of photometric redshifts is based on the TPZ software. The training sample is based on X-ray selected samples with available SDSS spectroscopy. We present here the results for the 40,000 3XMM sources with available SDSS counterparts. Our analysis provides very reliable photometric redshifts with sigma(mad)=0.05 and a fraction of outliers of 8% for the optically extended sources. We discuss the wide range of applications that are feasible using this unprecedented resource.

PN-CCD camera for XMM: performance of high time resolution/bright source operating modes

NASA Astrophysics Data System (ADS)

Kendziorra, Eckhard; Bihler, Edgar; Grubmiller, Willy; Kretschmar, Baerbel; Kuster, Markus; Pflueger, Bernhard; Staubert, Ruediger; Braeuninger, Heinrich W.; Briel, Ulrich G.; Meidinger, Norbert; Pfeffermann, Elmar; Reppin, Claus; Stoetter, Diana; Strueder, Lothar; Holl, Peter; Kemmer, Josef; Soltau, Heike; von Zanthier, Christoph

1997-10-01

The pn-CCD camera is developed as one of the focal plane instruments for the European photon imaging camera (EPIC) on board the x-ray multi mirror (XMM) mission to be launched in 1999. The detector consists of four quadrants of three pn-CCDs each, which are integrated on one silicon wafer. Each CCD has 200 by 64 pixels (150 micrometer by 150 micrometers) with 280 micrometers depletion depth. One CCD of a quadrant is read out at a time, while the four quadrants can be processed independently of each other. In standard imaging mode the CCDs are read out sequentially every 70 ms. Observations of point sources brighter than 1 mCrab will be effected by photon pile- up. However, special operating modes can be used to observe bright sources up to 150 mCrab in timing mode with 30 microseconds time resolution and very bright sources up to several crab in burst mode with 7 microseconds time resolution. We have tested one quadrant of the EPIC pn-CCD camera at line energies from 0.52 keV to 17.4 keV at the long beam test facility Panter in the focus of the qualification mirror module for XMM. In order to test the time resolution of the system, a mechanical chopper was used to periodically modulate the beam intensity. Pulse periods down to 0.7 ms were generated. This paper describes the performance of the pn-CCD detector in timing and burst readout modes with special emphasis on energy and time resolution.

FE K EMISSION AND ABSORPTION FEATURES IN THE XMM-EPIC SPECTRUM OF THE SEYFERT GALAXY IC 4329A

NASA Technical Reports Server (NTRS)

Markowitz, A.; Reeves, J. N.; Braito, V.

2001-01-01

We present a re-analysis of the XMM-Newton long-look of the X-ray bright Seyfert galaxy IC 4329a. The Fe K bandpass is dominated by two peaks, consistent with emission from neutral or near-neutral Fe Ka and KP. A relativistic diskline model whereby both peaks are the result of one doubly-peaked diskline profile is found to be a poor description of the data. Models using two relativistic disklines are found to describe the emission profile well. A low-inclination, moderately-relativistic dual-diskline model is possible if the contribution from narrow components, due to distant material, is small or absent. A high-inclination, moderately relativistic profile for each peak is possible if there are roughly equal contributions from both the broad and narrow components. Upper limits on Fe XXV and Fe XXVI emission and absorption at the systemic velocity of IC 4329a are obtained. We also present the results of RXTE monitoring of this source obtained so far; the combined XMM-Newton and RXTE data sets allow us to explore the time-resolved spectral behavior of this source on time scales ranging from hours to 2 years. We find no strong evidence for variability of the Fe Ka emission line on any time scale probed, likely due to the minimal level of continuum variability. We detect a narrow absorption line, at a energy of 7.68 keV in the rest frame of the source; its significance has been confirmed using Monte Carlo simulations. This feature is most likely due to absorption from Fe XXVI blueshifted to approximately 0.1c relative to the systemic velocity, making IC 4329a the lowest-redshift AGN known with a high-velocity, highly-ionized outflow component. As is often the case with similar outflows seen in high-luminosity quasars, the estimated mass outflow rate is larger than the inflow accretion rate, signaling that the outflow represents a substantial portion of the total energy budget of the AGN. The outflow could arise from a radiatively-driven disk wind, or it may be in the

X-Ray Temperatures, Luminosities, and Masses from XMM-Newton Follow-upof the First Shear-selected Galaxy Cluster Sample

NASA Astrophysics Data System (ADS)

Deshpande, Amruta J.; Hughes, John P.; Wittman, David

2017-04-01

We continue the study of the first sample of shear-selected clusters from the initial 8.6 square degrees of the Deep Lens Survey (DLS); a sample with well-defined selection criteria corresponding to the highest ranked shear peaks in the survey area. We aim to characterize the weak lensing selection by examining the sample’s X-ray properties. There are multiple X-ray clusters associated with nearly all the shear peaks: 14 X-ray clusters corresponding to seven DLS shear peaks. An additional three X-ray clusters cannot be definitively associated with shear peaks, mainly due to large positional offsets between the X-ray centroid and the shear peak. Here we report on the XMM-Newton properties of the 17 X-ray clusters. The X-ray clusters display a wide range of luminosities and temperatures; the L X -T X relation we determine for the shear-associated X-ray clusters is consistent with X-ray cluster samples selected without regard to dynamical state, while it is inconsistent with self-similarity. For a subset of the sample, we measure X-ray masses using temperature as a proxy, and compare to weak lensing masses determined by the DLS team. The resulting mass comparison is consistent with equality. The X-ray and weak lensing masses show considerable intrinsic scatter (˜48%), which is consistent with X-ray selected samples when their X-ray and weak lensing masses are independently determined. 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.

Chandra and XMM-Newton Study of the Supernova Remnant Kes 73 Hosting the Magnetar 1E 1841-045

NASA Astrophysics Data System (ADS)

Kumar, Harsha S.; Safi-Harb, Samar; Slane, Patrick O.; Gotthelf, E. V.

2014-01-01

We present a Chandra and XMM-Newton study of the supernova remnant (SNR) Kes 73 hosting the anomalous X-ray pulsar 1E 1841-045. The Chandra image reveals clumpy structures across the remnant with enhanced emission along the western rim. The X-ray emission fills the radio shell and spatially correlates with the infrared image. The global X-ray spectrum is described by a two-component thermal model with a column density N H = 2.6^{+0.4}_{-0.3}\\times1022 cm-2 and a total luminosity of LX = 3.3^{+0.7}_{-0.5}\\times1037 erg s-1 (0.5-10 keV, at an assumed distance of 8.5 kpc). The soft component is characterized by a temperature kTs = 0.5^{+0.1}_{-0.2} keV, a high ionization timescale, and enhanced Si and S abundances, suggesting emission that is dominated by shocked ejecta. The hard component has a temperature kTh = 1.6^{+0.8}_{-0.7} keV, a relatively low ionization timescale, and mostly solar abundances suggesting emission that is dominated by interstellar/circumstellar shocked material. A spatially resolved spectroscopy study reveals no significant variations in the spectral properties. We infer an SNR age ranging between 750 yr and 2100 yr, an explosion energy of 3.0^{+2.8}_{-1.8}\\times1050 erg and a shock velocity of (1.2 ± 0.3)×103 km s-1 (under the Sedov phase assumption). We also discuss the possible scenario for Kes 73 expanding into the late red-supergiant wind phase of its massive progenitor. Comparing the inferred metal abundances to core-collapse nucleosynthesis model yields, we estimate a progenitor mass gsim20 M ⊙, adding a candidate to the growing list of highly magnetized neutron stars proposed to be associated with very massive progenitors.

Discovery of Coherent Pulsations from the Ultraluminous X-Ray Source NGC 7793 P13

NASA Technical Reports Server (NTRS)

Furst, F.; Walton, D. J.; Harrison, F. A.; Stern, D.; Barret, D.; Brightman, M.; Fabian, A. C.; Grefenstette, B.; Madsen, K. K.; Middleton, M. J.;

Discovery of gamma- and X-ray pulsations from the young and energetic PSR J1357$-$6429 with Fermi and XMM-Newton

DOE PAGES

Lemoine-Goumard, M.; Zavlin, V. E.; Grondin, M. -H.; ...

2011-09-07

Context. Since the launch of the Fermi satellite, the number of known gamma-ray pulsars has increased tenfold. Most gamma-ray detected pulsars are young and energetic, and many are associated with TeV sources. PSR J1357-6429 is a high spin-down power pulsar (È = 3.1 × 1036 erg s -1), discovered during the Parkes multibeam survey of the Galactic plane, with significant timing noise typical of very young pulsars. In the very-high-energy domain (E > 100 GeV), H.E.S.S. has reported the detection of the extended source HESS J1356-645 (intrinsic Gaussian width of 12') whose centroid lies 7' from PSR J1357-6429. Aims. Wemore » search for gamma- and X-ray pulsations from this pulsar, characterize the neutron star emission and explore the environment of PSR J1357-6429. Methods. Using a rotational ephemeris obtained with 74 observations made with the Parkes telescope at 1.4 GHz, we phase-fold more than two years of gamma-ray data acquired by the Large Area Telescope on-board Fermi as well as those collected with XMM-Newton, and perform gamma-ray spectral modeling. Results. Significant gamma- and X-ray pulsations are detected from PSR J1357-6429. The light curve in both bands shows one broad peak. Gamma-ray spectral analysis of the pulsed emission suggests that it is well described by a simple power-law of index 1.5 ± 0.3 stat ± 0.3 syst with an exponential cut-off at 0.8 ± 0.3 stat ± 0.3 syst GeV and an integral photon flux above 100 MeV of (6.5 ± 1.6 stat ± 2.3 syst) × 10 -8 cm -2 s -1. The X-ray spectra obtained from the new data provide results consistent with previous work. Upper limits on the gamma-ray emission from its potential pulsar wind nebula (PWN) are also reported. Conclusions. Assuming a distance of 2.4 kpc, the Fermi LAT energy flux yields a gamma-ray luminosity for PSR J1357-6429 of L γ = (2.13 ± 0.25 stat ± 0.83 syst) × 1034 erg s -1, consistent with an relationship. The Fermi non-detection of the pulsar wind nebula associated with HESS J1356

Unveiling an X-ray counterpart to the Unid. TeV source HESS J1852-000

NASA Astrophysics Data System (ADS)

Kosack, Karl

2011-10-01

We propose to use XMM-Newton to attempt to identify the hard-spectrum very-high- energy (VHE) gamma-ray source HESS J1852-000, which has currently no clear counterpart in lower-energy wavebands. The VHE source lies near the shell-type supernova remnant Kes 78, which may be associated with part of the VHE emission, e.g. through the illumination of nearby molecular clouds by escaping hadrons, via direct shock interaction, or via an as-yet-undetected nearby pulsar wind nebula. We present an analysis of archival XMM data from the region near Kes 78 that shows evidence for X-ray emission from part of the shell, and we propose a pointing that would complement the existing data while covering the peaks of the VHE gamma-ray emission as well as several weak X-ray and radio hotspots.

CHANDRA and XMM-NEWTON observations of the bimodal PLANCK SZ-detected clustered CKG345.40-39.34 (A3716) with high and low entropy subcluster cores

DOE PAGES

Andrade-Santos, Felipe; Jones, Christine; Forman, William R.; ...

2015-04-22

Here, we present results from Chandra, XMM-Newton, and ROSAT observations of the Planck SZ-detected cluster A3716 (PLCKG345.40-39.34-G345). We show that G345 is, in fact, two subclusters separated on the sky by 400 kpc. We measure the subclusters' gas temperatures (~2–3 keV), total (~1–2 × 10 14more » $${{M}_{\\odot }}$$) and gas (~1–2 × 10 13 $${{M}_{\\odot }}$$) masses, gas mass fraction within r500, entropy profiles, and X-ray luminosities (~10 43 erg s -1). Using the gas density and temperature profiles for both subclusters, we show that there is good (0.8σ) agreement between the expected Sunyaev–Zel'dovich signal predicted from the X-ray data and that measured from the Planck mission, and better agreement within 0.6σ when we re-computed the Planck value assuming a two component cluster model, with relative amplitudes fixed based on the X-ray data. Dynamical analysis shows that the two galaxy subclusters are very likely ($$\\gt 97\\%$$ probability) gravitationally bound, and in the most likely scenario, the subclusters will undergo core passage in 500 ± 200 Myr. The northern subcluster is centrally peaked and has a low entropy core, while the southern subcluster has a high central entropy. Finally, the high central entropy in the southern subcluster can be explained either by the mergers of several groups, as suggested by the presence of five giant ellipticals or by active galactic nucleus energy injection, as suggested by the presence of a strong radio source in one of its massive elliptical galaxies, or by a combination of both processes.« less

Detailed Spectral Analysis of the 260 ks XMM-Newton Data of 1E 1207.4-5209 and Significance of a 2.1 keV Absorption Feature

NASA Astrophysics Data System (ADS)

Mori, Kaya; Chonko, James C.; Hailey, Charles J.

2005-10-01

We have reanalyzed the 260 ks XMM-Newton observation of 1E 1207.4-5209. There are several significant improvements over previous work. First, a much broader range of physically plausible spectral models was used. Second, we have used a more rigorous statistical analysis. The standard F-distribution was not employed, but rather the exact finite statistics F-distribution was determined by Monte Carlo simulations. This approach was motivated by the recent work of Protassov and coworkers and Freeman and coworkers. They demonstrated that the standard F-distribution is not even asymptotically correct when applied to assess the significance of additional absorption features in a spectrum. With our improved analysis we do not find a third and fourth spectral feature in 1E 1207.4-5209 but only the two broad absorption features previously reported. Two additional statistical tests, one line model dependent and the other line model independent, confirmed our modified F-test analysis. For all physically plausible continuum models in which the weak residuals are strong enough to fit, the residuals occur at the instrument Au M edge. As a sanity check we confirmed that the residuals are consistent in strength and position with the instrument Au M residuals observed in 3C 273.

Origin of central abundances in the hot intra-cluster medium. I. Individual and average abundance ratios from XMM-Newton EPIC

NASA Astrophysics Data System (ADS)

Mernier, F.; de Plaa, J.; Pinto, C.; Kaastra, J. S.; Kosec, P.; Zhang, Y.-Y.; Mao, J.; Werner, N.

2016-08-01

The hot intra-cluster medium (ICM) is rich in metals, which are synthesised by supernovae (SNe) explosions and accumulate over time into the deep gravitational potential well of clusters of galaxies. Since most of the elements visible in X-rays are formed by type Ia (SNIa) and/or core-collapse (SNcc) supernovae, measuring their abundances gives us direct information on the nucleosynthesis products of billions of SNe since the epoch of the star formation peak (z ~ 2-3). In this study, we use the EPIC and RGS instruments on board XMM-Newton to measure the abundances of nine elements (O, Ne, Mg, Si, S, Ar, Ca, Fe, and Ni) from a sample of 44 nearby cool-core galaxy clusters, groups, and elliptical galaxies. We find that the Fe abundance shows a large scatter (~20-40%) over the sample, within 0.2r500 and especially 0.05r500. Unlike the absolute Fe abundance, the abundance ratios (X/Fe) are uniform over the considered temperature range (~0.6-8 keV) and with a limited scatter. In addition to an unprecedented treatment of systematic uncertainties, we provide the most accurate abundance ratios measured so far in the ICM, including Cr/Fe and Mn/Fe which we firmly detected (>4σ with MOS and pn independently). We find that Cr/Fe, Mn/Fe, and Ni/Fe differ significantly from the proto-solar values. However, the large uncertainties in the proto-solar abundances prevent us from making a robust comparison between the local and the intra-cluster chemical enrichments. We also note that, interestingly, and despite the large net exposure time (~4.5 Ms) of our dataset, no line emission feature is seen around ~3.5 keV.

XMM TOO Observation

NASA Technical Reports Server (NTRS)

Kong, Albert

2005-01-01

The primary research goal of this project is to perform follow-up observations of a recurrent ultraluminous supersoft X-ray source (SSS) in Ml0l. The source was first discovered by ROSAT and was confirmed as a SSS with a blackbody temperature of about l00eV by Chandra. During 2000 March, Chandra detected it at Lx=4e39 erg per second, and then in 2000 October, its luminosity dropped to around le39 erg per second. During 2004, Chandra is conducting a monitoring program for Ml0l. The SSS was near the detection limit during January, March, and May; the X-ray spectra were harder with a power-law shape, and the X-ray luminosity was about 3e37 erg/second, a factor of greater than 200 fainter than that in the previous high state. The source was found to be in outburst again during the July 5 observation, with an X-ray luminosity of about 7e39 erg/second. Data taken on July 6,7, and 8 show that the source was in a strong outburst with a peak bolometric luminosity of about 7e39 erg/second. In general, the X-ray spectra are best described with an absorbed blackbody model with temperatures of approximately 50-100eV. In addition, we found absorption edges at 0.33, 0.57, 0.66, and 0.88 keV in two of the high state spectra. These features may signal the presence of highly ionized gas in the vicinity of the accretor (e.g., warm absorber). In order to study an ultraluminous SSS in outburst in detail, we proposed a TOO XMM observation to observe the source. The observation was taken on July 23 and the source was fainter with a luminosity of 6e38 ergs, and a harder X-ray spectrum with a power-law tail seen up to 7 keV. This clearly indicates that the source was in the decline stage with spectral change. In addition to the XMM observation, we also arranged radio observation and a simultaneous CFHT observation. The X-ray results were published in ATel and ApJL. There were several more Chandra observations taken after 2004 July. The source was in a low luminosity state but it underwent

Long Term Temporal and Spectral Evolution of Point Sources in Nearby Elliptical Galaxies

NASA Astrophysics Data System (ADS)

Durmus, D.; Guver, T.; Hudaverdi, M.; Sert, H.; Balman, Solen

2016-06-01

We present the results of an archival study of all the point sources detected in the lines of sight of the elliptical galaxies NGC 4472, NGC 4552, NGC 4649, M32, Maffei 1, NGC 3379, IC 1101, M87, NGC 4477, NGC 4621, and NGC 5128, with both the Chandra and XMM-Newton observatories. Specifically, we studied the temporal and spectral evolution of these point sources over the course of the observations of the galaxies, mostly covering the 2000 - 2015 period. In this poster we present the first results of this study, which allows us to further constrain the X-ray source population in nearby elliptical galaxies and also better understand the nature of individual point sources.

Seeing Red and Shooting Blanks: Study of Red Quasars and Blank X-Ray Sources

NASA Technical Reports Server (NTRS)

Oliversen, Ronald (Technical Monitor); Elvis, Martin

2005-01-01

A major paper describing the technique and providing a list of 'blanks' was published in the Astrophysical Journal (abstract below). The results revealed a fascinating trove of novel X-ray sources: high redshift clusters of galaxies found efficiently; X-ray absorbed, optically clean AGN, which may be the bright prototypes of Chandra Deep Survey sources; and several with a still unknown nature. Recent XMM-Newton results confirm the existence of this class of X-ray source with much refined positions. During the first year of this project we have made a major discovery. The second 'blanks' X-ray source observed with Chandra was found to be extended. Using Chandra data and ground-based R and K band imaging we estimated this to be a high redshift cluster of galaxies with z approx. 0.85. Spectroscopy agrees with this estimate (z=0.89). This success shows that our method of hunting down 'blank' field X-ray sources is a highly efficient method of finding the otherwise elusive high redshift clusters. With extensive follow-up we should be able to use 'blanks' to make cosmological tests. The paper is now in press in the Astrophysical Journal (abstract below.) The other Chandra source is point-like, showing that there are a variety of 'blank' source types. Other follow-up observations with XMM-Newton, and (newly approved in cycle 2) with Chandra are eagerly awaited. A follow-up paper uses a large amount of supporting data for the remaining blanks. A combination of ROSAT, Chandra and ground based data convincingly identified one of the blanks as a Ultra-luminous X-ray source (ULX) in a spiral galaxy (abstract below). This program resulted in 3 refereed papers in major journals, 4 conference proceedings and a significant fraction of the PhD thesis of Dr. Ilaria Cagnoni. Details of the publications are given.

X-ray-ing the Low Luminosity Supermassive Black Hole Accretion: the Crucial Role of Public Serendipitous Catalogs.

NASA Astrophysics Data System (ADS)

Constantin, Anca; Green, Paul; Haggard, Daryl

2018-01-01

For most of the nearby active galaxies, a mix of processes including emission from star-forming regions, other ionization sources (shocks, turbulence, etc.), nuclear obscuration, as well as host galaxy starlight obfuscate the true nature of their dominant ionization mechanism. X-ray emission is one of the most reliable primary signatures of accretion activity, and with the advent of the public catalogs, it became one of the most effective diagnostics as well. Working with large and significantly less biased samples that only serendipitous X-ray catalogs are able to provide, we were able to: 1) provide the most accurate estimates of the AGN fraction as a function of a diverse set of parameters; 2) confirm with X-rays a sequence from star-forming to active to passive galaxies that matches trends in both optical host galaxy characteristics and in the large scale environment; 3) discover intriguing similarities between accretion onto supermassive and stellar size black holes, with direct consequences for the physical significance of the Gamma-L/Ledd relation for AGN of both type I and II in the local universe. This presentation will summarize these exciting results, and will also report on novel extended efforts to decipher the link between the water megamaser emission and galactic nuclear activity, which are made possible only by the availability of the large sample statistics of carefully curated X-ray measurements uniquely offered by the combined Chandra and XMM catalogs.

Studying The Spectral Shape And The X-ray/uv Variability Of Active Galactic Nuclei With Data From Swift And Xmm Archives

NASA Astrophysics Data System (ADS)

Turriziani, Sara

2011-01-01

Many efforts have been made in understanding the underlying origin of variability in Active Galactic Nuclei (AGN), but at present they could give still no conclusive answers. Since a deeper knowledge of variability will enable to understand better the accretion process onto supermassive black holes, I built the first ensemble struction function analysis of the X-ray variability of samples of quasars with data from Swift and XMM-Newton archives in order to study the average properties of their variability. Moreover, it is known that UV and X-ray luminosities of quasars are correlated and recent studies quantified this relation across 5 orders of magnitude. In this context, I presents results on the X-ray/UV ratio from simultaneous observations in UV and X-ray bands of a sample of quasars with data from XMM-Newton archive. Lastly, I will present a complete sample of Swift/SDSS faint blazars and other non-thermal dominated AGNs. I used this sample to calculate the general statistical properties of faint blazars and radio galaxies and in particular their Radio LogN-LogS with fluxes down to 10 mJy, in order to gain knowledge on the contribution to Cosmic Microwave Background (CMB) and gamma-ray background radiation from the faint tail of the radio population. I acknowledge financial support through Grant ASI I/088/06/0.

The supersoft X-ray source in V5116 Sagittarii. I. The high resolution spectra

NASA Astrophysics Data System (ADS)

Sala, G.; Ness, J. U.; Hernanz, M.; Greiner, J.

2017-05-01

Context. Classical nova explosions occur on the surface of an accreting white dwarf in a binary system. After ejection of a fraction of the envelope and when the expanding shell becomes optically thin to X-rays, a bright source of supersoft X-rays arises, powered by residual H burning on the surface of the white dwarf. While the general picture of the nova event is well established, the details and balance of accretion and ejection processes in classical novae are still full of unknowns. The long-term balance of accreted matter is of special interest for massive accreting white dwarfs, which may be promising supernova Ia progenitor candidates. Nova V5116 Sgr 2005b was observed as a bright and variable supersoft X-ray source by XMM-Newton in March 2007, 610 days after outburst. The light curve showed a periodicity consistent with the orbital period. During one third of the orbit the luminosity was a factor of seven brighter than during the other two thirds of the orbital period. Aims: In the present work we aim to disentangle the X-ray spectral components of V5116 Sgr and their variability. Methods: We present the high resolution spectra obtained with XMM-Newton RGS and Chandra LETGS/HRC-S in March and August 2007. Results: The grating spectrum during the periods of high-flux shows a typical hot white dwarf atmosphere dominated by absorption lines of N VI and N VII. During the low-flux periods, the spectrum is dominated by an atmosphere with the same temperature as during the high-flux period, but with several emission features superimposed. Some of the emission lines are well modeled with an optically thin plasma in collisional equilibrium, rich in C and N, which also explains some excess in the spectra of the high-flux period. No velocity shifts are observed in the absorption lines, with an upper limit set by the spectral resolution of 500 km s-1, consistent with the expectation of a non-expanding atmosphere so late in the evolution of the post-nova. Based on

Optical flare of an X-ray source XMMSL1 J014956.7+533504

NASA Astrophysics Data System (ADS)

Korotkiy, S. A.; Sokolovsky, K. V.

2012-01-01

A bright (unfiltered magnitude 12.8) optical flare was detected on 2012 January 29 at position 01:49:56.77 +53:35:01.8 (+/-0.5", J2000) coinciding with an X-ray source listed in the XMM-Newton slew survey catalog XMMSL1 J014956.7+533504 (Saxton et al. 2008, A&A, 480, 611), an optical object USNO-B1.0 1435-0053799 (B1mag=15.96, R1mag=14.86; Monet et al. 2003, AJ, 125, 984), and a near-infrared object 2MASS 01495682+5335017.

Shedding New Light on the Innermost Regions of AGN with XMM, Suzaku and NuSTAR

NASA Astrophysics Data System (ADS)

Brenneman, Laura

We request funding for two years ($257,041 in total) in support of accepted XMM- Newton and Suzaku observations of six bright, nearby active galactic nuclei (AGN): MCG-6-30-15, Ark 120, SWIFT J2127.4+5654, 3C120, NGC 4151 and IC 4329A. The first four of these AGN are to be observed simultaneously with XMM and NuSTAR during XMM's AO11 cycle, while the last two AGN will be studied simultaneously with Suzaku and NuSTAR during Suzaku's AO7 cycle. All six AGN observations were approved with priority A, and our observing campaign totals 1.14 Msec of exposure time. The XMM and Suzaku programs share four common goals: (1) to measure the angular momenta of the supermassive black holes (SMBHs) at the hearts of these active galaxies, (2) to accurately characterize the physical properties of the poorly understood inner accretion disk/corona region in these AGN, and (3) to identify the driver(s) of the spectral variability across multiple physical timescales in these systems, and (4) to examine correlations that exist between the various physical properties of these SMBHs and their surroundings. These three science goals address a critical component of NASA's Physics of the Cosmos mission: "the behavior of matter and energy in extreme environments." The high prioritization and long exposures of our awarded XMM and Suzaku observations underscore the scientific merit of these goals, as judged by the high-energy astronomy community. Our observing campaign will yield simultaneous broad-band X-ray spectra (0.2-80 keV) of these AGN with the best signal-to-noise and spectral resolution ever obtained across this energy range, guaranteeing new insights into the physics at work in the innermost regions around SMBHs. Using a combination of timing analysis and detailed spectral modeling, we will achieve the first truly accurate understanding of the nature of the X-ray continuum in AGN. The low-background, high-energy data from NuSTAR in tandem with the sensitivity at lower energies from

PATCHY ACCRETION DISKS IN ULTRA-LUMINOUS X-RAY SOURCES

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

Miller, J. M.; Bachetti, M.; Barret, D.

2014-04-10

The X-ray spectra of the most extreme ultra-luminous X-ray sources—those with L ≥ 10{sup 40} erg s{sup –1}—remain something of a mystery. Spectral roll-over in the 5-10 keV band was originally detected in the deepest XMM-Newton observations of the brightest sources; this is confirmed in subsequent NuSTAR spectra. This emission can be modeled via Comptonization, but with low electron temperatures (kT{sub e} ≅ 2 keV) and high optical depths (τ ≅ 10) that pose numerous difficulties. Moreover, evidence of cooler thermal emission that can be fit with thin disk models persists, even in fits to joint XMM-Newton and NuSTAR observations.more » Using NGC 1313 X-1 as a test case, we show that a patchy disk with a multiple temperature profile may provide an excellent description of such spectra. In principle, a number of patches within a cool disk might emit over a range of temperatures, but the data only require a two-temperature profile plus standard Comptonization, or three distinct blackbody components. A mechanism such as the photon bubble instability may naturally give rise to a patchy disk profile, and could give rise to super-Eddington luminosities. It is possible, then, that a patchy disk (rather than a disk with a standard single-temperature profile) might be a hallmark of accretion disks close to or above the Eddington limit. We discuss further tests of this picture and potential implications for sources such as narrow-line Seyfert-1 galaxies and other low-mass active galactic nuclei.« less

Isaac Newton: Eighteenth-century Perspectives

NASA Astrophysics Data System (ADS)

Hall, A. Rupert

1999-05-01

This new product of the ever-flourishing Newton industry seems a bit far-fetched at first sight: who but a few specialists would be interested in the historiography of Newton biography in the eighteenth century? On closer inspection, this book by one of the most important Newton scholars of our day turns out to be of interest to a wider audience as well. It contains several biographical sketches of Newton, written in the decades after his death. The two most important ones are the Eloge by the French mathematician Bernard de Fontenelle and the Italian scholar Paolo Frisi's Elogio. The latter piece was hitherto unavailable in English translation. Both articles are well-written, interesting and sometimes even entertaining. They give us new insights into the way Newton was revered throughout Europe and how not even the slightest blemish on his personality or work could be tolerated. An example is the way in which Newton's famous controversy with Leibniz is treated: Newton is without hesitation presented as the wronged party. Hall has provided very useful historical introductions to the memoirs as well as footnotes where needed. Among the other articles discussed is a well-known memoir by John Conduitt, who was married to Newton's niece. This memoir, substantial parts of which are included in this volume, has been a major source of personal information for Newton biographers up to this day. In a concluding chapter, Hall gives a very interesting overview of the later history of Newton biography, in which he describes the gradual change from adoration to a more critical approach in Newton's various biographers. In short, this is a very useful addition to the existing biographical literature on Newton. A J Kox

Resolving the Large Scale Spectral Variability of the Luminous Seyfert 1 Galaxy 1H 0419-577: Evidence for a New Emission Component and Absorption by Cold Dense Matter

NASA Technical Reports Server (NTRS)

Pounds, K. A.; Reeves, J. N.; Page, K. L.; OBrien, P. T.

2004-01-01

An XMM-Newton observation of the luminous Seyfert 1 galaxy 1H 0419-577 in September 2002, when the source was in an extreme low-flux state, found a very hard X-ray spectrum at 1-10 keV with a strong soft excess below -1 keV. Comparison with an earlier XMM-Newton observation when 1H 0419-577 was X-ray bright indicated the dominant spectral variability was due to a steep power law or cool Comptonised thermal emission. Four further XMM-Newton observations, with 1H 0419-577 in intermediate flux states, now support that conclusion, while we also find the variable emission component in intermediate state difference spectra to be strongly modified by absorption in low ionisation matter. The variable soft excess then appears to be an artefact of absorption of the underlying continuum while the core soft emission can be attributed to re- combination in an extended region of more highly ionised gas. We note the wider implications of finding substantial cold dense matter overlying (or embedded in) the X-ray continuum source in a luminous Seyfert 1 galaxy.

X-Ray Properties of the Youngest Radio Sources and Their Environments

NASA Astrophysics Data System (ADS)

Siemiginowska, Aneta; Sobolewska, Małgosia; Migliori, Giulia; Guainazzi, Matteo; Hardcastle, Martin; Ostorero, Luisa; Stawarz, Łukasz

2016-05-01

We present the first results from our X-ray study of young radio sources classified as compact symmetric objects (CSOs). Using the Chandra X-ray Observatory we observed six CSOs for the first time in X-rays, and re-observed four CSOs already observed with XMM-Newton or BeppoSAX. We also included six other CSOs with archival data to built a pilot study of a sample of the 16 CSO sources observed in X-rays to date. All the sources are nearby, z\\lt 1, and the age of their radio structures (\\lt 3000 yr) has been derived from the expansion velocity of their hot spots. Our results show the heterogeneous nature of the CSOs’ X-ray emission, indicating a complex environment associated with young radio sources. The sample covers a range in X-ray luminosity, {L}2{--10{keV}}˜ {10}41-1045 erg s-1, and intrinsic absorbing column density of {N}{{H}}≃ {10}21-1022 cm-2. In particular, we detected extended X-ray emission in 1718-649 a hard photon index of {{Γ }}≃ 1 in 2021+614 and 1511+0518 consistent with either a Compton-thick absorber or non-thermal emission from compact radio lobes, and in 0710+439 an ionized iron emission line at {E}{rest}=(6.62+/- 0.04) keV and EW ˜ 0.15-1.4 keV, and a decrease by an order of magnitude in the 2-10 keV flux since the 2008 XMM-Newton observation in 1607+26. We conclude that our pilot study of CSOs provides a variety of exceptional diagnostics and highlights the importance of deep X-ray observations of large samples of young sources. This is necessary in order to constrain theoretical models for the earliest stage of radio source evolution and to study the interactions of young radio sources with the interstellar environment of their host galaxies.

X-ray observations of Galactic H.E.S.S. sources: an update

NASA Astrophysics Data System (ADS)

Puehlhofer, G.; Eger, P.; Sasaki, M.; Gottschall, D.; Capasso, M.; H. E. S. S. Collaboration

2016-06-01

X-ray diagnostics of TeV sources continues to be an important tool to identify the nature of newly detected sources as well as to pinpoint the physics processes that are at work in these highly energetic objects. The contribution aims at giving a review of recent studies that we have performed on TeV sources with H.E.S.S. and XMM-Newton and also other X-ray facilities. Here, we will mainly focus on Galactic objects such as gamma-ray binaries, pulsar wind nebulae, and supernova remnants (SNRs). Particular emphasis will be given to SNR studies, including recently identified SNRs such as HESS J1731-347 and HESS J1534-571 as well as a revisit of RX J1713.7-3946.

X-ray sources associated with young stellar objects in the star formation region CMa R1

NASA Astrophysics Data System (ADS)

Santos-Silva, Thais; Gregorio-Hetem, Jane; Montmerle, Thierry

2013-07-01

In previous works we studied the star formation scenario in the molecular cloud Canis Major R1 (CMa R1), derived from the existence of young stellar population groups near the Be stars Z CMa and GU CMa. Using data from the ROSAT X-ray satellite, having a field-of-view of ~ 1° in diameter, Gregorio-Hetem et al. (2009) discovered in this region young stellar objects mainly grouped in two clusters of different ages, with others located in between. In order to investigate the nature of these objects and to test a possible scenario of sequential star formation in this region, four fields (each 30 arcmin diameter, with some overlap) have been observed with the XMM-Newton satellite, with a sensitivity about 10 times better than ROSAT. The XMM-Newton data are currently under analysis. Preliminary results indicate the presence of about 324 sources, most of them apparently having one or more near-infrared counterparts showing typical colors of young stars. The youth of the X-ray sources was also confirmed by X-ray hardness ratio diagrams (XHRD), in different energy bands, giving an estimate of their Lx/Lbol ratios. In addition to these results, we present a detailed study of the XMM field covering the cluster near Z CMa. Several of these sources were classified as T Tauri and Herbig Ae/Be stars, using optical spectroscopy obtained with Gemini telescopes, in order to validate the use of XHRD applied to the entire sample. This classification is also used to confirm the relation between the luminosities in the near-infrared and X-ray bands expected for the T Tauri stars in CMa R1. In the present work we show the results of the study based on the spectra of about 90 sources found nearby Z CMa. We checked that the X-ray spectra (0.3 to 10 keV) of young objects is different from that observed in field stars and extragalactic objects. Some of the candidates also have light curve showing flares that are typical of T Tauri stars, which confirms the young nature of these X

The very faint hard state of the persistent neutron star X-ray binary SLX 1737-282 near the Galactic Centre

NASA Astrophysics Data System (ADS)

Armas Padilla, M.; Ponti, G.; De Marco, B.; Muñoz-Darias, T.; Haberl, F.

2018-01-01

We report on a detailed study of the spectral and temporal properties of the neutron star low-mass X-ray binary SLX 1737-282, which is located only ∼1° away from Sgr A*. The system is expected to have a short orbital period, even within the ultracompact regime, given its persistent nature at low X-ray luminosities and the long duration thermonuclear burst that it has displayed. We have analysed a Suzaku (18 ks) observation and an XMM-Newton (39 ks) observation taken 7 yr apart. We infer (0.5-10 keV) X-ray luminosities in the range of 3-6 × 1035ergs-1, in agreement with previous findings. The spectra are well described by a relatively cool (kTbb = 0.5 keV) blackbody component plus a Comptonized emission component with Γ ∼ 1.5-1.7. These values are consistent with the source being in a faint hard state, as confirmed by the ∼20 per cent fractional root-mean-square amplitude of the fast variability (0.1-7 Hz) inferred from the XMM-Newton data. The electron temperature of the corona is ≳7 keV for the Suzaku observation, but it is measured to be as low as ∼2 keV in the XMM-Newton data at higher flux. The latter is significantly lower than expected for systems in the hard state. We searched for X-ray pulsations and imposed an upper limit to their semi-amplitude of 2 per cent (0.001-7 Hz). Finally, we investigated the origin of the low-frequency variability emission present in the XMM-Newton data and ruled out an absorption dip origin. This constraint the orbital inclination of the system to ≲65° unless the orbital period is longer than 11 h (i.e. the length of the XMM-Newton observation).

Multiwavelength follow-up observations of the tidal disruption event candidate 2XMMi J184725.1-631724

NASA Astrophysics Data System (ADS)

Lin, Dacheng; Strader, Jay; Carrasco, Eleazar R.; Godet, Olivier; Grupe, Dirk; Webb, Natalie A.; Barret, Didier; Irwin, Jimmy A.

2018-03-01

The ultrasoft X-ray flare 2XMMi J184725.1-631724 was serendipitously detected in two XMM-Newton observations in 2006 and 2007, with a peak luminosity of 6 × 1043 erg s-1. It was suggested to be a tidal disruption event (TDE) because its position is consistent with the centre of an inactive galaxy. It is the only known X-ray TDE candidate whose X-ray spectra showed evidence of a weak steep power-law component besides a dominant supersoft thermal disc. We have carried out multiwavelength follow-up observations of the event. Multiple X-ray monitorings show that the X-ray luminosity has decayed significantly after 2011. Especially, in our deep Chandra observation in 2013, we detected a very faint counterpart that supports the nuclear origin of 2XMMi J184725.1-631724 but had an X-ray flux a factor of ˜1000 lower than in the peak of the event. Compared with follow-up ultraviolet (UV) observations, we found that there might be some enhanced UV emission associated with the TDE in the first XMM-Newton observation. We also obtained a high-quality UV-optical spectrum with the Southern Astrophysical Research (SOAR) Telescope and put a very tight constraint on the persistent nuclear activity, with a persistent X-ray luminosity expected to be lower than the peak of the flare by a factor of >2700. Therefore, our multiwavelength follow-up observations strongly support the TDE explanation of the event.

X-ray diving in the center of Sh2-129: looking for the driving source of Ou4

NASA Astrophysics Data System (ADS)

Grosso, Nicolas

2012-10-01

The outflow phenomenon is associated both with the early and the last phase of the stellar evolution. Recently, a unique bipolar outflow with an angular size of 1.2 degrees was discovered in the blister HII region Sh2-129. Ou4, nicknamed "The Giant Squid", is to our knowledge the bipolar outflow with the largest angular size ever found. We propose joint XMM-Newton/EPIC (35 ks) and Chandra/HRC-I (16 ks) observations to look for the driving source of Ou4 and to clarify the nature of this object.

Enhancing the view of a million galaxies

NASA Astrophysics Data System (ADS)

2004-06-01

Composite image hi-res Size hi-res: 851 KB Credits: ESA/Univ. of Leicester/I. Stewart and M. Watson XMM-Newton X-ray spectral colour composite image XMM-Newton X-ray spectral colour composite image of the Subaru/XMM-Newton Deep Field. The view gives an X-ray pseudo-colour representation of all the sources, coded according to their X-ray energy. More energetic sources are shown in blue and less energetic ones in red. This mosaic image, composed of 7 partially overlapping pointings, maps the full extent of the SXDF and corresponds to an exposure time exceeding one hundred hours. These data form the largest contiguous area over which deep X-ray observations have been performed. Composite image hi-res Size hi-res: 6215 KB Credits: NAOJ/Subaru Telescope XMM-Newton/Subaru colour composite image A colour composite image obtained by combining data taken with the Subaru Telescope in blue, red and near-infrared light. The image, worth over two hundred hours of exposure time, covers an area of sky seven times larger than the full moon. The images in blue light show details several hundred million times fainter than what can be seen with the naked eye. SXDS field hi-res Size hi-res: 448 KB Credits: NAOJ/Subaru Telescope SXDS field A particular of the SXDS field. The teardrop-shaped galaxy in the upper right portion of the frame is likely to have suffered from a collision with another galaxy. SXDS field hi-res Size hi-res: 358 KB Credits: NAOJ/Subaru Telescope SXDS field A particular of the SXDS field. The prominent spiral galaxy near the centre may be ineracting with a less-conspicuous dwarf galaxy to its lower right. One of the fundamental goals of modern astronomy is understanding the history of the Universe, and in particular learning about the processes that shape the formation and evolution of galaxies. To observe these processes as they unfold, astronomers must survey galaxies near and far, spanning a large enough volume of the Universe, so that local variations in the

Further constraints on neutron star crustal properties in the low-mass X-ray binary 1RXS J180408.9-342058

NASA Astrophysics Data System (ADS)

Parikh, A. S.; Wijnands, R.; Degenaar, N.; Ootes, L.; Page, D.

2018-05-01

We report on two new quiescent XMM-Newton observations (in addition to the earlier Swift/XRT and XMM-Newton coverage) of the cooling neutron star crust in the low-mass X-ray binary 1RXS J180408.9-342058. Its crust was heated during the ˜4.5 month accretion outburst of the source. From our quiescent observations, fitting the spectra with a neutron star atmosphere model, we found that the crust had cooled from ˜100 to ˜73 eV from ˜8 to ˜479 d after the end of its outburst. However, during the most recent observation, taken ˜860 d after the end of the outburst, we found that the crust appeared not to have cooled further. This suggested that the crust had returned to thermal equilibrium with the neutron star core. We model the quiescent thermal evolution with the theoretical crustal cooling code NSCool and find that the source requires a shallow heat source, in addition to the standard deep crustal heating processes, contributing ˜0.9 MeV per accreted nucleon during outburst to explain its observed temperature decay. Our high quality XMM-Newton data required an additional hard component to adequately fit the spectra. This slightly complicates our interpretation of the quiescent data of 1RXS J180408.9-342058. The origin of this component is not fully understood.

Resolving the Large Scale Spectral Variability of the Luminous Seyfert 1 Galaxy 1H 0419-577

NASA Technical Reports Server (NTRS)

Pounds, K. A.; Reeves, J. N.; Page, K. L.; OBrien, P. T.

2004-01-01

An XMM-Newton observation of the luminous Seyfert 1 galaxy 1H 0419-577 in September 2002, when the source was in an extreme low-flux state, found a very hard X-ray spectrum at 1-10 keV with a strong soft excess below approximately 1 keV. Comparison with an earlier XMM-Newton observation when 1H 0419-577 was X-ray bright indicated the dominant spectral variability was due to a steep power law or cool Comptonized thermal emission. Four further XMM-Newton observations, with 1H 0419-577 in intermediate flux states, now support that conclusion, while we also find the variable emission component in intermediate state difference spectra to be strongly modified by absorption in low ionisation matter. The variable soft excess is seen to be an artefact of absorption of the underlying continuum while the core soft emission is attributed to recombination in an extended region of more highly ionised gas. This new analysis underlines the importance of fully accounting for absorption in characterizing AGN X-ray spectra.

X-RAY SOURCES IN THE DWARF SPHEROIDAL GALAXY DRACO

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

Sonbas, E.; Rangelov, B.; Kargaltsev, O.

2016-04-10

We present the spectral analysis of an 87 ks XMM-Newton observation of Draco, a nearby dwarf spheroidal galaxy. Of the approximately 35 robust X-ray source detections, we focus our attention on the brightest of these sources, for which we report X-ray and multiwavelength parameters. While most of the sources exhibit properties consistent with active galactic nuclei, few of them possess the characteristics of low-mass X-ray binaries (LMXBs) and cataclysmic variable (CVs). Our analysis places constraints on the population of X-ray sources with L{sub X} > 3 × 10{sup 33} erg s{sup −1} in Draco, suggesting that there are no actively accreting black hole andmore » neutron star binaries. However, we find four sources that could be quiescent state LMXBs/CVs associated with Draco. We also place constraints on the central black hole luminosity and on a dark matter decay signal around 3.5 keV.« less

Newton's method

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

More, J. J.; Sorensen, D. C.

1982-02-01

Newton's method plays a central role in the development of numerical techniques for optimization. In fact, most of the current practical methods for optimization can be viewed as variations on Newton's method. It is therefore important to understand Newton's method as an algorithm in its own right and as a key introduction to the most recent ideas in this area. One of the aims of this expository paper is to present and analyze two main approaches to Newton's method for unconstrained minimization: the line search approach and the trust region approach. The other aim is to present some of themore » recent developments in the optimization field which are related to Newton's method. In particular, we explore several variations on Newton's method which are appropriate for large scale problems, and we also show how quasi-Newton methods can be derived quite naturally from Newton's method.« less

Surprise Discovery of Highly Developed Structure in the Young Universe

NASA Astrophysics Data System (ADS)

2005-03-01

ESO-VLT and ESA XMM-Newton Together Discover Earliest Massive Cluster of Galaxies Known Summary Combining observations with ESO's Very Large Telescope and ESA's XMM-Newton X-ray observatory, astronomers have discovered the most distant, very massive structure in the Universe known so far. It is a remote cluster of galaxies that is found to weigh as much as several thousand galaxies like our own Milky Way and is located no less than 9,000 million light-years away. The VLT images reveal that it contains reddish and elliptical, i.e. old, galaxies. Interestingly, the cluster itself appears to be in a very advanced state of development. It must therefore have formed when the Universe was less than one third of its present age. The discovery of such a complex and mature structure so early in the history of the Universe is highly surprising. Indeed, until recently it would even have been deemed impossible. PR Photo 05a/05: Discovery X-Ray Image of the Distant Cluster (ESA XMM-Netwon) PR Photo 05b/05: False Colour Image of XMMU J2235.3-2557 (FORS/VLT and ESA XMM-Newton) Serendipitous discovery ESO PR Photo 05a/05 ESO PR Photo 05a/05 Discovery X-Ray Image of the Distant Cluster (ESA XMM-Newton) [Preview - JPEG: 400 x 421 pix - 106k] [Normal - JPEG: 800 x 842 pix - 843k] [Full Res - JPEG: 2149 x 2262 pix - 2.5M] Caption: ESO PR Photo 05a/05 is a reproduction of the XMM-Newton observations of the nearby active galaxy NGC7314 (bright object in the centre) from which the newly found distant cluster (white box) was serendipitously identified. The circular field-of-view of XMM-Newton is half-a-degree in diameter, or about the same angular size as the Full Moon. The inset shows the diffuse X-ray emission from the distant cluster XMMU J2235.3-2557. Clusters of galaxies are gigantic structures containing hundreds to thousands of galaxies. They are the fundamental building blocks of the Universe and their study thus provides unique information about the underlying architecture of the

The SWIFT AGN and Cluster Survey. I. Number Counts of AGNs and Galaxy Clusters

NASA Astrophysics Data System (ADS)

Dai, Xinyu; Griffin, Rhiannon D.; Kochanek, Christopher S.; Nugent, Jenna M.; Bregman, Joel N.

2015-05-01

The Swift active galactic nucleus (AGN) and Cluster Survey (SACS) uses 125 deg2 of Swift X-ray Telescope serendipitous fields with variable depths surrounding γ-ray bursts to provide a medium depth (4× {{10}-15} erg cm-2 s-1) and area survey filling the gap between deep, narrow Chandra/XMM-Newton surveys and wide, shallow ROSAT surveys. Here, we present a catalog of 22,563 point sources and 442 extended sources and examine the number counts of the AGN and galaxy cluster populations. SACS provides excellent constraints on the AGN number counts at the bright end with negligible uncertainties due to cosmic variance, and these constraints are consistent with previous measurements. We use Wide-field Infrared Survey Explorer mid-infrared (MIR) colors to classify the sources. For AGNs we can roughly separate the point sources into MIR-red and MIR-blue AGNs, finding roughly equal numbers of each type in the soft X-ray band (0.5-2 keV), but fewer MIR-blue sources in the hard X-ray band (2-8 keV). The cluster number counts, with 5% uncertainties from cosmic variance, are also consistent with previous surveys but span a much larger continuous flux range. Deep optical or IR follow-up observations of this cluster sample will significantly increase the number of higher-redshift (z\\gt 0.5) X-ray-selected clusters.

Properties of the Scuba-2 850 μm Sources in the XMM-LSS Field

NASA Astrophysics Data System (ADS)

Seo, Hyunjong; Jeong, Woong-Seob; Kim, Seong Jin; Pyo, Jeonghyun; Kim, Min Gyu; Ko, Jongwan; Kim, Minjin; Kim, Sam

2017-02-01

We carry out the study of 850 μm sources in a part of the XMM-LSS field. The 850 μm imaging data were obtained by the SCUBA-2 on the James Clerk Maxwell Telescope(JCMT) for three days in July 2015 with an integration time of 6.1 hours, covering a circular area with a radius of 15'. We choose the central area up to a radius of 9.15 arcmin for the study, where the noise distribution is relatively uniform. The root mean square (rms) noise at the center is 2.7 mJy. We identify 17 sources with S/N > 3.5. Differential number count is estimated in flux range between 3.5 and 9.0 mJy after applying various corrections derived by imaging simulations, which is consistent with previous studies. For detailed study on the individual sources, we select three sources with more reliable measurements (S/N > 4.5), and construct their spectral energy distributions (SEDs) from optical to far-infrared band. Redshift distribution of the sources ranges from 0.36 to 3.28, and their physical parameters are extracted using MAGPHYS model, which yield infrared luminosity L_{IR}= 10^{11.3}-10^{13.4} L_{⊙}, star formation rate SFR = 10^{1.3}-10^{3.2} M_{⊙}yr^{-1} and dust temperature T_{D} = 30-53 K. We investigate the correlation between L_{IR} and T_{D}, which appears to be consistent with previous studies.}

The Star Formation History of SHADES Sources

NASA Astrophysics Data System (ADS)

Aretxaga, Itziar; SHADES Consortium; AzTEC Team

2006-12-01

We present the redshift distribution of the SHADES 850um selected galaxy population based on the rest-frame radio-mm-FIR colours of 120 robustly detected sources in the Lockman Hole East (LH) and Subaru XMM-Newton Deep Field (SXDF). The redshift of sources constrained with at least two photometric bands peaks at z 2.4 and has a near-Gaussian distribution. The inclusion of sources detected only at 850um, for which only very weak redshift constraints are available, leads to the possibility of a high-redshit tail. We find a small difference between the redshift distributions in the two fields; the SXDF peaking at a slightly lower redshift than the LH, which we mainly attribute to the noise properties of the photometry used. We discuss the impact of the AzTEC data on the further precission of these results. Finally we present a brief comparison with sub-mm galaxy formation models and their predicted and assumed redshift distributions and derive the contribution of these sources to the star formation rate density at different epochs.

Serendipitous Science Engagement: A Family Self-Ethnography

ERIC Educational Resources Information Center

Vedder-Weiss, Dana

2017-01-01

While opportunities for spontaneous, undesigned, serendipitous science engagement (SSE) are abundant and evidence regarding its affordances is accumulating, little is known about its nature. In this paper, I present a model defining and identifying SSE, which consists of a personal and a contextual continuum. To explore the nature of family SSE, I…

Pulse Phase Dependence of Low Energy Emission Lines in an X-ray pulsar 4U 1626-67 during its spin-up and spin-down phase

NASA Astrophysics Data System (ADS)

Beri, Aru; Paul, Biswajit; Dewangan, Gulab Chand

2016-07-01

We will present the results obtained from the new observation of an ultra-compact X-ray binary pulsar 4U 1626-67, carried out with the XMM-Newton observatory. 4U 1626-67, a unique accretion powered pulsar underwent two torque reversals since its discovery in 1977. Pulse phase resolved spectroscopy of this source performed using the data from the XMM-Newton observatory during its spin-down phase revealed the dependence of the emission lines on the pulse phase. O VII emission line at 0.569 keV showed the maximum variation by factor of 4. These variations were interpreted due to warps in the accretion disk (Beri et al. 2015). Radiation pressure induced warping is also believed to be the cause for spin-down. In light of this possible explanation for spin-down torque reversal we expect different line variability during the spin-up phase. We will discuss the implications of the results obtained after performing pulse phase resolved spectroscopy using data from the EPIC-pn during the current spin-up phase. Detailed study of the prominent Neon and Oxygen line complexes with the high resolution Reflection Grating Spectrometer (RGS) on-board XMM-Newton will also be presented.

The XCatDB, a Rich 3XMM Catalogue Interface

NASA Astrophysics Data System (ADS)

Michel, L.; Grisé, F.; Motch, C.; Gomez-Moran, A. N.

2015-09-01

The last release of the XMM catalog, the 3XMM-DR4 published in July 2013, is the largest X-ray catalog ever built. It includes lots of data products such as spectra, time series, images, previews, and extractions of archival catalogs matching the position of X-ray sources. The Strasbourg Observatory built an original interface called XCatDB. It was designed to make the best of this wide set of related products with an emphasis on the images. Besides, it offers an easy access to all other catalog parameters. Users can select data with very elaborate queries and can process them with online services such as an X-ray spectral fitting routine. The combination of all these features allows the users to select data of interest to the naked eye as well as to filter catalog parameters. Data selections can be picked out for further scientific analysis thanks to an interface operating external VO clients. The XcatDB has been developed with Saada.

XMM-Newton Proposal 03024201

NASA Astrophysics Data System (ADS)

Barth, Aaron

2004-10-01

POX 52 is a Narrow-Line Seyfert 1 galaxy with extreme and unusual properties. Its black hole mass, estimated from the optical spectrum of the AGN, is only ~10^5 solar masses; its host galaxy is a dwarf elliptical with a velocity dispersion of only 36+/-5 km/s; and it is radiating at L/L_Edd ~ 1. POX 52 offers a unique opportunity to study black hole accretion at high accretion rates in a mass range that has barely been explored previously. We request 100 ksec of EPIC-pn observations of this unique AGN in order to characterize its X-ray spectrum and absorption, to search for Fe K line emission, to study its variability properties, and to search for quasi-periodic oscillations with the aim of better constraining the black hole mass.

ESA's X-ray space observatory XMM takes first pictures

NASA Astrophysics Data System (ADS)

2000-02-01

Under the aegis of Prof. Roger Bonnet, ESA Director of Science, the mission's Principal Investigators will be presenting these spectacular first images at a press conference to be held on 9 February at the ESA Vilspa facility at Villafranca/Madrid in Spain, where the XMM Science Operations Centre is located. The event will also be the occasion for several major announcements concerning the XMM mission. In particular Professor Bonnet will launch the third XMM competition "Stargazing" - previously announced in September 1999. This will address European youngsters, 16 to 18 years old, who will be offered the unique opportunity of winning observing time using the X-ray telescope. Commissioning phase starts After a successful launch from Kourou on Ariane 504 on 10 December 1999, XMM was brought to its final operational orbit in the following week. The telescope doors on the X-ray Mirror Modules and on the Optical Monitor telescope were opened on 17/18 December. The Radiation Monitor was activated on 19 December and the spacecraft was put into a quiet mode over the Christmas and New Year period. The mission's scientific data is being received, processed and dispatched to astronomers by the XMM Science Operations Centre in Villafranca. Operations with the spacecraft restarted there on 4 January when, as part of the commissioning phase, all the science payloads were switched on one after the other for initial verifications. By the week of 17 January functional tests had begun on the Optical Monitor, the EPIC pn, the two EPIC MOS and the two RGS instruments. The internal doors of the EPIC cameras were opened whilst keeping the camera filter wheels closed. Astounding first images After a series of engineering exposures, all three EPIC cameras were used in turn, between 19-24 January, to take several views of two different extragalactic regions of the Universe. These views, featuring a variety of extended and X-ray point sources, were chosen to demonstrate the full

Serendipitous discovery of quadruply imaged quasars: two diamonds

NASA Astrophysics Data System (ADS)

Lucey, John R.; Schechter, Paul L.; Smith, Russell J.; Anguita, T.

2018-05-01

Gravitationally lensed quasars are powerful and versatile astrophysical tools, but they are challengingly rare. In particular, only ˜25 well-characterized quadruple systems are known to date. To refine the target catalogue for the forthcoming Taipan Galaxy Survey, the images of a large number of sources are being visually inspected in order to identify objects that are confused by a foreground star or galaxies that have a distinct multicomponent structure. An unexpected by-product of this work has been the serendipitous discovery of about a dozen galaxies that appear to be lensing quasars, i.e. pairs or quartets of foreground stellar objects in close proximity to the target source. Here, we report two diamond-shaped systems. Follow-up spectroscopy with the IMACS instrument on the 6.5m Magellan Baade telescope confirms one of these as a z = 1.975 quasar quadruply lensed by a double galaxy at z = 0.293. Photometry from publicly available survey images supports the conclusion that the other system is a highly sheared quadruply imaged quasar. In starting with objects thought to be galaxies, our lens finding technique complements the conventional approach of first identifying sources with quasar-like colours and subsequently finding evidence of lensing.

45 CFR 674.7 - Exception for serendipitous finds.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 3 2010-10-01 2010-10-01 false Exception for serendipitous finds. 674.7 Section 674.7 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION... meteorite for scientific research purposes, provided that the meteorite is collected in the manner most...

The 2-79 keV X-ray Spectrum of the Circinus Galaxy with NuSTAR, XMM-Newton and Chandra: a Fully Compton-Thick Active Galactic Nucleus

DOE PAGES

Arevalo, P.; Bauer, F. E.; Puccetti, S.; ...

2014-07-30

Here, the Circinus galaxy is one of the closest obscured active galactic nuclei (AGNs), making it an ideal target for detailed study. Combining archival Chandra and XMM-Newton data with new NuSTAR observations, we model the 2-79 keV spectrum to constrain the primary AGN continuum and to derive physical parameters for the obscuring material. Chandra's high angular resolution allows a separation of nuclear and off-nuclear galactic emission. In the off-nuclear diffuse emission, we find signatures of strong cold reflection, including high equivalent-width neutral Fe lines. This Compton-scattered off-nuclear emission amounts to 18% of the nuclear flux in the Fe line region,more » but becomes comparable to the nuclear emission above 30 keV. The new analysis no longer supports a prominent transmitted AGN component in the observed band. We find that the nuclear spectrum is consistent with Compton scattering by an optically thick torus, where the intrinsic spectrum is a power law of photon index Γ = 2.2-2.4, the torus has an equatorial column density of N H = (6-10) × 10 24 cm –2, and the intrinsic AGN 2-10 keV luminosity is (2.3-5.1) × 10 42 erg s –1. These values place Circinus along the same relations as unobscured AGNs in accretion rate versus Γ and L X versus L IR phase space. NuSTAR's high sensitivity and low background allow us to study the short timescale variability of Circinus at X-ray energies above 10 keV for the first time. Here, the lack of detected variability favors a Compton-thick absorber, in line with the spectral fitting results.« less

Analyzing Serendipitous Asteroid Observations in Imaging Data using PHOTOMETRYPIPELINE

NASA Astrophysics Data System (ADS)

Ard, Christopher; Mommert, Michael; Trilling, David E.

2016-10-01

Asteroids are nearly ubiquitous in the night sky, making them present in the majority of imaging data taken every night. Serendipitous asteroid observations represent a treasure trove to Solar System researchers: accurate positional measurements of asteroids provide important constraints on their sometimes highly uncertain orbits, whereas calibrated photometric measurements can be used to establish rotational periods, intrinsic colors, or photometric phase curves.We present an add-on to the PHOTOMETRYPIPELINE (PP, github.com/mommermi/photometrypipeline, see Poster presentation 123.42) that identifies asteroids that have been observed serendipitously and extracts astrometry and calibrated photometry for these objects. PP is an open-source Python 2.7 software suite that provides image registration, aperture photometry, photometric calibration, and target identification with only minimal human interaction.Asteroids are identified based on approximate positions that are pre-calculated for a range of dates. Using interpolated coordinates, we identify potential asteroids that might be in the observed field and query their exact positions and positional uncertainties from the JPL Horizons system. The method results in robust astrometry and calibrated photometry for all asteroids in the field as a function of time. Our measurements will supplement existing photometric databases of asteroids and improve their orbits.We present first results using this procedure based on imaging data from the Vatican Advanced Technology Telescope.This work was done in the framework of NAU's REU summer program that is supported by NSF grant AST-1461200. PP was developed in the framework of the "Mission Accessible Near-Earth Object Survey" (MANOS) and is supported by NASA SSO grants NNX15AE90G and NNX14AN82G.

Packet utilisation definitions for the ESA XMM mission

NASA Technical Reports Server (NTRS)

Nye, H. R.

1994-01-01

XMM, ESA's X-Ray Multi-Mirror satellite, due for launch at the end of 1999 will be the first ESA scientific spacecraft to implement the ESA packet telecommand and telemetry standards and will be the first ESOC-controlled science mission to take advantage of the new flight control system infrastructure development (based on object-oriented design and distributed-system architecture) due for deployment in 1995. The implementation of the packet standards is well defined at packet transport level. However, the standard relevant to the application level (the ESA Packet Utilization Standard) covers a wide range of on-board 'services' applicable in varying degrees to the needs of XMM. In defining which parts of the ESA PUS to implement, the XMM project first considered the mission objectives and the derived operations concept and went on to identify a minimum set of packet definitions compatible with these aspects. This paper sets the scene as above and then describes the services needed for XMM and the telecommand and telemetry packet types necessary to support each service.

Substructures in DAFT/FADA survey clusters based on XMM and optical data

NASA Astrophysics Data System (ADS)

Durret, F.; DAFT/FADA Team

2014-07-01

The DAFT/FADA survey was initiated to perform weak lensing tomography on a sample of 90 massive clusters in the redshift range [0.4,0.9] with HST imaging available. The complementary deep multiband imaging constitutes a high quality imaging data base for these clusters. In X-rays, we have analysed the XMM-Newton and/or Chandra data available for 32 clusters, and for 23 clusters we fit the X-ray emissivity with a beta-model and subtract it to search for substructures in the X-ray gas. This study was coupled with a dynamical analysis for the 18 clusters with at least 15 spectroscopic galaxy redshifts in the cluster range, based on a Serna & Gerbal (SG) analysis. We detected ten substructures in eight clusters by both methods (X-rays and SG). The percentage of mass included in substructures is found to be roughly constant with redshift, with values of 5-15%. Most of the substructures detected both in X-rays and with the SG method are found to be relatively recent infalls, probably at their first cluster pericenter approach.

X-ray and optical observations of four polars

NASA Astrophysics Data System (ADS)

Worpel, H.; Schwope, A. D.; Granzer, T.; Reinsch, K.; Schwarz, R.; Traulsen, I.

2016-08-01

Aims: We investigate the temporal and spectral behaviour of four polar cataclysmic variables from the infrared to X-ray regimes, refine our knowledge of the physical parameters of these systems at different accretion rates, and search for a possible excess of soft X-ray photons. Methods: We obtained and analysed four XMM-Newton X-ray observations of three of the sources, two of them discovered with the SDSS and one in the RASS. The X-ray data were complemented by optical photometric and spectroscopic observations and, for two sources, archival Swift observations. Results: SDSSJ032855.00+052254.2 was X-ray bright in two XMM-Newton and two Swift observations, and shows transitions from high and low accretion states on a timescale of a few months. The source shows no significant soft excess. We measured the magnetic field strength at the main accreting pole to be 39 MG and the inclination to be 45° ≤ I ≤ 77°, and we refined the long-term ephemeris. SDSSJ133309.20+143706.9 was X-ray faint. We measured a faint phase X-ray flux and plasma temperature for this source, which seems to spend almost all of its time accreting at a low level. Its inclination is less than about 76°. 1RXSJ173006.4+033813 was X-ray bright in the XMM-Newton observation. Its spectrum contained a modest soft blackbody component, not luminous enough to be considered a significant soft excess. We inferred a magnetic field strength at the main accreting pole of 20 to 25 MG, and that the inclination is less than 77° and probably less than 63°. V808 Aur, also known as CSS081231:J071126+440405, was X-ray faint in the Swift observation, but there is nonetheless strong evidence for bright and faint phases in X-rays and perhaps in UV. Residual X-ray flux from the faint phase is difficult to explain by thermal emission from the white dwarf surface, or by accretion onto the second pole. We present a revised distance estimate of 250 pc. Conclusions: The three systems we were able to study in detail

Super-Eddington accretion on to the neutron star NGC 7793 P13: Broad-band X-ray spectroscopy and ultraluminous X-ray sources

NASA Astrophysics Data System (ADS)

Walton, D. J.; Fürst, F.; Harrison, F. A.; Stern, D.; Bachetti, M.; Barret, D.; Brightman, M.; Fabian, A. C.; Middleton, M. J.; Ptak, A.; Tao, L.

2018-02-01

We present a detailed, broad-band X-ray spectral analysis of the ultraluminous X-ray source (ULX) pulsar NGC 7793 P13, a known super-Eddington source, utilizing data from the XMM-Newton, NuSTAR and Chandra observatories. The broad-band XMM-Newton+NuSTAR spectrum of P13 is qualitatively similar to the rest of the ULX sample with broad-band coverage, suggesting that additional ULXs in the known population may host neutron star accretors. Through time-averaged, phase-resolved and multi-epoch studies, we find that two non-pulsed thermal blackbody components with temperatures ∼0.5 and 1.5 keV are required to fit the data below 10 keV, in addition to a third continuum component which extends to higher energies and is associated with the pulsed emission from the accretion column. The characteristic radii of the thermal components appear to be comparable, and are too large to be associated with the neutron star itself, so the need for two components likely indicates the accretion flow outside the magnetosphere is complex. We suggest a scenario in which the thick inner disc expected for super-Eddington accretion begins to form, but is terminated by the neutron star's magnetic field soon after its onset, implying a limit of B ≲ 6 × 1012 G for the dipolar component of the central neutron star's magnetic field. Evidence of similar termination of the disc in other sources may offer a further means of identifying additional neutron star ULXs. Finally, we examine the spectrum exhibited by P13 during one of its unusual 'off' states. These data require both a hard power-law component, suggesting residual accretion on to the neutron star, and emission from a thermal plasma, which we argue is likely associated with the P13 system.

X-ray shout echoing through space

NASA Astrophysics Data System (ADS)

2004-01-01

a flash of X-rays hi-res Size hi-res: 3991 Kb Credits: ESA, S. Vaughan (University of Leicester) EPIC camera shows the expanding rings caused by a flash of X-rays XMM-Newton's X-ray EPIC camera shows the expanding rings caused by a flash of X-rays scattered by dust in our Galaxy. The X-rays were produced by a powerful gamma-ray burst that took place on 3 December 2003. The slowly fading afterglow of the gamma-ray burst is at the centre of the expanding rings. Other, unrelated, X-ray sources can also be seen. The time since the gamma-ray explosion is shown in each panel in hours. At their largest size, the rings would appear in the sky about five times smaller than the full moon. a flash of X-rays hi-res Size hi-res: 2153 Kb Credits: ESA, S. Vaughan (University of Leicester) EPIC camera shows the expanding rings caused by a flash of X-rays (Please choose "hi-res" version for animation) XMM-Newton's X-ray EPIC camera shows the expanding rings caused by a flash of X-rays scattered by dust in our Galaxy. The X-rays were produced by a powerful gamma-ray burst that took place on 3 December 2003. The slowly fading afterglow of the gamma-ray burst is at the centre of the expanding rings. Other, unrelated, X-ray sources can also be seen. The time since the gamma-ray explosion is shown in each panel in seconds. At their largest size, the rings would appear in the sky about five times smaller than the full moon. This echo forms when the powerful radiation of a gamma-ray burst, coming from far away, crosses a slab of dust in our Galaxy and is scattered by it, like the beam of a lighthouse in clouds. Using the expanding rings to precisely pin-point the location of this dust, astronomers can identify places where new stars and planets are likely to form. On 3 December 2003 ESA's observatory, Integral, detected a burst of gamma rays, lasting about 30 seconds, from the direction of a distant galaxy. Within minutes of the detection, thanks to a sophisticated alert network, many

BLACK HOLE MASS AND EDDINGTON RATIO DISTRIBUTION FUNCTIONS OF X-RAY-SELECTED BROAD-LINE AGNs AT z {approx} 1.4 IN THE SUBARU XMM-NEWTON DEEP FIELD

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

Nobuta, K.; Akiyama, M.; Ueda, Y.

2012-12-20

In order to investigate the growth of supermassive black holes (SMBHs), we construct the black hole mass function (BHMF) and Eddington ratio distribution function (ERDF) of X-ray-selected broad-line active galactic nuclei (AGNs) at z {approx} 1.4 in the Subaru XMM-Newton Deep Survey (SXDS) field. A significant part of the accretion growth of SMBHs is thought to take place in this redshift range. Black hole masses of X-ray-selected broad-line AGNs are estimated using the width of the broad Mg II line and 3000 A monochromatic luminosity. We supplement the Mg II FWHM values with the H{alpha} FWHM obtained from our NIRmore » spectroscopic survey. Using the black hole masses of broad-line AGNs at redshifts between 1.18 and 1.68, the binned broad-line AGN BHMFs and ERDFs are calculated using the V{sub max} method. To properly account for selection effects that impact the binned estimates, we derive the corrected broad-line AGN BHMFs and ERDFs by applying the maximum likelihood method, assuming that the ERDF is constant regardless of the black hole mass. We do not correct for the non-negligible uncertainties in virial BH mass estimates. If we compare the corrected broad-line AGN BHMF with that in the local universe, then the corrected BHMF at z = 1.4 has a higher number density above 10{sup 8} M{sub Sun} but a lower number density below that mass range. The evolution may be indicative of a downsizing trend of accretion activity among the SMBH population. The evolution of broad-line AGN ERDFs from z = 1.4 to 0 indicates that the fraction of broad-line AGNs with accretion rates close to the Eddington limit is higher at higher redshifts.« less

Rapid X-ray variability properties during the unusual very hard state in neutron-star low-mass X-ray binaries

NASA Astrophysics Data System (ADS)

Wijnands, R.; Parikh, A. S.; Altamirano, D.; Homan, J.; Degenaar, N.

2017-11-01

Here, we study the rapid X-ray variability (using XMM-Newton observations) of three neutron-star low-mass X-ray binaries (1RXS J180408.9-342058, EXO 1745-248 and IGR J18245-2452) during their recently proposed very hard spectral state. All our systems exhibit a strong to very strong noise component in their power density spectra (rms amplitudes ranging from 34 per cent to 102 per cent) with very low characteristic frequencies (as low as 0.01 Hz). These properties are more extreme than what is commonly observed in the canonical hard state of neutron-star low-mass X-ray binaries observed at X-ray luminosities similar to those we observe from our sources. This suggests that indeed the very hard state is a spectral-timing state distinct from the hard state, although we argue that the variability behaviour of IGR J18245-2452 is very extreme and possibly this source was in a very unusual state. We also compare our results with the rapid X-ray variability of the accreting millisecond X-ray pulsars IGR J00291+5934 and Swift J0911.9-6452 (also using XMM-Newton data) for which previously similar variability phenomena were observed. Although their energy spectra (as observed using the Swift X-ray telescope) were not necessarily as hard (i.e. for Swift J0911.9-6452) as for our other three sources, we conclude that likely both sources were also in very similar state during their XMM-Newton observations. This suggests that different sources that are found in this new state might exhibit different spectral hardness and one has to study both the spectral and the rapid variability to identify this unusual state.

Exceptional AGN long-timescale X-ray variability: The case of PHL 1092

NASA Astrophysics Data System (ADS)

Miniutti, G.; Brandt, W. N.; Schneider, D. P.; Fabian, A. C.; Gallo, L. C.; Boller, Th.

2012-12-01

PHL 1092 is a z ˜ 0.4 high-luminosity counterpart of the class of Narrow-Line Seyfert 1 galaxies. In 2008, PHL 1092 was found to be in a remarkably low X-ray flux state during an XMM-Newton observation. Its 2 keV flux density had dropped by a factor of ˜ 260 with respect to a previous observation performed 4.5 yr earlier. The UV flux remained almost constant, resulting in a significant steepening of the optical-to-X-ray slope αox from - 1.57 to - 2.51, making PHL 1092 one of the most extreme X-ray weak quasars with no observed broad absorption lines (BALs) in the UV. We have monitored the source since 2008 with three further XMM-Newton observations, producing a simultaneous UV and X-ray database spanning almost 10 yr in total in the activity of the source. We present here results from our monitoring campaign.

XMM-NEWTON MONITORING OF THE CLOSE PRE-MAIN-SEQUENCE BINARY AK SCO. EVIDENCE OF TIDE-DRIVEN FILLING OF THE INNER GAP IN THE CIRCUMBINARY DISK

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

Gomez de Castro, Ana Ines; Lopez-Santiago, Javier; Talavera, Antonio

2013-03-20

AK Sco stands out among pre-main-sequence binaries because of its prominent ultraviolet excess, the high eccentricity of its orbit, and the strong tides driven by it. AK Sco consists of two F5-type stars that get as close as 11 R{sub *} at periastron passage. The presence of a dense (n{sub e} {approx} 10{sup 11} cm{sup -3}) extended envelope has been unveiled recently. In this article, we report the results from an XMM-Newton-based monitoring of the system. We show that at periastron, X-ray and UV fluxes are enhanced by a factor of {approx}3 with respect to the apastron values. The X-raymore » radiation is produced in an optically thin plasma with T {approx} 6.4 Multiplication-Sign 10{sup 6} K and it is found that the N{sub H} column density rises from 0.35 Multiplication-Sign 10{sup 21} cm{sup -2} at periastron to 1.11 Multiplication-Sign 10{sup 21} cm{sup -2} at apastron, in good agreement with previous polarimetric observations. The UV emission detected in the Optical Monitor band seems to be caused by the reprocessing of the high-energy magnetospheric radiation on the circumstellar material. Further evidence of the strong magnetospheric disturbances is provided by the detection of line broadening of 278.7 km s{sup -1} in the N V line with Hubble Space Telescope/Space Telescope Imaging Spectrograph. Numerical simulations of the mass flow from the circumbinary disk to the components have been carried out. They provide a consistent scenario with which to interpret AK Sco observations. We show that the eccentric orbit acts like a gravitational piston. At apastron, matter is dragged efficiently from the inner disk border, filling the inner gap and producing accretion streams that end as ring-like structures around each component of the system. At periastron, the ring-like structures come into contact, leading to angular momentum loss, and thus producing an accretion outburst.« less

X-ray versus infrared selection of distant galaxy clusters: A case study using the XMM-LSS and SpARCS cluster samples

NASA Astrophysics Data System (ADS)

Willis, J. P.; Ramos-Ceja, M. E.; Muzzin, A.; Pacaud, F.; Yee, H. K. C.; Wilson, G.

2018-04-01

We present a comparison of two samples of z > 0.8 galaxy clusters selected using different wavelength-dependent techniques and examine the physical differences between them. We consider 18 clusters from the X-ray selected XMM-LSS distant cluster survey and 92 clusters from the optical-MIR selected SpARCS cluster survey. Both samples are selected from the same approximately 9 square degree sky area and we examine them using common XMM-Newton, Spitzer-SWIRE and CFHT Legacy Survey data. Clusters from each sample are compared employing aperture measures of X-ray and MIR emission. We divide the SpARCS distant cluster sample into three sub-samples: a) X-ray bright, b) X-ray faint, MIR bright, and c) X-ray faint, MIR faint clusters. We determine that X-ray and MIR selected clusters display very similar surface brightness distributions of galaxy MIR light. In addition, the average location and amplitude of the galaxy red sequence as measured from stacked colour histograms is very similar in the X-ray and MIR-selected samples. The sub-sample of X-ray faint, MIR bright clusters displays a distribution of BCG-barycentre position offsets which extends to higher values than all other samples. This observation indicates that such clusters may exist in a more disturbed state compared to the majority of the distant cluster population sampled by XMM-LSS and SpARCS. This conclusion is supported by stacked X-ray images for the X-ray faint, MIR bright cluster sub-sample that display weak, centrally-concentrated X-ray emission, consistent with a population of growing clusters accreting from an extended envelope of material.

Exploring the Evolution of Star Formation and Dwarf Galaxy Properties with JWST /MIRI Serendipitous Spectroscopic Surveys

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

Bonato, Matteo; Sajina, Anna; McKinney, Jed

The James Webb Space Telescope ’s Medium Resolution Spectrometer (MRS), will offer nearly two orders of magnitude improvement in sensitivity and >3× improvement in spectral resolution over our previous space-based mid-IR spectrometer, the Spitzer IRS. In this paper, we make predictions for spectroscopic pointed observations and serendipitous detections with the MRS. Specifically, pointed observations of Herschel sources require only a few minutes on source integration for detections of several star-forming and active galactic nucleus lines, out to z = 3 and beyond. But the same data will also include tens of serendipitous 0 ≲ z ≲ 4 galaxies per fieldmore » with infrared luminosities ranging ∼10{sup 6}–10{sup 13} L {sub ☉}. In particular, for the first time and for free we will be able to explore the L {sub IR} < 10{sup 9} L {sub ☉} regime out to z ∼ 3. We estimate that with ∼ 100 such fields, statistics of these detections will be sufficient to constrain the evolution of the low- L end of the infrared luminosity function, and hence the star formation rate function. The above conclusions hold for a wide range in the potential low- L end of the IR luminosity function, and account for the PAH deficit in low- L , low-metallicity galaxies.« less

Ensemble X-ray variability of active galactic nuclei. II. Excess variance and updated structure function

NASA Astrophysics Data System (ADS)

Vagnetti, F.; Middei, R.; Antonucci, M.; Paolillo, M.; Serafinelli, R.

2016-09-01

Context. Most investigations of the X-ray variability of active galactic nuclei (AGN) have been concentrated on the detailed analyses of individual, nearby sources. A relatively small number of studies have treated the ensemble behaviour of the more general AGN population in wider regions of the luminosity-redshift plane. Aims: We want to determine the ensemble variability properties of a rich AGN sample, called Multi-Epoch XMM Serendipitous AGN Sample (MEXSAS), extracted from the fifth release of the XMM-Newton Serendipitous Source Catalogue (XMMSSC-DR5), with redshift between ~0.1 and ~5, and X-ray luminosities in the 0.5-4.5 keV band between ~1042 erg/s and ~1047 erg/s. Methods: We urge caution on the use of the normalised excess variance (NXS), noting that it may lead to underestimate variability if used improperly. We use the structure function (SF), updating our previous analysis for a smaller sample. We propose a correction to the NXS variability estimator, taking account of the light curve duration in the rest frame on the basis of the knowledge of the variability behaviour gained by SF studies. Results: We find an ensemble increase of the X-ray variability with the rest-frame time lag τ, given by SF ∝ τ0.12. We confirm an inverse dependence on the X-ray luminosity, approximately as SF ∝ LX-0.19. We analyse the SF in different X-ray bands, finding a dependence of the variability on the frequency as SF ∝ ν-0.15, corresponding to a so-called softer when brighter trend. In turn, this dependence allows us to parametrically correct the variability estimated in observer-frame bands to that in the rest frame, resulting in a moderate (≲15%) shift upwards (V-correction). Conclusions: Ensemble X-ray variability of AGNs is best described by the structure function. An improper use of the normalised excess variance may lead to an underestimate of the intrinsic variability, so that appropriate corrections to the data or the models must be applied to prevent

X-ray Luminosity and Absorption Column Fluctuations in the H2O Maser Galaxy NGC 4258 from Weeks to Years

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

Argon, A.

2004-07-30

The authors report monitoring of the 0.3-10 keV spectrum of NGC 4258 with the XMM-Newton observatory at five epochs over 1.5 years. They also report reprocessing of an overlapping four epoch series of archival Chandra observations (0.5-10 keV). By including earlier ASCA and Beppo-SAX observations, they present a new, nine year time-series of models fit to the X-ray spectrum of NGC 4258. They model the Chandra and XMM-Newton data self-consistently with partially absorbed, hard power-law, soft thermal plasma, and soft power-law components. Over the nine years, the photo-electric absorbing column ({approx} 10{sup 23} cm{sup -2}) did not vary detectably, exceptmore » for a {approx} 40% drop between two ASCA epochs separated by 3 years (in 1993 and 1996) and a {approx} 60% rise between two XMM-Newton epochs separated by just 5 months (in 2001 and 2002). In contrast, factor of 2-3 changes are seen in absorbed flux on the timescale of years. These are uncorrelated with changes in absorbing column and indicative of central engine variability. The most rapid change in luminosity (5-10 keV) that the authors detect (with XMM-Newton and Chandra) is on the order of 30% over 19 days. The warped disk that is a known source of H{sub 2}O maser emission in NGC 4258 is believed to cross the line of sight to the central engine. They propose that the variations in absorbing column arise from inhomogeneities in the rotating disk, as they sweep across the line of sight. They estimate that the inhomogeneities are {approx} 10{sup 15} cm in size.« less

Turbulence measurements in clusters of galaxies with XMM-Newton

NASA Astrophysics Data System (ADS)

Pinto, C.; Fabian, A.; de Plaa, J.; Sanders, J.

2014-07-01

The kinematics structure of the intracluster medium (ICM) in clusters of galaxies is related to the their evolution. AGN feedback, sloshing of gas within the potential well, and galaxy mergers are thought to generate ICM velocity widths of several hundred km/s. Appropriate determinations of turbulent broadening are crucial not only to understand the effects of the central engine onto the evolution of the clusters, but are also mandatory to obtain realistic (emission) line fits and abundances estimate. We have analyzed the data from the CHEERS catalog which includes 1.5 Ms of new observations (PI: Jelle de Plaa) and archival data for a total of 29 clusters and groups of galaxies, and elliptical galaxies. This campaign provided us with a unique database that significantly improves the quality of the existing observations and the measurements of chemical abundances and turbulent broadening. We have applied the continuum-subtraction spectral-fitting method of Sanders and Fabian and measured turbulence, temperatures, and abundances for the sources in the catalog. For some sources we obtain tight estimates of velocity broadening which is related to the past AGN activity and mergers. We will show our results at the conference and their relevance in the context of future missions.

Compton Thick AGN in the XMM-COSMOS field

NASA Astrophysics Data System (ADS)

Lanzuisi, G.; Perna, M.; Delvecchio, I.; Berta, S.; Brusa, M.; Gruppioni, C.; Comastri, A.

2016-06-01

I will present results we published in two recent papers (Lanzuisi et al. 2015, A&A 573A 137, Lanzuisi et al. 2015, A≈A 578A 120) on the properties of X-ray selected Compton Thick (CT, NH>10^{24} cm^{-2}) AGN, in the XMM-COSMOS survey. We exploited the rich multi-wavelength dataset available in this field, to show that CT AGN tend to harbor smaller, rapidly growing SMBH with respect to unobscured AGN, and have a higher chance of being hosted by star-forming, merging and post-merger systems. We also demonstrated the detectability of even more heavily obscured AGN (NH>10^{25} cm^{-2}), thanks to a truly multi-wavelength approach in the same field, and to the unrivaled XMM sensitivity. The extreme source detected in this way shows strong evidences of ongoing powerful AGN feedback, detected as blue-shifted wings of high ionization optical emission lines such as [NeV] and [FeVII], as well as of the [OIII] emission line. The results obtained from these works point toward a scenario in which highly obscured AGN occupy a peculiar place in the galaxy-AGN co-evolution process, in which both the host and the SMBH rapidly evolve toward the local relations.

XMM telescope goes on show for the first time

NASA Astrophysics Data System (ADS)

1997-05-01

After years of little-publicized effort in various parts of Europe, one of the finished XMM telescopes is presented for the first time to the press and other visitors during a press briefing on 22 May at the Centre Spatial de LiŠge (CSL) in Belgium. As the telescope is a flight model due to go into space, the inspection is hands-off, through a clean-room window. But visitors can see the multi-mirror module looking like a log of wood 70 centimetres wide and 60 centimetres long. In cross-section the nesting mirrors make concentric rings resembling the rings of annual growth in a tree --except that there are narrow gaps between the mirrors, to let in the X- rays. Galileo and Newton would not recognize the XMM module as a telescope, but they never had to focus X-rays, which ignore lenses and ordinary mirrors. The German physicist Hans Wolter invented a near-cylindrical mirror that narrows in a geometric fashion, first along a parabola and then a hyperbola. Some of the X-rays entering through the wider end are twice reflected from the interior wall at grazing angles, and go to a focus. When Wolter's concept went into telescopes for X-ray astronomy, most of the X-rays simply missed the mirror, so that any signal was weak. The remedy was to fill the interior with smaller concentric mirrors, to catch more of the X-rays. In practice, that meant either a few mirrors, fashioned and aligned with care to achieve a high resolving power, or many cruder mirrors which sacrificed optical sharpness for the sake of sensitivity. The XMM telescopes are the first to achieve both sharpness and sensitivity, thanks to innovations by European industry made possible by XMM's status as a Cornerstone Mission in ESA's science programme. Carl Zeiss in Germany provided mandrels (moulds) of 58 sizes, all carefully polished to the required paraboloidal-hyperboloidal shape. Media Lario in Italy made the reflective surface by depositing gold on the mandrel under vacuum, and then backed it with nickel

An Improved Newton's Method.

ERIC Educational Resources Information Center

Mathews, John H.

1989-01-01

Describes Newton's method to locate roots of an equation using the Newton-Raphson iteration formula. Develops an adaptive method overcoming limitations of the iteration method. Provides the algorithm and computer program of the adaptive Newton-Raphson method. (YP)

The WWW Cabinet of Curiosities: A Serendipitous Research Tool

ERIC Educational Resources Information Center

Arnold, Josie

2012-01-01

This paper proposes that the WWW is able to be fruitfully understood as a research tool when we utilise the metaphor of the cabinet of curiosities, the wunderkammer. It unpeels some of the research attributes of the metaphor as it reveals the multiplicity of connectivity on the web that provides serendipitous interactions between unexpected…

Characterizing the X-ray Emission in Small Magellanic Cloud Supernova Remnants

NASA Astrophysics Data System (ADS)

Man, Nicole; Auchettl, Katie; Lopez, Laura

2018-01-01

The Small Magellanic Cloud is a close, metal-poor galaxy with active star formation, and it has a diverse population of 24 supernova remnants (SNRs) that have been identified at several wavelengths. Past work has characterized the X-ray emission in these sources separately and aimed to constrain their explosive origins from observations with Chandra and XMM-Newton. Three SNRs have possible evidence for Type Ia explosions based on strong Fe-L emission in their X-ray spectra, although the environments and intermediate-mass element abundances are more consistent with those of core-collapse SNe. In this poster, we analyze the archival Chandra and XMM-Newton observations of the SMC SNR sample, and we model the sources' X-ray spectra in a systematic way to derive the plasma properties and to constrain the nature of the explosions. In one SNR, we note the presence of an X-ray binary near the source's geometric center, suggesting the compact object was produced in the SN explosion. As one of only three SNRs known in the Local Group to host a binary system, this source is worthy of follow-up investigations to probe explosions of massive stars in binary systems.

X-ray versus infrared selection of distant galaxy clusters: a case study using the XMM-LSS and SpARCS cluster samples

NASA Astrophysics Data System (ADS)

Willis, J. P.; Ramos-Ceja, M. E.; Muzzin, A.; Pacaud, F.; Yee, H. K. C.; Wilson, G.

2018-07-01

We present a comparison of two samples of z> 0.8 galaxy clusters selected using different wavelength-dependent techniques and examine the physical differences between them. We consider 18 clusters from the X-ray-selected XMM Large Scale Structure (LSS) distant cluster survey and 92 clusters from the optical-mid-infrared (MIR)-selected Spitzer Adaptation of the Red Sequence Cluster survey (SpARCS) cluster survey. Both samples are selected from the same approximately 9 sq deg sky area and we examine them using common XMM-Newton, Spitizer Wide-Area Infrared Extra-galactic (SWIRE) survey, and Canada-France-Hawaii Telescope Legacy Survey data. Clusters from each sample are compared employing aperture measures of X-ray and MIR emission. We divide the SpARCS distant cluster sample into three sub-samples: (i) X-ray bright, (ii) X-ray faint, MIR bright, and (iii) X-ray faint, MIR faint clusters. We determine that X-ray- and MIR-selected clusters display very similar surface brightness distributions of galaxy MIR light. In addition, the average location and amplitude of the galaxy red sequence as measured from stacked colour histograms is very similar in the X-ray- and MIR-selected samples. The sub-sample of X-ray faint, MIR bright clusters displays a distribution of brightest cluster galaxy-barycentre position offsets which extends to higher values than all other samples. This observation indicates that such clusters may exist in a more disturbed state compared to the majority of the distant cluster population sampled by XMM-LSS and SpARCS. This conclusion is supported by stacked X-ray images for the X-ray faint, MIR bright cluster sub-sample that display weak, centrally concentrated X-ray emission, consistent with a population of growing clusters accreting from an extended envelope of material.

Classification of X-ray sources in the direction of M31

NASA Astrophysics Data System (ADS)

Vasilopoulos, G.; Hatzidimitriou, D.; Pietsch, W.

2012-01-01

M31 is our nearest spiral galaxy, at a distance of 780 kpc. Identification of X-ray sources in nearby galaxies is important for interpreting the properties of more distant ones, mainly because we can classify nearby sources using both X-ray and optical data, while more distant ones via X-rays alone. The XMM-Newton Large Project for M31 has produced an abundant sample of about 1900 X-ray sources in the direction of M31. Most of them remain elusive, giving us little signs of their origin. Our goal is to classify these sources using criteria based on properties of already identified ones. In particular we construct candidate lists of high mass X-ray binaries, low mass X-ray binaries, X-ray binaries correlated with globular clusters and AGN based on their X-ray emission and the properties of their optical counterparts, if any. Our main methodology consists of identifying particular loci of X-ray sources on X-ray hardness ratio diagrams and the color magnitude diagrams of their optical counterparts. Finally, we examined the X-ray luminosity function of the X-ray binaries populations.

The XMM Large Scale Structure Survey

NASA Astrophysics Data System (ADS)

Pierre, Marguerite

2005-10-01

We propose to complete, by an additional 5 deg2, the XMM-LSS Survey region overlying the Spitzer/SWIRE field. This field already has CFHTLS and Integral coverage, and will encompass about 10 deg2. The resulting multi-wavelength medium-depth survey, which complements XMM and Chandra deep surveys, will provide a unique view of large-scale structure over a wide range of redshift, and will show active galaxies in the full range of environments. The complete coverage by optical and IR surveys provides high-quality photometric redshifts, so that cosmological results can quickly be extracted. In the spirit of a Legacy survey, we will make the raw X-ray data immediately public. Multi-band catalogues and images will also be made available on short time scales.

Radio/X-ray monitoring of the broad-line radio galaxy 3C 382. High-energy view with XMM-Newtonand NuSTAR

NASA Astrophysics Data System (ADS)

Ursini, F.; Petrucci, P.-O.; Matt, G.; Bianchi, S.; Cappi, M.; Dadina, M.; Grandi, P.; Torresi, E.; Ballantyne, D. R.; De Marco, B.; De Rosa, A.; Giroletti, M.; Malzac, J.; Marinucci, A.; Middei, R.; Ponti, G.; Tortosa, A.

2018-05-01

We present the analysis of five joint XMM-Newton/NuSTARobservations, 20 ks each and separated by 12 days, of the broad-line radio galaxy 3C 382. The data were obtained as part of a campaign performed in September-October 2016 simultaneously with VLBA. The radio data and their relation with the X-ray ones will be discussed in a following paper. The source exhibits a moderate flux variability in the UV/X-ray bands, and a limited spectral variability especially in the soft X-ray band. In agreement with past observations, we find the presence of a warm absorber, an iron Kα line with no associated Compton reflection hump, and a variable soft excess well described by a thermal Comptonization component. The data are consistent with a "two-corona" scenario, in which the UV emission and soft excess are produced by a warm (kT ≃ 0.6 keV), optically thick (τ ≃ 20) corona consistent with being a slab fully covering a nearly passive accretion disc, while the hard X-ray emission is due to a hot corona intercepting roughly 10% of the soft emission. These results are remarkably similar to those generally found in radio-quiet Seyferts, thus suggesting a common accretion mechanism.

X-ray time lags in PG 1211+143

NASA Astrophysics Data System (ADS)

Lobban, A. P.; Vaughan, S.; Pounds, K.; Reeves, J. N.

2018-05-01

We investigate the X-ray time lags of a recent ˜630 ks XMM-Newton observation of PG 1211+143. We find well-correlated variations across the XMM-Newton EPIC bandpass, with the first detection of a hard lag in this source with a mean time delay of up to ˜3 ks at the lowest frequencies. We find that the energy-dependence of the low-frequency hard lag scales approximately linearly with log(E) when averaged over all orbits, consistent with the propagating fluctuations model. However, we find that the low-frequency lag behaviour becomes more complex on time-scales longer than a single orbit, suggestive of additional modes of variability. We also detect a high-frequency soft lag at ˜10-4 Hz with the magnitude of the delay peaking at ≲ 0.8 ks, consistent with previous observations, which we discuss in terms of small-scale reverberation.

A population of isolated hard X-ray sources near the supernova remnant Kes 69

NASA Astrophysics Data System (ADS)

Bocchino, F.; Bykov, A. M.; Chen, Y.; Krassilchtchikov, A. M.; Levenfish, K. P.; Miceli, M.; Pavlov, G. G.; Uvarov, Yu. A.; Zhou, X.

2012-05-01

Recent X-ray observations of the supernova remnant (SNR) IC 443 interacting with molecular clouds detected a new population of hard X-ray sources related to the remnant itself, which has been proposed to be fast ejecta fragments propagating within the dense environment. Encouraged by these studies, we obtained a deep XMM-Newton observation of the SNR Kes 69, which also shows signs of a shock-cloud interaction. We report on the detection of 18 hard X-ray sources in the field of Kes 69, which is a number sognificantly higher than expected for the Galactic source population in the field. The sources are spatially correlated with CO emission from the cloud in the remnant environment. The spectra of 3 of the 18 sources can be described as hard power-laws with photon indices smaller than two plus line emission associated with K-shell transitions. We discuss the two most promising scenarios for the interpretation of the sources, namely fast ejecta fragments (as in IC 443) and cataclysmic variables. While most of the observational evidence is consistent with the former interpretation, we cannot rule out the latter.

Testing the Paradigm that Ultra-Luminous X-Ray Sources as a Class Represent Accreting Intermediate

NASA Technical Reports Server (NTRS)

Berghea, C. T.; Weaver, K. A.; Colbert, E. J. M.; Roberts, T. P.

2008-01-01

To test the idea that ultraluminous X-ray sources (ULXs) in external galaxies represent a class of accreting Intermediate-Mass Black Holes (IMBHs), we have undertaken a program to identify ULXs and a lower luminosity X-ray comparison sample with the highest quality data in the Chandra archive. We establish a general property of ULXs that the most X-ray luminous objects possess the fattest X-ray spectra (in the Chandra band pass). No prior sample studies have established the general hardening of ULX spectra with luminosity. This hardening occurs at the highest luminosities (absorbed luminosity > or equals 5x10(exp 39) ergs/s) and is in line with recent models arguing that ULXs are actually stellar-mass black holes. From spectral modeling, we show that the evidence originally taken to mean that ULXs are IMBHs - i.e., the "simple IMBH model" - is nowhere near as compelling when a large sample of ULXs is looked at properly. During the last couple of years, XMM-Newton spectroscopy of ULXs has to some large extent begun to negate the simple IMBH model based on fewer objects. We confirm and expand these results, which validates the XMM-Newton work in a broader sense with independent X-ray data. We find (1) that cool disk components are present with roughly equal probability and total flux fraction for any given ULX, regardless of luminosity, and (2) that cool disk components extend below the standard ULX luminosity cutoff of 10(exp 39) ergs/s, down to our sample limit of 10(exp 38:3) ergs/s. The fact that cool disk components are not correlated with luminosity damages the argument that cool disks indicate IMBHs in ULXs, for which a strong statistical support was never made.

Newton's Apple

ERIC Educational Resources Information Center

Hendry, Archibald W.

2007-01-01

Isaac Newton may have seen an apple fall, but it was Robert Hooke who had a better idea of where it would land. No one really knows whether or not Isaac Newton actually saw an apple fall in his garden. Supposedly it took place in 1666, but it was a tale he told in his old age more than 60 years later, a time when his memory was failing and his…

Tracking the Iron Kα line and the Ultra Fast Outflow in NGC 2992 at different accretion states

NASA Astrophysics Data System (ADS)

Marinucci, A.; Bianchi, S.; Braito, V.; Matt, G.; Nardini, E.; Reeves, J.

2018-06-01

The Seyfert 2 galaxy NGC 2992 has been monitored eight times by XMM-Newton in 2010 and then observed again in 2013, while in 2015 it was simultaneously targeted by Swift and NuSTAR. XMM-Newton always caught the source in a faint state (2-10 keV fluxes ranging from 0.3 to 1.6× 10-11 erg cm-2 s-1) but NuSTAR showed an increase in the 2-10 keV flux up to 6× 10-11 erg cm-2 s-1. We find possible evidence of an Ultra Fast Outflow with velocity v1 = 0.21 ± 0.01c (detected at about 99% confidence level) in such a flux state. The UFO in NGC 2992 is consistent with being ejected at a few tens of gravitational radii only at accretion rates greater than 2% of the Eddington luminosity. The analysis of the low flux 2010/2013 XMM data allowed us to determine that the Iron Kα emission line complex in this object is likely the sum of three distinct components: a constant, narrow one due to reflection from cold, distant material (likely the molecular torus); a narrow, but variable one which is more intense in brighter observations and a broad relativistic one emitted in the innermost regions of the accretion disk, which has been detected only in the 2003 XMM observation.

An Extremely Luminous and Variable Ultraluminous X-ray Source in the Outskirts of Circinus Observed with Nustar

NASA Technical Reports Server (NTRS)

Walton, D. J.; Fuerst, F.; Harrison, F.; Stern, D.; Bachetti, M.; Barret, D.; Bauer, F.; Boggs, S. E.; Christensen, F. E.; Craig, W. W.;

Luminosity of serendipitous x-ray QSOs

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

Margon, B.; Chanan, G.A.; Downes, R.A.

1982-02-01

We have identified the optical counterparts of 47 serendipitously discovered Einstein Observatory X-ray sources with previously unreported quasi-stellar objects. The mean ratio of X-ray to optical luminosity of this sample agrees reasonably well with that derived from X-ray observations of previously known QSOs. However, despite the fact that our limiting magnitude V = 18.5 should permit detection of typical QSOs (i.e., M/sub c/ = -26) to z = 0.9, the mean redshift of our sample is only z = 0.42 Thus the mean luminosity of these objects, M/sub c/ = -24, differs significantly from that of previous QSO surveys withmore » similar optical thresholds. The existence of large numbers of these lower luminosity QSOs which are difficult to discover by previous selection techniques, provides observational confirmation of the steep luminosity function inferred indirectly from optical counts. However, possible explanations for the lack of higher luminosity QSOs in our sample prove even more interesting. If one accepts the global value of the X-ray to optical luminosity ratio proposed by Zamorani et al, and Ku, Helfand, and Lucy, then reconciliation of this ratio with our observations severely constrains the QSO space density and luminosity functions. Alternatively, the ''typical'' QSO-a radio quiet, high redshift (z>1), optically luminous but not superluminous (M/sub c/> or =-27) object-may not be a strong X-ray source. This inference is not in conflict with existing results from Einstein X-ray surveys of preselected QSOs, which also fail to detect such objects. The contribution of QSOs to the diffuse X-ray background radiation is therefore highly uncertain, but may be quite small. Current X-ray data probably do not place significant constraints on the optical number counts of faint QSOs.« less

The X-ray luminous galaxy cluster XMMU J1007.4+1237 at z = 1.56. The dawn of starburst activity in cluster cores

NASA Astrophysics Data System (ADS)

Fassbender, R.; Nastasi, A.; Böhringer, H.; Šuhada, R.; Santos, J. S.; Rosati, P.; Pierini, D.; Mühlegger, M.; Quintana, H.; Schwope, A. D.; Lamer, G.; de Hoon, A.; Kohnert, J.; Pratt, G. W.; Mohr, J. J.

2011-03-01

Context. Observational galaxy cluster studies at z > 1.5 probe the formation of the first massive M > 1014 M⊙ dark matter halos, the early thermal history of the hot ICM, and the emergence of the red-sequence population of quenched early-type galaxies. Aims: We present first results for the newly discovered X-ray luminous galaxy cluster XMMU J1007.4+1237 at z = 1.555, detected and confirmed by the XMM-Newton Distant Cluster Project (XDCP) survey. Methods: We selected the system as a serendipitous weak extended X-ray source in XMM-Newton archival data and followed it up with two-band near-infrared imaging and deep optical spectroscopy. Results: We can establish XMMU J1007.4+1237 as a spectroscopically confirmed, massive,bona fide galaxy cluster with a bolometric X-ray luminosity of Lbol_X,500≃(2.1 ± 0.4)× 10^{44} erg/s, a red galaxy population centered on the X-ray emission, and a central radio-loud brightest cluster galaxy. However, we see evidence for the first time that the massive end of the galaxy population and the cluster red-sequence are not yet fully in place. In particular, we find ongoing starburst activity for the third ranked galaxy close to the center and another slightly fainter object. Conclusions: At a lookback time of 9.4 Gyr, the cluster galaxy population appears to be caught in an important evolutionary phase, prior to full star-formation quenching and mass assembly in the core region. X-ray selection techniques are an efficient means of identifying and probing the most distant clusters without any prior assumptions about their galaxy content. Based on observations under programme ID 081.A-0312 collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, and observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC).Figure 2 and Tables 1 and 2 are only

Ultraluminous X-ray sources: new distance indicators?

NASA Astrophysics Data System (ADS)

Różańska, A.; Bresler, K.; Bełdycki, B.; Madej, J.; Adhikari, T. P.

2018-05-01

Aims: In this paper we fit the NuSTAR and XMM-Newton data of three sources: NGC 7793 P13, NGC5907 ULX1, and Circinus ULX5. Methods: Our single model contains emission from a non-spherical system: a neutron star plus an accretion disk directed towards the observer. Results: We obtained a very good fit with the reduced χ2 per degree of freedom equal to 1.08 for P13, 1.01 for ULX1, and 1.14 for ULX5. The normalization of our model constrains the distance to the source. The resulting distances are D = 3.41-0.10+0.11, 6.55-0.81+0.69, and 2.60-0.03+0.05 Mpc for P13, ULX1, and ULX5 respectively. The distances to P13 and ULX5 are in perfect agreement with previous distance measurements to their host galaxies. Conclusions: Our results confirm that P13, ULX1, and ULX5 may contain central hot neutron stars. When the outgoing emission is computed by integration over the emitting surface and successfully fitted to the data, then the resulting model normalization is the direct distance indicator.

An Extremely Luminous and Variable Ultraluminous X-Ray Source in the Outskirts of Circinus Observed with NuSTAR

NASA Astrophysics Data System (ADS)

Walton, D. J.; Fuerst, F.; Harrison, F.; Stern, D.; Bachetti, M.; Barret, D.; Bauer, F.; Boggs, S. E.; Christensen, F. E.; Craig, W. W.; Fabian, A. C.; Grefenstette, B. W.; Hailey, C. J.; Madsen, K. K.; Miller, J. M.; Ptak, A.; Rana, V.; Webb, N. A.; Zhang, W. W.

2013-12-01

Following a serendipitous detection with the Nuclear Spectroscopic Telescope Array (NuSTAR), we present a multi-epoch spectral and temporal analysis of an extreme ultraluminous X-ray source (ULX) located in the outskirts of the Circinus galaxy, hereafter Circinus ULX5, including coordinated XMM-Newton+NuSTAR follow-up observations. The NuSTAR data presented here represent one of the first instances of a ULX reliably detected at hard (E > 10 keV) X-rays. Circinus ULX5 is variable on long time scales by at least a factor of ~5 in flux, and was caught in a historically bright state during our 2013 observations (0.3-30.0 keV luminosity of 1.6 × 1040 erg s-1). During this epoch, the source displayed a curved 3-10 keV spectrum, broadly similar to other bright ULXs. Although pure thermal models result in a high energy excess in the NuSTAR data, this excess is too weak to be modeled with the disk reflection interpretation previously proposed to explain the 3-10 keV curvature in other ULXs. In addition to flux variability, clear spectral variability is also observed. While in many cases the interpretation of spectral components in ULXs is uncertain, the spectral and temporal properties of all the high quality data sets currently available strongly support a simple disk-corona model reminiscent of that invoked for Galactic binaries, with the accretion disk becoming more prominent as the luminosity increases. However, although the disk temperature and luminosity are well correlated across all time scales currently probed, the observed luminosity follows LvpropT 1.70 ± 0.17, flatter than expected for simple blackbody radiation. The spectral variability displayed here is highly reminiscent of that observed from known Galactic black hole binaries (BHBs) at high luminosities. This comparison implies a black hole mass of ~90 M ⊙ for Circinus ULX5. However, given the diverse behavior observed from Galactic BHB accretion disks, this mass estimate is still uncertain. Finally, the

IGR J16318-4848: 7 Years of INTEGRAL Observations

NASA Technical Reports Server (NTRS)

Barragan, Laura; Wilms, Joern; kreykenbohm, Ingo; Hanke, manfred; Fuerst, Felix; Pottschmidt, Katja; Rothschild, Richard

2011-01-01

Since the discovery of IGR 116318-4848 in 2003 January, INTEGRAL has accumulated more than 5.8 Ms in IBIS/ISGRI. We present the first extensive analysis of the archival INTEGRAL data (IBIS/ISGRI, and JEM-X when available) for this source, together with the observations carried out by XMM-Newton (twice in 2003, and twice in 2004) and Suzaku (2006). The source is very variable in the long-term, with periods of low activity, where the source is almost not detected, and flares with a luminosity approximately 10 times greater than its average value (5.4 cts/s). IGR 116318-4848 is a HMXB containing a sgB[e] star and a compact object (most probably a neutron star) deeply embedded in the stellar wind of the mass donor. The variability of the source (also in the short-term) can be ascribed to the wind of the optical star being very clumpy. We study the variation of the spectral parameters in time scales of INTEGRAL revolutions. The photoelectric absorption is, with NH around 10(exp 24)/ square cm, unusually high. During brighter phases the strong K-alpha iron line known from XMM-Newton and Suzaku observations is also detectable with the JEM-X instrument.

Testing the Paradigm that Ultraluminous X-Ray Sources as a Class Represent Accreting Intermediate-Mass Black Holes

NASA Astrophysics Data System (ADS)

Berghea, C. T.; Weaver, K. A.; Colbert, E. J. M.; Roberts, T. P.

2008-11-01

To test the idea that ultraluminous X-ray sources (ULXs) in external galaxies represent a class of accreting intermediate-mass black holes (IMBHs), we have undertaken a program to identify ULXs and a lower luminosity X-ray comparison sample with the highest quality data in the Chandra archive. We establish as a general property of ULXs that the most X-ray-luminous objects possess the flattest X-ray spectra (in the Chandra bandpass). No prior sample studies have established the general hardening of ULX spectra with luminosity. This hardening occurs at the highest luminosities (absorbed luminosity >=5 × 1039 erg s-1) and is in line with recent models arguing that ULXs are actually stellar mass black holes. From spectral modeling, we show that the evidence originally taken to mean that ULXs are IMBHs—i.e., the "simple IMBH model"—is nowhere near as compelling when a large sample of ULXs is looked at properly. During the last couple of years, XMM-Newton spectroscopy of ULXs has to a large extent begun to negate the simple IMBH model based on fewer objects. We confirm and expand these results, which validates the XMM-Newton work in a broader sense with independent X-ray data. We find that (1) cool-disk components are present with roughly equal probability and total flux fraction for any given ULX, regardless of luminosity, and (2) cool-disk components extend below the standard ULX luminosity cutoff of 1039 erg s-1, down to our sample limit of 1038.3 erg s-1. The fact that cool-disk components are not correlated with luminosity damages the argument that cool disks indicate IMBHs in ULXs, for which strong statistical support was never found.

Optical identification of X-ray source 1RXS J180431.1-273932 as a magnetic cataclysmic variable

NASA Astrophysics Data System (ADS)

Masetti, N.; Nucita, A. A.; Parisi, P.

2012-08-01

The X-ray source 1RXS J180431.1-273932 has been proposed as a new member of the symbiotic X-ray binary (SyXB) class of systems, which are composed of a late-type giant that loses matter to an extremely compact object, most likely a neutron star. In this paper, we present an optical campaign of imaging plus spectroscopy on selected candidate counterparts of this object. We also reanalyzed the available archival X-ray data collected with XMM-Newton. We find that the brightest optical source inside the 90% X-ray positional error circle is spectroscopically identified as a magnetic cataclysmic variable (CV), most likely of intermediate polar type, through the detection of prominent Balmer, He i, He ii, and Bowen blend emissions. On either spectroscopic or statistical grounds, we discard as counterparts of the X-ray source the other optical objects in the XMM-Newton error circle. A red giant star of spectral type M5 III is found lying just outside the X-ray position: we consider this latter object as a fore-/background one and likewise rule it out as a counterpart of 1RXS J180431.1-273932. The description of the X-ray spectrum of the source using a bremsstrahlung plus black-body model gives temperatures of kTbr ~ 40 keV and kTbb ~ 0.1 keV for these two components. We estimate a distance of d ~ 450 pc and a 0.2-10 keV X-ray luminosity of LX ~ 1.7 × 1032 erg s-1 for this system and, using the information obtained from the X-ray spectral analysis, a mass MWD ~ 0.8 M⊙ for the accreting white dwarf (WD). We also confirm an X-ray periodicity of 494 s for this source, which we interpret as the spin period of the WD. In summary, 1RXS J180431.1-273932 is identified as a magnetic CV and its SyXB nature is excluded. Partly based on observations collected at the Italian Telescopio Nazionale Galileo, located at the Observatorio del Roque de los Muchachos (Canary Islands, Spain).Reduced data used for imaging and spectra is only available at the CDS via anonymous ftp to cdsarc

Discrete X-Ray Sources Between M81 and NGC3077

NASA Technical Reports Server (NTRS)

Kilgard, Roy E.; Mushotzky, Richard F. (Technical Monitor)

2005-01-01

Analysis is now complete on the XMM-Newton and Chandra/HRC fields for the interaction region between M81 and NGC 3077. In addition, we have recently obtained ground-based optical data (KPNO 4-meter mosaic and CFHT 12K) for 2 regions of this field: one region near the edge of the D25 ellipse of M81 and a second region containing NGC 3077 and the furthest end of the HI bridge. Durrell et at. (private communication) find many young star clusters within the HI bridge, and we are in the process of performing the astrometric corrections to look for young stellar counterparts to the X-ray sources. We plan to present our results at the January 2006 AAS meeting in Washington, D.C., and are preparing a paper for submission to MNRAS in the near future with Co-Is M. Ward (U. Durham), T. Roberts (U. Leicester), A. Prestwich (CfA), A. Zezas (CfA), P. Durrell (Youngstown State), and Megan DeCesar (PSU).

Isaac Newton learns Hebrew: Samuel Johnson's Nova cubi Hebræi tabella

PubMed Central

Joalland, Michael; Mandelbrote, Scott

2016-01-01

This article concerns the earliest evidence for Isaac Newton's use of Hebrew: a manuscript copy by Newton of part of a work intended to provide a reader of the Hebrew alphabet with the ability to identify or memorize more than 1000 words and to begin to master the conjugations of the Hebrew verb. In describing the content of this unpublished manuscript and establishing its source and original author for the first time, we suggest how and when Newton may have initially become acquainted with the language. Finally, basing our discussion in part on an examination of the reading marks that Newton left in the surviving copies of Hebrew grammars and lexicons that he owned, we will argue that his interest in Hebrew was not intended to achieve linguistic proficiency but remained limited to particular theological queries of singular concern.

ESA's Integral discovers hidden black holes

NASA Astrophysics Data System (ADS)

2003-10-01

discovered so far? Astronomers, who have been observing the object regularly, guess that it had remained invisible because there must be a very thick shell of obscuring material surrounding it. If that was the case, only the most energetic radiation from the object could get through the shell; less-energetic radiation would be blocked. That could explain why space telescopes that are sensitive only to low-energy radiation had overlooked the object, while Integral, specialised in detecting very energetic emissions, did see it. To test their theory, astronomers turned to ESA's XMM-Newton space observatory, which observes the sky in the X-ray wavelengths. As well as being sensitive to high-energy radiation, XMM-Newton is also able to check for the presence of obscuring material. Indeed, XMM-Newton detected this object last February, as well as the existence of a dense 'cocoon' of cold gas with a diameter of similar size to that of the Earth's orbit around the Sun. This obscuring material forming the cocoon is probably 'stellar wind', namely gas ejected by the supermassive companion star. Astronomers think that this gas may be accreted by the compact black hole, forming a dense shell around it. This obscuring cloud traps most of the energy produced inside it. The main author of these results, Roland Walter of the Integral Science Data Centre, Switzerland, explained: "Only photons with the highest energies [above 10 keV] could escape from that cocoon. IGR J16318-4848 has therefore not been detected by surveys performed at lower energies, nor by previous gamma-ray missions that were much less sensitive than Integral." The question now is to find out how many of these objects lurk in the Galaxy. XMM-Newton and Integral together are the perfect tools to do the job. They have already discovered two more new sources embedded in obscuring material. Future observations are planned. Christoph Winkler, ESA Project Scientist for Integral, said: "These early examples of using two

Sometimes "Newton's Method" Always "Cycles"

ERIC Educational Resources Information Center

Latulippe, Joe; Switkes, Jennifer

2012-01-01

Are there functions for which Newton's method cycles for all non-trivial initial guesses? We construct and solve a differential equation whose solution is a real-valued function that two-cycles under Newton iteration. Higher-order cycles of Newton's method iterates are explored in the complex plane using complex powers of "x." We find a class of…

X-rays from HD 100546- A Young Herbig Star Orbited by Giant Protoplanets

NASA Astrophysics Data System (ADS)

Skinner, Stephen

A protoplanetary system consisting of at least two giant planets has beendetected orbiting the young nearby Herbig Be star HD 100546. The inner protoplanet orbits inside a gap within 14 AU of the star and is exposed to strong stellar UV and X-ray radiation. The detection of very warm disk gas provides evidence that stellar heating is affecting physical conditions in the planet-forming environment. We obtained a deep 74 ksec X-ray observation of HD 100546 in 2015 with XMM-Newton yielding an excellent-quality spectrum. We propose here to analyze the XMM-Newton data to determine the X-ray ionization and heating rates in the disk. X-ray ionization and heating affect the thermal and chemical structure of the disk and are key parameters for constructing realistic planet formation models. We are requesting ADAP funding to support the analysis and publication of this valuable XMM-Newton data set, which is now in the public archive.

A tidal disruption-like X-ray flare from the quiescent galaxy SDSS J120136.02+300305.5

NASA Astrophysics Data System (ADS)

Saxton, R. D.; Read, A. M.; Esquej, P.; Komossa, S.; Dougherty, S.; Rodriguez-Pascual, P.; Barrado, D.

2012-05-01

Aims: The study of tidal disruption flares from galactic nuclei has historically been hampered by a lack of high quality spectral observations taken around the peak of the outburst. Here we introduce the first results from a program designed to identify tidal disruption events at their peak by making near-real-time comparisons of the flux seen in XMM-Newton slew sources with that seen in ROSAT. Methods: Flaring extragalactic sources, which do not appear to be AGN, are monitored with Swift and XMM-Newton to track their temporal and spectral evolution. Timely optical observations are made to monitor the reaction of circumnuclear material to the X-ray flare. Results: SDSS J120136.02+300305.5 was detected in an XMM-Newton slew from June 2010 with a flux 56 times higher than an upper limit from ROSAT, corresponding to LX ~ 3 × 1044 erg s-1. It has the optical spectrum of a quiescent galaxy (z = 0.146). Overall the X-ray flux has evolved consistently with the canonical t-5/3 model, expected for returning stellar debris, fading by a factor ~300 over 300 days. In detail the source is very variable and became invisible to Swift between 27 and 48 days after discovery, perhaps due to self-absorption. The X-ray spectrum is soft but is not the expected tail of optically thick thermal emission. It may be fit with a Bremsstrahlung or double-power-law model and is seen to soften with time and declining flux. Optical spectra taken 12 days and 11 months after discovery indicate a deficit of material in the broad line and coronal line regions of this galaxy, while a deep radio non-detection implies that a jet was not launched during this event. Partly based on observations collected at the German-Spanish Astronomical Center, Calar Alto, jointly operated by the Max-Planck-institut für Astronomie Heidelberg and the Instituto de Astrofísica de Andalucía (CSIC) and observations made with the WHT operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio

Evidence for Intermediate Polars as the Origin of the Galactic Center Hard X-Ray Emission

NASA Technical Reports Server (NTRS)

Hailey, Charles J.; Mori, Kaya; Perez, Kerstin; Canipe, Alicia M.; Hong, Jaesub; Tomsick, John A.; Boggs, Steven E.; Christensen, Finn E.; Craig, William W.; Fornasini, Francesa;

The Superwind Galaxy NGC 4666

NASA Astrophysics Data System (ADS)

2010-09-01

The galaxy NGC 4666 takes pride of place at the centre of this new image, made in visible light with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. NGC 4666 is a remarkable galaxy with very vigorous star formation and an unusual "superwind" of out-flowing gas. It had previously been observed in X-rays by the ESA XMM-Newton space telescope, and the image presented here was taken to allow further study of other objects detected in the earlier X-ray observations. The prominent galaxy NGC 4666 in the centre of the picture is a starburst galaxy, about 80 million light-years from Earth, in which particularly intense star formation is taking place. The starburst is thought to be caused by gravitational interactions between NGC 4666 and its neighbouring galaxies, including NGC 4668, visible to the lower left. These interactions often spark vigorous star-formation in the galaxies involved. A combination of supernova explosions and strong winds from massive stars in the starburst region drives a vast flow of gas from the galaxy into space - a so-called "superwind". The superwind is huge in scale, coming from the bright central region of the galaxy and extending for tens of thousands of light-years. As the superwind gas is very hot it emits radiation mostly as X-rays and in the radio part of the spectrum and cannot be seen in visible light images such as the one presented here. This image was made as part of a follow-up to observations made with the ESA XMM-Newton space telescope in X-rays. NGC 4666 was the target of the original XMM-Newton observations, but thanks to the telescope's wide field-of-view many other X-ray sources were also seen in the background. One such serendipitous detection is a faint galaxy cluster seen close to the bottom edge of the image, right of centre. This cluster is much further away from us than NGC 4666, at a distance of about three billion light-years. In order to fully understand the nature of

Isaac Newton: Man, Myth, and Mathematics.

ERIC Educational Resources Information Center

Rickey, V. Frederick

1987-01-01

This article was written in part to celebrate the anniversaries of landmark mathematical works by Newton and Descartes. It's other purpose is to dispel some myths about Sir Isaac Newton and to encourage readers to read Newton's works. (PK)

From Newton to Einstein.

ERIC Educational Resources Information Center

Ryder, L. H.

1987-01-01

Discusses the history of scientific thought in terms of the theories of inertia and absolute space, relativity and gravitation. Describes how Sir Isaac Newton used the work of earlier scholars in his theories and how Albert Einstein used Newton's theories in his. (CW)

Probing the Nature of Short Swift Bursts via Deep INTEGRAL Monitoring of GRB 050925

NASA Technical Reports Server (NTRS)

Sakamoto, T.; Barbier, L.; Barthelmy, S. D.; Cummings, J. R.; Fenimore, E. E.; Gehrels, N.; Krimm, H. A.; Markwardt, C. B.; Palmer, D. M.; Parsons, A. M.;

X-ray Weak Broad-line Qquasars: Absorption or Intrinsic X-ray Weakness

NASA Technical Reports Server (NTRS)

Mushotzky, Richard (Technical Monitor); Risaliti, Guida

2005-01-01

XMM observations of X-ray weak quasars have been performed during 2003 and 2004. The data for all the observations have become available in 2004 (there has been a delay of several months on the initial schedule, due to high background flares which contaminated the observations: as a consequence, most of them had to be rescheduled). We have reduced and analyzed all the data, and obtained interesting scientific results. Out of the eight sources, 4 are confirmed to be extremely X-ray weak, in agreement with the results of previous Chandra observations. 3 sources are confined to be highly variable both in flux (by factor 20-50) and in spectral properties (dramatic changes in spectral index). For both these groups of objects we are completing a publication: 1) For the X-ray weak sources, a paper is submitted with a complete analysis of the X-ray spectra both from Chandra and XMM-Newton, and a comparison with optical and near-IR photometry obtained from all-sky surveys. Possible models for the unusual spectral energy distribution of these sources are also presented. 2) For the variable sources, a paper is being finalized where the X-ray spectra obtained with XMM-Newton are compared with previous X-ray observations and with observations at other wavelengths. It is shown that these sources are high luminosity and extreme cases of the highly variable class of narrow-line Seyfert Is. In order to further understand the nature of these X-ray weak quasars, we submitted proposals for spectroscopy at optical and infrared telescopes. We obtained time at the TNG 4 meter telescope for near-IR observations and at the Hobby-Eberly Telescope for optical high-resolution spectroscopy. These observations have been performed in early 2004. They will complement the XMM data and will lead to understanding of whether the X-ray weakness of these sources is an intrinsic property or is due to absorption by circum-nuclear material. The infrared spectra of the variable sources have been already

Inexact adaptive Newton methods

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

Bertiger, W.I.; Kelsey, F.J.

1985-02-01

The Inexact Adaptive Newton method (IAN) is a modification of the Adaptive Implicit Method/sup 1/ (AIM) with improved Newton convergence. Both methods simplify the Jacobian at each time step by zeroing coefficients in regions where saturations are changing slowly. The methods differ in how the diagonal block terms are treated. On test problems with up to 3,000 cells, IAN consistently saves approximately 30% of the CPU time when compared to the fully implicit method. AIM shows similar savings on some problems, but takes as much CPU time as fully implicit on other test problems due to poor Newton convergence.

XAssist: A System for the Automation of X-ray Astrophysics Analysis

NASA Astrophysics Data System (ADS)

Ptak, A.; Griffiths, R.

XAssist is a NASA AISR-funded project for the automation of X-ray astrophysics, with emphasis on galaxies. It is nearing completion of its initially funded effort, and is working well for Chandra and ROSAT data. Initial support for XMM-Newton data is present as well. It is capable of data reprocessing, source detection, and preliminary spatial, temporal and spectral analysis for each source with sufficient counts. The bulk of the system is written in Python, which in turn drives underlying software (CIAO for Chandra data, etc.). Future work will include a GUI (mainly for beginners and status monitoring) and the exposure of at least some functionality as web services. The latter will help XAssist to eventually become part of the VO, making advanced queries possible, such as determining the X-ray fluxes of counterparts to HST or SDSS sources (including the use of unpublished X-ray data), and add the ability of ``on-the-fly'' X-ray processing. Pipelines are running on ROSAT, Chandra and now XMM-Newton observations of galaxies to demonstrate XAssist's capabilities, and the results are available online (in real time) at http://www.xassist.org. XAssist itself as well as various associated projects are available for download.

THE 31 DEG{sup 2} RELEASE OF THE STRIPE 82 X-RAY SURVEY: THE POINT SOURCE CATALOG

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

LaMassa, Stephanie M.; Urry, C. Megan; Ananna, Tonima

We release the next installment of the Stripe 82 X-ray survey point-source catalog, which currently covers 31.3 deg{sup 2} of the Sloan Digital Sky Survey (SDSS) Stripe 82 Legacy field. In total, 6181 unique X-ray sources are significantly detected with XMM-Newton (>5σ) and Chandra (>4.5σ). This catalog release includes data from XMM-Newton cycle AO 13, which approximately doubled the Stripe 82X survey area. The flux limits of the Stripe 82X survey are 8.7 × 10{sup −16} erg s{sup −1} cm{sup −2}, 4.7 × 10{sup −15} erg s{sup −1} cm{sup −2}, and 2.1 × 10{sup −15} erg s{sup −1} cm{sup −2} in the soft (0.5–2 keV), hardmore » (2–10 keV), and full bands (0.5–10 keV), respectively, with approximate half-area survey flux limits of 5.4 × 10{sup −15} erg s{sup −1} cm{sup −2}, 2.9 × 10{sup −14} erg s{sup −1} cm{sup −2}, and 1.7 × 10{sup −14} erg s{sup −1} cm{sup −2}. We matched the X-ray source lists to available multi-wavelength catalogs, including updated matches to the previous release of the Stripe 82X survey; 88% of the sample is matched to a multi-wavelength counterpart. Due to the wide area of Stripe 82X and rich ancillary multi-wavelength data, including coadded SDSS photometry, mid-infrared WISE coverage, near-infrared coverage from UKIDSS and VISTA Hemisphere Survey, ultraviolet coverage from GALEX, radio coverage from FIRST, and far-infrared coverage from Herschel, as well as existing ∼30% optical spectroscopic completeness, we are beginning to uncover rare objects, such as obscured high-luminosity active galactic nuclei at high-redshift. The Stripe 82X point source catalog is a valuable data set for constraining how this population grows and evolves, as well as for studying how they interact with the galaxies in which they live.« less

Luminous Binary Supersoft X-Ray Sources

NASA Technical Reports Server (NTRS)

Oliversen, Ronald J. (Technical Monitor); DiStefano, Roseanne

2005-01-01

One of the key accomplishments of the two preceding years was our development of an algorithm to select SSSs in external galaxies which have been observed by Chandra or XMM-Newton. By applying this algorithm to data from a number of galaxies, we discovered an extension of the class of SSSs to sources that are somewhat harder (100 - 300 eV, instead of tens of eV), but which are nevertheless much softer than canonical X-ray sources. We call these new sources quasisoft sources (QSSs). During this past year, we have built on and extended this work. We have (1) continued to identify SSSs and QSSs in external galaxies, (2) worked on models for the sources and find that black hole models seem promising for a subset of them, and (3) have studied individual systems, especially M101-ULX1. This special system has been observed as an SSS in its high &ate, with a luminosity in excess of 10(exp 41) erg/s. It has also been observed as a QSS when it is less luminous, and as a hard source in its low state. It is one of the best candidates to be an accreting intermediate-mass black hole. We have several papers in preparation. Below we list papers which are complete, including only new work and papers whose status has changed (e.g., been accepted for publication) since our last report. In addition, our work on QSSs has received some publicity. It was the subject of a Chandra press release and was picked up by several media outlets.

Discovery of Extremely Embedded X-ray Sources in the R Coronae Australis Star Forming Core

NASA Technical Reports Server (NTRS)

Hamaguchi, Ken-Ji; Corcoran, Michael F.; Petre, Rob; White, Nicholas E.; Stelzer, Beate; Nedachi, Ko; Kobayashi, Naoto

2004-01-01

We detected three extremely embedded X-ray sources in the R Corona Australis (R CrA) star forming core, IRS 7 region. Two weak X-ray sources are associated with the VLA centimeter radio sources 10E & W, whereas the third brightest source detected in the two XMM-Newton observations on March 2003 has no counterpart at any wavelengths. The large K-band upper-limit (19.4m) measured with the University of Hawaii 88-inch Telescope and strong absorption derived in X-rays (N(sub H) approx. 2.8 x 10(exp 23)/sq cm equivalent to A(sub v) approx. 180 m) indicate that the source is younger than typical Class I protostars, i.e. a Class 0 protostar or an intermittent phase between Class 0 and Class I protostars. The X-ray luminosity was less than one thirtieth (log L(sub x) less than or approx. equals 29.3 ergs/s) in the former Chandra observation in October 2000, which suggests that the X-ray activity, probably generated by magnetic activity, is triggered by an intermittent mass accretion episode such as FU Ori type outbursts. Because the source was detected at high significance in the XMM-Newton observations (approx. 2,000 cnts), X-ray properties of such young protostars can be well investigated for the first time. The light curves were constant in the 1st observation and increased linearly by a factor of two during 30 ksec in the 2nd observation. Both spectra showed iron K lines originated in hot thin-thermal plasma and fluorescence by cold gas. They can be reproduced by an absorbed thin-thermal plasma model with a Gaussian component at 6.4 keV (kT approx. 3-4 keV, L(sub x) approx. 7-20 x 10(exp 30) ergs/s). The rising timescale of the light curves in the 2nd observation was too slow for magnetically generated X-ray flares, whereas large equivalent width of the fluorescence iron K line in the 1st observation (approx. 810 eV) requires strong partial covering of the X-ray source. These results suggest that a confined hot (perhaps accretion) spot on the protostellar core was

X-ray Properties and the Environment of Compact Radio Sources.

NASA Astrophysics Data System (ADS)

Siemiginowska, Aneta; Sobolewska, Malgorzata; Guainazzi, Matteo; Hardcastle, Martin; Migliori, Giulia; Ostorero, Luisa; Stawarz, Lukasz

2018-01-01

Compact extragalactic radio sources provide important insights into the initial stages of radio source evolution and probe states of a black hole activity at the time of the formation of the relativistic outflow. Such outflows propagate out to hundreds kpc distances from the origin and impact environment on many scales, and thus influence evolution of structures in the universe. These compact sources show radio features typically observed in large-scale radio galaxies (jets, lobes, hot spots), but contained within the central 1 kpc region of the host galaxy. Compact Symmetric Objects (CSOs, a subclass of GigaHertz Peaked spectrum radio sources) are symmetric and not affected by beaming. Their linear radio size can be translated into a source age if one measures the expansion velocity of the radio structures. Such ages has been measured for a small sample of CSOs. Using the Chandra X-ray Observatory and XMM-Newton we observed a pilot samples of 16 CSOs in X-rays (6 for the first time). Our results show heterogeneous nature of the CSOs X-ray emission indicating a range of AGN luminosities and a complex environment. In particular, we identified four Compton Thick sources with a dense medium (equivalent column > 1e24 cm^-2) capable of disturbing/slowing down the jet and confining the jet to a small region. Thus for the first time we gain the observational evidence in X-ray domain in favor of the hypothesis that in a sub-population of CSOs the radio jets may be confined by the dense X-ray obscuring medium. As a consequence, the kinematic ages of these CSOs may be underestimated.. We discuss the implications of our results on the emission models of CSOs, the earliest stages of the radio source evolution, jet interactions with the ISM, diversity of the environments in which the jets expand, and jet-galaxy co-evolution.Partial support for this work was provided by the NASA grants GO1-12145X, GO4-15099X, NNX10AO60G, NNX17AC23G and XMM AO15 project 78461. This work supported

SPECTRAL ENERGY DISTRIBUTIONS OF TYPE 1 ACTIVE GALACTIC NUCLEI IN THE COSMOS SURVEY. I. THE XMM-COSMOS SAMPLE

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

Elvis, M.; Hao, H.; Civano, F.

2012-11-01

The 'Cosmic Evolution Survey' (COSMOS) enables the study of the spectral energy distributions (SEDs) of active galactic nuclei (AGNs) because of the deep coverage and rich sampling of frequencies from X-ray to radio. Here we present an SED catalog of 413 X-ray (XMM-Newton)-selected type 1 (emission line FWHM > 2000 km s{sup -1}) AGNs with Magellan, SDSS, or VLT spectrum. The SEDs are corrected for Galactic extinction, broad emission line contributions, constrained variability, and host galaxy contribution. We present the mean SED and the dispersion SEDs after the above corrections in the rest-frame 1.4 GHz to 40 keV, and showmore » examples of the variety of SEDs encountered. In the near-infrared to optical (rest frame {approx}8 {mu}m-4000 A), the photometry is complete for the whole sample and the mean SED is derived from detections only. Reddening and host galaxy contamination could account for a large fraction of the observed SED variety. The SEDs are all available online.« less

Turning around Newton's Second Law

ERIC Educational Resources Information Center

Goff, John Eric

2004-01-01

Conceptual and quantitative difficulties surrounding Newton's second law often arise among introductory physics students. Simply turning around how one expresses Newton's second law may assist students in their understanding of a deceptively simple-looking equation.

OPTICAL–INFRARED PROPERTIES OF FAINT 1.3 mm SOURCES DETECTED WITH ALMA

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

Hatsukade, Bunyo; Yabe, Kiyoto; Ohta, Kouji

2015-09-10

We report optical-infrared (IR) properties of faint 1.3 mm sources (S{sub 1.3mm} = 0.2–1.0 mJy) detected with the Atacama Large Millimeter/submillimeter Array (ALMA) in the Subaru/XMM-Newton Deep Survey field. We searched for optical/IR counterparts of eight ALMA-detected sources (≥4.0σ, the sum of the probability of spurious source contamination is ∼1) in a K-band source catalog. Four ALMA sources have K-band counterpart candidates within a 0.″4 radius. Comparison between ALMA-detected and undetected K-band sources in the same observing fields shows that ALMA-detected sources tend to be brighter, more massive, and more actively forming stars. While many of the ALMA-identified submillimeter-bright galaxiesmore » (SMGs) in previous studies lie above the sequence of star-forming galaxies in the stellar mass–star formation rate plane, our ALMA sources are located in the sequence, suggesting that the ALMA-detected faint sources are more like “normal” star-forming galaxies rather than “classical” SMGs. We found a region where multiple ALMA sources and K-band sources reside in a narrow photometric redshift range (z ∼ 1.3–1.6) within a radius of 5″ (42 kpc if we assume z = 1.45). This is possibly a pre-merging system and we may be witnessing the early phase of formation of a massive elliptical galaxy.« less

From ultraluminous X-ray sources to ultraluminous supersoft sources: NGC 55 ULX, the missing link

NASA Astrophysics Data System (ADS)

Pinto, C.; Alston, W.; Soria, R.; Middleton, M. J.; Walton, D. J.; Sutton, A. D.; Fabian, A. C.; Earnshaw, H.; Urquhart, R.; Kara, E.; Roberts, T. P.

2017-07-01

In recent work with high-resolution reflection grating spectrometers (RGS) aboard XMM-Newton, Pinto et al. have discovered that two bright and archetypal ultraluminous X-ray sources (ULXs) have strong relativistic winds in agreement with theoretical predictions of high accretion rates. It has been proposed that such winds can become optically thick enough to block and reprocess the disc X-ray photons almost entirely, making the source appear as a soft thermal emitter or ultraluminous supersoft X-ray source (ULS). To test this hypothesis, we have studied a ULX where the wind is strong enough to cause significant absorption of the hard X-ray continuum: NGC 55 ULX. The RGS spectrum of NGC 55 ULX shows a wealth of emission and absorption lines blueshifted by significant fractions of the light speed (0.01-0.20)c indicating the presence of a powerful wind. The wind has a complex dynamical structure with the ionization state increasing with the outflow velocity, which may indicate launching from different regions of the accretion disc. The comparison with other ULXs such as NGC 1313 X-1 and NGC 5408 X-1 suggests that NGC 55 ULX is being observed at higher inclination. The wind partly absorbs the source flux above 1 keV, generating a spectral drop similar to that observed in ULSs. The softening of the spectrum at lower (˜ Eddington) luminosities and the detection of a soft lag agree with the scenario of wind clumps crossing the line of sight, partly absorbing and reprocessing the hard X-rays from the innermost region.

A multi-reference filtered-x-Newton narrowband algorithm for active isolation of vibration and experimental investigations

NASA Astrophysics Data System (ADS)

Wang, Chun-yu; He, Lin; Li, Yan; Shuai, Chang-geng

2018-01-01

In engineering applications, ship machinery vibration may be induced by multiple rotational machines sharing a common vibration isolation platform and operating at the same time, and multiple sinusoidal components may be excited. These components may be located at frequencies with large differences or at very close frequencies. A multi-reference filtered-x Newton narrowband (MRFx-Newton) algorithm is proposed to control these multiple sinusoidal components in an MIMO (multiple input and multiple output) system, especially for those located at very close frequencies. The proposed MRFx-Newton algorithm can decouple and suppress multiple sinusoidal components located in the same narrow frequency band even though such components cannot be separated from each other by a narrowband-pass filter. Like the Fx-Newton algorithm, good real-time performance is also achieved by the faster convergence speed brought by the 2nd-order inverse secondary-path filter in the time domain. Experiments are also conducted to verify the feasibility and test the performance of the proposed algorithm installed in an active-passive vibration isolation system in suppressing the vibration excited by an artificial source and air compressor/s. The results show that the proposed algorithm not only has comparable convergence rate as the Fx-Newton algorithm but also has better real-time performance and robustness than the Fx-Newton algorithm in active control of the vibration induced by multiple sound sources/rotational machines working on a shared platform.

PEOPLE IN PHYSICS: Newton's apple

NASA Astrophysics Data System (ADS)

Sandford Smith, Daniel

1997-03-01

This essay has a long history. It was triggered at university by one of my tutors describing the dispute between Robert Hooke and Isaac Newton. He conjured up an image of Newton sitting at his desk doing calculations while Hooke went down mineshafts trying to detect a change in the strength of gravity. To someone who was finding the maths content of a physics degree somewhat challenging this was a symbolic image. I believe that the story of Newton and the apple illustrates the complex nature of scientific discovery.

Optical identification of IGR J18308-1232 as a Cataclysmic Variable

NASA Astrophysics Data System (ADS)

Parisi, P.; Masetti, N.; Jimenez, E.; Chavushyan, V.; Bassani, L.; Bazzano, A.; Bird, A. J.

2008-09-01

We report on a spectroscopic analysis of optical sources inside the error circle of the XMM-Newton slew source XMMLS1 J183049.6-123218 (see Ibarra et al., ATel #1527), associated with the unidentified INTEGRAL source IGR J18308-1232 (Bird et al. 2007, ApJS, 170, 175). The observations were performed on 2008 June 28, starting at 06:37 UT, with the Boller & Chivens spectrograph mounted on the 2.1m telescope of the Observatorio Astronomico Nacional (San Pedro Martir, Baja California, Mexico), for a total exposure time of 7200 s.

The XXL Survey. VI. The 1000 brightest X-ray point sources

NASA Astrophysics Data System (ADS)

Fotopoulou, S.; Pacaud, F.; Paltani, S.; Ranalli, P.; Ramos-Ceja, M. E.; Faccioli, L.; Plionis, M.; Adami, C.; Bongiorno, A.; Brusa, M.; Chiappetti, L.; Desai, S.; Elyiv, A.; Lidman, C.; Melnyk, O.; Pierre, M.; Piconcelli, E.; Vignali, C.; Alis, S.; Ardila, F.; Arnouts, S.; Baldry, I.; Bremer, M.; Eckert, D.; Guennou, L.; Horellou, C.; Iovino, A.; Koulouridis, E.; Liske, J.; Maurogordato, S.; Menanteau, F.; Mohr, J. J.; Owers, M.; Poggianti, B.; Pompei, E.; Sadibekova, T.; Stanford, A.; Tuffs, R.; Willis, J.

2016-06-01

Context. X-ray extragalactic surveys are ideal laboratories for the study of the evolution and clustering of active galactic nuclei (AGN). Usually, a combination of deep and wide surveys is necessary to create a complete picture of the population. Deep X-ray surveys provide the faint population at high redshift, while wide surveys provide the rare bright sources. Nevertheless, very wide area surveys often lack the ancillary information available for modern deep surveys. The XXL survey spans two fields of a combined 50 deg2 observed for more than 6Ms with XMM-Newton, occupying the parameter space that lies between deep surveys and very wide area surveys; at the same time it benefits from a wealth of ancillary data. Aims: This paper marks the first release of the XXL point source catalogue including four optical photometry bands and redshift estimates. Our sample is selected in the 2 - 10 keV energy band with the goal of providing a sizable sample useful for AGN studies. The limiting flux is F2 - 10 keV = 4.8 × 10-14 erg s-1 cm-2. Methods: We use both public and proprietary data sets to identify the counterparts of the X-ray point-like sources by means of a likelihood ratio test. We improve upon the photometric redshift determination for AGN by applying a Random Forest classification trained to identify for each object the optimal photometric redshift category (passive, star forming, starburst, AGN, quasi-stellar objects (QSO)). Additionally, we assign a probability to each source that indicates whether it might be a star or an outlier. We apply Bayesian analysis to model the X-ray spectra assuming a power-law model with the presence of an absorbing medium. Results: We find that the average unabsorbed photon index is ⟨Γ⟩ = 1.85 ± 0.40 while the average hydrogen column density is log ⟨NH⟩ = 21.07 ± 1.2 cm-2. We find no trend of Γ or NH with redshift and a fraction of 26% absorbed sources (log NH> 22) consistent with the literature on bright sources (log

Identification of Hard X-ray Sources in Galactic Globular Clusters: Simbol-X Simulations

NASA Astrophysics Data System (ADS)

Servillat, M.

2009-05-01

Globular clusters harbour an excess of X-ray sources compared to the number of X-ray sources in the Galactic plane. It has been proposed that many of these X-ray sources are cataclysmic variables that have an intermediate magnetic field, i.e. intermediate polars, which remains to be confirmed and understood. We present here several methods to identify intermediate polars in globular clusters from multiwavelength analysis. First, we report on XMM-Newton, Chandra and HST observations of the very dense Galactic globular cluster NGC 2808. By comparing UV and X-ray properties of the cataclysmic variable candidates, the fraction of intermediate polars in this cluster can be estimated. We also present the optical spectra of two cataclysmic variables in the globular cluster M 22. The HeII (4868 Å) emission line in these spectra could be related to the presence of a magnetic field in these objects. Simulations of Simbol-X observations indicate that the angular resolution is sufficient to study X-ray sources in the core of close, less dense globular clusters, such as M 22. The sensitivity of Simbol-X in an extended energy band up to 80 keV will allow us to discriminate between hard X-ray sources (such as magnetic cataclysmic variables) and soft X-ray sources (such as chromospherically active binaries).

ESA uncovers Geminga's `hot spot'

NASA Astrophysics Data System (ADS)

2004-07-01

regions of the star, they found that the ‘colour’ of the X-rays, which corresponds to their energy, changed as Geminga rotated. In particular, they could clearly see a distinct colour change when the hot spot came into view and then disappeared behind the star. This research closes the gap between the X-ray and gamma-ray emission from neutron stars. XMM-Newton has shown that they both can originate through the same physical mechanism, namely the acceleration of charged particles in the magnetosphere of these degenerate stars. "XMM-Newton’s Geminga observation has been particularly fruitful," said Norbert Schartel, ESA’s Project Scientist for XMM-Newton. "Last year, it yielded the discovery of the source tails and now it has found its rotating hot spot." Caraveo is already applying this new technique to other pulsating neutron stars observed by XMM-Newton looking for hot spots. This research represents an important new tool for understanding the physics of neutron stars. Notes for editors The original paper appeared on 16 July 2004, in Science magazine, under the title 'Phase-resolved spectroscopy of Geminga shows rotating hotspot(s)'. Besides P. Caraveo, the author list includes A. De Luca, S. Mereghetti, A. Pellizzoni and G. Bignami. During the search to track down this elusive celestial object, a co-author on the paper, Giovanni Bignami, named it Geminga almost 30 years ago. He was Principal Investigator of XMM-Newton's EPIC camera from 1987 to 1997 and is now Director of the Centre d'Etude Spatiale des Rayonnements (CESR, Toulouse). Geminga was first glimpsed as a mysterious source of gamma rays, coming from somewhere in the constellation Gemini by NASA's SAS-2 spacecraft in 1973. While searching to pin down its exact location and nature, Bignami named it Geminga because it was a ‘Gemini gamma-ray source’. As an astronomer in Milan, Italy, he was also aware that in his native dialect ‘gh'èminga’ means ‘it is not there’, which he found amusing. It

VizieR Online Data Catalog: X-ray supernova remnants in LMC (Maggi+, 2016)

NASA Astrophysics Data System (ADS)

Maggi, P.; Haberl, F.; Kavanagh, P. J.; Sasaki, M.; Bozzetto, L. M.; Filipovic, M. D.; Vasilopoulos, G.; Pietsch, W.; Points, S. D.; Chu, Y.-H.; Dickel, J.; Ehle, M.; Williams, R.; Greiner, J.

2016-03-01

The processing of all available XMM-Newton data in the LMC region, and those of the VLP survey in particular, was done with the data reduction pipeline developed in our research group over several years. Various non-X-ray data were used to supplement the XMM-Newton observations. They allow us to assess e.g. the relation between the population of SNRs and large scale structure of the LMC, or to evaluate doubtful candidates in the sample compilation. We compiled a sample of 59 definite SNRs, cleaned of misclassified objects and doubtful candidates. (2 data files).

The Incidence of Buried Dual AGN in Advanced Mergers: New results from Chandra

NASA Astrophysics Data System (ADS)

Pfeifle, Ryan William; Satyapal, Shobita; Secrest, Nathan; Gliozzi, Mario; Ricci, Claudio; Ellison, Sara L.; Blecha, Laura; Rothberg, Barry; Constantin, Anca

2018-01-01

Since the vast majority of galaxies contain supermassive black holes (SMBHs) and galaxy interactions trigger nuclear gas accretion, a direct consequence of the hierarchical model of galaxy formation would be the existence of dual active galactic nuclei (AGN). The existence, frequency, and characteristics of such dual AGN have important astrophysical implications on the SMBH mass function, the interplay between SMBHs and the host galaxy, and the M-sigma relation. Despite decades of searching, and strong theoretical reasons for their existence, observationally confirmed cases of dual AGN are extremely rare, and most have been discovered serendipitously. Using the all-sky WISE survey, we identified a population of over one hundred strongly interacting galaxies that display extreme red mid-infrared colors thus far exclusively associated with extragalactic sources possessing powerful AGN. In a recent Chandra, XMM-Newton, and NuSTAR investigation of advanced mergers selected by WISE, we find dual AGN candidates in 8 out of 15 mergers, all of which show no evidence for AGN based on optical spectroscopy. Our results demonstrate that 1) optical studies miss a significant fraction of single and dual AGN in advanced mergers, and 2) mid-infrared pre-selection is extremely effective in identifying dual AGN candidates in late-stage mergers. Our multi-wavelength observations suggest that the buried AGN in these mergers are highly absorbed, with intrinsic column densities in excess of NH > 1024 cm-2, consistent with hydrodynamic simulations.

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).

Subsampled Hessian Newton Methods for Supervised Learning.

PubMed

Wang, Chien-Chih; Huang, Chun-Heng; Lin, Chih-Jen

2015-08-01

Newton methods can be applied in many supervised learning approaches. However, for large-scale data, the use of the whole Hessian matrix can be time-consuming. Recently, subsampled Newton methods have been proposed to reduce the computational time by using only a subset of data for calculating an approximation of the Hessian matrix. Unfortunately, we find that in some situations, the running speed is worse than the standard Newton method because cheaper but less accurate search directions are used. In this work, we propose some novel techniques to improve the existing subsampled Hessian Newton method. The main idea is to solve a two-dimensional subproblem per iteration to adjust the search direction to better minimize the second-order approximation of the function value. We prove the theoretical convergence of the proposed method. Experiments on logistic regression, linear SVM, maximum entropy, and deep networks indicate that our techniques significantly reduce the running time of the subsampled Hessian Newton method. The resulting algorithm becomes a compelling alternative to the standard Newton method for large-scale data classification.

Edme Mariotte and Newton's Cradle

ERIC Educational Resources Information Center

Cross, Rod

2012-01-01

The first recorded experiments describing the phenomena made popular by Newton's cradle appear to be those conducted by Edme Mariotte around 1670. He was quoted in Newton's "Principia," along with Wren, Wallis, and Huygens, as having conducted pioneering experiments on the collisions of pendulum balls. Each of these authors concluded that momentum…

Telecommunications Handbook: Connecting to Newton.

ERIC Educational Resources Information Center

Baker, Christopher; And Others

This handbook was written by the Argonne National Laboratory for use with their electronic bulletin board system (BBS) called Newton. Newton is an educational BBS for use by teachers, students, and parents. Topics range from discussions of science fair topics to online question and answer sessions with scientists. Future capabilities will include…

Newton's Cradle in Physics Education

ERIC Educational Resources Information Center

Gauld, Colin F.

2006-01-01

Newton's Cradle is a series of bifilar pendulums used in physics classrooms to demonstrate the role of the principles of conservation of momentum and kinetic energy in elastic collisions. The paper reviews the way in which textbooks use Newton's Cradle and points out the unsatisfactory nature of these treatments in almost all cases. The literature…

High-order Newton-penalty algorithms

NASA Astrophysics Data System (ADS)

Dussault, Jean-Pierre

2005-10-01

Recent efforts in differentiable non-linear programming have been focused on interior point methods, akin to penalty and barrier algorithms. In this paper, we address the classical equality constrained program solved using the simple quadratic loss penalty function/algorithm. The suggestion to use extrapolations to track the differentiable trajectory associated with penalized subproblems goes back to the classic monograph of Fiacco & McCormick. This idea was further developed by Gould who obtained a two-steps quadratically convergent algorithm using prediction steps and Newton correction. Dussault interpreted the prediction step as a combined extrapolation with respect to the penalty parameter and the residual of the first order optimality conditions. Extrapolation with respect to the residual coincides with a Newton step.We explore here higher-order extrapolations, thus higher-order Newton-like methods. We first consider high-order variants of the Newton-Raphson method applied to non-linear systems of equations. Next, we obtain improved asymptotic convergence results for the quadratic loss penalty algorithm by using high-order extrapolation steps.

Newton's Metaphysics of Space as God's Emanative Effect

NASA Astrophysics Data System (ADS)

Jacquette, Dale

2014-09-01

In several of his writings, Isaac Newton proposed that physical space is God's "emanative effect" or "sensorium," revealing something interesting about the metaphysics underlying his mathematical physics. Newton's conjectures depart from Plato and Aristotle's metaphysics of space and from classical and Cambridge Neoplatonism. Present-day philosophical concepts of supervenience clarify Newton's ideas about space and offer a portrait of Newton not only as a mathematical physicist but an independent-minded rationalist philosopher.

NuSTAR Reveals Extreme Absorption in z < 0.5 Type 2 Quasars

NASA Astrophysics Data System (ADS)

Lansbury, G. B.; Gandhi, P.; Alexander, D. M.; Assef, R. J.; Aird, J.; Annuar, A.; Ballantyne, D. R.; Baloković, M.; Bauer, F. E.; Boggs, S. E.; Brandt, W. N.; Brightman, M.; Christensen, F. E.; Civano, F.; Comastri, A.; Craig, W. W.; Del Moro, A.; Grefenstette, B. W.; Hailey, C. J.; Harrison, F. A.; Hickox, R. C.; Koss, M.; LaMassa, S. M.; Luo, B.; Puccetti, S.; Stern, D.; Treister, E.; Vignali, C.; Zappacosta, L.; Zhang, W. W.

2015-08-01

The intrinsic column density (NH) distribution of quasars is poorly known. At the high obscuration end of the quasar population and for redshifts z < 1, the X-ray spectra can only be reliably characterized using broad-band measurements that extend to energies above 10 keV. Using the hard X-ray observatory NuSTAR, along with archival Chandra and XMM-Newton data, we study the broad-band X-ray spectra of nine optically selected (from the SDSS), candidate Compton-thick (NH > 1.5 × 1024 cm-2) type 2 quasars (CTQSO2s); five new NuSTAR observations are reported herein, and four have been previously published. The candidate CTQSO2s lie at z < 0.5, have observed [O iii] luminosities in the range 8.4\\lt {log}({L}[{{O} {{III}}]}/{L}⊙ )\\lt 9.6, and show evidence for extreme, Compton-thick absorption when indirect absorption diagnostics are considered. Among the nine candidate CTQSO2s, five are detected by NuSTAR in the high-energy (8-24 keV) band: two are weakly detected at the ≈3σ confidence level and three are strongly detected with sufficient counts for spectral modeling (≳90 net source counts at 8-24 keV). For these NuSTAR-detected sources direct (i.e., X-ray spectral) constraints on the intrinsic active galactic nucleus properties are feasible, and we measure column densities ≈2.5-1600 times higher and intrinsic (unabsorbed) X-ray luminosities ≈10-70 times higher than pre-NuSTAR constraints from Chandra and XMM-Newton. Assuming the NuSTAR-detected type 2 quasars are representative of other Compton-thick candidates, we make a correction to the NH distribution for optically selected type 2 quasars as measured by Chandra and XMM-Newton for 39 objects. With this approach, we predict a Compton-thick fraction of {f}{CT}={36}-12+14 %, although higher fractions (up to 76%) are possible if indirect absorption diagnostics are assumed to be reliable.

Toward milli-Newton electro- and magneto-static microactuators

NASA Technical Reports Server (NTRS)

Fan, Long-Sheng

1993-01-01

Microtechnologies can potentially push integrated electro- and magnetostatic actuators toward the regime where constant forces in the order of milli-Newton (or torques in the order of micro-Newton meter) can be generated with constant inputs within a volume of 1.0 x 1.0 x 0.02 mm with 'conventional' technology. 'Micro' actuators are, by definition, actuators with dimensions confined within a millimeter cube. Integrated microactuators based on electrostatics typically have force/torque in the order of sub-micro-Newton (sub-nano-Newton meter). These devices are capable of moving small objects at MHz frequencies. On the other hand, suppose we want to move a one cubic millimeter object around with 100 G acceleration; a few milli-Newton force will be required. Thus, milli-Newton microactuators are very desirable for some immediate applications, and it challenges micromechanical researchers to develop new process technologies, designs, and materials toward this goal.

Development of High Resolution Hard X-Ray Telescope with Multilayer Coatings

NASA Technical Reports Server (NTRS)

Brinton, John C. (Technical Monitor); Gorenstein, Paul

2004-01-01

The major objective of this program is the development of a focusing hard X-ray telescope with moderately high angular resolution, i .e. comparable to the telescopes of XMM-Newton. The key ingredients of the telescope are a depth graded multilayer coatings and electroformed nickel substrates that are considerably lighter weight than those of previous missions such as XMM-Newton, which have had conventional single metal layer reflective coatings and have operated at much lower energy X-rays. The ultimate target mission for this technology is the Hard X-Ray Telescope (HXT) of the Constellation X-Ray Mission. However, it is applicable to potential SMEX and MIDEX programs as well.

The XMM Cluster Outskirts Project (X-COP)

NASA Astrophysics Data System (ADS)

Eckert, D.

2017-10-01

The outskirts of galaxy clusters (typically the regions located beyond R500) are the regions where the transition between the virialized ICM and the infalling material from the large-scale structure takes place. As such, they play a central role in our understanding of the processes leading to the virialization of the accreting gas within the central dark-matter halo. I will give an overview of the XMM cluster outskirts project (X-COP), a very large program on XMM to study the virial region of galaxy clusters with unprecedented details. I will show how X-ray observations can be combined with the Sunyaev-Zeldovich signal to recover the thermodynamic properties and hydrostatic mass of the ICM, bypassing the need for expensive X-ray spectroscopic observations. I will discuss the results obtained using this technique on Abell 2142 and Abell 2319 and give prospects for the results expected using the full X-COP sample. I will also present recent results on the search for warm-hot baryons in the filaments connected to clusters, emphasizing on the discovery of 3 filaments of 10-million-degree gas connected to the massive cluster Abell 2744.

3, 2, 1 … Discovering Newton's Laws

NASA Astrophysics Data System (ADS)

Lutz, Joe; Sylvester, Kevin; Oliver, Keith; Herrington, Deborah

2017-03-01

"For every action there is an equal and opposite reaction." "Except when a bug hits your car window, the car must exert more force on the bug because Newton's laws only apply in the physics classroom, right?" Students in our classrooms were able to pick out definitions as well as examples of Newton's three laws; they could recite the laws and even solve for force, mass, and acceleration. However, when given "real world" questions, they would quickly revert to naive explanations. This frustration led to an examination of our approach to teaching Newton's laws. Like many, we taught Newton's laws in their numerical order—first, second, and then third. Students read about the laws, copied definitions, and became proficient with vocabulary before they applied the laws in a lab setting. This paper discusses how we transformed our teaching of Newton's laws by flipping the order (3, 2, 1) and putting the activity before concept, as well as how these changes affected student outcomes.

Jets, hotspots and lobes: what X-ray observations tell us about extra-galactic radio sources.

PubMed

Hardcastle, Martin J

2005-12-15

The brightest and most numerous discrete radio sources in the sky, radio galaxies and quasars, are powered by twin jets of plasma which emerge at relativistic speeds from very small regions at the centre of large elliptical galaxies, powered by mass infall on to supermassive black holes. The jets can carry material out to very large distances (millions of light years) where it forms balloon-like lobes. Until recently it has been impossible to make definite statements about the energy or the nature of the matter supplied by the jets, or the dynamics of the lobes as they expand into the external medium. This has meant that crucial questions about the generation of radio sources and their effect on their environment have gone unanswered. The situation has been revolutionized by the launch at the start of this decade of a new generation of X-ray observatories, Chandra and XMM-Newton. In this article, I explain why observations with these instruments have made such a difference, what we have learned as a result and why the community remains divided on some important features of the interpretation of the data.

Long-term evolution of the neutron-star spin period of SXP 1062

NASA Astrophysics Data System (ADS)

Sturm, R.; Haberl, F.; Oskinova, L. M.; Schurch, M. P. E.; Hénault-Brunet, V.; Gallagher, J. S.; Udalski, A.

2013-08-01

Context. The Be/X-ray binary SXP 1062 is of especial interest owing to the large spin period of the neutron star, its large spin-down rate, and the association with a supernova remnant constraining its age. This makes the source an important probe for accretion physics. Aims: To investigate the long-term evolution of the spin period and associated spectral variations, we performed an XMM-Newton target-of-opportunity observation of SXP 1062 during X-ray outburst. Methods: Spectral and timing analysis of the XMM-Newton data was compared with previous studies, as well as complementary Swift/XRT monitoring and optical spectroscopy with the SALT telescope were obtained. Results: The spin period was measured to be Ps = (1071.01 ± 0.16) s on 2012 Oct. 14. The X-ray spectrum is similar to that of previous observations. No convincing cyclotron absorption features, which could be indicative for a high magnetic field strength, are found. The high-resolution RGS spectra indicate the presence of emission lines, which may not completely be accounted for by the SNR emission. The comparison of multi-epoch optical spectra suggest an increasing size or density of the decretion disc around the Be star. Conclusions: SXP 1062 showed a net spin-down with an average of Ṗs = (2.27 ± 0.44) s yr-1 over a baseline of 915 days. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA and on observations made with the Southern African Large Telescope (SALT).The reduced SALT spectra is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/556/A139

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

Christodoulou, Dimitris M.; Laycock, Silas G. T.; Yang, Jun

We have combined the published observations of high-mass X-ray binary (HMXB) pulsars in the Magellanic Clouds with a new processing of the complete archival data sets from the XMM-Newton and Chandra observatories in an attempt to trace the lowest propeller line below which accretion to polar caps is inhibited by the centrifugal force and the pulsations from the most weakly magnetized pulsars cease. Previously published data reveal that some of the faster-spinning pulsars with spin periods of P {sub S} < 12 s, detected at relatively low X-ray luminosities L {sub X} , appear to define such a line inmore » the P {sub S} – L {sub X} diagram, characterized by a magnetic moment of μ = 3 × 10{sup 29} G cm{sup 3}. This value implies the presence of surface magnetic fields of B ≥ 3 × 10{sup 11} G in the compact objects of this class. Only a few quiescent HMXBs are found below the propeller line: LXP4.40 and SXP4.78, for which XMM-Newton and Chandra null detections respectively placed firm upper limits on their X-ray fluxes in deep quiescence; and A0538-66, for which many sub-Eddington detections have never measured any pulsations. On the other hand, the data from the XMM-Newton and Chandra archives show clearly that, during routine observation cycles, several sources have been detected below the propeller line in extremely faint, nonpulsating states that can be understood as the result of weak magnetospheric emission when accretion to the poles is centrifugally stalled or severely diminished. We also pay attention to the anomalous X-ray pulsar CXOU J010043.1-721134 that was reported in HMXB surveys. Its pulsations and locations near and above the propeller line indicate that this pulsar could be accreting from a fossil disk.« less

"To Improve upon Hints of Things": Illustrating Isaac Newton.

PubMed

Schilt, Cornelis J

2016-01-01

When Isaac Newton died in 1727 he left a rich legacy in terms of draft manuscripts, encompassing a variety of topics: natural philosophy, mathematics, alchemy, theology, and chronology, as well as papers relating to his career at the Mint. One thing that immediately strikes us is the textuality of Newton's legacy: images are sparse. Regarding his scholarly endeavours we witness the same practice. Newton's extensive drafts on theology and chronology do not contain a single illustration or map. Today we have all of Newton's draft manuscripts as witnesses of his working methods, as well as access to a significant number of books from his own library. Drawing parallels between Newton's reading practices and his natural philosophical and scholarly work, this paper seeks to understand Newton's recondite writing and publishing politics.

On the Nature of the Bright Short-Period X-Ray Source in the Circinus Galaxy Field

NASA Technical Reports Server (NTRS)

Weisskopf, Martin C.; Wu, Kinwah; Tennant, Allyn F.; Swartz, Douglas A.; Ghosh, Kajal K.

2004-01-01

The spectrum and light curve of the bright X-ray source CG X-1 in the field of the Circinus galaxy are reexamined. Previous analyses have concluded that the source is an accreting black hole of mass > or approx. 50 solar masses although it has been noted that the light curve resembles that of an AM Herculis system. Here we show that the short period and an assumed main-sequence companion constrain the mass of the companion to less than 1 solar mass. Furthermore, a possible eclipse seen during one of the Chandra observations and a subsequent XMM-Newton observation constrain the mass of the compact object to less than 60 solar masses. If such a system lies in the Circinus galaxy, then the accreting object must either radiate anisotropically or strongly violate the Eddington limit. Even if the emission is beamed, then the companion star that intercepts this flux during eclipse will be driven out of thermal equilibrium and evaporate within approx. 10(exp 3) yr. We find that the observations cannot rule out an AM Herculis system in the Milky Way and that such a system can account for the variations seen in the light curve.

Detection of blueshifted emission and absorption and a relativistic iron line in the X-ray spectrum of ESO323-G077

NASA Astrophysics Data System (ADS)

Jiménez-Bailón, E.; Krongold, Y.; Bianchi, S.; Matt, G.; Santos-Lleó, M.; Piconcelli, E.; Schartel, N.

2008-12-01

We report on the X-ray observation of the Seyfert 1 galaxy ESO323-G077 performed with XMM-Newton. The EPIC spectra show a complex spectrum with conspicuous absorption and emission features. The continuum emission can be modelled with a power law with an index of 1.99 +/- 0.02 in the whole XMM-Newton energy band, marginally consistent with typical values of type I objects. An absorption component with an uncommonly high equivalent hydrogen column (nH = 5.82+0.12-0.11 × 1022cm-2) is affecting the soft part of the spectrum. Additionally, two warm absorption components are also present in the spectrum. The lower ionized one, mainly imprinting the soft band of the spectrum, has an ionization parameter of logU = 2.14+0.06-0.07 and an outflowing velocity of v = 3200+600-200kms-1. Two absorption lines located at ~6.7 and ~7.0keV can be modelled with the highly ionized absorber. The ionization parameter and outflowing velocity of the gas measured are logU = 3.26+0.19-0.15 and v = 1700+600-400kms-1, respectively. Four emission lines were also detected in the soft energy band. The most likely explanation for these emission lines is that they are associated with an outflowing gas with a velocity of ~2000kms-1. The data suggest that the same gas which is causing the absorption could also being responsible of these emission features. Finally, the XMM-Newton spectrum shows the presence of a relativistic iron emission line likely originated in the accretion disc of a Kerr black hole with an inclination of ~25°. We propose a model to explain the observed X-ray properties which invokes the presence of a two-phase outflow with cone-like structure and a velocity of the order of 2000- 4000kms-1. The inner layer of the cone would be less ionized, or even neutral, than the outer layer. The inclination angle of the source would be lower than the opening angle of the outflowing cone. Partially based on observations obtained with XMM-Newton, an ESA science mission with instruments and

Semismooth Newton method for gradient constrained minimization problem

NASA Astrophysics Data System (ADS)

Anyyeva, Serbiniyaz; Kunisch, Karl

2012-08-01

In this paper we treat a gradient constrained minimization problem, particular case of which is the elasto-plastic torsion problem. In order to get the numerical approximation to the solution we have developed an algorithm in an infinite dimensional space framework using the concept of the generalized (Newton) differentiation. Regularization was done in order to approximate the problem with the unconstrained minimization problem and to make the pointwise maximum function Newton differentiable. Using semismooth Newton method, continuation method was developed in function space. For the numerical implementation the variational equations at Newton steps are discretized using finite elements method.

Characterisation of a candidate dual AGN

NASA Astrophysics Data System (ADS)

Lena, D.; Panizo-Espinar, G.; Jonker, P. G.; Torres, M.; Heida, M.

2018-05-01

We present Chandra and optical observations of a candidate dual AGN discovered serendipitously while searching for recoiling black holes via a cross-correlation between the serendipitous XMM source catalog (2XMMi) and SDSS-DR7 galaxies with a separation no larger than ten times the sum of their Petrosian radii. The system has a stellar mass ratio M1/M2 ≈ 0.7. One of the galaxies (Source 1) shows clear evidence for AGN activity in the form of hard X-ray emission and optical emission-line diagnostics typical of AGN ionisation. The nucleus of the other galaxy (Source 2) has a soft X-ray spectrum, bluer colours, and optical emission line ratios dominated by stellar photoionisation with a "composite" signature, which might indicate the presence of a weak AGN. When plotted on a diagram with X-ray luminosity vs [OIII] luminosity both nuclei fall within the locus defined by local Seyfert galaxies. From the optical spectrum we estimate the electron densities finding n1 < 27 e- cm-3 and n2 ≈ 200 e- cm-3. From a 2D decomposition of the surface brightness distribution we infer that both galaxies host rotationally supported bulges (Sersic index <1). While the active nature of Source 1 can be established with confidence, whether the nucleus of Source 2 is active remains a matter of debate. Evidence that a faint AGN might reside in its nucleus is, however, tantalising.

Characterization of a candidate dual AGN

NASA Astrophysics Data System (ADS)

Lena, D.; Panizo-Espinar, G.; Jonker, P. G.; Torres, M. A. P.; Heida, M.

2018-07-01

We present Chandra and optical observations of a candidate dual active galactic nucleus (AGN) discovered serendipitously while searching for recoiling black holes via a cross-correlation between the serendipitous XMM source catalogue (2XMMi) and SDSS-DR7 galaxies with a separation no larger than 10 times the sum of their Petrosian radii. The system has a stellar mass ratio M1/M2 ≈ 0.7. One of the galaxies (Source 1) shows clear evidence for AGN activity in the form of hard X-ray emission and optical emission-line diagnostics typical of AGN ionization. The nucleus of the other galaxy (Source 2) has a soft X-ray spectrum, bluer colours, and optical emission-line ratios dominated by stellar photoionization with a `composite' signature, which might indicate the presence of a weak AGN. When plotted on a diagram with X-ray luminosity versus [OIII] luminosity, both nuclei fall within the locus defined by local Seyfert galaxies. From the optical spectrum, we estimate the electron densities finding n1 < 27 e- cm-3 and n2 ≈ 200 e- cm-3. From a 2D decomposition of the surface brightness distribution, we infer that both galaxies host rotationally supported bulges (Sérsic index <1). While the active nature of Source 1 can be established with confidence, whether the nucleus of Source 2 is active remains a matter of debate. Evidence that a faint AGN might reside in its nucleus is, however, tantalizing.

Newton-Cartan gravity and torsion

NASA Astrophysics Data System (ADS)

Bergshoeff, Eric; Chatzistavrakidis, Athanasios; Romano, Luca; Rosseel, Jan

2017-10-01

We compare the gauging of the Bargmann algebra, for the case of arbitrary torsion, with the result that one obtains from a null-reduction of General Relativity. Whereas the two procedures lead to the same result for Newton-Cartan geometry with arbitrary torsion, the null-reduction of the Einstein equations necessarily leads to Newton-Cartan gravity with zero torsion. We show, for three space-time dimensions, how Newton-Cartan gravity with arbitrary torsion can be obtained by starting from a Schrödinger field theory with dynamical exponent z = 2 for a complex compensating scalar and next coupling this field theory to a z = 2 Schrödinger geometry with arbitrary torsion. The latter theory can be obtained from either a gauging of the Schrödinger algebra, for arbitrary torsion, or from a null-reduction of conformal gravity.

A Long Decay of X-Ray Flux and Spectral Evolution in the Supersoft Active Galactic Nucleus GSN 069

NASA Astrophysics Data System (ADS)

Shu, X. W.; Wang, S. S.; Dou, L. M.; Jiang, N.; Wang, J. X.; Wang, T. G.

2018-04-01

GSN 069 is an optically identified very low-mass active galactic nuclei (AGN) that shows supersoft X-ray emission. The source is known to exhibit a huge X-ray outburst, with flux increased by more than a factor of ∼240 compared to the quiescence state. We report its long-term evolution in the X-ray flux and spectral variations over a timescale of ∼decade, using both new and archival X-ray observations from the XMM-Newton and Swift. The new Swift observations detected the source in its lowest level of X-ray activity since the outburst, a factor of ∼4 lower in the 0.2–2 keV flux than that obtained with the XMM-Newton observations nearly eight years ago. Combining with the historical X-ray measurements, we find that the X-ray flux is decreasing slowly. There seemed to be spectral softening associated with the drop of X-ray flux. In addition, we find evidence for the presence of a weak, variable, hard X-ray component, in addition to the dominant thermal blackbody emission reported before. The long decay of X-ray flux and spectral evolution, as well as the supersoft X-ray spectra, suggest that the source could be a tidal disruption event (TDE), though a highly variable AGN cannot be fully ruled out. Further continued X-ray monitoring would be required to test the TDE interpretation, by better determining the flux evolution in the decay phase.

Pulse phase-coherent timing and spectroscopy of CXOU J164710.2-45521 outbursts

NASA Astrophysics Data System (ADS)

Rodríguez Castillo, Guillermo A.; Israel, Gian Luca; Esposito, Paolo; Pons, José A.; Rea, Nanda; Turolla, Roberto; Viganò, Daniele; Zane, Silvia

2014-06-01

We present a long-term phase-coherent timing analysis and pulse-phase resolved spectroscopy for the two outbursts observed from the transient anomalous X-ray pulsar CXOU J164710.2-455216. For the first outburst we used 11 Chandra and XMM-Newton observations between 2006 September and 2009 August, the longest baseline yet for this source. We obtain a coherent timing solution with P = 10.61065583(4) s, Ṗ = 9.72(1) × 10-13 s s-1 and P̈ = -1.05(5) × 10-20 s s-2. Under the standard assumptions this implies a surface dipolar magnetic field of ˜1014 G, confirming this source as a standard B magnetar. We also study the evolution of the pulse profile (shape, intensity and pulsed fraction) as a function of time and energy. Using the phase-coherent timing solution we perform a phase-resolved spectroscopy analysis, following the spectral evolution of pulse-phase features, which hints at the physical processes taking place on the star. The results are discussed from the perspective of magnetothermal evolution models and the untwisting magnetosphere model. Finally, we present similar analysis for the second, less intense, 2011 outburst. For the timing analysis we used Swift data together with 2 XMM-Newton and Chandra pointings. The results inferred for both outbursts are compared and briefly discussed in a more general framework.

X-Ray Probes of Jupiter's Auroral Zones, Galilean Moons, and the Io Plasma Torus

NASA Technical Reports Server (NTRS)

Elsner, R. F.; Ramsey, B. D.; Swartz, D. A.; Rehak, P.; Waite, J. H., Jr.; Cooper, J. F.; Johnson, R. E.

2005-01-01

Remote observations from the Earth orbiting Chandra X-ray Observatory and the XMM-Newton Observatory have shown the the Jovian system is a rich and complex source of x-ray emission. The planet's auroral zones and its disk are powerful sources of x-ray emission, though with different origins. Chandra observations discovered x-ray emission from the Io plasma torus and from the Galilean moons Io, Europa, and possibly Ganymede. The emission from the moons is due to bombardment of their surfaces by highly energetic magnetospheric protons, and oxygen and sulfur ions, producing fluorescent x-ray emission lines from the elements in their surfaces against an intense background continuum. Although very faint when observed from Earth orbit, an imaging x-ray spectrometer in orbit around the icy Galilean moons would provide a detail mapping of the elemental composition in their surfaces. Here we review the results of Chandra and XMM-Newton observations of the Jovian system and describe the characteristics of X-MIME, an imaging x-ray spectrometer undergoing study for possible application to future missions to Jupiter such as JIMO. X-MIME has the ultimate goal of providing detailed high-resolution maps of the elemental abundances of the surfaces of Jupiter's icy moons and Io, as well as detailed study of the x-ray mission from the Io plasma torus, Jupiter's auroral zones, and the planetary disk.

A DEEP CHANDRA OBSERVATION OF THE WOLF-RAYET + BLACK HOLE BINARY NGC 300 X-1

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

Binder, B.; Williams, B. F.; Anderson, S. F.

We have obtained a 63 ks Chandra ACIS-I observation of the Wolf-Rayet + black hole binary NGC 300 X-1. We measure rapid low-amplitude variability in the 0.35-8 keV light curve. The power density spectrum has a power-law index {gamma} = 1.02 {+-} 0.15 consistent with an accreting black hole in a steep power-law state. When compared to previous studies of NGC 300 X-1 performed with XMM-Newton, we find the source at the low end of the previously measured 0.3-10 keV luminosity. The spectrum of NGC 300 X-1 is dominated by a power law ({Gamma} = 2.0 {+-} 0.3) with amore » contribution at low energies by a thermal component. We estimate the 0.3-10 keV luminosity to be 2.6{sup +0.8}{sub -1.0} Multiplication-Sign 10{sup 38} erg s{sup -1}. The timing and spectroscopic properties of NGC 300 X-1 are consistent with being in a steep power-law state, similar to earlier observations performed with XMM-Newton. We additionally compare our observations to known high-mass X-ray binaries and ultraluminous X-ray sources, and find the properties of NGC 300 X-1 are most consistent with black hole high-mass X-ray binaries.« less

Observations of X-ray flares in G-K dwarfs by XMM-Newton

NASA Astrophysics Data System (ADS)

Pandey, Jeewan Chandra

Eclipsing binary BD +5 706 is best investigated member of rare class of cool Algols, which differ from clasical Algol systems in that the mass gaining component is also a late-type star. The analysis of X-ray lightcurve of this system registered by ROSAT suggested the primary component to be the dominant source of activity in the system (Torres et al, AJ 125, 3237, 2003). We reconstruct the spatial structure of coronal emission within the system according to the method proposed by Siarkowski, and show that coronal emission is most likely attributed to both components.

Exploring the Powerful Ionised Wind in the Seyfert Galaxy PG1211+143

NASA Astrophysics Data System (ADS)

Pounds, Ken

2013-10-01

Highly-ionised high-speed winds in AGN (UFOs) were first detected with XMM-Newton a decade ago, and are now established as a key factor in the study of SMBH accretion, and in the growth and metal enrichment of their host galaxies. However, information on the ionisation and dynamical structure, and the ultimate fate of UFOs remains very limited. We request a 600ks extended XMM-Newton study of the prototype UFO PG1211+143 in AO-13, to obtain high quality EPIC and RGS spectra, to map the flow structure and variability, while seeking evidence for the anticipated interaction with the ISM and possible conversion of the energetic wind to a momentum-driven flow.

3, 2, 1 ... Discovering Newton's Laws

ERIC Educational Resources Information Center

Lutz, Joe; Sylvester, Kevin; Oliver, Keith; Herrington, Deborah

2017-01-01

"For every action there is an equal and opposite reaction." "Except when a bug hits your car window, the car must exert more force on the bug because Newton's laws only apply in the physics classroom, right?" Students in our classrooms were able to pick out definitions as well as examples of Newton's three laws; they could…

Stellar atmosphere modeling of extremely hot, compact stars

NASA Astrophysics Data System (ADS)

Rauch, Thomas; Ringat, Ellen; Werner, Klaus

Present X-ray missions like Chandra and XMM-Newton provide excellent spectra of extremely hot white dwarfs, e.g. burst spectra of novae. Their analysis requires adequate NLTE model atmospheres. The Tuebingen Non-LTE Model-Atmosphere Package (TMAP) can calculate such model at-mospheres and spectral energy distributions at a high level of sophistication. We present a new grid of models that is calculated in the parameter range of novae and supersoft X-ray sources and show examples of their application.

The physical origin of the X-ray emission from SN 1987A

NASA Astrophysics Data System (ADS)

Miceli, M.; Orlando, S.; Petruk, O.

2017-10-01

We revisit the spectral analysis of the set of archive XMM-Newton observations of SN 1987A through our 3-D hydrodynamic model describing the whole evolution from the onset of the supernova to the full remnant development. For the first time the spectral analysis accounts for the single observations and for the evolution of the system self-consistently. We adopt a forward modeling approach which allows us to directly synthesize, from the model, X-ray spectra and images in different energy bands. We fold the synthetic observables through the XMM-Newton instrumental response and directly compare models and actual data. We find that our simulation provides an excellent fit to the data, by reproducing simultaneously X-ray fluxes, spectral features, and morphology of SN 1987A at all evolutionary stages. Our analysis enables us to obtain a deep insight on the physical origin of the observed multi-thermal emission, by revealing the contribution of shocked surrounding medium, dense clumps of the circumstellar ring, and ejecta to the total emission. We finally provide predictions for future observations (to be performed with XMM-Newton in the next future and with the forthcoming Athena X-ray telescope in approximately 10 years), showing the growing contribution of the ejecta X-ray emission.

Revealing the X-Ray Emission Processes of Old Rotation-Powered Pulsars: XMM-Newton Observations of PSR B0950+08, PSR B0823+26 and PSR J2043+2740

NASA Technical Reports Server (NTRS)

Becker, Werner; Weisskopf, Martin C.; Tenant, Allyn F.; Jessmer, Axel; Zhang, Shiang N.

2004-01-01

We have completed part of a program to study the X-ray emission properties of old rotation-powered pulsars with XMM-Newton in order to probe and identify the origin of their X radiation. The X-ray emission from these old pulsars is largely dominated by non-thermal processes. None of the observed spectra required adding a thermal component consisting of either a hot polar cap or surface cooling emission to model the data. The energy spectrum of PSR B0950+08 is best described by a single power law of photon-index alpha = 1.93(sup +0.14)(sub -0.12). Three-sigma temperature upper limits for possible contributions from a heated polar cap or the whole neutron star surface are T(sup infinity)(sub pc) < 0.87 x 10(exp 6) K and T(sup infinity)(sub s) < 0.48 x 10(exp 6) K, respectively. We also find that the X-ray emission from PSR B0950+08 is pulsed with two peaks per rotation period. The phase separation between the two X-ray peaks is approx. 144 deg (maximum to maximum) which is similar to the pulse peak separation observed in the radio band at 1.4 GHz. The fraction of X-ray pulsed photons is approx. 30%. A phase resolved spectral analysis confirms the nonthermal nature of the pulsed emission and finds power law slopes of alpha = 2.4(sup +0.52)(sub -0.42) and alpha = 1.93(sup +0.29)(sub -0.24) for the pulse peaks P1 and P2, respectively. The spectral emission properties observed for PSR B0823+26 are similar to those of PSR B0950+08. Its energy spectrum is very well described by a single power law with photon-index alpha = 2.5(sup +0.52)(sub -0.24. Three-sigma temperature upper limits for thermal contributions from a hot polar cap or from the entire neutron star surface are T(sup infinity)(sub pc) < 1.17 x 10(exp 6) K and T(sup infinity)(sub s) < 0.5 x 10(exp 6) K, respectively. There is evidence for pulsed X-ray emission at the - 97% confidence level with a pulsed fraction of 49 +/- 22%. For PSR 52043+2740 we report the first detection of X-ray emission. A power law

Newton's Strange Collisions.

ERIC Educational Resources Information Center

Erlichson, Herman

1995-01-01

Discusses Newton's apparent oversight of the role of energy considerations in collisions between two spherical bodies related to the third corollary of his "Laws of Motion." Investigates several theories that provide solutions to the mysterious oversight. (LZ)

Globally convergent techniques in nonlinear Newton-Krylov

NASA Technical Reports Server (NTRS)

Brown, Peter N.; Saad, Youcef

1989-01-01

Some convergence theory is presented for nonlinear Krylov subspace methods. The basic idea of these methods is to use variants of Newton's iteration in conjunction with a Krylov subspace method for solving the Jacobian linear systems. These methods are variants of inexact Newton methods where the approximate Newton direction is taken from a subspace of small dimensions. The main focus is to analyze these methods when they are combined with global strategies such as linesearch techniques and model trust region algorithms. Most of the convergence results are formulated for projection onto general subspaces rather than just Krylov subspaces.

The role of competing knowledge structures in undermining learning: Newton's second and third laws

NASA Astrophysics Data System (ADS)

Low, David J.; Wilson, Kate F.

2017-01-01

We investigate the development of student understanding of Newton's laws using a pre-instruction test (the Force Concept Inventory), followed by a series of post-instruction tests and interviews. While some students' somewhat naive, pre-existing models of Newton's third law are largely eliminated following a semester of teaching, we find that a particular inconsistent model is highly resilient to, and may even be strengthened by, instruction. If test items contain words that cue students to think of Newton's second law, then students are more likely to apply a "net force" approach to solving problems, even if it is inappropriate to do so. Additional instruction, reinforcing physical concepts in multiple settings and from multiple sources, appears to help students develop a more connected and consistent level of understanding. We recommend explicitly encouraging students to check their work for consistency with physical principles, along with the standard checks for dimensionality and order of magnitude, to encourage reflective and rigorous problem solving.

NuSTAR Detection of a Hard X-Ray Source in the Supernova Remnant-molecular Cloud Interaction Site of IC 443

NASA Astrophysics Data System (ADS)

Zhang, Shuo; Tang, Xiaping; Zhang, Xiao; Sun, Lei; Gotthelf, Eric V.; Zhang, Zhi-Yu; Li, Hui; Cheng, Allen; Pasham, Dheeraj; Baganoff, Frederick K.; Perez, Kerstin; Hailey, Charles J.; Mori, Kaya

2018-06-01

We report on a broadband study of a complex X-ray source (1SAX J0618.0+2227) associated with the interaction site of the supernova remnant (SNR) IC 443 and ambient molecular cloud (MC) using NuSTAR, XMM-Newton, and Chandra observations. Its X-ray spectrum is composed of both thermal and nonthermal components. The thermal component can be equally well represented by either a thin plasma model with kT = 0.19 keV or a blackbody model with kT = 0.11 keV. The nonthermal component can be fit with either a power law with Γ ∼ 1.7 or a cutoff power law with Γ ∼ 1.5 and a cutoff energy at E cut ∼ 18 keV. Using the newly obtained NuSTAR data set, we test three possible scenarios for isolated X-ray sources in the SNR–MC interaction site: (1) a pulsar wind nebula (PWN); (2) an SNR ejecta fragment; and (3) a shocked molecular clump. We conclude that this source is most likely composed of an SNR ejecta (or a PWN) and surrounding shocked molecular clumps. The nature of this hard X-ray source in the SNR–MC interaction site of IC 443 may shed light on unidentified X-ray sources with hard X-ray spectra in rich environments for star-forming regions, such as the Galactic center.

Neural Generalized Predictive Control: A Newton-Raphson Implementation

NASA Technical Reports Server (NTRS)

Soloway, Donald; Haley, Pamela J.

1997-01-01

An efficient implementation of Generalized Predictive Control using a multi-layer feedforward neural network as the plant's nonlinear model is presented. In using Newton-Raphson as the optimization algorithm, the number of iterations needed for convergence is significantly reduced from other techniques. The main cost of the Newton-Raphson algorithm is in the calculation of the Hessian, but even with this overhead the low iteration numbers make Newton-Raphson faster than other techniques and a viable algorithm for real-time control. This paper presents a detailed derivation of the Neural Generalized Predictive Control algorithm with Newton-Raphson as the minimization algorithm. Simulation results show convergence to a good solution within two iterations and timing data show that real-time control is possible. Comments about the algorithm's implementation are also included.

Isaac Newton Olympics.

ERIC Educational Resources Information Center

Cox, Carol

2001-01-01

Presents the Isaac Newton Olympics in which students complete a hands-on activity at seven stations and evaluate what they have learned in the activity and how it is related to real life. Includes both student and teacher instructions for three of the activities. (YDS)

Isaac Newton and the astronomical refraction.

PubMed

Lehn, Waldemar H

2008-12-01

In a short interval toward the end of 1694, Isaac Newton developed two mathematical models for the theory of the astronomical refraction and calculated two refraction tables, but did not publish his theory. Much effort has been expended, starting with Biot in 1836, in the attempt to identify the methods and equations that Newton used. In contrast to previous work, a closed form solution is identified for the refraction integral that reproduces the table for his first model (in which density decays linearly with elevation). The parameters of his second model, which includes the exponential variation of pressure in an isothermal atmosphere, have also been identified by reproducing his results. The implication is clear that in each case Newton had derived exactly the correct equations for the astronomical refraction; furthermore, he was the first to do so.

27 CFR 9.152 - Malibu-Newton Canyon.

Code of Federal Regulations, 2010 CFR

2010-04-01

....” (2) Then south along Kanan Dume Road to the point where an unnamed, unimproved dirt road referred to... Canyon Road to an unnamed, unimproved dirt road referred to by the petitioner as Newton Mountain Way at... southeastern ridgeline of Newton Canyon, to an unnamed, unimproved dirt road referred to by the petitioner as...

3D CSEM data inversion using Newton and Halley class methods

NASA Astrophysics Data System (ADS)

Amaya, M.; Hansen, K. R.; Morten, J. P.

2016-05-01

For the first time in 3D controlled source electromagnetic data inversion, we explore the use of the Newton and the Halley optimization methods, which may show their potential when the cost function has a complex topology. The inversion is formulated as a constrained nonlinear least-squares problem which is solved by iterative optimization. These methods require the derivatives up to second order of the residuals with respect to model parameters. We show how Green's functions determine the high-order derivatives, and develop a diagrammatical representation of the residual derivatives. The Green's functions are efficiently calculated on-the-fly, making use of a finite-difference frequency-domain forward modelling code based on a multi-frontal sparse direct solver. This allow us to build the second-order derivatives of the residuals keeping the memory cost in the same order as in a Gauss-Newton (GN) scheme. Model updates are computed with a trust-region based conjugate-gradient solver which does not require the computation of a stabilizer. We present inversion results for a synthetic survey and compare the GN, Newton, and super-Halley optimization schemes, and consider two different approaches to set the initial trust-region radius. Our analysis shows that the Newton and super-Halley schemes, using the same regularization configuration, add significant information to the inversion so that the convergence is reached by different paths. In our simple resistivity model examples, the convergence speed of the Newton and the super-Halley schemes are either similar or slightly superior with respect to the convergence speed of the GN scheme, close to the minimum of the cost function. Due to the current noise levels and other measurement inaccuracies in geophysical investigations, this advantageous behaviour is at present of low consequence, but may, with the further improvement of geophysical data acquisition, be an argument for more accurate higher-order methods like those

Keynes, Newton and the Royal Society: the events of 1942 and 1943

PubMed Central

Kuehn, Daniel

2013-01-01

Most discussions of John Maynard Keynes's activities in connection with Newton are restricted to the sale in 1936 at Sotheby's of Newton's Portsmouth Papers and to Keynes's 1946 essay ‘Newton, the Man’. This paper provides a history of Keynes's Newton-related work in the interim, highlighting especially the events of 1942 and 1943, which were particularly relevant to the Royal Society's role in the domestic and international promotion of Newton's legacy. During this period, Keynes lectured twice on Newton, leaving notes that would later be read by his brother Geoffrey in the famous commemoration of the Newton tercentenary in 1946. In 1943 Keynes assisted the Royal Society in its recognition of the Soviet celebrations and in the acquisition and preservation of more of the Newton library. In each instance Keynes took the opportunity to promote his interpretation of Newton as ‘the last of the magicians’: a scientist who had one foot in the pre-modern world and whose approach to understanding the world was as much intuitive as it was methodical. PMID:24686919

Giant Black Hole Rips Apart Star

NASA Astrophysics Data System (ADS)

2004-02-01

was equivalent to a supernova. "Now, with all the data in hand, we have the smoking gun proof that this spectacular event has occurred," said coauthor Günther Hasinger, also of MPE. The black hole in the center of RX J1242-11 is estimated to have a mass of about 100 million times Earth's Sun. By contrast, the destroyed star probably had a mass about equal to the Sun, making it a lopsided battle of gravity. "This is the ultimate David versus Goliath battle, but here David loses," said Hasinger. The astronomers estimated about one percent of the star's mass was ultimately consumed, or accreted, by the black hole. This small amount is consistent with predictions that the momentum and energy of the accretion process will cause most of the destroyed star's gas to be flung away from the black hole. XMM-Newton Spectrum &Illustration of RX J1242-11 XMM-Newton Spectrum & Illustration of RX J1242-11 The force that disrupted the star in RX J1242-11 is an extreme example of the tidal force caused by differences in gravity acting on the front and back of an object. The tidal force from the Moon causes tides in Earth's oceans. A tidal force from Jupiter pulled Comet Shoemaker-Levy apart, before it plunged into the giant planet. The odds stellar tidal disruption will happen in a typical galaxy are low, about one in 10,000 annually. If it happened at the center of the Milky Way Galaxy, 26,000 light-years from Earth, the resulting X-ray outburst would be about 50,000 times brighter than the brightest X-ray source in our galaxy, beside the Sun, but it would not pose a threat to Earth. Other dramatic flares have been seen from galaxies, but this is the first studied with the high-spatial resolution of Chandra and the high-spectral resolution of XMM-Newton. Both instruments made a critical advance. Chandra showed the RX J1242-11 event occurred in the center of a galaxy, where the black hole lurks. The XMM-Newton spectrum revealed the fingerprints expected for the surroundings of a black

ULX spectra revisited: Are accreting, highly magnetized neutron stars the engines of ultraluminous X-ray sources?

NASA Astrophysics Data System (ADS)

Koliopanos, F.; Vasilopoulos, G.; Bachetti, M.; Godet, O.; Webb, N.; Barret, D.

2017-10-01

In light of recent discoveries of pulsating ULXs and recently introduced models placing neutron stars as the central engines of ULXs, we revisit the spectra of seventeen ULXs, in search of indications that favor this hypothesis. To this end we examined the spectra from XMM-Newton observations of all seventeen sources in our sample. For six sources, these were complimented with spectra from public NuSTAR observations. We demonstrate that the notable ({>}6 keV) spectral curvature observed in most ULXs, is most likely due to thermal emission, with T{>} 1keV. More importantly, we find that a double thermal model (comprised of a 'cool' and 'hot' thermal component) - often associated with emission from neutron star X-ray binaries - describes all ULX spectra in our list. We propose that the dual thermal spectrum is the result of accretion onto highly magnetized NSs, as predicted in recent theoretical models (Mushtukov et al. 2017). We further argue that this finding offers an additional and compelling argument in favor of neutron stars as prime candidates for powering ULXs, as has been recently suggested (King & Lasota 2016; King et al. 2017). In my talk I will discuss the implications of our interpretation along with its merits and shortcomings.

X-rays from the Solar System

NASA Astrophysics Data System (ADS)

Dennerl, K.

2017-10-01

While the beginning of X-ray astronomy was motivated by solar system studies (Sun and Moon), the main research interest soon shifted outwards to much more distant and exotic objects. However, the ROSAT discovery of X-rays from comets in 1996 and the insight that this `new' kind of X-ray emission, charge exchange, was underestimated for a long time, has demonstrated that solar system studies are still important for X-ray astrophysics in general. While comets provide the best case for studying the physics of charge exchange, the X-ray signatures of this process have now also been detected at Venus, Mars, and Jupiter, thanks to Chandra and XMM-Newton. An analysis of the X-ray data of solar system objects, however, is challenging in many respects. This is particularly true for comets, which appear as moving, extended X-ray sources, emitting a line-rich spectrum at low energies. Especially for XMM-Newton, which has the unparalleled capability to observe with five highly sensitive X-ray instruments plus an optical monitor simultaneously, it is a long way towards photometrically and spectroscopically calibrated results, which are consistent between all its instruments. I will show this in my talk, where I will also summarize the current state of solar system X-ray research.

NGC 4388- Spectral Studies of the First Seyfert 2 Seen by INTEGRAL

NASA Technical Reports Server (NTRS)

Beckman, V.; Gehrels, N.; Favre, P.; Courvoisier, T. J.-L.; Walter, R.; Malzac, J.; Petrucci, P.-O.

2004-01-01

We present first INTEGRAL and XMM-Newton ob- servations of a Seyfert galaxy, the type 2 AGN NGC 4388. Several INTEGRAL observations performed in 2003 allow us to study the spectrum in the 20 - 300 keV range. In addition two XMM-Newton observations give detailed insight into the 0.2 - 10 keV emission. Comparison with previous observations by BeppoSAX, SIGMA and CGROIOSSE show that the overall spectrum for soft X-rays up to the gamma-rays can be described by a highly absorbed and variable non-thermal component in addition to constant non-absorbed thermal emission of low abundance (2 - 5%Za), plus a constant Fe K alpha line. The hard X-ray component is well described by a simple power law with a mean photon index of 1 = 1.7. During the INTEGRAL observations the flux at 100 keV increased by a factor of 1.5. The analysis of XMM-Newton data implies that the emission below 3 keV is decoupled from the AGN and probably due to extended emission as seen in Chandra observations. The constant iron line emission is apparently also decoupled from the direct emission of the central engine and likely to be generated in the obscuring material, e.g. in the molecular torus or even further away.

Discovery of Soft Spectral Component and Transient 22.7s Quasi Periodic Oscillations of SAX J2103.5+4545

NASA Technical Reports Server (NTRS)

Inam, S. C.; Baykal, A.; Swank, J.; Stark, M. J.

2003-01-01

XMM-Newton observed SAX J2103.5+4545 on January 6, 2003, while RXTE was monitoring the source. Using RXTE-PCA dataset between December 3, 2002 and January 29, 2003, the spin period and average spin-up rate during the XMM-Newton observations were found to be 354.7940+/-0.0008 s and (7.4 +/- 0.9) x 10(exp -13) Hz/s respectively. In the power spectrum of the 0.9-11 keV EPIC-PN lightcurve, we found quasi periodic oscillations around 0.044 Hz (22.7 s) with an rms fractional amplitude approx. 6.6 %. We interpreted this QPO feature as the Keplerian motion of inhomogeneities through the inner disk. In the X-ray spectrum, in addition to the power law component with high energy cutoff and approx. 6.4 keV fluorescent iron emission line, we discovered a soft component consistent with a blackbody emission with kT approx. 1.9 keV. The pulse phase spectroscopy of the source revealed that the blackbody flux peaked at the peak of the pulse with an emission radius approx. 0.3 km, suggesting the polar cap on the neutron star approx. 6.42 keV was shown to peak at the off-pulse phase, supporting the idea that this feature arises from fluorescent emission of the circumstellar material around the neutron star rather than the hot region in the vicinity of the neutron star polar cap.

X-Ray Brightening and UV Fading of Tidal Disruption Event ASASSN-15oi

NASA Astrophysics Data System (ADS)

Gezari, S.; Cenko, S. B.; Arcavi, I.

2017-12-01

We present late-time observations by Swift and XMM-Newton of the tidal disruption event (TDE) ASASSN-15oi that reveal that the source brightened in the X-rays by a factor of ∼10 one year after its discovery, while it faded in the UV/optical by a factor of ∼100. The XMM-Newton observations measure a soft X-ray blackbody component with {{kT}}{bb}∼ 45 {eV}, corresponding to radiation from several gravitational radii of a central ∼ {10}6 {M}ȯ black hole. The last Swift epoch taken almost 600 days after discovery shows that the X-ray source has faded back to its levels during the UV/optical peak. The timescale of the X-ray brightening suggests that the X-ray emission could be coming from delayed accretion through a newly forming debris disk and that the prompt UV/optical emission is from the prior circularization of the disk through stream–stream collisions. The lack of spectral evolution during the X-ray brightening disfavors ionization breakout of a TDE “veiled” by obscuring material. This is the first time a TDE has been shown to have a delayed peak in soft X-rays relative to the UV/optical peak, which may be the first clear signature of the real-time assembly of a nascent accretion disk, and provides strong evidence for the origin of the UV/optical emission from circularization, as opposed to reprocessed emission of accretion radiation.

Newton-Krylov-Schwarz: An implicit solver for CFD

NASA Technical Reports Server (NTRS)

Cai, Xiao-Chuan; Keyes, David E.; Venkatakrishnan, V.

1995-01-01

Newton-Krylov methods and Krylov-Schwarz (domain decomposition) methods have begun to become established in computational fluid dynamics (CFD) over the past decade. The former employ a Krylov method inside of Newton's method in a Jacobian-free manner, through directional differencing. The latter employ an overlapping Schwarz domain decomposition to derive a preconditioner for the Krylov accelerator that relies primarily on local information, for data-parallel concurrency. They may be composed as Newton-Krylov-Schwarz (NKS) methods, which seem particularly well suited for solving nonlinear elliptic systems in high-latency, distributed-memory environments. We give a brief description of this family of algorithms, with an emphasis on domain decomposition iterative aspects. We then describe numerical simulations with Newton-Krylov-Schwarz methods on aerodynamics applications emphasizing comparisons with a standard defect-correction approach, subdomain preconditioner consistency, subdomain preconditioner quality, and the effect of a coarse grid.

X-RAY PROPERTIES OF THE NORTHERN GALACTIC CAP SOURCES IN THE 58 MONTH SWIFT/BAT CATALOG

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

Vasudevan, Ranjan V.; Mushotzky, Richard F.; Shimizu, Thomas T.

2013-02-15

We present a detailed X-ray spectral analysis of the non-beamed, hard X-ray selected active galactic nuclei (AGNs) in the northern Galactic cap of the 58 month Swift Burst Alert Telescope (Swift/BAT) catalog, consisting of 100 AGNs with b > 50 Degree-Sign . This sky area has excellent potential for further dedicated study due to a wide range of multi-wavelength data that are already available, and we propose it as a low-redshift analog to the 'deep field' observations of AGNs at higher redshifts (e.g., CDFN/S, COSMOS, Lockman Hole). We present distributions of luminosity, absorbing column density, and other key quantities formore » the catalog. We use a consistent approach to fit new and archival X-ray data gathered from XMM-Newton, Swift/XRT, ASCA, and Swift/BAT. We probe to deeper redshifts than the 9 month BAT catalog ((z) = 0.043 compared to (z) = 0.03 for the 9 month catalog), and uncover a broader absorbing column density distribution. The fraction of obscured (log N {sub H} {>=} 22) objects in the sample is {approx}60%, and 43%-56% of the sample exhibits 'complex' 0.4-10 keV spectra. We present the properties of iron lines, soft excesses, and ionized absorbers for the subset of objects with sufficient signal-to-noise ratio. We reinforce previous determinations of the X-ray Baldwin (Iwasawa-Taniguchi) effect for iron K{alpha} lines. We also identify two distinct populations of sources; one in which a soft excess is well-detected and another where the soft excess is undetected, suggesting that the process responsible for producing the soft excess is not at work in all AGNs. The fraction of Compton-thick sources (log N {sub H} > 24.15) in our sample is {approx}9%. We find that 'hidden/buried AGNs' (which may have a geometrically thick torus or emaciated scattering regions) constitute {approx}14% of our sample, including seven objects previously not identified as hidden. Compton reflection is found to be important in a large fraction of our sample using joint

Newton's Experimentum Crucis Reconsidered

ERIC Educational Resources Information Center

Holtsmark, Torger

1970-01-01

Certain terminological inconsistencies in the teaching of optical theory at the elementary level are traced back to Newton who derived them from Euclidean geometrical optics. Discusses this terminological ambiguity which influenced later textbooks. (LS)

Infinity and Newton's Three Laws of Motion

NASA Astrophysics Data System (ADS)

Lee, Chunghyoung

2011-12-01

It is shown that the following three common understandings of Newton's laws of motion do not hold for systems of infinitely many components. First, Newton's third law, or the law of action and reaction, is universally believed to imply that the total sum of internal forces in a system is always zero. Several examples are presented to show that this belief fails to hold for infinite systems. Second, two of these examples are of an infinitely divisible continuous body with finite mass and volume such that the sum of all the internal forces in the body is not zero and the body accelerates due to this non-null net internal force. So the two examples also demonstrate the breakdown of the common understanding that according to Newton's laws a body under no external force does not accelerate. Finally, these examples also make it clear that the expression `impressed force' in Newton's formulations of his first and second laws should be understood not as `external force' but as `exerted force' which is the sum of all the internal and external forces acting on a given body, if the body is infinitely divisible.

Why Did Newton See Indigo in the Spectrum?

ERIC Educational Resources Information Center

Biernson, George

1972-01-01

The arrangement of colors in Newton's color circle suggests that it was derived from paint mixtures, not light mixtures. If this is true it may be concluded that what Newton called indigo represents violet in modern terminology, and what he called violet represents purple. (Author/TS)

Bright X-ray transient in the LMC

NASA Astrophysics Data System (ADS)

Saxton, R.; Read, A. M.; Li, D. Y.

2018-01-01

We report a bright X-ray transient in the LMC from an XMM-Newton slew made on 5th January 2018. The source, XMMSL2 J053629.4-675940, had a soft X-ray (0.2-2 keV) count rate in the EPIC-pn detector, medium filter of 1.82+/-0.56 c/s, equivalent to a flux Fx=2.3+/-0.7E-12 ergs/s/cm2 for a nominal spectrum of a power-law of slope 2 absorbed by a column NH=3E20 cm^-2.

Spectral Characteristics of Young Stars Associated with the Sh2-296 Nebula

NASA Astrophysics Data System (ADS)

Fernandes, Beatriz; Gregorio-Hetem, Jane

Aiming to contribute to the understanding of star formation and evolution in the Canis Major (CMa R1) Molecular Clouds Complex, we analyze the spectral characteristics of a population of young stars associated with the arc-shaped nebula Sh2-296. Our XMM/Newton observations detected 109 X-ray sources in the region and optical spectroscopy was performed with Gemini telescope for 85 optical counterparts. We identified and characterized 51 objects that present features typically found in young objects, such as Hα emission and strong absorption on the Li I line.

Short-Term Variability and Power Spectral Density Analysis of the Radio-Loud Active Galactic Nucleus 3C 390.3

NASA Astrophysics Data System (ADS)

Gliozzi, Mario; Papadakis, Iossif E.; Eracleous, Michael; Sambruna, Rita M.; Ballantyne, David R.; Braito, Valentina; Reeves, James N.

2009-09-01

We investigate the short-term variability properties and the power spectral density (PSD) of the broad-line radio galaxy (BLRG) 3C 390.3 using observations made by XMM-Newton, RXTE, and Suzaku on several occasions between 2004 October and 2006 December. The main aim of this work is to derive model-independent constraints on the origin of the X-ray emission and on the nature of the central engine in 3C 390.3. On timescales of the order of few hours, probed by uninterrupted XMM-Newton light curves, the flux of 3C 390.3 is consistent with being constant in all energy bands. On longer timescales, probed by the 2-day RXTE and Suzaku observations, the flux variability becomes significant. The latter observation confirms that the spectral variability behavior of 3C 390.3 is consistent with the spectral evolution observed in (radio-quiet) Seyfert galaxies: the spectrum softens as the source brightens. The correlated variability between soft and hard X-rays, observed during the Suzaku exposure and between the two XMM-Newton pointings, taken 1 week apart, argues against scenarios characterized by the presence of two distinct variable components in the 0.5-10 keV X-ray band. A detailed PSD analysis carried out over five decades in frequency suggests the presence of a break at T br = 43+34 -25 days at a 92% confidence level. This is the second tentative detection of a PSD break in a radio-loud, non-jet dominated active galactic nucleus (AGN), after the BLRG 3C 120, and appears to be in general agreement with the relation between T br, M BH, and L bol, followed by Seyfert galaxies. Our results indicate that the X-ray variability properties of 3C 390.3 are broadly consistent with those of radio-quiet AGN, suggesting that the X-ray emission mechanism in 3C 390.3 is similar to that of nearby Seyfert galaxies without any significant contribution from a jet component.

The high-energy view of the broad-line radio galaxy 3C 111

NASA Astrophysics Data System (ADS)

Ballo, L.; Braito, V.; Reeves, J. N.; Sambruna, R. M.; Tombesi, F.

2011-12-01

We present the analysis of Suzaku and XMM-Newton observations of the broad-line radio galaxy (BLRG) 3C 111. Its high-energy emission shows variability, a harder continuum with respect to the radio-quiet active galactic nucleus population, and weak reflection features. Suzaku found the source in a minimum flux level; a comparison with the XMM-Newton data implies an increase of a factor of 2.5 in the 0.5-10 keV flux, in the 6 months separating the two observations. The iron K complex is detected in both data sets, with rather low equivalent width(s). The intensity of the iron K complex does not respond to the change in continuum flux. An ultrafast, high-ionization outflowing gas is clearly detected in the Suzaku/X-ray Imaging Spectrometer data; the absorber is most likely unstable. Indeed, during the XMM-Newton observation, which was 6 months after, the absorber was not detected. No clear rollover in the hard X-ray emission is detected, probably due to the emergence of the jet as a dominant component in the hard X-ray band, as suggested by the detection above ˜100 keV with the GSO onboard Suzaku, although the present data do not allow us to firmly constrain the relative contribution of the different components. The fluxes observed by the γ-ray satellites CGRO and Fermi would be compatible with the putative jet component if peaking at energies E˜ 100 MeV. In the X-ray band, the jet contribution to the continuum starts to be significant only above 10 keV. If the detection of the jet component in 3C 111 is confirmed, then its relative importance in the X-ray energy band could explain the different observed properties in the high-energy emission of BLRGs, which are otherwise similar in their other multiwavelength properties. Comparison between X-ray and γ-ray data taken at different epochs suggests that the strong variability observed for 3C 111 is probably driven by a change in the primary continuum.

X-ray and optical spectroscopy of the massive young open cluster IC 1805

NASA Astrophysics Data System (ADS)

Rauw, G.; Nazé, Y.

2016-10-01

Context. Very young open clusters are ideal places to study the X-ray properties of a homogeneous population of early-type stars. In this respect, the IC 1805 open cluster is very interesting as it hosts the O4 If+ star HD 15570 thought to be in an evolutionary stage intermediate between a normal O-star and a Wolf-Rayet star. Aims: Such a star could provide a test for theoretical models aiming at explaining the empirical scaling relation between the X-ray and bolometric luminosities of O-type stars. Methods: We have observed IC 1805 with XMM-Newton and further collected optical spectroscopy of some of the O-star members of the cluster. Results: The optical spectra allow us to revisit the orbital solutions of BD+60° 497 and HD 15558, and provide the first evidence of binarity for BD+60° 498. X-ray emission from colliding winds does not appear to play an important role among the O-stars of IC 1805. Notably, the X-ray fluxes do not vary significantly between archival X-ray observations and our XMM-Newton pointing. The very fast rotator BD+60° 513, and to a lesser extent the O4 If+ star HD 15570 appear somewhat underluminous. Whilst the underluminosity of HD 15570 is only marginally significant, its amplitude is found to be compatible with theoretical expectations based on its stellar and wind properties. A number of other X-ray sources are detected in the field, and the brightest objects, many of which are likely low-mass pre-main sequence stars, are analyzed in detail. Based on observations collected with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA member states and the USA (NASA), and with the TIGRE telescope (La Luz, Mexico).Table A.1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/594/A82

TRANSIENT X-RAY SOURCE POPULATION IN THE MAGELLANIC-TYPE GALAXY NGC 55

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

Jithesh, V.; Wang, Zhongxiang, E-mail: jithesh@shao.ac.cn

2016-04-10

We present the spectral and temporal properties of 15 candidate transient X-ray sources detected in archival XMM-Newton and Chandra observations of the nearby Magellanic-type, SB(s)m galaxy NGC 55. Based on an X-ray color classification scheme, the majority of the sources may be identified as X-ray binaries (XRBs), and six sources are soft, including a likely supernova remnant. We perform a detailed spectral and variability analysis of the data for two bright candidate XRBs. Both sources displayed strong short-term X-ray variability, and their X-ray spectra and hardness ratios are consistent with those of XRBs. These results, combined with their high X-raymore » luminosities (∼10{sup 38} erg s{sup −1}), strongly suggest that they are black hole (BH) binaries. Seven less luminous sources have spectral properties consistent with those of neutron star or BH XRBs in both normal and high-rate accretion modes, but one of them is the likely counterpart to a background galaxy (because of positional coincidence). From our spectral analysis, we find that the six soft sources are candidate super soft sources (SSSs) with dominant emission in the soft (0.3–2 keV) X-ray band. Archival Hubble Space Telescope optical images for seven sources are available, and the data suggest that most of them are likely to be high-mass XRBs. Our analysis has revealed the heterogeneous nature of the transient population in NGC 55 (six high-mass XRBs, one low-mass XRBs, six SSSs, one active galactic nucleus), helping establish the similarity of the X-ray properties of this galaxy to those of other Magellanic-type galaxies.« less

How concept images affect students' interpretations of Newton's method

NASA Astrophysics Data System (ADS)

Engelke Infante, Nicole; Murphy, Kristen; Glenn, Celeste; Sealey, Vicki

2018-07-01

Knowing when students have the prerequisite knowledge to be able to read and understand a mathematical text is a perennial concern for instructors. Using text describing Newton's method and Vinner's notion of concept image, we exemplify how prerequisite knowledge influences understanding. Through clinical interviews with first-semester calculus students, we determined how evoked concept images of tangent lines and roots contributed to students' interpretation and application of Newton's method. Results show that some students' concept images of root and tangent line developed throughout the interview process, and most students were able to adequately interpret the text on Newton's method. However, students with insufficient concept images of tangent line and students who were unwilling or unable to modify their concept images of tangent line after reading the text were not successful in interpreting Newton's method.

A Massive Galaxy Cluster At z=1.45 From The XMM Cluster Survey: Discovery, Confirmation And Implications For The L-T Relation And Cosmology

NASA Astrophysics Data System (ADS)

Sabirli, Kivanc; Romer, A. K.; Davidson, M.; Stanford, S. A.; Viana, P. T.; Hilton, M.; Collins, C. A.; Kay, S. T.; Liddle, A. R.; Mann, R. G.; Miller, C. J.; Nichol, R. C.; West, M. J.; Conselice, C. J.; Spinrad, H.; Stern, D.; XCS Collaboration

2006-06-01

We report the discovery of the hottest cluster known at z > 1. It was identified as an extended X-ray source in the XMM Cluster Survey (XCS, Romer et al., 2001) and optical spectroscopy shows that 6 galaxies within a 60 arcsec diameter region lie at z = 1.45 ± 0.01. Hence its redshift is the highest currently known for a spectroscopically-confirmed cluster. Analysis of the X-ray spectra yields kT = 7.9+2.8-1.8 keV (90% confidence) and suggests that it is relatively massive for such a high redshift cluster.We acknowledge financial support from NASA grant NAG-11634 (AKR, RCN, KS, MD, PTPV), The Royal Astronomical Society's Hosie Request (MD, KS), PPARC (ARL, STK, RGM), the NASA XMM program (KS), the Institute of Astronomy at the University of Edinburgh (MD), Liverpool John Moores University (MH), Carnegie Mellon University (KS, AKR), and NSF grant AST-0205960 (MJW).

There is grandeur in this view of Newton: Charles Darwin, Isaac Newton and Victorian conceptions of scientific virtue.

PubMed

Bellon, Richard

2014-01-01

For Victorian men of science, the scientific revolution of the seventeenth century represented a moral awakening. Great theoretical triumphs of inductive science flowed directly from a philosophical spirit that embraced the virtues of self-discipline, courage, patience and humility. Isaac Newton exemplified this union of moral and intellectual excellence. This, at least, was the story crafted by scientific leaders like David Brewster, Thomas Chalmers, John Herschel, Adam Sedgwick and William Whewell. Not everyone accepted this reading of history. Evangelicals who decried the 'materialism' of mainstream science assigned a different meaning to Newton's legacy on behalf of their 'scriptural' alternative. High-church critics of science like John Henry Newman, on the other hand, denied that Newton's secular achievements carried any moral significance at all. These debates over Newtonian standards of philosophical behavior had a decisive influence on Charles Darwin as he developed his theory of evolution by natural selection. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Newton method for the magnetohydrodynamic equilibrium equations

NASA Astrophysics Data System (ADS)