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Sample records for galaxies ii near-infrared

  1. COMPARATIVE STUDY OF ASYMMETRY ORIGIN OF GALAXIES IN DIFFERENT ENVIRONMENTS. II. NEAR-INFRARED OBSERVATIONS

    SciTech Connect

    Plauchu-Frayn, I.; Coziol, R. E-mail: rcoziol@astro.ugto.m

    2010-08-15

    In this second paper of two analyses, we present near-infrared (NIR) morphological and asymmetry studies performed in a sample of 92 galaxies found in different density environments: galaxies in compact groups (CGs; HCGs in the Hickson Catalog of Compact Groups of Galaxies), isolated pairs of galaxies (KPGs in Karachentsev's list of isolated pairs of galaxies), and isolated galaxies (KIGs in Karachentseva's Catalog of Isolated Galaxies). Both studies have proved useful for identifying the effect of interactions on galaxies. In the NIR, the properties of the galaxies in HCGs, KPGs, and KIGs are more similar than they are in the optical. This is because the NIR band traces the older stellar populations, which formed earlier and are more relaxed than the younger populations. However, we found asymmetries related to interactions in both KPG and HCG samples. In HCGs, the fraction of asymmetric galaxies is even higher than what we found in the optical. In the KPGs the interactions look like very recent events, while in the HCGs galaxies are more morphologically evolved and show properties suggesting they suffered more frequent interactions. The key difference seems to be the absence of star formation in the HCGs; while interactions produce intense star formation in the KPGs, we do not see this effect in the HCGs. This is consistent with the dry merger hypothesis; the interaction between galaxies in CGs is happening without the presence of gas. If the gas was spent in stellar formation (to build the bulge of the numerous early-type galaxies), then the HCGs possibly started interacting sometime before the KPGs. On the other hand, the dry interaction condition in CGs suggests that the galaxies are on merging orbits, and consequently such system cannot be that much older either. Cosmologically speaking, the difference in formation time between pairs of galaxies and CGs may be relatively small. The two phenomena are typical of the formation of structures in low

  2. Supermassive black holes and their host galaxies. II. The correlation with near-infrared luminosity revisited

    SciTech Connect

    Läsker, Ronald; Van de Ven, Glenn; Ferrarese, Laura; Shankar, Francesco

    2014-01-01

    We present an investigation of the scaling relations between supermassive black hole (SMBH) masses, M {sub •}, and their host galaxies' K-band bulge (L {sub bul}) and total (L {sub tot}) luminosities. The wide-field WIRCam imager at the Canada-France-Hawaii-Telescope was used to obtain the deepest and highest resolution near-infrared images available for a sample of 35 galaxies with securely measured M {sub •}, selected irrespective of Hubble type. For each galaxy, we derive bulge and total magnitudes using a two-dimensional image decomposition code that allows us to account, if necessary, for large- and small-scale disks, cores, bars, nuclei, rings, envelopes, and spiral arms. We find that the present-day M {sub •}-L {sub bul} and M {sub •}-L {sub tot} relations have consistent intrinsic scatter, suggesting that M {sub •} correlates equally well with bulge and total luminosity of the host. Our analysis provides only mild evidence of a decreased scatter if the fit is restricted to elliptical galaxies. The log-slopes of the M {sub •}-L {sub bul} and M {sub •}-L {sub tot} relations are 0.75 ± 0.10 and 0.92 ± 0.14, respectively. However, while the slope of the M {sub •}-L {sub bul} relation depends on the detail of the image decomposition, the characterization of M {sub •}-L {sub tot} does not. Given the difficulties and ambiguities of decomposing galaxy images into separate components, our results indicate that L {sub tot} is more suitable as a tracer of SMBH mass than L {sub bul}, and that the M {sub •}-L {sub tot} relation should be used when studying the co-evolution of SMBHs and galaxies.

  3. Blue compact dwarf galaxies. II - Near-infrared studies and stellar populations

    NASA Technical Reports Server (NTRS)

    Thuan, T. X.

    1983-01-01

    An IR photometric survey was performed of 36 blue compact dwarf galaxies (BCDG) where intense bursts of star formation have been observed. The survey covered the J, H, and K lines, with all readings taken at the level of a few mJy. Although the near-IR fluxes observed in the galaxies are due to K and M giants, the bursts have calculated ages of less than 50 million yr. However, the BCDG galaxies surveyed are not young, with the least chemically evolved galaxy observed, I Zw 18, featuring 50 pct of its stars formed prior to its last burst, but with a missing mass that is not accounted for by H I interferometric observations. It is concluded that the old stars must be more spatially extended than the young stars, and a mixture of OB stars with the K and M giants is projected as capable of displaying the colors observed. The star formation processes in the BCDG galaxies is defined as dependent on the total mass of the galaxies, with low mass galaxies having a high ratio of star formation, compared to their previous rates.

  4. A Wide Area Survey for High-Redshift Massive Galaxies. II. Near-Infrared Spectroscopy of BzK-Selected Massive Star-Forming Galaxies

    NASA Astrophysics Data System (ADS)

    Onodera, Masato; Arimoto, Nobuo; Daddi, Emanuele; Renzini, Alvio; Kong, Xu; Cimatti, Andrea; Broadhurst, Tom; Alexander, Dave M.

    2010-05-01

    Results are presented from near-infrared spectroscopic observations of a sample of BzK-selected, massive star-forming galaxies (sBzKs) at 1.5 < z < 2.3 that were obtained with OHS/CISCO at the Subaru telescope and with SINFONI at the Very Large Telescope. Among the 28 sBzKs observed, Hα emission was detected in 14 objects, and for 11 of them the [N II] λ6583 flux was also measured. Multiwavelength photometry was also used to derive stellar masses and extinction parameters, whereas Hα and [N II] emissions have allowed us to estimate star formation rates (SFRs), metallicities, ionization mechanisms, and dynamical masses. In order to enforce agreement between SFRs from Hα with those derived from rest-frame UV and mid-infrared, additional obscuration for the emission lines (that originate in H II regions) was required compared to the extinction derived from the slope of the UV continuum. We have also derived the stellar mass-metallicity relation, as well as the relation between stellar mass and specific SFR (SSFR), and compared them to the results in other studies. At a given stellar mass, the sBzKs appear to have been already enriched to metallicities close to those of local star-forming galaxies of similar mass. The sBzKs presented here tend to have higher metallicities compared to those of UV-selected galaxies, indicating that near-infrared selected galaxies tend to be a chemically more evolved population. The sBzKs show SSFRs that are systematically higher, by up to ~2 orders of magnitude, compared to those of local galaxies of the same mass. The empirical correlations between stellar mass and metallicity, and stellar mass and SSFR are then compared with those of evolutionary population synthesis models constructed either with the simple closed-box assumption, or within an infall scenario. Within the assumptions that are built-in such models, it appears that a short timescale for the star formation (sime100 Myr) and large initial gas mass appear to be required

  5. A NEAR-INFRARED TEMPLATE DERIVED FROM I Zw 1 FOR THE Fe II EMISSION IN ACTIVE GALAXIES

    SciTech Connect

    Garcia-Rissmann, A.; Rodriguez-Ardila, A.; Sigut, T. A. A.; Pradhan, A. K.

    2012-05-20

    In active galactic nucleus spectra, a series of Fe II multiplets form a pseudo-continuum that extends from the ultraviolet to the near-infrared (NIR). This emission is believed to originate in the broad-line region, and it has been known for a long time that pure photoionization fails to reproduce it in the most extreme cases, as does the collisional excitation alone. The most recent models by Sigut and Pradhan include details of the Fe II ion microphysics and cover a wide range in the ionization parameter log U{sub ion} = (- 3.0 {yields} -1.3) and density log n{sub H} = (9.6 {yields} 12.6). With the aid of such models and a spectral synthesis approach, we studied for the first time in detail the NIR emission of I Zw 1. The main goals were to confirm the role played by Ly{alpha} fluorescence mechanisms in the production of the Fe II spectrum and to construct the first semi-empirical NIR Fe II template that best represents this emission, consequently allowing its clean subtraction in other sources. A good overall match between the observed Fe II+Mg II features with those predicted by the best-fitted model was obtained, corroborating the Ly{alpha} fluorescence as a key process to understand the Fe II spectrum. The best model was fine-tuned by applying a deconvolution method to the observed Fe II+Mg II spectrum. This derived semi-empirical template was then fitted to the spectrum of Ark 564, showing that it nicely reproduced its observed Fe II+Mg II emission. Our work extends the current set of available Fe II templates into the NIR region.

  6. Near-infrared observations of IRAS minisurvey galaxies

    NASA Technical Reports Server (NTRS)

    Carico, David P.; Soifer, B. T.; Elias, J. H.; Matthews, K.; Neugebauer, G.; Beichman, C.; Persson, C. J.; Persson, S. E.

    1987-01-01

    Near infrared photometry at J, H, and K was obtained for 82 galaxies from the IRAS minisurvey. The near infrared colors of these galaxies cover a larger range in J-H and H-K than do normal field spiral galaxies, and evidence is presented of a tighter correlation between the near and far infrared emission in far infrared bright galaxies than exists between the far infrared and the visible emission. These results suggest the presence of dust in the far infrared bright galaxies, with hot dust emission contributing to the 2.2 micron emission, and extinction by dust affecting both the near infrared colors and the visible luminosities. In addition, there is some indication that the infrared emission in many of the minisurvey galaxies is coming from a strong nuclear component.

  7. New insights to the photometric structure of Blue Compact Dwarf Galaxies from deep near-infrared studies. II. The sample of northern BCDs

    NASA Astrophysics Data System (ADS)

    Noeske, K. G.; Papaderos, P.; Cairós, L. M.; Fricke, K. J.

    2005-01-01

    This paper is part of a series of publications which present a systematic study of Blue Compact Dwarf (BCD) Galaxies in the near infrared (NIR). Compared to the visible light, NIR data allow a better separation of the starburst emission from the light distribution of the old stellar low-surface brightness (LSB) host galaxy. We analyze deep NIR broad band images of a sample of 11 BCDs, observed with the Calar Alto 3.6 m telescope. This work enlarges the samples presented in preceding papers of this study (Noeske et al. \\cite{Noeske2003}, A&A, 410, 481; Cairós et al. \\cite{c03a}, ApJ, 593, 312) by BCDs of the most common morphological type, displaying a regular elliptical LSB host galaxy. The data presented here allow the detection and quantitative study of the extended stellar LSB host galaxy in all sample BCDs. The NIR surface brightness profiles (SBPs) of the LSB host galaxies agree at large galactocentric radii with those from optical studies, showing also an exponential intensity decrease and compatible scale lengths. Similar to Noeske et al. (\\cite{Noeske2003}), we find centrally flattening exponential (type V) SBPs of the host galaxy for several BCDs. Such SBPs remain mostly undetected in optical bands, due to the comparatively stronger starburst emission at these wavelengths. We apply a modified exponential distribution to decompose and quantitatively analyze SBPs of LSB hosts with a type V intensity distribution. We present the results of the surface photometry and the decomposition of SBPs, and discuss individual objects with respect to morphological details of their star-forming regions. Table 2 is also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http:/ /cdsweb.u-strasbg.fr/ cgi-bin/ qcat?J/A+A/429/115 Figures 2 to 11 are only available in electronic form at http://www.edpsciences.org German-Spanish Astronomical Center, Calar Alto, operated by the Max-Planck-Institute for Astronomy, Heidelberg

  8. AKARI NEAR-INFRARED SPECTROSCOPY OF LUMINOUS INFRARED GALAXIES

    SciTech Connect

    Lee, Jong Chul; Lee, Myung Gyoon; Hwang, Ho Seong

    2012-09-01

    We present the AKARI near-infrared (NIR; 2.5-5 {mu}m) spectroscopic study of 36 (ultra)luminous infrared galaxies ((U)LIRGs) at z = 0.01-0.4. We measure the NIR spectral features including the strengths of 3.3 {mu}m polycyclic aromatic hydrocarbon emission and hydrogen recombination lines (Br{alpha} and Br{beta}), optical depths at 3.1 and 3.4 {mu}m, and NIR continuum slope. These spectral features are used to identify optically elusive, buried active galactic nuclei (AGNs). We find that half of the (U)LIRGs optically classified as non-Seyferts show AGN signatures in their NIR spectra. Using a combined sample of (U)LIRGs with NIR spectra in the literature, we measure the contribution of buried AGNs to the infrared luminosity from the spectral energy distribution fitting to the IRAS photometry. The contribution of these buried AGNs to the infrared luminosity is 5%-10%, smaller than the typical AGN contribution of (U)LIRGs including Seyfert galaxies (10%-40%). We show that NIR continuum slopes correlate well with WISE [3.4]-[4.6] colors, which would be useful for identifying a large number of buried AGNs using the WISE data.

  9. RESOLVED NEAR-INFRARED STELLAR POPULATIONS IN NEARBY GALAXIES

    SciTech Connect

    Dalcanton, Julianne J.; Williams, Benjamin F.; Rosenfield, Philip A.; Gilbert, Karoline E-mail: ben@astro.washington.edu E-mail: kgilbert@astro.washington.edu; and others

    2012-01-01

    We present near-infrared (NIR) color-magnitude diagrams (CMDs) for the resolved stellar populations within 26 fields of 23 nearby galaxies ({approx}< 4 Mpc), based on images in the F110W and F160W filters taken with the Wide-Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). The CMDs are measured in regions spanning a wide range of star formation histories, including both old dormant and young star-forming populations. We match key NIR CMD features with their counterparts in more familiar optical CMDs, and identify the red core helium-burning (RHeB) sequence as a significant contributor to the NIR flux in stellar populations younger than a few 100 Myr old. The strength of this feature suggests that the NIR mass-to-light ratio can vary significantly on short timescales in star-forming systems. The NIR luminosity of star-forming galaxies is therefore not necessarily proportional to the stellar mass. We note that these individual RHeB stars may also be misidentified as old stellar clusters in images of nearby galaxies. For older stellar populations, we discuss the CMD location of asymptotic giant branch (AGB) stars in the HST filter set and explore the separation of AGB subpopulations using a combination of optical and NIR colors. We empirically calibrate the magnitude of the NIR tip of the red giant branch in F160W as a function of color, allowing future observations in this widely adopted filter set to be used for distance measurements. We also analyze the properties of the NIR red giant branch (RGB) as a function of metallicity, showing a clear trend between NIR RGB color and metallicity. However, based on the current study, it appears unlikely that the slope of the NIR RGB can be used as an effective metallicity indicator in extragalactic systems with comparable data. Finally, we highlight issues with scattered light in the WFC3, which becomes significant for exposures taken close to a bright Earth limb.

  10. Galaxy Evolution from Deep Optical and Near-Infrared Surveys

    NASA Astrophysics Data System (ADS)

    Moustakas, Leonidas Alexander

    1998-09-01

    We use very deep optical and near-infrared imaging surveys to set constraints on galaxy evolution models, based on the numbers, colors, and morphologies of infrared-excess galaxies that are found in the field. We concentrate on a curious population of extremely faint (K > 20) infrared-excess galaxies whose blue-optical colors are not consistent with the expectations of any passive evolution models. These ``faint red-outlier galaxies'' (FROGs) are distinct from the redder and brighter ``extremely red objects'' (EROs; R-K~=6 ). In a concerted effort to identify a good sample of FROG s and to study their properties, we used Keck/NIRC to image several independent high-galactic latitude fields. Much of the analysis presented here is drawn from a very deep 3.24 arcmin2 K-band ( Klim~24 at 3σ) mosaic in the deep Westphal HST/WFPC2 pointing of the Groth Survey Strip, for which F606W and F814W data were publically available. The surface density of FROGs is found to be ~ 3.3 +/- 1 arcmin-2, more than ten times that of EROs. Whereas reliable photometric redshifts are not forthcoming without the development of more relevant models, the colors are broadly consistent with the redshift range 1.2 < z < 2.3. If placed at z ~ 1.5, FROGs occur at space densities of about 10% of the local f* space density of K-selected galaxies. To map wavelength-dependent morphologies of two FROGs, we observed a portion of our main survey field with HST/NICMOS imaging through the F160W (1.6 μm) filter. The target was resolved into two r~=0''.6 objects with similar colors, separated by ~0''.7. This is suggestive of old and dynamically-relaxed systems. The colors of FROGs are not satisfactorily fit by dust-reddened Bruzual-Charlot models at any redshift and for a broad range of assumed star formation histories. The best possible fits are consistent with very large amounts of reddening, E(B - V) ~ 1. If the infrared-excess in EROs and FROGs is taken to be entirely due to the effects of dust, then we

  11. NEAR-INFRARED IMAGING OF SIX METAL-RICH QUASAR ABSORBER GALAXY FIELDS

    SciTech Connect

    Straka, Lorrie A.; Kulkarni, Varsha P.; York, Donald G.

    2011-06-15

    Absorption lines in quasar spectra allow us to locate and study intervening galaxies. In order to obtain a clearer picture of these absorber galaxies, we have used the Near-Infrared Camera Fabry-Perot System at Apache Point Observatory to obtain near-infrared broadband images in one or more filters (J and K{sub s} ) of six quasar fields containing metal-rich low-z damped or sub-damped Ly{alpha} systems. These data allow us to search for the galaxies and constrain their luminosities. Candidate absorber galaxies are detected at 2.''01-7.''38 separation from the quasar in three out of six fields in the J and K{sub s} bands at >3{sigma} level with luminosities ranging from log(L/L{sub sun}) = 10.44-10.36 in the J band (for E-Sc type galaxies) and log(L/L{sub sun}) = 11.59-10.03 in the K{sub s} band for our detections. We place limits on the remaining fields with no detections of log(L/L{sub sun}) <10.83-9.75 for the J band and log(L/L{sub sun}) <10.43-10.05 for the K{sub s} band. We are also able to utilize Sloan Digital Sky Survey spectra for each field to calculate optical fluxes and limits as well as limits on star formation rate via [O II]{lambda}3727 emission in spectra. Our data, combined with other recent imaging results for metal-rich absorbers, suggest a possible positive correlation between absorber metallicity and galaxy luminosity, although the samples are still small.

  12. Excitation Mechanisms of Near-Infrared Emission Lines in LINER Galaxies

    NASA Astrophysics Data System (ADS)

    Boehle, Anna

    2017-01-01

    I will present high spatial resolution, integral field spectroscopic observations of the nearby LINER (low ionization nuclear emission line region) galaxy NGC 404. LINERs are found at the centers of ~1/3 of galaxies within 40 Mpc, but their physical nature is not well understood. Although NGC 404 is thought to host a intermediate mass black hole at its center, it is unclear whether accretion onto the black hole or another mechanism such as shock excitation drives its LINER emission. We use the OSIRIS near-infrared integral field spectrograph at Keck Observatory behind laser guide star adaptive optics to map the strength and kinematics of [FeII], H2, and hydrogen recombination lines in the nucleus of NGC 404. These observations have a spatial pixel sampling of 0.5 pc and span the central 30 pc of the galaxy. We find that the ionized and molecular gas show differences in their morphology and kinematics on parsec scales. In particular, there are regions with line ratios of [FeII]/Pa-β that are much higher than previously seen in spatially integrated spectra, significantly restricting the possible excitation mechanisms of the near-infrared emission lines in this source. We are also applying these analysis techniques to 10 additional nearby LINERs, a part of a larger sample of 14 sources, to understand what drives the emission lines in these active galaxies. As a part of this program, I worked on the upgrade of the detector in the OSIRIS spectrograph, which has allowed observations for this survey obtained since January 2016 to be taken with increased instrument sensitivity of a factor of ~2 at J-band wavelengths (1.2 - 1.4 microns) and ~1.6 at H- and K-band wavelengths (1.5 - 2.4 microns). I will present results from the LINER survey, the OSIRIS detector upgrade, and also touch on related work using stellar orbits around the Milky Way supermassive black hole Sgr A* to constrain the mass and distance to our own Galactic Center.

  13. Near-Infrared Spectroscopy of the Blue Compact Dwarf Galaxy Markarian 59

    NASA Astrophysics Data System (ADS)

    Izotov, Yuri I.; Thuan, Trinh X.; Wilson, John C.

    2009-10-01

    We present near-infrared (NIR) spectroscopic observations of the blue compact dwarf (BCD) galaxy Markarian 59 (Mrk 59), obtained with the TripleSpec spectrograph mounted on the 3.5 m Apache Point Observatory telescope. The NIR spectrum of Mrk 59, which covers the 0.90 μm-2.40 μm wavelength range, shows atomic hydrogen, molecular hydrogen, helium, sulfur, and iron emission lines. The NIR data have been supplemented by a Sloan Digital Sky Survey optical spectrum. We found extinction in the BCD to be low (A(V) = 0.24 mag) and to be the same in both the optical and NIR ranges. The NIR light does not reveal hidden star formation. The H2 emission comes from dense clumps and the H2 vibrational emission-line intensities can be accounted for by photon excitation. No shock excitation is needed. A CLOUDY photoionization model of Mrk 59 reproduces well the observed optical and NIR emission-line fluxes. There is no need to invoke sources of ionization other than stellar radiation. The [Fe II] 1.257 and 1.643 μm emission lines, often used as supernova shock indicators in low-excitation high-metallicity starburst galaxies, cannot play such a role in high-excitation low-metallicity H II regions such as Mrk 59.

  14. THE COSMIC NEAR-INFRARED BACKGROUND. II. FLUCTUATIONS

    SciTech Connect

    Fernandez, Elizabeth R.; Komatsu, Eiichiro; Shapiro, Paul R.; Iliev, Ilian T.

    2010-02-20

    The near-infrared background (NIRB) is one of a few methods that can be used to observe the redshifted light from early stars at a redshift of 6 and above, and thus it is imperative to understand the significance of any detection or nondetection of the NIRB. Fluctuations of the NIRB can provide information on the first structures, such as halos and their surrounding ionized regions in the intergalactic medium (IGM). We combine, for the first time, N-body simulations, radiative transfer code, and analytic calculations of luminosity of early structures to predict the angular power spectrum (C{sub l} ) of fluctuations in the NIRB. We study in detail the effects of various assumptions about the stellar mass, the initial mass spectrum of stars, the metallicity, the star formation efficiency (f{sub *}), the escape fraction of ionizing photons (f{sub esc}), and the star formation timescale (t{sub SF}), on the amplitude as well as the shape of C{sub l} . The power spectrum of NIRB fluctuations is maximized when f{sub *} is the largest (as C{sub l} {proportional_to} f {sup 2}{sub *}) and f{sub esc} is the smallest (as more nebular emission is produced within halos). A significant uncertainty in the predicted amplitude of C{sub l} exists due to our lack of knowledge of t{sub SF} of these early populations of galaxies, which is equivalent to our lack of knowledge of the mass-to-light ratio of these sources. We do not see a turnover in the NIRB angular power spectrum of the halo contribution, which was claimed to exist in the literature, and explain this as the effect of high levels of nonlinear bias that was ignored in the previous calculations. This is partly due to our choice of the minimum mass of halos contributing to NIRB ({approx}2 x 10{sup 9} M{sub sun}), and a smaller minimum mass, which has a smaller nonlinear bias, may still exhibit a turnover. Therefore, our results suggest that both the amplitude and shape of the NIRB power spectrum provide important information

  15. Spatially resolved optical and near-infrared spectroscopy of the low-metallicity galaxy UGC 4483

    NASA Technical Reports Server (NTRS)

    Skillman, Evan D.; Televich, Roberto J.; Kennicutt, Robert C., Jr.; Garnett, Donald R.; Terlevich, Elena

    1994-01-01

    UGC 4483 is a dwarf irregular galaxy in the M81 group. Narrow-band imaging has revealed an H II region in UGC 4483 with an H alpha flux approximately = 1 x 10 (exp - 13) ergs/sq cm/s. Optical and near-infrared spectroscopy of this H ll region yields He, N, O, Ne, and S abundances for the interstellar matter (ISM) in this galaxy. The spectra were acquired with several different telescope/instrument combinations in order to assess the quality of the derived uncertainties. With oxygen abundance of 3.3 x 10 (exp -5) (12 + log (O/H) = 7.5), this galaxy is similar to GR 8 and among the most metal poor dwarf irregulars known to date. However, the H II region in UGC 4483 has high excitation and higher surface brightness than GR 8, allowing very accurate abundance estimates. The N/O ratio is 3%, in good agreement with other low-metallicity dwarf galaxies. The S/O abundance ratio in UGC 4483 is close to the solar ratio, consistent with results for I Zw 18 and other low-metallicity dwarf irregulars. A He/H abundance of 0.079 +/- 0.002 is derived from observations of the lambda 6678 He ll emission line. A comparison of observations obtained with different telescopes and with the same telescope on different nights supports our relatively small estimated uncertainty in this measurement. We determine that the neutral helium fraction is insignificant through both direct observations of the He(+)/H(+) ratio across the nebula and through photoionization modeling. This results in a helium mass fraction of 0.239 +/- 0.006, consistent with the most recent theoretical and observational determinations of the primordial helium abundance. We also discuss remaining systematic uncertainties in the calculation of the primordial helium abundance

  16. Circumnuclear Regions In Barred Spiral Galaxies. 1; Near-Infrared Imaging

    NASA Technical Reports Server (NTRS)

    Perez-Ramirez, D.; Knapen, J. H.; Peletier, R. F.; Laine, S.; Doyon, R.; Nadeau, D.

    2000-01-01

    We present sub-arcsecond resolution ground-based near-infrared images of the central regions of a sample of twelve barred galaxies with circumnuclear star formation activity, which is organized in ring-like regions typically one kiloparsec in diameter. We also present Hubble Space Telescope near-infrared images of ten of our sample galaxies, and compare them with our ground-based data. Although our sample galaxies were selected for the presence of circumnuclear star formation activity, our broad-band near-infrared images are heterogeneous, showing a substantial amount of small-scale structure in some galaxies, and practically none in others. We argue that, where it exists, this structure is caused by young stars, which also cause the characteristic bumps or changes in slope in the radial profiles of ellipticity, major axis position angle, surface brightness and colour at the radius of the circumnuclear ring in most of our sample galaxies. In 7 out of 10 HST images, star formation in the nuclear ring is clearly visible as a large number of small emitting regions, organised into spiral arm fragments, which are accompanied by dust lanes. NIR colour index maps show much more clearly the location of dust lanes and, in certain cases, regions of star formation than single broad-band images. Circumnuclear spiral structure thus outlined appears to be common in barred spiral galaxies with circumnuclear star formation.

  17. Near-infrared surface photometry and morphology in virgo cluster spiral galaxy nuclear regions

    NASA Astrophysics Data System (ADS)

    Rauscher, Bernard J.

    1995-04-01

    This paper presents very high spatial resolution (seeing 0.75 arcsec FWHM) K band surface photometry of 15 Virgo cluster spiral galaxy nuclear regions (radii less then 1 kpc). It presents B and I CCD images of 13 of these galaxies. The goals of the study were: (1) to begin to establish a K band baseline of normal spiral galaxy nuclear regions against which peculiar galaxies may be compared, (2) to provide better contsraints on N-body models, and (3) to complement near-infrared studies of large scale structure in spiral galaxies with very high resolution imaging of the important nuclear regions. The principle findings are (1) between 1/4 and 1/3 of these nuclear regions show K band evidence of traxiality, (2) approximately 1/2 of these galaxies have axisymmetric nuclear regions, and (3) NGC 4321 has a bar that is not detectable in the optical images.

  18. The optical and near-infrared colors of galaxies, 1: The photometric data

    NASA Technical Reports Server (NTRS)

    Bershady, Matthew A.; Hereld, Mark; Kron, Richard G.; Koo, David C.; Munn, Jeffrey A.; Majewski, Steven R.

    1994-01-01

    We present optical and near-infrared photometry and spectroscopic redshifts of a well defined sample of 171 field galaxies selected from three high galactic latitude fields. This data set forms the basis for subsequent studies to characterize the trends, dispersion, and evolution of rest-frame colors and image structure. A subset of 143 galaxies constitutes a magnitude-limited sample to B approx. 19.9-20.75 (depending on field), with a median redshift of 0.14, and a maximum redshift of 0.54. This subset is statistically representative in its sampling of the apparent color distribution of galaxies. Thirty six galaxies were selected to have the reddest red-optical colors in two redshift intervals between 0.2 less than z less than 0.3. Photometric passbands are similar to U, B, V, I, and K, and sample galaxy spectral energy distributions between 0.37 and 2.2 micrometers in the observed frame, or down to 0.26 micrometers in the rest frame for the most distant galaxies. B and K images of the entire sample are assembled to form the first optical and near-infrared atlas of a statistically-representative sample of field galaxies. We discuss techniques for faint field-galaxy photometry, including a working definition of a total magnitude, and a method for matching magnitudes in different passbands and different seeing conditions to ensure reliable, integrated colors. Photographic saturation, which substantially affects the brightest 12% of our sample in the optical bands, is corrected with a model employing measured plate-density distributions for each galaxy, calibrated via similar measurements for stars as a function of known saturation level. Both the relative and absolute calibration of our photometry are demonstrated.

  19. Statistical Correlations Between Near-Infrared Luminosities and Ring Sizes in Field Ringed Galaxies

    NASA Astrophysics Data System (ADS)

    Wu, Wentao

    2008-01-01

    Statistically complete samples of inner-pseudo-, inner-, and outer-ringed galaxies can be extracted from the Catalog of Southern Ringed Galaxies. Redshifts and near-infrared (NIR) photometric data are available for the samples, allowing the derivation of the statistical correlations between the total NIR luminosities (L NIR) and the projected ring major axes in the physical scale (D) for these galaxies. For any of the three types of rings, the correlations are approximately L NIR vprop D 1.2 among the early-type ringed galaxies (the most commonly observed ringed galaxies). The correlations among late-type ringed galaxies appear significantly different. The results contradict the previous suggestion by Kormendy (1979, ApJ, 227, 714), who gave LB vprop D 2 (LB : B-band galaxy luminosity). The relations can be used in future to test theoretical simulations of dynamical structures of ringed galaxies as well as those of ring formation under the framework of cosmological models. Currently the results indicate at most small differences in the relative contributions of disk components to total galaxy masses and in the initial disk velocity dispersions between commonly observed ringed galaxies of similar type. The correlations also suggest a new approach to effectively use ring sizes as tertiary cosmological distance indicators, to help enhance the reliability of the measurement of the Hubble Constant.

  20. NEAR-INFRARED POLARIMETRY OF A NORMAL SPIRAL GALAXY VIEWED THROUGH THE TAURUS MOLECULAR CLOUD COMPLEX

    SciTech Connect

    Clemens, Dan P.; Cashman, L. R.; Pavel, M. D. E-mail: pavelmi@utexas.edu

    2013-03-15

    Few normal galaxies have been probed using near-infrared polarimetry, even though it reveals magnetic fields in the cool interstellar medium better than either optical or radio polarimetry. Deep H-band (1.6 {mu}m) linear imaging polarimetry toward Taurus serendipitously included the galaxy 2MASX J04412715+2433110 with adequate sensitivity and resolution to map polarization across nearly its full extent. The observations revealed the galaxy to be a steeply inclined ({approx}75 Degree-Sign ) disk type with a diameter, encompassing 90% of the Petrosian flux, of 4.2 kpc at a distance of 53 Mpc. Because the sight line passes through the Taurus Molecular Cloud complex, the foreground polarization needed to be measured and removed. The foreground extinction A{sub V} of 2.00 {+-} 0.10 mag and reddening E(H - K) of 0.125 {+-} 0.009 mag were also assessed and removed, based on analysis of Two Micron All Sky Survey, UKIRT Infrared Deep Sky Survey, Spitzer, and Wide-field Infrared Survey Explorer photometry using the Near-Infrared Color Excess, NICE-Revisited, and Rayleigh-Jeans Color Excess methods. Corrected for the polarized foreground, the galaxy polarization values range from 0% to 3%. The polarizations are dominated by a disk-parallel magnetic field geometry, especially to the northeast, while either a vertical field or single scattering of bulge light produces disk-normal polarizations to the southwest. The multi-kiloparsec coherence of the magnetic field revealed by the infrared polarimetry is in close agreement with short-wavelength radio synchrotron observations of edge-on galaxies, indicating that both cool and warm interstellar media of disk galaxies may be threaded by common magnetic fields.

  1. 450 d of Type II SN 2013ej in optical and near-infrared

    NASA Astrophysics Data System (ADS)

    Yuan, Fang; Jerkstrand, A.; Valenti, S.; Sollerman, J.; Seitenzahl, I. R.; Pastorello, A.; Schulze, S.; Chen, T.-W.; Childress, M. J.; Fraser, M.; Fremling, C.; Kotak, R.; Ruiter, A. J.; Schmidt, B. P.; Smartt, S. J.; Taddia, F.; Terreran, G.; Tucker, B. E.; Barbarino, C.; Benetti, S.; Elias-Rosa, N.; Gal-Yam, A.; Howell, D. A.; Inserra, C.; Kankare, E.; Lee, M. Y.; Li, K. L.; Maguire, K.; Margheim, S.; Mehner, A.; Ochner, P.; Sullivan, M.; Tomasella, L.; Young, D. R.

    2016-09-01

    We present optical and near-infrared photometric and spectroscopic observations of SN 2013ej, in galaxy M74, from 1 to 450 d after the explosion. SN 2013ej is a hydrogen-rich supernova, classified as a Type IIL due to its relatively fast decline following the initial peak. It has a relatively high peak luminosity (absolute magnitude MV = -17.6) but a small 56Ni production of ˜0.023 M⊙. Its photospheric evolution is similar to other Type II SNe, with shallow absorption in the Hα profile typical for a Type IIL. During transition to the radioactive decay tail at ˜100 d, we find the SN to grow bluer in B - V colour, in contrast to some other Type II supernovae. At late times, the bolometric light curve declined faster than expected from 56Co decay and we observed unusually broad and asymmetric nebular emission lines. Based on comparison of nebular emission lines most sensitive to the progenitor core mass, we find our observations are best matched to synthesized spectral models with a MZAMS = 12-15 M⊙ progenitor. The derived mass range is similar to but not higher than the mass estimated for Type IIP progenitors. This is against the idea that Type IIL are from more massive stars. Observations are consistent with the SN having a progenitor with a relatively low-mass envelope.

  2. Near-infrared (Fe II) and Pa Beta imaging and spectroscopy of Arp 220

    NASA Technical Reports Server (NTRS)

    Armus, L.; Shupe, D. L.; Matthews, K.; Soifer, B. T.; Neugebauer, G.

    1995-01-01

    We have imaged the ultraluminous infrared galaxy Arp 220 in light of the near-infrared (Fe II) 1.257 micron and Pa-beta lines, and have obtained spectra in the J- and H-band atmospheric windows. Arp 220 is a strong source of (Fe II) and Pa-beta emission, with luminosities of 1.3 x 10(exp 41) and 9.2 x 10(exp 40) ergs/s, respectively. The (Fe II) and Pa-beta emission are both extended over the central 2 sec-3 sec, but with different morphologies. We suggest that the extended (Fe II) emission is produced through the interaction of fast shocks with ambient gas in the interstellar medium (ISM) at the base of the outflowing, supernovae-driven superwind mapped by Heckman et al. (1987). The bolometric luminosity of the starburst required to power this wind is estimated to be at least 2 x 10(exp 11) solar luminosity. If the spatially unresolved (Fe II) emission is produced via a large number of supernova remnants, the implied rate is approximately 0.6/yr. The overall luminosity of such a starburst could account for a large fraction (1/2-1/3) of the Arp 220 energy budget, but the large deficit of ionizing photons (as counted by the Pa-beta luminosity) requires that the starburst be rapidly declining and/or have a low upper mass cutoff. Alternatively, dust may effectively compete with the gas for ionizing photons, or much of the ionizing radiation may escape through 'holes' in the ISM. It is also possible that a buried active galactic nuclei (AGN) produces a large fraction of the unresolved (Fe II) and Pa-beta emission. We briefly discuss these possibilities in light of these new imaging and spectroscopic data.

  3. The nature of extreme emission line galaxies at z = 1-2: kinematics and metallicities from near-infrared spectroscopy

    SciTech Connect

    Maseda, Michael V.; Van der Wel, Arjen; Rix, Hans-Walter; Da Cunha, Elisabete; Meidt, Sharon E.; Pacifici, Camilla; Momcheva, Ivelina; Van Dokkum, Pieter; Nelson, Erica J.; Brammer, Gabriel B.; Ferguson, Henry C.; Koekemoer, Anton M.; Franx, Marijn; Fumagalli, Mattia; Bell, Eric F.; Förster-Schreiber, Natascha M.; Koo, David C.; Marchesini, Danilo; Patel, Shannon G.; and others

    2014-08-10

    We present near-infrared spectroscopy of a sample of 22 Extreme Emission Line Galaxies at redshifts 1.3 < z < 2.3, confirming that these are low-mass (M{sub *} = 10{sup 8}-10{sup 9} M{sub ☉}) galaxies undergoing intense starburst episodes (M{sub *}/SFR ∼ 10-100 Myr). The sample is selected by [O III] or Hα emission line flux and equivalent width using near-infrared grism spectroscopy from the 3D-HST survey. High-resolution NIR spectroscopy is obtained with LBT/LUCI and VLT/X-SHOOTER. The [O III]/Hβ line ratio is high (≳ 5) and [N II]/Hα is always significantly below unity, which suggests a low gas-phase metallicity. We are able to determine gas-phase metallicities for seven of our objects using various strong-line methods, with values in the range 0.05-0.30 Z{sub ☉} and with a median of 0.15 Z{sub ☉}; for three of these objects we detect [O III] λ4363, which allows for a direct constraint on the metallicity. The velocity dispersion, as measured from the nebular emission lines, is typically ∼50 km s{sup –1}. Combined with the observed star-forming activity, the Jeans and Toomre stability criteria imply that the gas fraction must be large (f{sub gas} ≳ 2/3), consistent with the difference between our dynamical and stellar mass estimates. The implied gas depletion timescale (several hundred Myr) is substantially longer than the inferred mass-weighted ages (∼50 Myr), which further supports the emerging picture that most stars in low-mass galaxies form in short, intense bursts of star formation.

  4. Near-infrared background anisotropies from diffuse intrahalo light of galaxies.

    PubMed

    Cooray, Asantha; Smidt, Joseph; De Bernardis, Francesco; Gong, Yan; Stern, Daniel; Ashby, Matthew L N; Eisenhardt, Peter R; Frazer, Christopher C; Gonzalez, Anthony H; Kochanek, Christopher S; Kozłowski, Szymon; Wright, Edward L

    2012-10-25

    Unresolved anisotropies of the cosmic near-infrared background radiation are expected to have contributions from the earliest galaxies during the epoch of reionization and from faint, dwarf galaxies at intermediate redshifts. Previous measurements were unable to pinpoint conclusively the dominant origin because they did not sample spatial scales that were sufficiently large to distinguish between these two possibilities. Here we report a measurement of the anisotropy power spectrum from subarcminute to one-degree angular scales, and find the clustering amplitude to be larger than predicted by the models based on the two existing explanations. As the shot-noise level of the power spectrum is consistent with that expected from faint galaxies, a new source population on the sky is not necessary to explain the observations. However, a physical mechanism that increases the clustering amplitude is needed. Motivated by recent results related to the extended stellar light profile in dark-matter haloes, we consider the possibility that the fluctuations originate from intrahalo stars of all galaxies. We find that the measured power spectrum can be explained by an intrahalo light fraction of 0.07 to 0.2 per cent relative to the total luminosity in dark-matter haloes of 10(9) to 10(12) solar masses at redshifts of about 1 to 4.

  5. Near-Infrared Spectroscopic Analysis of Galaxy Mergers: Revealing Obscured Accretion

    NASA Astrophysics Data System (ADS)

    Ferguson, Jason; Constantin, Anca; Satyapal, Shobita; Rothberg, Barry

    2017-01-01

    Galaxy interactions are ubiquitous and are believed to play a pivotal role in the formation and evolution of galaxies via facilitating gas inflows toward the central region of galaxies. These interactions are expected to trigger accretion of matter onto the central supermassive black holes, i.e., AGN activity. Nevertheless, despite decades of searching, observationally confirmed dual AGNs remain extremely rare. We present here a thorough near-infrared characterization of six examples of interacting galaxies with unambiguous confirmation of on-going mergers that are optically quiescent but have red mid-infrared colors that are associated with extragalactic sources with powerful AGN. We show Large Binocular Telescope spectra of nuclear regions that reveal a rich variety of emission and absorption features which allow us to explore several diagnostic tests for the AGN activity as well as for properties of the underlying stellar population. We find strong evidence for AGN emission in five out of these six interacting systems, which provides strong support for the efficiency with which the mid-infrared pre-selection technique finds dual AGN, and thus could exponentially increase the population of dual accretion systems in advanced mergers.

  6. Near-Infrared Photometric Properties of Red Supergiant Stars in Neaby Galaxies: NGC 4214, NGC 4736 and M51

    NASA Astrophysics Data System (ADS)

    Jung, DooSeok; Chun, Sang-Hyun; Choudhury, Samyaday; Sohn, Young-Jong

    2017-01-01

    Red supergiant stars (RSGs) are post-main sequence phase of massive stars which can be easily resolved in nearby galaxies due to their bright luminosity as compared to the low-mass stars. RSGs are cool, and hence have a dominant light output at near-infrared (NIR) wavelengths. To investigate the photometric properties of RSGs in a few nearby galaxies, we observed NGC 4214, NGC 4736 and M51 by using the WFCAM detector mounted on the UKIRT telescope at Hawaii, and obtained the NIR (JHK bands) imaging data. After carrying out the photometry, the age ranges of RSGs in each galaxy were estimated by over-plotting PARSEC isochrones to the (J-K, K) colour-magnitude diagram: log(tyr) = 6.9 - 7.3 for NGC 4214; log(tyr) = 7.0 - 8.0 for NGC 4736; and log(tyr) = 6.7 - 6.9 for M51. The effective temperatures and luminosities of RSGs were calculated using MARCS synthetic fluxes, and these results were used to compare the properties of RSGs in Hertzsprung-Russell (H-R) diagram of dominant H II regions within each galaxy, over-plotted with PARSEC evolutionary tracks. The RSGs in NGC 4214 and NGC 4736 are found to have a mass of 9 M⊙ - 30 M⊙, and the maximum luminosities found to be almost constant with log(L/L⊙) = 5.6 - 5.7. However, the location of the RSGs in the H-R diagram are not consistent with the evolutionary tracks for M51.(Key Words: stars: massive - supergiants - galaxies: photometry - galaxies: stellar content - infrared: stars)

  7. Supermassive black holes and their host galaxies. I. Bulge luminosities from dedicated near-infrared data

    SciTech Connect

    Läsker, Ronald; Van de Ven, Glenn; Ferrarese, Laura

    2014-01-01

    In an effort to secure, refine, and supplement the relation between central supermassive black hole masses, M {sub •}, and the bulge luminosities of their host galaxies, L {sub bul}, we obtained deep, high spatial resolution K-band images of 35 nearby galaxies with securely measured M {sub •}, using the wide-field WIRCam imager at the Canada-France-Hawaii-Telescope. A dedicated data reduction and sky subtraction strategy was adopted to estimate the brightness and structure of the sky, a critical step when tracing the light distribution of extended objects in the near-infrared. From the final image product, bulge and total magnitudes were extracted via two-dimensional profile fitting. As a first order approximation, all galaxies were modeled using a simple Sérsic-bulge+exponential-disk decomposition. However, we found that such models did not adequately describe the structure that we observed in a large fraction of our sample galaxies which often include cores, bars, nuclei, inner disks, spiral arms, rings, and envelopes. In such cases, we adopted profile modifications and/or more complex models with additional components. The derived bulge magnitudes are very sensitive to the details and number of components used in the models, although total magnitudes remain almost unaffected. Usually, but not always, the luminosities and sizes of the bulges are overestimated when a simple bulge+disk decomposition is adopted in lieu of a more complex model. Furthermore, we found that some spheroids are not well fit when the ellipticity of the Sérsic model is held fixed. This paper presents the details of the image processing and analysis, while we discuss how model-induced biases and systematics in bulge magnitudes impact the M {sub •}-L {sub bul} relation in a companion paper.

  8. Near-infrared surface photometry of a sample of barred galaxies

    NASA Astrophysics Data System (ADS)

    Gadotti, D. A.; Athanassoula, E.; Carrasco, L.; Bosma, A.; de Souza, R. E.; Recillas, E.

    2007-11-01

    We have obtained deep J and Ks images of a sample of nine barred galaxies in order to collect a reliable and homogeneous set of images to which N-body simulations of barred galaxies will be compared. The observations were performed using the new near-infrared camera available at the 2.1-m telescope of the Observatorio Astrofísico Guillermo Haro (OAGH) in Cananea, Sonora, Mexico. We present the results of surface photometry techniques applied to the observed images, as well as to the deprojected images. These results include radial profiles of surface brightness (elliptically averaged), colour, position angle, ellipticity and the b4 Fourier component. In addition, we present isophotal maps, colour maps, surface brightness profiles along the bar major and minor axes, characteristic radial scalelengths and bar length estimates. We discuss how projection effects can influence these measurements and the uncertainties introduced by deprojecting galaxy images. We show that analytical expressions can be used to obtain reliable estimates of deprojected bar lengths, ellipticities and position angles directly from the observed images. These expressions are based on the assumption that the outer parts of the bar are vertically thin, as shown by theoretical work. The usefulness of our data in addressing issues on bar formation and evolution is also discussed. In particular, we present results showing a steep drop in the ellipticity profile, as expected for bar formation processes in which the dark matter halo plays a fundamental role. Furthermore, we show that the location of this drop is a good indicator of the end of the bar in strongly barred galaxies, as predicted by numerical models.

  9. DEEP K{sub s} -NEAR-INFRARED SURFACE PHOTOMETRY OF 80 DWARF IRREGULAR GALAXIES IN THE LOCAL VOLUME

    SciTech Connect

    Fingerhut, Robin L.; McCall, Marshall L.; Argote, Mauricio; Cluver, Michelle E.; Nishiyama, Shogo; Rekola, Rami T. F.; Richer, Michael G.; Vaduvescu, Ovidiu; Woudt, Patrick A. E-mail: mccall@yorku.c E-mail: mcluver@ipac.caltech.ed E-mail: rareko@utu.f E-mail: ovidiuv@ing.iac.e

    2010-06-10

    We present deep near-infrared (K{sub s}) images and surface photometry for 80 dwarf irregular galaxies (dIs) within {approx}5 Mpc of the Milky Way. The galaxy images were obtained at five different facilities between 2004 and 2006. The image reductions and surface photometry have been performed using methods specifically designed for isolating faint galaxies from the high and varying near-infrared sky level. Fifty-four of the 80 dIs have surface brightness profiles which could be fit to a hyperbolic-secant (sech) function, while the remaining profiles could be fit to the sum of a sech and a Gaussian function. From these fits, we have measured central surface brightnesses, scale lengths, and integrated magnitudes. This survey is part of a larger study of the connection between large-scale structure and the global properties of dIs, the hypothesized building-blocks of more massive galaxies.

  10. TESTING FOR A LARGE LOCAL VOID BY INVESTIGATING THE NEAR-INFRARED GALAXY LUMINOSITY FUNCTION

    SciTech Connect

    Keenan, R. C.; Wang, W.-H.; Barger, A. J.; Wold, I.; Cowie, L. L.; Trouille, L.

    2012-08-01

    Recent cosmological modeling efforts have shown that a local underdensity on scales of a few hundred Mpc (out to z {approx} 0.1) could produce the apparent acceleration of the expansion of the universe observed via Type Ia supernovae. Several studies of galaxy counts in the near-infrared (NIR) have found that the local universe appears underdense by {approx}25%-50% compared with regions a few hundred Mpc distant. Galaxy counts at low redshifts sample primarily L {approx} L* galaxies. Thus, if the local universe is underdense, then the normalization of the NIR galaxy luminosity function (LF) at z > 0.1 should be higher than that measured for z < 0.1. Here we present a highly complete (>90%) spectroscopic sample of 1436 galaxies selected in the H band (1.6 {mu}m) to study the normalization of the NIR LF at 0.1 < z < 0.3 and address the question of whether or not we reside in a large local underdensity. Our survey sample consists of all galaxies brighter than 18th magnitude in the H band drawn from six widely separated fields at high Galactic latitudes, which cover a total of {approx}2 deg{sup 2} on the sky. We find that for the combination of our six fields, the product {phi}*L* at 0.1 < z < 0.3 is {approx}30% higher than that measured at lower redshifts. While our statistical errors in this measurement are on the {approx}10% level, we find the systematics due to cosmic variance may be larger still. We investigate the effects of cosmic variance on our measurement using the COSMOS cone mock catalogs from the Millennium Simulation and recent empirical estimates of cosmic variance. We find that our survey is subject to systematic uncertainties due to cosmic variance at the 15% level (1{sigma}), representing an improvement by a factor of {approx}2 over previous studies in this redshift range. We conclude that observations cannot yet rule out the possibility that the local universe is underdense at z < 0.1. The fields studied in this work have a large amount of publicly

  11. Near-infrared polarimetry of the edge-on galaxy NGC 891

    SciTech Connect

    Montgomery, J. D.; Clemens, D. P. E-mail: clemens@bu.edu

    2014-05-01

    The edge-on galaxy NGC 891 was probed using near-infrared (NIR) imaging polarimetry in the H band (1.6 μm) with the Mimir instrument on the 1.8 m Perkins Telescope. Polarization was detected with a signal-to-noise ratio greater than three out to a surface brightness of 18.8 mag arcsec{sup –2}. The unweighted average and dispersion in polarization percentage (P) across the full disk were 0.7% and 0.3%, respectively, and the same quantities for polarization position angle (P.A.) were 12° and 19°, respectively. At least one polarization null point, where P falls nearly to zero, was detected in the northeast disk but not the southwest disk. Several other asymmetries in P between the northern and southern disk were found and may be related to spiral structure. Profiles of P and P.A. along the minor axis of NGC 891 suggest a transition from magnetic (B) field tracing dichroic polarization near the disk mid-plane to scattering dominated polarization off the disk mid-plane. A comparison between NIR P.A. and radio (3.6 cm) synchrotron polarization P.A. values revealed similar B-field orientations in the central-northeast region, which suggests that the hot plasma and cold, star-forming interstellar medium may share a common B-field. Disk-perpendicular polarizations previously seen at optical wavelengths are likely caused by scattered light from the bright galaxy center and are unlikely to be tracing poloidal B-fields in the outer disk.

  12. Star formation in grand-design, spiral galaxies. Young, massive clusters in the near-infrared

    NASA Astrophysics Data System (ADS)

    Grosbøl, P.; Dottori, H.

    2012-06-01

    Aims: Spiral structure is a prominent feature in many disk galaxies and is often outlined by bright, young objects. We study the distribution of young stellar clusters in grand-design spiral galaxies and thereby determine whether strong spiral perturbations can influence star formation. Methods: Deep, near-infrared JHK-maps were observed for ten nearby, grand-design, spiral galaxies using HAWK-I at the Very Large Telescope. Complete, magnitude-limited candidate lists of star-forming complexes were obtained by searching within the K-band maps. The properties of the complexes were derived from (H - K) - (J - H) diagrams including the identification of the youngest complexes (i.e. ≲7 Myr) and the estimation of their extinction. Results: Young stellar clusters with ages ≲7 Myr have significant internal extinction in the range of AV = 3-7m, while older ones typically have AV < 1m. The cluster luminosity function (CLF) is well-fitted by a power law with an exponent of around -2 and displays no evidence of a high luminosity cut-off. The brightest cluster complexes in the disk reach luminosities of MK = -15.5m or estimated masses of 106 M⊙. At radii with a strong, two-armed spiral pattern, the star formation rate in the arms is higher by a factor of 2-5 than in the inter-arm regions. The CLF in the arms is also shifted towards brighter MK by at least 0.4m. We also detect clusters with colors compatible with Large Magellanic Cloud intermediate age clusters and Milky Way globular clusters. The (J - K) - MK diagram of several galaxies shows, for the brightest clusters, a clear separation between young clusters that are highly attenuated by dust and older ones with low extinction. Conclusions: The gap in the (J - K) - MK diagrams implies that there has been a rapid expulsion of dust at an age around 7 Myr, possibly triggered by supernovae. Strong spiral perturbations concentrate the formation of clusters in the arm regions and shifts their CLF towards brighter magnitudes

  13. Large Magellanic Cloud Near-infrared Synoptic Survey. IV. Leavitt Laws for Type II Cepheid Variables

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Anupam; Macri, Lucas M.; Rejkuba, Marina; Kanbur, Shashi M.; Ngeow, Chow-Choong; Singh, Harinder P.

    2017-04-01

    We present time-series observations of Population II Cepheids in the Large Magellanic Cloud at near-infrared (JHK s ) wavelengths. Our sample consists of 81 variables with accurate periods and optical (VI) magnitudes from the OGLE survey, covering various subtypes of pulsators (BL Herculis, W Virginis, and RV Tauri). We generate light-curve templates using high-quality I-band data in the LMC from OGLE and K s -band data in the Galactic bulge from VISTA Variables in Via Láctea survey and use them to obtain robust mean magnitudes. We derive period–luminosity (P–L) relations in the near-infrared and Period–Wesenheit (P–W) relations by combining optical and near-infrared data. Our P–L and P–W relations are consistent with published work when excluding long-period RV Tauris. We find that Pop II Cepheids and RR Lyraes follow the same P–L relations in the LMC. Therefore, we use trigonometric parallax from the Gaia DR1 for VY Pyx and the Hubble Space Telescope parallaxes for k Pav and 5 RR Lyrae variables to obtain an absolute calibration of the Galactic K s -band P–L relation, resulting in a distance modulus to the LMC of {μ }{LMC}=18.54+/- 0.08 mag. We update the mean magnitudes of Pop II Cepheids in Galactic globular clusters using our light-curve templates and obtain distance estimates to those systems, anchored to a precise late-type eclipsing binary distance to the LMC. We find that the distances to these globular clusters based on Pop II Cepheids are consistent (within 2σ ) with estimates based on the {M}V-[{Fe}/{{H}}] relation for horizontal branch stars.

  14. CONTAMINATION OF BROADBAND PHOTOMETRY BY NEBULAR EMISSION IN HIGH-REDSHIFT GALAXIES: INVESTIGATIONS WITH KECK'S MOSFIRE NEAR-INFRARED SPECTROGRAPH

    SciTech Connect

    Schenker, Matthew A; Ellis, Richard S; Konidaris, Nick P; Stark, Daniel P

    2013-11-01

    Earlier work has raised the potential importance of nebular emission in the derivation of the physical characteristics of high-redshift Lyman break galaxies. Within certain redshift ranges, and especially at z ≅ 6-7, such lines may be strong enough to reduce estimates of the stellar masses and ages of galaxies compared with those derived assuming the broadband photometry represents stellar light alone. To test this hypothesis at the highest redshifts where such lines can be probed with ground-based facilities, we examine the near-infrared spectra of a representative sample of 28 3.0 < z < 3.8 Lyman break galaxies using the newly commissioned MOSFIRE near-infrared spectrograph at the Keck I telescope. We use these data to derive the rest-frame equivalent widths (EWs) of [O III] emission and show that these are comparable with estimates derived using the spectral energy distribution (SED) fitting technique introduced for sources of known redshift by Stark et al. Although our current sample is modest, its [O III] EW distribution is consistent with that inferred for Hα based on SED fitting of Stark et al.'s larger sample of 3.8 < z < 5 galaxies. For a subset of survey galaxies, we use the combination of optical and near-infrared spectroscopy to quantify kinematics of outflows in z ≅ 3.5 star-forming galaxies and discuss the implications for reionization measurements. The trends we uncover underline the dangers of relying purely on broadband photometry to estimate the physical properties of high-redshift galaxies and emphasize the important role of diagnostic spectroscopy.

  15. Contamination of Broadband Photometry by Nebular Emission in High-redshift Galaxies: Investigations with Keck's MOSFIRE Near-infrared Spectrograph

    NASA Astrophysics Data System (ADS)

    Schenker, Matthew A.; Ellis, Richard S.; Konidaris, Nick P.; Stark, Daniel P.

    2013-11-01

    Earlier work has raised the potential importance of nebular emission in the derivation of the physical characteristics of high-redshift Lyman break galaxies. Within certain redshift ranges, and especially at z ~= 6-7, such lines may be strong enough to reduce estimates of the stellar masses and ages of galaxies compared with those derived assuming the broadband photometry represents stellar light alone. To test this hypothesis at the highest redshifts where such lines can be probed with ground-based facilities, we examine the near-infrared spectra of a representative sample of 28 3.0 < z < 3.8 Lyman break galaxies using the newly commissioned MOSFIRE near-infrared spectrograph at the Keck I telescope. We use these data to derive the rest-frame equivalent widths (EWs) of [O III] emission and show that these are comparable with estimates derived using the spectral energy distribution (SED) fitting technique introduced for sources of known redshift by Stark et al. Although our current sample is modest, its [O III] EW distribution is consistent with that inferred for Hα based on SED fitting of Stark et al.'s larger sample of 3.8 < z < 5 galaxies. For a subset of survey galaxies, we use the combination of optical and near-infrared spectroscopy to quantify kinematics of outflows in z ~= 3.5 star-forming galaxies and discuss the implications for reionization measurements. The trends we uncover underline the dangers of relying purely on broadband photometry to estimate the physical properties of high-redshift galaxies and emphasize the important role of diagnostic spectroscopy.

  16. Near-infrared Structure of Fast and Slow-rotating Disk Galaxies

    NASA Astrophysics Data System (ADS)

    Schechtman-Rook, Andrew; Bershady, Matthew A.

    2014-11-01

    We investigate the stellar disk structure of six nearby edge-on spiral galaxies using high-resolution JHK s-band images and three-dimensional radiative transfer models. To explore how mass and environment shape spiral disks, we selected galaxies with rotational velocities between 69 km s-1 150 km s-1) galaxies, only NGC 4013 has the super-thin+thin+thick nested disk structure seen in NGC 891 and the Milky Way, albeit with decreased oblateness, while NGC 1055, a disturbed massive spiral galaxy, contains disks with hz <~ 200 pc. NGC 4565, another fast-rotator, contains a prominent ring at a radius ~5 kpc but no super-thin disk. Despite these differences, all fast-rotating galaxies in our sample have inner truncations in at least one of their disks. These truncations lead to Freeman Type II profiles when projected face-on. Slow-rotating galaxies are less complex, lacking inner disk truncations and requiring fewer disk components to reproduce their light distributions. Super-thin disk components in undisturbed disks contribute ~25% of the total K s-band light, up to that of the thin-disk contribution. The presence of super-thin disks correlates with infrared flux ratios; galaxies with super-thin disks have f{K_s}/f60 μ m ≤ 0.12 for integrated light, consistent with super-thin disks being regions of ongoing star-formation. Attenuation-corrected vertical color gradients in (J - K s) correlate with the observed disk structure and are consistent with population gradients with young-to-intermediate ages closer to the mid-plane, indicating that disk heating—or cooling—is a ubiquitous phenomenon.

  17. Visible and Near-Infrared Spectroscopy of Seyfert 1 and Narrow-Line Seyfert 1 Galaxies

    NASA Astrophysics Data System (ADS)

    Rodríguez-Ardila, Alberto; Pastoriza, Miriani G.; Donzelli, Carlos J.

    2000-01-01

    This paper studies the continuum and emission-line properties of a sample composed of 16 normal Seyfert 1 and seven narrow-line Seyfert 1 (NLS1) galaxies using optical and near-IR CCD spectroscopy. The continuum emission of the galaxies can be described in terms of a combination of stellar population, a nonstellar continuum of power-law form, and Fe II emission. A significative difference in the optical spectral index between NLS1's and normal Seyfert 1's is observed; the latter is steeper. Most NLS1's show Fe II/Hβ ratios larger than those observed in the other Seyfert 1's. In the IRAS band, both groups of galaxies have very similar properties. We have searched for the presence of optically thin gas in the broad-line region (BLR) of the galaxies by comparing the broad O I λ8446 and Hα emission-line profiles. Our analysis show that in the NLS1's, both profiles are similar in shape and width. This result contradicts the hypothesis of thin gas emission in the high-velocity part of the BLR to explain the ``narrowness'' of broad optical permitted lines in these objects. Evidence of narrow O I λ8446 emission is found in six galaxies of our sample, implying that this line is not restricted to a pure BLR phenomenon. In the narrow-line region, we find similar luminosities in the permitted and high-ionization lines of NLS1's and normal Seyfert 1's. However, low-ionization lines such as [O I] λ6300, [O II] λ3727, and [S II] λλ6717, 6731 are intrinsically less luminous in NLS1's. Physical properties derived from density- and temperature-sensitive line ratios suggest that the [O II] and [S II] emitting zones are overlapping in normal Seyfert 1's and separated in NLS1's. Based on observations made at CASLEO. Complejo Astronómico El Leoncito (CASLEO) is operated under agreement between the Consejo Nacional de Investigaciones Científicas y técnicas de la República Argentina and the National Universities of La Plata, Córdoba and San Juán.

  18. Ultraviolet to near-infrared spectral distributions of star-forming galaxies: Metallicity and age effects

    NASA Technical Reports Server (NTRS)

    Storchi-Bergmann, Thaisa; Calzetti, Daniela; Kinney, Anne L.

    1994-01-01

    Spectral distributions from the UV to the near-IR of a sample of 44 star-forming galaxies are used to calculate the metallicity (O/H), star-formation rate (SFR) and age of the starbursts. The oxygen abundance covers the range 8.3 less than O/H less than 9.4 and nitrogen (N) is found to be mostly a product of secondary nucleosynthesis for O/H greater than 8.4. Due to its secondary origin, N/O ratios up to approximately equals 4 times the solar value can be obtained for metal-rich starbursts. The SFR ranges 0.01 to 100 solar mass/year. The lower metallicity galaxies seem to be experiencing an instantaneous burst of star formation, with ages ranging from under 5 x 10(exp 6) to 10(exp 7) yr. The highest metallicity galaxies are most probably experiencing a continuous burst. Correlations between the calculated quantities and several spectral features are investigated. We found a highly significant correlation between the equivalent width W(C IV lambda 1550)-a stellar (absorption) feature- and the oxygen abundance of the emitting gas (O/H). Thus we show for the first time that the stellar metallicity is well correlated with the gas metallicity in star-bursting galaxies. The equivalent width W(Si IV lambda 1400) and the emission line ratio (N II) lambda lambda 6548.84/H(sub alpha) also correlate well with O/H, and all three features can be used as metallicity indicators for star-forming galaxies. The continuum color between lambda 1400 and lambda 3500 (C(14 - 35)) is shown to correlate with O/H, although it is better correlated with E(B - V). It was not possible to disentangle the metallicity from the reddening effect in C(14- 35). We estimate that the reddening affecting the UV continuum is about half the one derived from the Balmer decrement of the emitting gas. The SFR correlates well with the galaxy luminosity and there is no dependence of the continuum color on the SFR. The higher metallicities are only found in the more luminous galaxies, while low metallicities are

  19. Near-infrared structure of fast and slow-rotating disk galaxies

    SciTech Connect

    Schechtman-Rook, Andrew; Bershady, Matthew A.

    2014-11-10

    We investigate the stellar disk structure of six nearby edge-on spiral galaxies using high-resolution JHK {sub s}-band images and three-dimensional radiative transfer models. To explore how mass and environment shape spiral disks, we selected galaxies with rotational velocities between 69 km s{sup –1} 150 km s{sup –1}) galaxies, only NGC 4013 has the super-thin+thin+thick nested disk structure seen in NGC 891 and the Milky Way, albeit with decreased oblateness, while NGC 1055, a disturbed massive spiral galaxy, contains disks with h{sub z} ≲ 200 pc. NGC 4565, another fast-rotator, contains a prominent ring at a radius ∼5 kpc but no super-thin disk. Despite these differences, all fast-rotating galaxies in our sample have inner truncations in at least one of their disks. These truncations lead to Freeman Type II profiles when projected face-on. Slow-rotating galaxies are less complex, lacking inner disk truncations and requiring fewer disk components to reproduce their light distributions. Super-thin disk components in undisturbed disks contribute ∼25% of the total K {sub s}-band light, up to that of the thin-disk contribution. The presence of super-thin disks correlates with infrared flux ratios; galaxies with super-thin disks have f{sub K{sub s}}/f{sub 60} {sub μm}≤0.12 for integrated light, consistent with super-thin disks being regions of ongoing star-formation. Attenuation-corrected vertical color gradients in (J – K {sub s}) correlate with the observed disk structure and are consistent with population gradients with young-to-intermediate ages closer to the mid-plane, indicating that disk heating—or cooling—is a ubiquitous phenomenon.

  20. High Resolution Optical/Near-Infrared Imaging of Cool Ultraluminous Infrared Galaxies

    NASA Technical Reports Server (NTRS)

    Surace, J.; Sanders, D.; Evans, A.

    1999-01-01

    We present here new multiwavelength observations with 1.5 and 4x the spatial resolution of previous ground-based observations at optical and near-infrared wavelengths; despite being ground-based, they allow us to isolate interesting features such as the star-forming knots detected in the warm ULIG sample.

  1. Star Formation in Ultraluminous Infrared Galaxies Probed with AKARI Near-infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Yano, Kenichi; Nakagawa, Takao; Isobe, Naoki; Shirahata, Mai

    2016-12-01

    We conducted systematic observations of the H i Brα line (4.05 μm) and the polycyclic aromatic hydrocarbon (PAH) feature (3.3 μm) in 50 nearby (z\\lt 0.3) ultraluminous infrared galaxies (ULIRGs) with AKARI. The Brα line is predicted to be the brightest among the H i lines under conditions of high dust extinction ({A}V\\gt 15 mag). The Brα line traces ionizing photons from OB stars and so is used as an indicator of star formation on the assumption of the initial mass function. We detected the Brα line in 33 ULIRGs. The luminosity of the line ({L}{Brα }) correlates well with that of the 3.3 μm PAH emission ({L}3.3). Thus we utilize {L}3.3 as an indicator of star formation in fainter objects where the Brα line is undetected. The mean {L}{Brα }/{L}{IR} ratio in LINERs/Seyferts is significantly lower than that in H ii galaxies. This difference is reconfirmed with the {L}3.3/{L}{IR} ratio in the larger sample (46 galaxies). Using the ratios, we estimate that the contribution of starburst in LINERs/Seyferts is ∼ 67 % , and active galactic nuclei contribute the remaining ∼ 33 % . However, comparing the number of ionizing photons, {Q}{Brα }, derived from {L}{Brα } with that, Q IR, expected from the star formation rate required to explain {L}{IR}, we find that the mean {Q}{Brα }/{Q}{IR} ratio is only (55.5 ± 7.5)% even in H ii galaxies, which are thought to be energized by pure starburst. This deficit of ionizing photons traced by the Brα line is significant even taking heavy dust extinction into consideration. We propose that dust within H ii regions absorbs a significant fraction of ionizing photons.

  2. Multifunctional in vivo vascular imaging using near-infrared II fluorescence

    PubMed Central

    Hong, Guosong; Lee, Jerry C.; Robinson, Joshua T.; Raaz, Uwe; Xie, Liming; Huang, Ngan F.; Cooke, John P.; Dai, Hongjie

    2013-01-01

    In vivo real-time epifluorescence imaging of mouse hindlimb vasculatures in the second near-infrared region (NIR-II, 1.1–1.4 µm) is performed using single-walled carbon nanotubes (SWNTs) as fluorophores. Both high spatial resolution (~30 µm) and temporal resolution (<200 ms/frame) for small vessel imaging are achieved 1~3 mm deep in the tissue owing to the beneficial NIR-II optical window that affords deep anatomical penetration and low scattering. This spatial resolution is unattainable by traditional NIR imaging (NIR-I, 0.75–0.9 µm) or microscopic computed tomography (micro-CT), while the temporal resolution far exceeds scanning microscopic imaging techniques. Arterial and venous vessels are unambiguously differentiated using a dynamic contrast-enhanced NIR-II imaging technique based on their distinct hemodynamics. Further, the deep tissue penetration, high spatial and temporal resolution of NIR-II imaging allow for precise quantifications of blood velocity in both normal and ischemic femoral arteries, which are beyond the capability of ultrasonography at lower blood velocity. PMID:23160236

  3. Physical Properties of Emission-Line Galaxies at 2 from Near-Infrared Spectroscopy with Magellan FIRE

    NASA Astrophysics Data System (ADS)

    Masters, Daniel C.; McCarthy, P. J.; Malkan, M. A.; Siana, B. D.; Scarlata, C.; Hathi, N. P.; Atek, H.; Henry, A. L.; WISP Team

    2014-01-01

    We present results from near-infrared spectroscopy with Magellan FIRE of 26 strong emission-line galaxies at 2.2 and 1.5. The sample was selected from the WFC3 Infrared Spectroscopic Parallels (WISP) survey, which uses the near-infrared grism capability of the Hubble Space Telescope Wide Field Camera 3 to detect emission-line galaxies over 0.5 < z < 2.3. High-resolution ( 5000) follow-up spectroscopy with Magellan FIRE over 1.0--2.5 microns resolves important rest-frame optical emission lines, allowing us to measure physical properties such as dust obscuration, metal abundance, star formation rate, ionization parameter, and emission line kinematics. We also analyze the properties of composite spectra derived from the FIRE-observed sample. With this relatively large sample of rest-frame optical spectra we can make statistical inferences about the population of emission-line galaxies at 2. We find that the galaxies are low metallicity ( 1/5-1/2 Z_solar) as determined from the R23 calibration. The galaxies are low dust extinction on average (E(B-V 0.2) but with significant scatter. The dust-corrected H-alpha star formation rates range from ~10--150 M_sun yr^-1 with a mean of 50 M_su yr^-1. The average ionization parameter for the sample, log U ~ -2.5, is higher than typically found for star-forming galaxies in the local universe but consistent with those found in more intense starbursting regions in galaxies such as M82. Emission line velocity dispersions are measured to be 71 +- 38 km s^-1, in good agreement with other studies that have probed the H-alpha kinematics of star-forming galaxies at similar redshift. The galaxies are compact, with half-light radii of < 2 kpc, and ~50% show evidence for multiple structures or asymmetries in the WFC3 imaging. Based on the line velocity dispersions and the location of the galaxies on BPT diagnostic plots, there is little evidence for significant AGN contribution to most emission-line galaxies at 2.

  4. A near-infrared census of the multicomponent stellar structure of early-type dwarf galaxies in the Virgo cluster

    SciTech Connect

    Janz, J.; Laurikainen, E.; Salo, H.; Lisker, T.; Hansson, K. S. A.; Meyer, H. T.; Paudel, S.; Peletier, R. F.; Den Brok, M.; Niemi, S.-M.; Toloba, E.; Falcón-Barroso, J.; Ryś, A.

    2014-05-10

    The fraction of star-forming to quiescent dwarf galaxies varies from almost infinity in the field to zero in the centers of rich galaxy clusters. What is causing this pronounced morphology-density relation? What do quiescent dwarf galaxies look like when studied in detail, and what conclusions can be drawn about their formation mechanism? Here we study a nearly magnitude-complete sample (–19 < M{sub r} < –16 mag) of 121 Virgo cluster early types with deep near-infrared images from the SMAKCED project. We fit two-dimensional models with optional inner and outer components, as well as bar and lens components (in ∼15% of the galaxies), to the galaxy images. While a single Sérsic function may approximate the overall galaxy structure, it does not entirely capture the light distribution of two-thirds of our galaxies, for which multicomponent models provide a better fit. This fraction of complex galaxies shows a strong dependence on luminosity, being larger for brighter objects. We analyze the global and component-specific photometric scaling relations of early-type dwarf galaxies and discuss similarities with bright early and late types. The dwarfs' global galaxy parameters show scaling relations that are similar to those of bright disk galaxies. The inner components are mostly fitted with Sérsic n values close to 1. At a given magnitude, they are systematically larger than the bulges of spirals, suggesting that they are not ordinary bulges. We argue that the multicomponent structures in early-type dwarfs are mostly a phenomenon inherent to the disks and may indeed stem from environmental processing.

  5. Platinum (II) azatetrabenzoporphyrins for near-infrared organic light emitting diodes

    NASA Astrophysics Data System (ADS)

    Huang, L.; Park, C. D.; Fleetham, T.; Li, J.

    2016-12-01

    This article describes a series of platinum (II) azatetrabenzoporphyrin emitters for near-infrared (NIR) organic light emitting diode (OLED) applications. Platinum (II) aza-triphenyltetrabenzoporphyrin (PtNTBP) results in a 72 nm shift in the photoluminescent (PL) emission spectrum to 842 nm compared to 770 nm of the platinum (II) tetraphenyltetrabenzoporphyrin (PtTPTBP). Also, the full width at half maximum of the emission spectrum of PtNTBP was significantly narrowed to 27 nm compared to 40 nm for PtTPTBP. The multilayer devices fabricated by thermal vacuum evaporation process employing PtTPTBP, PtNTBP, and cis-PtN2TBP exhibit electroluminescent (EL) emission peak at 770 nm, 848 nm, and 846 nm with the peak external quantum efficiency (EQE) of 8.0%, 2.8%, and 1.5%, respectively. Even with the decrease in EQE of devices employing PtNTBP and cis-PtN2TBP compared with those employing PtTPTBP, the combination of the spectral narrowing and the bathochromic shift to lower energy EL emission demonstrates the promise of PtNTBP for NIR applications. In the meanwhile, the solution-processed single-layer device using PtNTBP demonstrates the EQE of 0.33% and the peak EL emission at 844 nm.

  6. The mass-metallicity and fundamental metallicity relations at z > 2 using very large telescope and Subaru near-infrared spectroscopy of zCOSMOS galaxies

    SciTech Connect

    Maier, C.; Ziegler, B. L.; Lilly, S. J.; Peng, Y.; Contini, T.; Pérez Montero, E.; Balestra, I.

    2014-09-01

    In the local universe, there is good evidence that, at a given stellar mass M, the gas-phase metallicity Z is anti-correlated with the star formation rate (SFR) of the galaxies. It has also been claimed that the resulting Z(M, SFR) relation is invariant with redshift—the so-called 'fundamental metallicity relation' (FMR). Given a number of difficulties in determining metallicities, especially at higher redshifts, the form of the Z(M, SFR) relation and whether it is really independent of redshift is still very controversial. To explore this issue at z > 2, we used VLT-SINFONI and Subaru-MOIRCS near-infrared spectroscopy of 20 zCOSMOS-deep galaxies at 2.1 < z < 2.5 to measure the strengths of up to five emission lines: [O II] λ3727, Hβ, [O III] λ5007, Hα, and [N II] λ6584. This near-infrared spectroscopy enables us to derive O/H metallicities, and also SFRs from extinction corrected Hα measurements. We find that the mass-metallicity relation (MZR) of these star-forming galaxies at z ≈ 2.3 is lower than the local Sloan Digital Sky Survey (SDSS) MZR by a factor of three to five, a larger change than found by Erb et al. using [N II]/Hα-based metallicities from stacked spectra. We discuss how the different selections of the samples and metallicity calibrations used may be responsible for this discrepancy. The galaxies show direct evidence that the SFR is still a second parameter in the MZR at these redshifts. However, determining whether the Z(M, SFR) relation is invariant with epoch depends on the choice of extrapolation used from local samples, because z > 2 galaxies of a given mass have much higher SFRs than the local SDSS galaxies. We find that the zCOSMOS galaxies are consistent with a non-evolving FMR if we use the physically motivated formulation of the Z(M, SFR) relation from Lilly et al., but not if we use the empirical formulation of Mannucci et al.

  7. The Mass-Metallicity and Fundamental Metallicity Relations at z > 2 Using Very Large Telescope and Subaru Near-infrared Spectroscopy of zCOSMOS Galaxies

    NASA Astrophysics Data System (ADS)

    Maier, C.; Lilly, S. J.; Ziegler, B. L.; Contini, T.; Pérez Montero, E.; Peng, Y.; Balestra, I.

    2014-09-01

    In the local universe, there is good evidence that, at a given stellar mass M, the gas-phase metallicity Z is anti-correlated with the star formation rate (SFR) of the galaxies. It has also been claimed that the resulting Z(M, SFR) relation is invariant with redshift—the so-called "fundamental metallicity relation" (FMR). Given a number of difficulties in determining metallicities, especially at higher redshifts, the form of the Z(M, SFR) relation and whether it is really independent of redshift is still very controversial. To explore this issue at z > 2, we used VLT-SINFONI and Subaru-MOIRCS near-infrared spectroscopy of 20 zCOSMOS-deep galaxies at 2.1 < z < 2.5 to measure the strengths of up to five emission lines: [O II] λ3727, Hβ, [O III] λ5007, Hα, and [N II] λ6584. This near-infrared spectroscopy enables us to derive O/H metallicities, and also SFRs from extinction corrected Hα measurements. We find that the mass-metallicity relation (MZR) of these star-forming galaxies at z ≈ 2.3 is lower than the local Sloan Digital Sky Survey (SDSS) MZR by a factor of three to five, a larger change than found by Erb et al. using [N II]/Hα-based metallicities from stacked spectra. We discuss how the different selections of the samples and metallicity calibrations used may be responsible for this discrepancy. The galaxies show direct evidence that the SFR is still a second parameter in the MZR at these redshifts. However, determining whether the Z(M, SFR) relation is invariant with epoch depends on the choice of extrapolation used from local samples, because z > 2 galaxies of a given mass have much higher SFRs than the local SDSS galaxies. We find that the zCOSMOS galaxies are consistent with a non-evolving FMR if we use the physically motivated formulation of the Z(M, SFR) relation from Lilly et al., but not if we use the empirical formulation of Mannucci et al. AND SUBARU

  8. VLT/X-SHOOTER NEAR-INFRARED SPECTROSCOPY AND HST IMAGING OF GRAVITATIONALLY LENSED z ∼ 2 COMPACT QUIESCENT GALAXIES

    SciTech Connect

    Geier, S.; Man, A. W. S.; Krühler, T.; Toft, S.; Fynbo, J. P. U.; Richard, J.; Marchesini, D.

    2013-11-10

    Quiescent massive galaxies at z ∼ 2 are thought to be the progenitors of present-day massive ellipticals. Observations revealed them to be extraordinarily compact. Until now, the determination of stellar ages, star formation rates, and dust properties via spectroscopic measurements has been feasible only for the most luminous and massive specimens (∼3 × M*). Here we present a spectroscopic study of two near-infrared-selected galaxies that are close to the characteristic stellar mass M* (∼0.9 × M* and ∼1.3 × M*) and whose observed brightness has been boosted by the gravitational lensing effect. We measure the redshifts of the two galaxies to be z = 1.71 ± 0.02 and z = 2.15 ± 0.01. By fitting stellar population synthesis models to their spectrophotometric spectral energy distributions we determine their ages to be 2.4{sup +0.8}{sub -0.6} Gyr and 1.7 ± 0.3 Gyr, respectively, which implies that the two galaxies have higher mass-to-light ratios than most quiescent z ∼ 2 galaxies in other studies. We find no direct evidence for active star formation or active galactic nucleus activity in either of the two galaxies, based on the non-detection of emission lines. Based on the derived redshifts and stellar ages we estimate the formation redshifts to be z=4.3{sup +3.4}{sub -1.2} and z=4.3{sup +1.0}{sub -0.6}, respectively. We use the increased spatial resolution due to the gravitational lensing to derive constraints on the morphology. Fitting Sérsic profiles to the de-lensed images of the two galaxies confirms their compactness, with one of them being spheroid-like and the other providing the first confirmation of a passive lenticular galaxy at a spectroscopically derived redshift of z ∼ 2.

  9. WINGS: a WIde-field nearby Galaxy-cluster survey. III. Deep near-infrared photometry of 28 nearby clusters

    NASA Astrophysics Data System (ADS)

    Valentinuzzi, T.; Woods, D.; Fasano, G.; Riello, M.; D'Onofrio, M.; Varela, J.; Bettoni, D.; Cava, A.; Couch, W. J.; Dressler, A.; Fritz, J.; Moles, M.; Omizzolo, A.; Poggianti, B. M.; Kjærgaard, P.

    2009-07-01

    Context: This is the third paper in a series devoted to the WIde-field Nearby Galaxy-cluster Survey (WINGS). WINGS is a long-term project aimed at gathering wide-field, multiband imaging and spectroscopy of galaxies in a complete sample of 77 X-ray selected, nearby clusters (0.04galaxies and galaxy clusters. Aims: This paper presents the near-infrared (J,K) photometric catalogs of 28 clusters of the WINGS sample and describes the procedures followed to construct them. Methods: The raw data has been reduced at CASU and special care has been devoted to the final coadding, drizzling technique, astrometric solution, and magnitude calibration for the WFCAM pipeline-processed data. We constructed the photometric catalogs based on the final calibrated, coadded mosaics (≈0.79 deg^2) in J (19 clusters) and K (27 clusters) bands. A customized interactive pipeline was used to clean the catalogs and to make mock images for photometric errors and completeness estimates. Results: We provide deep near-infrared photometric catalogs (90% complete in detection rate at total magnitudes J≈ 20.5, K≈ 19.4, and in classification rate at J≈19.5 and K≈ 18.5), giving positions, geometrical parameters, total and aperture magnitudes for all detected sources. For each field we classify the detected sources as stars, galaxies, and objects of “unknown” nature. Based on observations taken at the United Kingdom Infra-Red Telescope, operated by the Joint Astronomy Centre on behalf of the Science and Technology Facilities Council of the UK. J and K photometric catalogs are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/501/851

  10. Near-infrared integral field spectroscopy of star-forming galaxies

    NASA Technical Reports Server (NTRS)

    Dale, D. A.; Roussel, H.; Contursi, A.; Helou, G.; Dinerstein, H. L.; Hunter, D. A.; Hollenbach, D. J.; Egami, E.; Matthews, K.; Murphy, T. W. Jr; Lafon, C. E.; Rubin, R. H.

    2004-01-01

    The Palomar Integral Field Spectrograph was used to probe a variety of environments in nine nearby galaxies that span a range of morphological types, luminosities, metallicities, and infrared-to-blue ratios.

  11. DEEP NEAR-INFRARED SPECTROSCOPY OF PASSIVELY EVOLVING GALAXIES AT z {approx}> 1.4

    SciTech Connect

    Onodera, M.; Carollo, M.; Lilly, S.; Renzini, A.; Mancini, C.; Cappellari, M.; Strazzullo, V.; Daddi, E.; Gobat, R.; McCracken, H. J.; Ilbert, O.; Capak, P.; Cimatti, A.; Giavalisco, M.; Koekemoer, A. M.; Kong, X.; Motohara, K.; Ohta, K.; and others

    2012-08-10

    We present the results of new near-IR spectroscopic observations of passive galaxies at z {approx}> 1.4 in a concentration of BzK-selected galaxies in the COSMOS field. The observations have been conducted with Subaru/MOIRCS, and have resulted in absorption lines and/or continuum detection for 18 out of 34 objects. This allows us to measure spectroscopic redshifts for a sample that is almost complete to K{sub AB} = 21. COSMOS photometric redshifts are found in fair agreement overall with the spectroscopic redshifts, with a standard deviation of {approx}0.05; however, {approx}30% of objects have photometric redshifts systematically underestimated by up to {approx}25%. We show that these systematic offsets in photometric redshifts can be removed by using these objects as a training set. All galaxies fall in four distinct redshift spikes at z = 1.43, 1.53, 1.67, and 1.82, with this latter one including seven galaxies. SED fits to broadband fluxes indicate stellar masses in the range of {approx}4-40 Multiplication-Sign 10{sup 10} M{sub Sun} and that star formation was quenched {approx}1 Gyr before the cosmic epoch at which they are observed. The spectra of several individual galaxies have allowed us to measure their H{delta}{sub F} indices and the strengths of the 4000 A break, which confirms their identification as passive galaxies, as does a composite spectrum resulting from the co-addition of 17 individual spectra. The effective radii of the galaxies have been measured on the COSMOS HST/ACS i{sub F814W}-band image, confirming the coexistence at these redshifts of passive galaxies, which are substantially more compact than their local counterparts with others that follow the local effective radius-stellar mass relation. For the galaxy with the best signal-to-noise spectrum we were able to measure a velocity dispersion of 270 {+-} 105 km s{sup -1} (error bar including systematic errors), indicating that this galaxy lies closely on the virial relation given its stellar

  12. MOIRCS DEEP SURVEY. VI. NEAR-INFRARED SPECTROSCOPY OF K-SELECTED STAR-FORMING GALAXIES AT z {approx} 2

    SciTech Connect

    Yoshikawa, Tomohiro; Akiyama, Masayuki; Kajisawa, Masaru; Tokoku, Chihiro; Yamada, Toru; Ichikawa, Takashi; Alexander, David M.; Ohta, Kouji; Suzuki, Ryuji; Tanaka, Ichi; Omata, Koji; Nishimura, Tetsuo; Uchimoto, Yuka K.; Konishi, Masahiro; Koekemoer, Anton M.; Brandt, Niel

    2010-07-20

    We present the results of near-infrared multi-object spectroscopic observations for 37 BzK-color-selected star-forming galaxies conducted with MOIRCS on the Subaru Telescope. The sample is drawn from the K{sub s} -band-selected catalog of the MOIRCS Deep Survey in the GOODS-N region. About half of our samples are selected from the publicly available 24 {mu}m-source catalog of the Multiband Imaging Photometer for Spitzer on board the Spitzer Space Telescope. H{alpha} emission lines are detected from 23 galaxies, of which the median redshift is 2.12. We derived the star formation rates (SFRs) from extinction-corrected H{alpha} luminosities. The extinction correction is estimated from the spectral energy distribution (SED) fitting of multiband photometric data covering UV to near-infrared wavelengths. The Balmer decrement of the stacked emission lines shows that the amount of extinction for the ionized gas is larger than that for the stellar continuum. From a comparison of the extinction-corrected H{alpha} luminosity and other SFR indicators, we found that the relation between the dust properties of stellar continuum and ionized gas is different depending on the intrinsic SFR (differential extinction). We compared SFRs estimated from extinction-corrected H{alpha} luminosities with stellar masses estimated from SED fitting. The comparison shows no correlation between SFR and stellar mass. Some galaxies with stellar mass smaller than {approx}10{sup 10} M{sub sun} show SFRs higher than {approx}100 M{sub sun} yr{sup -1}. The specific SFRs (SSFRs) of these galaxies are remarkably high; galaxies which have SSFR higher than {approx}10{sup -8} yr{sup -1} are found in eight of the present sample. From the best-fit parameters of SED fitting for these high-SSFR galaxies, we find that the average age of the stellar population is younger than 100 Myr, which is consistent with the implied high SSFR. The large SFR implies the possibility that the high-SSFR galaxies significantly

  13. Early-type galaxies in the near-infrared: 1.5-2.4 μm spectroscopy

    NASA Astrophysics Data System (ADS)

    Cesetti, M.; Ivanov, V. D.; Morelli, L.; Pizzella, A.; Buson, L.; Corsini, E. M.; Dalla Bontà, E.; Stiavelli, M.; Bertola, F.

    2009-04-01

    Context: Near-infrared (hereafter NIR) data may provide complementary information to the traditional optical population synthesis analysis of unresolved stellar populations because the spectral energy distribution of the galaxies in the 1-2.5 μm range is dominated by different types of stars than at optical wavelengths. Furthermore, NIR data are less affected by dust absorption and hence could constrain the stellar populations in dust-obscured galaxies. Aims: We attempt to develop observational constraints on the stellar populations of unresolved stellar systems in the NIR. Methods: To achieve this goal, we require benchmark NIR spectra of “simple” early-type galaxies, to test and calibrate the outputs of population synthesis models. We obtained low-resolution (R ~ 1000) long-slit spectra between 1.5 and 2.4 μm for 14 nearby early-type galaxies using SofI at the ESO 3.5-m New Technology Telescope and higher resolution (R ~ 3000) long-slit spectra, centered on Mgi at ~1.51 μm for a heterogeneous sample of 5 nearby galaxies observed with ISAAC at Antu, one of the 8.2-m ESO Very Large Telescope. Results: We defined spectral indices corresponding to CO, Nai, Cai and Mgi absorption lines and measured their strengths in the galaxies spectrum. We defined a new global NIR metallicity index, suitable for abundance measurements in low-resolution spectra. Finally, we created an average-combined NIR spectrum of an early-type galaxy, from a homogeneous subset of our data set. Conclusions: The NIR galaxy spectra are similar to each other and some of the line index strengths correlate with both the iron abundance [Fe/H] and optical metal line indices of the galaxies. The data suggest that the NIR metal features, in combination with a hydrogen absorption feature, may break the age-metallicity degeneracy in a similar way the Mg and Fe features in the rest-frame optical wavelength range. Based on observations made with ESO Telescopes at the La Silla and Paranal Observatory

  14. Observational studies on the near-infrared unidentified emission bands in galactic H II regions

    SciTech Connect

    Mori, Tamami I.; Onaka, Takashi; Sakon, Itsuki; Ohsawa, Ryou; Bell, Aaron C.; Ishihara, Daisuke; Shimonishi, Takashi

    2014-03-20

    Using a large collection of near-infrared spectra (2.5-5.4 μm) of Galactic H II regions and H II region-like objects, we perform a systematic investigation of astronomical polycyclic aromatic hydrocarbon (PAH) features. Thirty-six objects were observed using the infrared camera on board the AKARI satellite as a part of a director's time program. In addition to the well known 3.3-3.6 μm features, most spectra show a relatively weak emission feature at 5.22 μm with sufficient signal-to-noise ratios, which we identify as the PAH 5.25 μm band (previously reported). By careful analysis, we find good correlations between the 5.25 μm band and both the aromatic hydrocarbon feature at 3.3 μm and the aliphatic hydrocarbon features at around 3.4-3.6 μm. The present results give us convincing evidence that the astronomical 5.25 μm band is associated with C-H vibrations, as suggested by previous studies, and show its potential to probe the PAH size distribution. The analysis also shows that the aliphatic-to-aromatic ratio of I {sub 3.4-3.6} {sub μm}/I {sub 3.3} {sub μm} decreases against the ratio of the 3.7 μm continuum intensity to the 3.3 μm band, I {sub cont,} {sub 3.7} {sub μm}/I {sub 3.3} {sub μm}, which is an indicator of the ionization fraction of PAHs. The midinfrared color of I {sub 9} {sub μm}/I {sub 18} {sub μm} also declines steeply against the ratio of the hydrogen recombination line Brα at 4.05 μm to the 3.3 μm band, I {sub Brα}/I {sub 3.3} {sub μm}. These facts indicate possible dust processing inside or at the boundary of ionized gas.

  15. Near-Infrared Properties of Moderate-Redshift Galaxy Clusters: Luminosity Functions and Density Profiles

    SciTech Connect

    Muzzin, Adam; Yee, H.K.C.; Hall, Patrick B.; Ellingson, E.; Lin, Huan; /Fermilab

    2006-12-01

    We present K-band imaging for 15 of the Canadian Network for Observational Cosmology (CNOC1) clusters. The extensive spectroscopic dataset available for these clusters allows us to determine the cluster K-band luminosity function and density profile without the need for statistical background subtraction. The luminosity density and number density profiles can be described by NFW models with concentration parameters of c{sub l} = 4.28 {+-} 0.70 and c{sub g} = 4.13 {+-} 0.57 respectively. Comparing these to the dynamical mass analysis of the same clusters shows that the galaxy luminosity and number density profiles are similar to the dark matter profile, and are not less concentrated like in local clusters. The luminosity functions show that the evolution of K. over the redshift range 0.2 < z < 0.5 is consistent with a scenario where the majority of stars in cluster galaxies form at high-redshift (z{sub f} > 1.5) and evolve passively thereafter. The best-fit for the faint-end slope of the luminosity function is {alpha} = -0.84 {+-} 0.08, which indicates that it does not evolve between z = 0 and z = 0.3. Using Principal Component Analysis of the spectra we classify cluster galaxies as either star-forming/recently-star-forming (EM+BAL) or non-star forming (ELL) and compute their respective luminosity functions. The faint-end slope of the ELL luminosity function is much shallower than for the EM+BAL galaxies at z = 0.3, and suggests the number of faint ELL galaxies in clusters decreases by a factor of {approx} 3 from z = 0 to z = 0.3. The redshift evolution of K* for both EM+BAL and ELL types is consistent with a passively evolving stellar population formed at high-redshift. Passive evolution in both classes, as well as the total cluster luminosity function, demonstrates that the bulk of the stellar population in all bright cluster galaxies is formed at high-redshift and subsequent transformations in morphology/color/spectral-type have little effect on the total stellar

  16. Cerebral near infrared spectroscopy oximetry in extremely preterm infants: phase II randomised clinical trial

    PubMed Central

    Pellicer, Adelina; Alderliesten, Thomas; Austin, Topun; van Bel, Frank; Benders, Manon; Claris, Olivier; Dempsey, Eugene; Franz, Axel R; Fumagalli, Monica; Gluud, Christian; Grevstad, Berit; Hagmann, Cornelia; Lemmers, Petra; van Oeveren, Wim; Pichler, Gerhard; Plomgaard, Anne Mette; Riera, Joan; Sanchez, Laura; Winkel, Per; Wolf, Martin; Greisen, Gorm

    2015-01-01

    Objective To determine if it is possible to stabilise the cerebral oxygenation of extremely preterm infants monitored by cerebral near infrared spectroscopy (NIRS) oximetry. Design Phase II randomised, single blinded, parallel clinical trial. Setting Eight tertiary neonatal intensive care units in eight European countries. Participants 166 extremely preterm infants born before 28 weeks of gestation: 86 were randomised to cerebral NIRS monitoring and 80 to blinded NIRS monitoring. The only exclusion criterion was a decision not to provide life support. Interventions Monitoring of cerebral oxygenation using NIRS in combination with a dedicated treatment guideline during the first 72 hours of life (experimental) compared with blinded NIRS oxygenation monitoring with standard care (control). Main outcome measures The primary outcome measure was the time spent outside the target range of 55-85% for cerebral oxygenation multiplied by the mean absolute deviation, expressed in %hours (burden of hypoxia and hyperoxia). One hour with an oxygenation of 50% gives 5%hours of hypoxia. Secondary outcomes were all cause mortality at term equivalent age and a brain injury score assessed by cerebral ultrasonography. Randomisation Allocation sequence 1:1 with block sizes 4 and 6 in random order concealed for the investigators. The allocation was stratified for gestational age (<26 weeks or ≥26 weeks). Blinding Cerebral oxygenation measurements were blinded in the control group. All outcome assessors were blinded to group allocation. Results The 86 infants randomised to the NIRS group had a median burden of hypoxia and hyperoxia of 36.1%hours (interquartile range 9.2-79.5%hours) compared with 81.3 (38.5-181.3) %hours in the control group, a reduction of 58% (95% confidence interval 35% to 73%, P<0.001). In the experimental group the median burden of hypoxia was 16.6 (interquartile range 5.4-68.1) %hours, compared with 53.6 (17.4-171.3) %hours in the control group (P=0.0012). The

  17. AKARI INFRARED CAMERA SURVEY OF THE LARGE MAGELLANIC CLOUD. II. THE NEAR-INFRARED SPECTROSCOPIC CATALOG

    SciTech Connect

    Shimonishi, Takashi; Onaka, Takashi; Kato, Daisuke; Sakon, Itsuki; Ita, Yoshifusa; Kawamura, Akiko; Kaneda, Hidehiro

    2013-02-01

    We performed a near-infrared spectroscopic survey toward an area of {approx}10 deg{sup 2} of the Large Magellanic Cloud (LMC) with the infrared satellite AKARI. Observations were carried out as part of the AKARI Large-area Survey of the Large Magellanic Cloud (LSLMC). The slitless multi-object spectroscopic capability of the AKARI/IRC enabled us to obtain low-resolution (R {approx} 20) spectra in 2-5 {mu}m for a large number of point sources in the LMC. As a result of the survey, we extracted about 2000 infrared spectra of point sources. The data are organized as a near-infrared spectroscopic catalog. The catalog includes various infrared objects such as young stellar objects (YSOs), asymptotic giant branch (AGB) stars, supergiants, and so on. It is shown that 97% of the catalog sources have corresponding photometric data in the wavelength range from 1.2 to 11 {mu}m, and 67% of the sources also have photometric data up to 24 {mu}m. The catalog allows us to investigate near-infrared spectral features of sources by comparison with their infrared spectral energy distributions. In addition, it is estimated that about 10% of the catalog sources are observed at more than two different epochs. This enables us to study a spectroscopic variability of sources by using the present catalog. Initial results of source classifications for the LSLMC samples are presented. We classified 659 LSLMC spectra based on their near-infrared spectral features by visual inspection. As a result, it is shown that the present catalog includes 7 YSOs, 160 C-rich AGBs, 8 C-rich AGB candidates, 85 O-rich AGBs, 122 blue and yellow supergiants, 150 red super giants, and 128 unclassified sources. Distributions of the classified sources on the color-color and color-magnitude diagrams are discussed in the text. Continuous wavelength coverage and high spectroscopic sensitivity in 2-5 {mu}m can only be achieved by space observations. This is an unprecedented large-scale spectroscopic survey toward the

  18. Near-infrared spectrophotometry of four Seyfert 1 galaxies and NGC 1275

    NASA Technical Reports Server (NTRS)

    Rudy, R. J.; Jones, B.; Levan, P. D.; Puetter, R. C.; Smith, H. E.; Willner, S. P.; Tokunaga, A. T.

    1982-01-01

    Low-resolution spectrophotometry from 2 to 4 microns is reported for the four Seyfert 1 galaxies Mrk 335, 3C 120, Mrk 509, NGC 7469, and the peculiar emission-line galaxy NGC 1275. The spectrum of NGC 7469 exhibits a strong 3.3-micron dust feature, indicating a thermal origin for the bulk of its considerable nonstellar infrared emission. NGC 1275 has a large stellar contribution to its infrared flux at wavelengths shortward of 3 microns. The spectrum from 3 to 4 microns fits a power law which fits the 10-micron and 20-micron broad bands, as well. A thermal model which can explain the spectrum of NGC 1275 is discussed. Mrk 335 displays a complex spectrum suggestive of thermal dust emission. 3C 120 and Mrk 509 have nonstellar infrared emission shortward of 2 microns, but the data are ambiguous as to whether this emission is thermal or nonthermal in origin.

  19. Near-Infrared Continuum and 3.3um PAH Imaging of the Starburst Ring in the Type I Seyfert Galaxy NGC 7469

    NASA Technical Reports Server (NTRS)

    Mazzarella, J.; Voit, G.; Soifer, B.; Matthews, K.; Graham, J.; Armus, L.; Shupe, D.

    1993-01-01

    High resolution near-infrared images of the type 1 Seyfert Galaxy NGC 7469 have been obtained to probe its dusty nuclear environment. Direct images are relatively featureless, but residual images created by subtacting a smooth model based on best-fitting elliptical isoophotes reveal a tight inner spiral whose high surface-brightness portions correspond to a previously detected 3.

  20. Time-resolved visible/near-infrared spectrometric observations of the Galaxy 11 geostationary satellite

    NASA Astrophysics Data System (ADS)

    Bédard, Donald; Wade, Gregg A.

    2017-01-01

    Time-resolved spectrometric measurements of the Galaxy 11 geostationary satellite were collected on three consecutive nights in July 2014 with the 1.6-m telescope at the Observatoire du Mont-Mégantic in Québec, Canada. Approximately 300 low-resolution spectra (R ≈ 700 , where R = λ / Δλ) of the satellite were collected each night, covering a spectral range between 425 and 850 nm. The two objectives of the experiment were to conduct material-type identification from the spectra and to study how the spectral energy distribution inferred from these measurements varied as the illumination and observation geometry changed on nightly timescales. We present results that indicate the presence of a highly reflective aluminized surface corresponding to the solar concentrator arrays of the Galaxy 11 spacecraft. Although other material types could not be identified using the spectra, the results showed that the spectral energy distribution of the reflected sunlight from the Galaxy 11 spacecraft varied significantly, in a systematic manner, over each night of observation. The variations were quantified using colour indices calculated from the time-resolved spectrometric measurements.

  1. NEAR-INFRARED ADAPTIVE OPTICS IMAGING OF INFRARED LUMINOUS GALAXIES: THE BRIGHTEST CLUSTER MAGNITUDE-STAR FORMATION RATE RELATION

    SciTech Connect

    Randriamanakoto, Z.; Väisänen, P.; Escala, A.; Kankare, E.; Kotilainen, J.; Mattila, S.; Ryder, S.

    2013-10-01

    We have established a relation between the brightest super star cluster (SSC) magnitude in a galaxy and the host star formation rate (SFR) for the first time in the near-infrared (NIR). The data come from a statistical sample of ∼40 luminous IR galaxies (LIRGs) and starbursts utilizing K-band adaptive optics imaging. While expanding the observed relation to longer wavelengths, less affected by extinction effects, it also pushes to higher SFRs. The relation we find, M{sub K} ∼ –2.6log SFR, is similar to that derived previously in the optical and at lower SFRs. It does not, however, fit the optical relation with a single optical to NIR color conversion, suggesting systematic extinction and/or age effects. While the relation is broadly consistent with a size-of-sample explanation, we argue physical reasons for the relation are likely as well. In particular, the scatter in the relation is smaller than expected from pure random sampling strongly suggesting physical constraints. We also derive a quantifiable relation tying together cluster-internal effects and host SFR properties to possibly explain the observed brightest SSC magnitude versus SFR dependency.

  2. Optical and Near Infrared studies of the photometric structure and starburst activity of Blue Compact Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Noeske, K. G.

    2003-03-01

    This thesis describes three studies of Blue Compact Dwarf Galaxies (BCDs), focussed on the structure of the stellar components, the star-forming activity, and the environment of such galaxies, as well as the physical background of their morphological variety. The analysis of deep Near Infrared (NIR) image data of a significant sample of BCDs allows to study the evolved stellar low surface brightness (LSB) components of BCDs more precisely than previous studies at visible wavelengths. Azimuthally averaged radial surface brightness profiles (SBPs) show an exponential intensity distribution of the stellar LSB components at large galactocentric radii. This result, along with the derived exponential scale lengths which are systematically smaller than those of dwarf Irregular and dwarf Elliptical galaxies, agrees with previous optical studies. Towards smaller radii, however, the NIR data reveal an inwards-flattening of the SBPs of the stellar LSB components with respect to their outer exponential slopes in more than half of the BCDs under study. Such inwards-flattening exponential SBPs are frequent in dwarf Irregulars and dwarf Ellipticals, but were hitherto largely undiscovered in the stellar hosts of BCDs. The physical origin of such SBPs in dwarf galaxies is to date not understood. Empirical approaches to their systematization and quantitative investigation are discussed, along with the various implications of the discovery of such SBPs in many BCDs for the understanding of such galaxies. Based on the derived structural information on the stellar LSB components and the starburst components, the hypothesis is raised that below a certain threshold density of the stellar LSB component, of the order of 0.4 solar masses per cubic parsec, burst-like star formation does not occur in gas-rich dwarf galaxies. On this hypothesis, the observed relations between the structure of the stellar LSB components of BCDs and their luminosity can be reproduced, as well as the systematic

  3. Galaxies in southern bright star fields. I. Near-infrared imaging

    NASA Astrophysics Data System (ADS)

    Baker, Andrew J.; Davies, Richard I.; Lehnert, M. D.; Thatte, N. A.; Vacca, W. D.; Hainaut, O. R.; Jarvis, M. J.; Miley, G. K.; Röttgering, H. J. A.

    2003-08-01

    As a prerequisite for cosmological studies using adaptive optics techniques, we have begun to identify and characterize faint sources in the vicinity of bright stars at high Galactic latitudes. The initial phase of this work has been a program of Ks imaging conducted with SOFI at the ESO NTT. From observations of 42 southern fields evenly divided between the spring and autumn skies, we have identified 391 additional stars and 1589 galaxies lying at separations Delta theta <= 60arcsec from candidate guide stars in the magnitude range 9.0 <= R <= 12.4. When analyzed as a ``discrete deep field'' with 131 arcmin2 area, our dataset gives galaxy number counts that agree with those derived previously over the range 16 <= Ks < 20.5. This consistency indicates that in the aggregate, our fields should be suitable for future statistical studies. We provide our source catalogue as a resource for users of large telescopes in the southern hemisphere. Based on observations obtained at the European Southern Observatory, Chile, for programmes 66.A-0361 and 68.A-0440. The entirety of Table \\ref{t-src} is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/406/593}

  4. UVUDF: Ultraviolet Through Near-infrared Catalog and Photometric Redshifts of Galaxies in the Hubble Ultra Deep Field

    NASA Astrophysics Data System (ADS)

    Rafelski, Marc; Teplitz, Harry I.; Gardner, Jonathan P.; Coe, Dan; Bond, Nicholas A.; Koekemoer, Anton M.; Grogin, Norman; Kurczynski, Peter; McGrath, Elizabeth J.; Bourque, Matthew; Atek, Hakim; Brown, Thomas M.; Colbert, James W.; Codoreanu, Alex; Ferguson, Henry C.; Finkelstein, Steven L.; Gawiser, Eric; Giavalisco, Mauro; Gronwall, Caryl; Hanish, Daniel J.; Lee, Kyoung-Soo; Mehta, Vihang; de Mello, Duilia F.; Ravindranath, Swara; Ryan, Russell E.; Scarlata, Claudia; Siana, Brian; Soto, Emmaris; Voyer, Elysse N.

    2015-07-01

    We present photometry and derived redshifts from up to eleven bandpasses for 9927 galaxies in the Hubble Ultra Deep field (UDF), covering an observed wavelength range from the near-ultraviolet (NUV) to the near-infrared (NIR) with Hubble Space Telescope observations. Our Wide Field Camera 3 (WFC3)/UV F225W, F275W, and F336W image mosaics from the ultra-violet UDF (UVUDF) imaging campaign are newly calibrated to correct for charge transfer inefficiency, and use new dark calibrations to minimize background gradients and pattern noise. Our NIR WFC3/IR image mosaics combine the imaging from the UDF09 and UDF12 campaigns with CANDELS data to provide NIR coverage for the entire UDF field of view. We use aperture-matched point-spread function corrected photometry to measure photometric redshifts in the UDF, sampling both the Lyman break and Balmer break of galaxies at z˜ 0.8-3.4, and one of the breaks over the rest of the redshift range. Our comparison of these results with a compilation of robust spectroscopic redshifts shows an improvement in the galaxy photometric redshifts by a factor of two in scatter and a factor three in outlier fraction (OLF) over previous UDF catalogs. The inclusion of the new NUV data is responsible for a factor of two decrease in the OLF compared to redshifts determined from only the optical and NIR data, and improves the scatter at z\\lt 0.5 and at z\\gt 2. The panchromatic coverage of the UDF from the NUV through the NIR yields robust photometric redshifts of the UDF, with the lowest OLF available.

  5. Near-infrared observations of galaxies in Pisces-Perseus. V. On the origin of bulges

    NASA Astrophysics Data System (ADS)

    Hunt, L. K.; Pierini, D.; Giovanardi, C.

    2004-02-01

    We investigate the scaling relations of bulge and disk structural parameters for a sample of 108 disk galaxies. Structural parameters of individual galaxies are obtained from two-dimensional bulge/disk decomposition of their H-band surface brightness distributions. Bulges are modelled with a generalized exponential (Sérsic) with variable integer shape index n. We find that bulge effective scalelengths reB and luminosity MB increase with increasing n, but disk properties are independent of bulge shape. As Hubble type T increases, bulges become less luminous and their mean effective surface brightness <μeB> gets fainter; disk <μeD> shows a similar, but much weaker, trend. When bulge parameters (<μeB>, reB, MB) are compared with disk ones (<μeD>, reD, MD), they are tightly correlated for n=1 bulges. The correlations gradually worsen with increasing n such that n=4 bulges appear virtually independent of their disks. The Kormendy relation, <μeB> vs. reB, is shown to depend on bulge shape n; the two parameters are tightly correlated in n=4 bulges (r=0.8), and increasingly less so as n decreases; disk <μeD> and reD are well correlated (r=0.7). Bulge-to-disk size ratios reB/reD are independent of Hubble type, but smaller for exponential bulges; the mean reB/reD for n=1 bulges is 4 times smaller than that for n=4, with a spread which is 9 times smaller. Strongly barred SB galaxies with exponential bulges are more luminous than their unbarred counterparts. Exponential bulges appear to be closely related to their underlying disks, while bulges with higher n values are less so; n=4 bulges and their disks apparently have no relation. We interpret our results as being most consistent with a secular evolutionary scenario, in which dissipative processes in the disk are responsible for building up the bulges in most spirals. Based on observations at the TIRGO, NOT, and VATT telescopes. TIRGO (Gornergrat, CH) is operated by IRA-CNR, Arcetri, Firenze. NOT (La Palma, Canary

  6. Near-infrared Spectroscopy of Nearby Seyfert Galaxies: Is There Evidence for Shock Excitation in Narrow-line Regions?

    NASA Astrophysics Data System (ADS)

    Terao, K.; Nagao, T.; Hashimoto, T.; Yanagisawa, K.; Matsuoka, K.; Toba, Y.; Ikeda, H.; Taniguchi, Y.

    2016-12-01

    One of the important unsettled problems regarding active galactic nuclei (AGNs) is the major ionization mechanism of gas clouds in AGN narrow-line regions (NLRs). In order to investigate this issue, we present our J-band spectroscopic observations of a sample of 26 nearby Seyfert galaxies. In our study, we use the flux ratio of the following two forbidden emission lines, [Fe ii]1.257 μm and [P ii]1.188 μm, because it is known that this ratio is sensitive to the ionization mechanism. We obtain the [Fe ii]/[P ii] flux ratio or its lower limit for 19 objects. In addition to our data, we compile this flux ratio (or its lower limit) for 23 nearby Seyfert galaxies from the literature. Based on the collected data, we find that three Seyfert galaxies show very large lower limits of the [Fe ii]/[P ii] flux ratios (≳10): NGC 2782, NGC 5005, and Mrk 463. It is thus suggested that the contribution of the fast shock in the gas excitation is significantly large for them. However, more than half of the Seyfert galaxies in our sample show moderate [Fe ii]/[P ii] flux ratios (∼2), which is consistent with pure photoionization by power-law ionizing continuum emission. We also find that the [Fe ii]/[P ii] flux ratio shows no clear correlation with the radio loudness, suggesting that the radio jet is not the primary origin of shocks in NLRs of Seyfert galaxies.

  7. A comparison of the near-infrared spectral features of early-type galaxies in the Coma Cluster, the Virgo cluster and the field

    NASA Technical Reports Server (NTRS)

    Houdashelt, Mark L.; Frogel, Jay A.

    1993-01-01

    Earlier researchers derived the relative distance between the Coma and Virgo clusters from color-magnitude relations of the early-type galaxies in each cluster. They found that the derived distance was color-dependent and concluded that the galaxies of similar luminosity in the two clusters differ in their red stellar populations. More recently, the color-dependence of the Coma-Virgo distance modulus has been called into question. However, because these two clusters differ so dramatically in their morphologies and kinematics, it is plausible that the star formation histories of the member galaxies also differed. If the conclusions of earlier researchers are indeed correct, then some signature of the resulting stellar population differences should appear in the near-infrared and/or infrared light of the respective galaxies. We have collected near-infrared spectra of 17 Virgo and 10 Coma early-type galaxies; this sample spans about four magnitudes in luminosity in each cluster. Seven field E/S0 galaxies have been observed for comparison. Pseudo-equivalent widths have been measured for all of the field galaxies, all but one of the Virgo members, and five of the Coma galaxies. The features examined are sensitive to the temperature, metallicity, and surface gravity of the reddest stars. A preliminary analysis of these spectral features has been performed, and, with a few notable exceptions, the measured pseudo-equivalent widths agree well with previously published values.

  8. Understanding Active Galactic Nuclei using near-infrared high angular resolution polarimetry II: Preliminary results

    NASA Astrophysics Data System (ADS)

    Marin, F.; Grosset, L.; Goosmann, R.; Gratadour, D.; Rouan, D.; Clénet, Y.; Pelat, D.; Rojas Lobos, P. A.

    2016-12-01

    In this second research note of a series of two, we present the first near-infrared results we obtained when modeling Active Galactic Nuclei (AGN). Our first proceedings showed the comparison between the MontAGN and STOKES Monte Carlo codes. Now we use our radiative transfer codes to simulate the polarization maps of a prototypical, NGC 1068-like, type-2 radio-quiet AGN. We produced high angular resolution infrared (1 μm) polarization images to be compared with recent observations in this wavelength range. Our preliminary results already show a good agreement between the models and observations but cannot account for the peculiar linear polarization angle of the torus such as observed. tet{Gratadour2015} found a polarization position angle being perpendicular to the bipolar outflows axis. Further work is needed to improve the models by adding physical phenomena such as dichroism and clumpiness.

  9. Gemini Near Infrared Field Spectrograph Observations of the Seyfert 2 Galaxy Mrk 573: In Situ Acceleration of Ionized and Molecular Gas off Fueling Flows

    NASA Astrophysics Data System (ADS)

    Fischer, Travis C.; Machuca, C.; Diniz, M. R.; Crenshaw, D. M.; Kraemer, S. B.; Riffel, R. A.; Schmitt, H. R.; Baron, F.; Storchi-Bergmann, T.; Straughn, A. N.; Revalski, M.; Pope, C. L.

    2017-01-01

    We present near-infrared and optical emission-line and stellar kinematics of the Seyfert 2 galaxy Mrk 573 using the Near-Infrared Field Spectrograph (NIFS) at Gemini North and Dual Imaging Spectrograph at Apache Point Observatory, respectively. By obtaining full kinematic maps of the infrared ionized and molecular gas and stellar kinematics in a ∼700 × 2100 pc2 circumnuclear region of Mrk 573, we find that kinematics within the Narrow-Line Region are largely due to a combination of both rotation and in situ acceleration of material originating in the host disk. Combining these observations with large-scale, optical long-slit spectroscopy that traces ionized gas emission out to several kpcs, we find that rotation kinematics dominate the majority of the gas. We find that outflowing gas extends to distances less than 1 kpc, suggesting that outflows in Seyfert galaxies may not be powerful enough to evacuate their entire bulges.

  10. DEEP NEAR-INFRARED SURVEY OF THE PIPE NEBULA. II. DATA, METHODS, AND DUST EXTINCTION MAPS

    SciTech Connect

    Roman-Zuniga, Carlos G.; Lada, Charles J.; Lombardi, Marco

    2010-12-20

    We present a new set of high-resolution dust extinction maps of the nearby and essentially starless Pipe Nebula molecular cloud. The maps were constructed from a concerted deep near-infrared imaging survey with the ESO-VLT, ESO-NTT, CAHA 3.5 m telescopes, and 2MASS data. The new maps have a resolution three times higher than the previous extinction map of this cloud by Lombardi et al. and are able to resolve structures down to 2600 AU. We detect 244 significant extinction peaks across the cloud. These peaks have masses between 0.1 and 18.4 M{sub sun}, diameters between 1.2 and 5.7 x 10{sup 4} AU (0.06 and 0.28 pc), and mean densities of about 10{sup 4} cm{sup -3}, all in good agreement with previous results. From the analysis of the mean surface density of companions we find a well-defined scale near 1.4 x 10{sup 4} AU below which we detect a significant decrease in structure of the cloud. This scale is smaller than the Jeans length calculated from the mean density of the peaks. The surface density of peaks is not uniform but instead it displays clustering. Extinction peaks in the Pipe Nebula appear to have a spatial distribution similar to the stars in Taurus, suggesting that the spatial distribution of stars evolves directly from the primordial spatial distribution of high-density material.

  11. Near-infrared spectra and intrinsic luminosities of candidate type II quasars at 2 < z < 3.4

    SciTech Connect

    Greene, Jenny E.; Strauss, Michael A.; Pattarakijwanich, Petchara; Alexandroff, Rachael; Zakamska, Nadia L.; Liu, Guilin; Lang, Dustin; Hamann, Frederick; Ross, Nicholas P.; Myers, Adam D.; Brandt, W. Niel; Schneider, Donald P.; York, Donald

    2014-06-10

    We present JHK near-infrared (NIR) spectroscopy of 25 candidate Type II quasars selected from the Sloan Digital Sky Survey (SDSS), using Triplespec on the Apache Point Observatory 3.5 m telescope, the Folded-port InfraRed Echellette at the Magellan/Baade 6.5 m telescope, and the Gemini Near-Infrared Spectrograph on Gemini. At redshifts of 2 < z < 3.4, our NIR spectra probe the rest-frame optical region of these targets, which were initially selected to have strong lines of C IV and Ly α, with FWHM < 2000 km s{sup –1} from the SDSS pipeline. We use the [O III] λ5007 line shape as a model for the narrow-line region emission and find that Hα consistently requires a broad component with FWHMs ranging from 1000 to 7500 km s{sup –1}. Interestingly, the C IV lines also require broad bases, but with considerably narrower widths of 1000-4500 km s{sup –1}. Estimating the extinction using the Balmer decrement and also the relationship in lower-z quasars between rest equivalent width and luminosity in the [O III] line, we find typical A{sub V} values of 0-2 mag, which naturally explains the attenuated C IV lines relative to Hα. We propose that our targets are moderately obscured quasars. We also describe one unusual object with three distinct velocity peaks in its [O III] spectrum.

  12. The black hole mass of NGC 4151. II. Stellar dynamical measurement from near-infrared integral field spectroscopy

    SciTech Connect

    Onken, Christopher A.; Ferrarese, Laura; Valluri, Monica; Brown, Jonathan S.; McGregor, Peter J.; Peterson, Bradley M.; Pogge, Richard W.; Bentz, Misty C.; Vestergaard, Marianne; Storchi-Bergmann, Thaisa; Riffel, Rogemar A. E-mail: mvalluri@umich.edu

    2014-08-10

    We present a revised measurement of the mass of the central black hole (M{sub BH} ) in the Seyfert 1 galaxy NGC 4151. The new stellar dynamical mass measurement is derived by applying an axisymmetric orbit-superposition code to near-infrared integral field data obtained using adaptive optics with the Gemini Near-infrared Integral Field Spectrograph (NIFS). When our models attempt to fit both the NIFS kinematics and additional low spatial resolution kinematics, our results depend sensitively on how χ{sup 2} is computed—probably a consequence of complex bar kinematics that manifest immediately outside the nuclear region. The most robust results are obtained when only the high spatial resolution kinematic constraints in the nuclear region are included in the fit. Our best estimates for the black hole mass and H-band mass-to-light ratio are M{sub BH} ∼ 3.76 ± 1.15 × 10{sup 7} M{sub ☉} (1σ error) and Y{sub H} ∼ 0.34 ± 0.03 M{sub ☉}/L{sub ☉} (3σ error), respectively (the quoted errors reflect the model uncertainties). Our black hole mass measurement is consistent with estimates from both reverberation mapping (3.57{sub −0.37}{sup +0.45}×10{sup 7} M{sub ⊙}) and gas kinematics (3.0{sub −2.2}{sup +0.75}×10{sup 7} M{sub ⊙}; 1σ errors), and our best-fit mass-to-light ratio is consistent with the photometric estimate of Y{sub H} = 0.4 ± 0.2 M{sub ☉}/L{sub ☉}. The NIFS kinematics give a central bulge velocity dispersion σ{sub c} = 116 ± 3 km s{sup –1}, bringing this object slightly closer to the M{sub BH}-σ relation for quiescent galaxies. Although NGC 4151 is one of only a few Seyfert 1 galaxies in which it is possible to obtain a direct dynamical black hole mass measurement—and thus, an independent calibration of the reverberation mapping mass scale—the complex bar kinematics makes it less than ideally suited for this purpose.

  13. LUMINOUS AND HIGH STELLAR MASS CANDIDATE GALAXIES AT z Almost-Equal-To 8 DISCOVERED IN THE COSMIC ASSEMBLY NEAR-INFRARED DEEP EXTRAGALACTIC LEGACY SURVEY

    SciTech Connect

    Yan Haojing; Finkelstein, Steven L.; Huang, Kuang-Han; Ryan, Russell E.; Ferguson, Henry C.; Koekemoer, Anton M.; Grogin, Norman A.; Dickinson, Mark; Newman, Jeffrey A.; Somerville, Rachel S.; Dave, Romeel; Faber, S. M.; Guo Yicheng; Giavalisco, Mauro; Lee, Kyoung-soo; Reddy, Naveen; Siana, Brian D.; Cooray, Asantha R.; Hathi, Nimish P.; and others

    2012-12-20

    One key goal of the Hubble Space Telescope Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey is to track galaxy evolution back to z Almost-Equal-To 8. Its two-tiered ''wide and deep'' strategy bridges significant gaps in existing near-infrared surveys. Here we report on z Almost-Equal-To 8 galaxy candidates selected as F105W-band dropouts in one of its deep fields, which covers 50.1 arcmin{sup 2} to 4 ks depth in each of three near-infrared bands in the Great Observatories Origins Deep Survey southern field. Two of our candidates have J < 26.2 mag, and are >1 mag brighter than any previously known F105W-dropouts. We derive constraints on the bright end of the rest-frame ultraviolet luminosity function of galaxies at z Almost-Equal-To 8, and show that the number density of such very bright objects is higher than expected from the previous Schechter luminosity function estimates at this redshift. Another two candidates are securely detected in Spitzer Infrared Array Camera images, which are the first such individual detections at z Almost-Equal-To 8. Their derived stellar masses are on the order of a few Multiplication-Sign 10{sup 9} M{sub Sun }, from which we obtain the first measurement of the high-mass end of the galaxy stellar mass function at z Almost-Equal-To 8. The high number density of very luminous and very massive galaxies at z Almost-Equal-To 8, if real, could imply a large stellar-to-halo mass ratio and an efficient conversion of baryons to stars at such an early time.

  14. Near-infrared continuum and 3.3 micrometer(s) polycyclic aromatic hydrocarbon imaging of the starburst ring in the type 1 Seyfert galaxy NGC 7469

    NASA Technical Reports Server (NTRS)

    Mazzarella, J. M.; Voit, G. M.; Soifer, B. T.; Matthews, K.; Graham, J. R.; Armus, L.; Shupe, D.

    1994-01-01

    High resolution near-infrared images of the type 1 Seyfert galaxy NGC 7469 have been obtained to probe its dusty nuclear environment. Direct J, H, and K images are relatively featureless, but residual images created by subtracting a smooth model based on best-fitting elliptical isophotes reveal a tight inner spiral whose high surface-brightness portions correspond to a previously detected 3 sec (1 kpc) diameter ring of radio continuum emission. The inner infrared spiral arms extended approximately equal to 4 sec NW and SE from the nucleus, and the NW arm joins up with large-scale spiral structure visible in the R band. The residual images also show a bar-like structure aligned with the brightest infrared/radio hotspots at PA approximately equal to 50 deg. Three infrared hotspots are detected which align remarkably well with 6 cm radio continuum sources. The near-infrared ring and the hotspots are visible in the residual images, and in a high-resolution direct K-band image restored to an effective resolution of 0.65 sec (FWHM) using the Richardson-Lucy algorithm. The infrared hotspots have luminosities of nuL(sub nu) (2.2 micrometer(s)) approximately equal to 10(exp 8) solar luminosity (M(sub k) approximately equal to -16 mag), suggesting they are either giant H II regions or individual supernovae. The two brightest regions may be associated with enhanced star formation triggered by orbit crowding of gas where spiral arms emerge from an inner bar. Narrowband (delta lambda/lambda approximately 1.5%) imaging in the 3.28 micrometer(s) dust emission feature and surrounding continuum confirms the 3 sec diameter 3.28 micrometer(s) emission region detected previously using multiaperture photometry. The extended polycyclic aromatic hydrocarbon (PAH) emission is slightly elongated and aligned with published 1O III1 line emission and 12.5 micrometer(s) continuum emission, apparently tracing the starburst. The presence of approximately equal to 25% of the total 3.28 micrometer

  15. Cats: Optical to Near-Infrared Colors of the Bulge and Disk of Two z = 0.7 Galaxies Using Hubble Space Telescope and Keck Laser Adaptive Optics Imaging

    NASA Astrophysics Data System (ADS)

    Steinbring, E.; Melbourne, J.; Metevier, A. J.; Koo, D. C.; Chun, M. R.; Simard, L.; Larkin, J. E.; Max, C. E.

    2008-10-01

    We have employed laser guide star (LGS) adaptive optics (AO) on the Keck II telescope to obtain near-infrared (NIR) images in the Extended Groth Strip deep galaxy survey field. This is a continuation of our Center for Adaptive Optics Treasury Survey program of targeting 0.5 < z < 1 galaxies where existing images with the Hubble Space Telescope (HST) are already in hand. Our AO field has already been imaged by the Advanced Camera for Surveys and the Near Infrared Camera and Multiobject Spectrograph (NICMOS). Our AO images at 2.2 μm (K') are comparable in depth to those from the HST, have Strehl ratios up to 0.4, and full width at half-maximum resolutions superior to that from NICMOS. By sampling the field with the LGS at different positions, we obtain better quality AO images than with an immovable natural guide star. As examples of the power of adding LGS AO to HST data, we study the optical to NIR colors and color gradients of the bulge and disk of two galaxies in the field with z = 0.7. All authors except L.S. are affiliated with the Center for Adaptive Optics.

  16. An early phase of environmental effects on galaxy properties unveiled by near-infrared spectroscopy of protocluster galaxies at z > 2

    NASA Astrophysics Data System (ADS)

    Shimakawa, Rhythm; Kodama, Tadayuki; Tadaki, Ken-ichi; Hayashi, Masao; Koyama, Yusei; Tanaka, Ichi

    2015-03-01

    This work presents the results from our near-infrared spectroscopy of narrow-band-selected Hα emitters (HAEs) in two rich overdensities (PKS 1138-262 at z = 2.2 and USS 1558-003 at z = 2.5) with the Multi-Object Infrared Camera and Spectrograph on the Subaru telescope. These protoclusters are promising candidates for the most massive class of galaxy clusters seen today (Paper I). The confirmed HAEs in the protoclusters at z > 2 show high excitation levels as characterized by much higher [O III]/Hβ or [O III]/Hα line ratios than those of general galaxies at low-z. Such a high excitation level may not only be driven by high specific star formation rates and lower gaseous metallicities, but also be contributed by some other effects. We investigate the environmental dependence of gaseous metallicities by comparing the HAEs in the protoclustrers with those in the general field at similar redshifts. We find that the gaseous metallicities of protocluster galaxies are more chemically enriched than those of field galaxies at a given stellar mass in the range of M⋆ ≲ 1011 M⊙. This can be attributed to many processes, such as intrinsic (or nature) effects, external (or nurture) effects, and/or some systematic sampling effects. The intrinsic (nature) effect leads to the advanced stage of `downsizing' galaxy evolution in protoclusters. On the other hand, the external (nurture) effects include the recycling of chemically enriched gas due to the higher pressure of intergalactic medium and/or stripping of outer gas in the reservoir in protoclusters. We also find that the offset of the mass-metallicity relation in dense environment becomes larger at higher redshifts. This can be naturally understood by the fact that the inflow/outflow rates in star-forming galaxies are much higher at higher redshifts. Therefore, the environmental dependence of such `feeding' and `feedback' mechanisms in galaxy formation is probably playing major roles in producing the offset of the mass

  17. NEAR-INFRARED IMAGING OF A z = 6.42 QUASAR HOST GALAXY WITH THE HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3

    SciTech Connect

    Mechtley, M.; Windhorst, R. A.; Cohen, S. H.; Jansen, R. A.; Scannapieco, E.; Ryan, R. E.; Koekemoer, A. M.; Schneider, G.; Fan, X.; Hathi, N. P.; Keel, W. C.; Roettgering, H.; Schneider, D. P.; Strauss, M. A.; Yan, H. J.

    2012-09-10

    We report on deep near-infrared F125W (J) and F160W (H) Hubble Space Telescope Wide Field Camera 3 images of the z = 6.42 quasar J1148+5251 to attempt to detect rest-frame near-ultraviolet emission from the host galaxy. These observations included contemporaneous observations of a nearby star of similar near-infrared colors to measure temporal variations in the telescope and instrument point-spread function (PSF). We subtract the quasar point source using both this direct PSF and a model PSF. Using direct subtraction, we measure an upper limit for the quasar host galaxy of m{sub J} > 22.8 and m{sub H} > 23.0 AB mag (2 {sigma}). After subtracting our best model PSF, we measure a limiting surface brightness from 0.''3 to 0.''5 radius of {mu}{sub J} > 23.5 and {mu}{sub H} > 23.7 AB mag arcsec{sup -2} (2 {sigma}). We test the ability of the model subtraction method to recover the host galaxy flux by simulating host galaxies with varying integrated magnitude, effective radius, and Sersic index, and conducting the same analysis. These models indicate that the surface brightness limit ({mu}{sub J} > 23.5 AB mag arcsec{sup -2}) corresponds to an integrated upper limit of m{sub J} > 22-23 AB mag, consistent with the direct subtraction method. Combined with existing far-infrared observations, this gives an infrared excess log (IRX) > 1.0 and corresponding ultraviolet spectral slope {beta} > -1.2 {+-} 0.2. These values match those of most local luminous infrared galaxies, but are redder than those of almost all local star-forming galaxies and z {approx_equal} 6 Lyman break galaxies.

  18. Large Magellanic Cloud Near-infrared Synoptic Survey. II. The Wesenheit Relations and Their Application to the Distance Scale

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Anupam; Kanbur, Shashi M.; Macri, Lucas M.; Singh, Harinder P.; Ngeow, Chow-Choong; Wagner-Kaiser, R.; Sarajedini, Ata

    2016-04-01

    We present new near-infrared (NIR) Cepheid period-Wesenheit (P-W) relations in the LMC using time-series observations from the Large Magellanic Cloud NIR Synoptic Survey. We also derive optical+NIR P-W relations using V and I magnitudes from the Optical Gravitational Lensing Experiment. We employ our new JHKs data to determine an independent distance to the LMC of {μ }{{LMC}}\\=\\18.47+/- 0.07(statistical) mag, using an absolute calibration of the Galactic relations based on several distance determination methods and accounting for the intrinsic scatter of each technique. We also derive new NIR period-luminosity and Wesenheit relations for Cepheids in M31 using observations from the Panchromatic Hubble Andromeda Treasury survey. We use the absolute calibrations of the Galactic and LMC {W}J,H relations to determine the distance modulus of M31, {μ }{{M31}}\\=\\24.46+/- 0.20 mag. We apply a simultaneous fit to Cepheids in several Local Group galaxies covering a range of metallicities (7.7\\lt 12+{log}[{{O}}/{{H}}]\\lt 8.6 dex) to determine a global slope of -3.244 ± 0.016 mag dex-1 for the {W}J,{Ks} relation and obtain robust distance estimates. Our distances are in good agreement with recent TRGB based distance estimates and we do not find any evidence for a metallicity dependence in the NIR P-W relations.

  19. Systematic Variations in CO2/H2O Ice Abundance Ratios in Nearby Galaxies Found with AKARI Near-infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Yamagishi, M.; Kaneda, H.; Ishihara, D.; Oyabu, S.; Onaka, T.; Shimonishi, T.; Suzuki, T.

    2015-07-01

    We report CO2/H2O ice abundance ratios in seven nearby star-forming galaxies based on the AKARI near-infrared (2.5-5.0 μm) spectra. The CO2/H2O ice abundance ratios show clear variations between 0.05 and 0.2 with the averaged value of 0.14 ± 0.01. The previous study on M82 revealed that the CO2/H2O ice abundance ratios strongly correlate with the intensity ratios of the hydrogen recombination Brα line to the polycyclic aromatic hydrocarbon (PAH) 3.3 μm feature. In the present study, however, we find no correlation for the seven galaxies as a whole due to systematic differences in the relation between CO2/H2O ice abundance and Brα/PAH 3.3 μm intensity ratios from galaxy to galaxy. This result suggests that there is another parameter that determines the CO2/H2O ice abundance ratios in a galaxy in addition to the Brα/PAH 3.3 μm ratios. We find that the CO2/H2O ice abundance ratios positively correlate with the specific star formation rates of the galaxies. From these results, we conclude that CO2/H2O ice abundance ratios tend to be high in young star-forming galaxies.

  20. THE COSMOS-WIRCam NEAR-INFRARED IMAGING SURVEY. I. BzK-SELECTED PASSIVE AND STAR-FORMING GALAXY CANDIDATES AT z approx> 1.4

    SciTech Connect

    McCracken, H. J.; Mellier, Y.; Capak, P.; Salvato, M.; Scoville, N. Z.; Aussel, H.; Daddi, E.; Sanders, D. B.; Ilbert, O.; Kneib, J.-P.; Le Fevre, O.; Kartaltepe, J.; Willott, C. J.; Mancini, C.; Renzini, A.; Cook, R.; Koekemoer, A. M.; Murayama, T.; Shioya, Y.

    2010-01-01

    We present a new near-infrared survey covering the 2 deg{sup 2} COSMOS field conducted using WIRCam at the Canada-France-Hawaii Telescope. By combining our near-infrared data with Subaru B and z images, we construct a deep, wide-field optical-infrared catalog. At K{sub s} < 23 (AB magnitudes), our survey completeness is greater than 90% and 70% for stars and galaxies, respectively, and contains 143,466 galaxies and 13,254 stars. Using the BzK diagram, we divide our galaxy catalog into quiescent and star-forming galaxy candidates. At z approx 2, our catalogs contain 3931 quiescent and 25,757 star-forming galaxies representing the largest and most secure sample at these depths and redshifts to date. Our counts of quiescent galaxies turns over at K{sub s} approx 22, an effect that we demonstrate cannot be due to sample incompleteness. Both the number of faint and bright quiescent objects in our catalogs exceed the predictions of a recent semi-analytic model of galaxy formation, indicating potentially the need for further refinements in the amount of merging and active galactic nucleus feedback at z approx 2 in these models. We measure the angular correlation function for each sample and find that the slope of the field galaxy correlation function flattens to 1.5 by K{sub s} approx 23. At small angular scales, the angular correlation function for passive BzK galaxies is considerably in excess of the clustering of dark matter. We use precise 30-band photometric redshifts to derive the spatial correlation length and the redshift distributions for each object class. At K{sub s} < 22, we find r {sup g}amma{sup /1.8}{sub 0} = 7.0 +- 0.5h {sup -1} Mpc for the passive BzK candidates and 4.7 +- 0.8 h {sup -1} Mpc for the star-forming BzK galaxies. Our pBzK galaxies have an average photometric redshift of z{sub p} approx 1.4, in approximate agreement with the limited spectroscopic information currently available. The stacked K{sub s} image will be made publicly available from

  1. Highly efficient near-infrared light-emitting diodes by using type-II CdTe/CdSe core/shell quantum dots as a phosphor.

    PubMed

    Shen, Huaibin; Zheng, Ying; Wang, Hongzhe; Xu, Weiwei; Qian, Lei; Yang, Yixing; Titov, Alexandre; Hyvonen, Jake; Li, Lin Song

    2013-11-29

    In this paper, we present an innovative method for the synthesis of CdTe/CdSe type-II core/shell structure quantum dots (QDs) using 'greener' chemicals. The PL of CdTe/CdSe type-II core/shell structure QDs ranges from 600 to 820 nm, and the as-synthesized core/shell structures show narrow size distributions and stable and high quantum yields (50–75%). Highly efficient near-infrared light-emitting diodes (LEDs) have been demonstrated by employing the CdTe/CdSe type-II core/shell QDs as emitters. The devices fabricated based on these type-II core/shell QDs show color-saturated near-infrared emission from the QD layers, a low turn-on voltage of 1.55 V, an external quantum efficiency (EQE) of 1.59%, and a current density and maximum radiant emittance of 2.1 × 10(3) mA cm−2 and 17.7 mW cm−2 at 8 V; it is the first report to use type-II core/shell QDs as near-infrared emitters and these results may offer a practicable platform for the realization of near-infrared QD-based light-emitting diodes, night-vision-readable displays, and friend/foe identification system.

  2. Prediction of potential mushroom yield by visible and near-infrared spectroscopy using fresh phase II compost.

    PubMed

    Sharma, H S S; Kilpatrick, M; Lyons, G

    2005-08-01

    Potential mushroom (Agaricus bisporus) yield of phase II compost is determined by interactions of key quality parameters including dry matter, nitrogen dry matter, ammonia, pH, conductivity, thermophilic microorganisms, C : N ratio, fiber fractions, ash, and certain minerals. This study was aimed at generating robust visible and near-infrared (Vis-NIR) calibrations for predicting potential yield, using spectra from fresh phase II compost. Four compost comparative trials were carried out during the winter and summer months of 2001-2003, under controlled experimental conditions employing six commercially prepared composts, with eight replicate (8 bag) plots per treatment (48 x 8 = 384). The substrates were prepared by windrow or bunker phase I, followed by phase II production. The fresh samples were scanned for Vis-NIR (400-2498 nm) spectra, averaged, transformed, and regressed against the recorded yield by employing a modified partial least squares algorithm. The best calibration model generated from the database explained 84% of yield variation within the data set with a standard error of calibration of 13.75 kg/tonne of fresh compost. The model was successfully tested for robustness with yield results obtained from a validation trial, carried out under similar experimental conditions in early 2004, and the standard error of prediction was 18.21 kg/tonne, which was slightly higher than the mean experimental error (17.94 kg/tonne) of the trial. The accuracy of the model is acceptable for estimating potential yield by classifying phase II substrate as poor (180-220 kg), medium (220-260 kg), and high (260-300 kg) yielding compost. The yield prediction model is being transferred to a new instrument based at Loughgall for routine evaluation of commercial phase II samples.

  3. Strain-balanced Si/SiGe type-II superlattices for near-infrared photodetection

    SciTech Connect

    Ali, Dyan; Richardson, Christopher J. K.

    2014-07-21

    Strain balanced silicon-silicon germanium type-II superlattice p-i-n photodetectors grown on a silicon germanium relaxed buffer layer are shown to exhibit an absorption band that extends beyond 0.7 eV (λ = 1.77 μm) with dark current densities of 27 μA cm{sup −2}. Simulations of the absorption edge, which are based on x-ray diffraction characterization, low observed dark current densities, and low dislocation densities, are consistent with fully strained heterostructures. Potential applications for devices made from this heterostructure design could include integrated silicon detectors, or low-noise absorption regions for infrared-extended silicon based avalanche photodiodes.

  4. Structure of selected basic zinc/copper (II) phosphate minerals based upon near-infrared spectroscopy - Implications for hydrogen bonding

    NASA Astrophysics Data System (ADS)

    Frost, Ray L.; Reddy, B. Jagannadha; Palmer, Sara J.; Keeffe, Eloise C.

    2011-03-01

    The NIR spectra of reichenbachite, scholzite and parascholzite have been studied at 298 K. The spectra of the minerals are different, in line with composition and crystal structural variations. Cation substitution effects are significant in their electronic spectra and three distinctly different electronic transition bands are observed in the near-infrared spectra at high wavenumbers in the 12,000-7600 cm -1 spectral region. Reichenbachite electronic spectrum is characterised by Cu(II) transition bands at 9755 and 7520 cm -1. A broad spectral feature observed for ferrous ion in the 12,000-9000 cm -1 region both in scholzite and parascholzite. Some what similarities in the vibrational spectra of the three phosphate minerals are observed particularly in the OH stretching region. The observation of strong band at 5090 cm -1 indicates strong hydrogen bonding in the structure of the dimorphs, scholzite and parascholzite. The three phosphates exhibit overlapping bands in the 4800-4000 cm -1 region resulting from the combinations of vibrational modes of (PO 4) 3- units.

  5. Visible and near-infrared calibrations for quality assessment of fresh phase I and II mushroom (Agaricus bisporus) compost.

    PubMed

    Sharma, H S S; Kilpatrick, M; Lyons, G; Sturgeon, S; Archer, J; Moore, S; Cheung, L; Finegan, K

    2005-11-01

    Previous studies have shown that visible and near-infrared spectra (Vis-NIR) of dry and milled compost can be used for generating partial least squares (PLS) calibrations of phase II compost parameters including ammonia, nitrogen dry matter (NDM), dry matter (DM), pH, conductivity, carbon, microbial population, and potential productivity. The objective of this study was to develop robust calibrations for some of the key parameters from the spectra of fresh phase I and II composts. Samples of substrates from six commercial production yards were obtained during winter and summer months of 2000-2004 to monitor changes in quality and were analyzed for the test factors. Vis-NIR reflectance measurements of fresh samples (740) were made over the range of 400-2500 nm. After mathematical pretreatments, PLS calibrations of the key parameters were developed using the NIR (1100-2500 nm) and visible and NIR (400-2500 nm) regions and subsequently validated using an independent sample set of 123 phase I and II samples obtained during 2004-2005. The phase I and II standard errors of laboratory measurements of ammonia, pH, conductivity, DM, NDM, and ash were lower than the standard error of predictions of the same parameters, respectively, by the best NIR or Vis-NIR models. The degree of precision for some of the calibrations, especially ammonia, NDM, and DM, is suitable for composters to monitor changes in quality parameters during production. The laboratory measurement errors for phase I samples were greater than those of the phase II samples, except for ash, due to a higher degree of heterogeneity in the substrate. The calibrations, especially for pH, conductivity, and ash, need to be improved with new sample sets. A major advantage of NIR spectroscopy is the ability to assess substrate quality for a range of target parameters simultaneously, within a few hours of receiving the samples. The main drawbacks are the expensive instrumentation, expertise, and training necessary for

  6. Conversion of the spin state of the manganese complex in photosystem II induced by near-infrared light.

    PubMed

    Boussac, A; Girerd, J J; Rutherford, A W

    1996-06-04

    The manganese complex (Mn4) which is responsible for water oxidation in photosystem II is EPR detectable in the S2 state, one of the five redox states of the enzyme cycle. The S2 state is observable at 10 K either as a multiline signal (spin 1/2) or as a signal at g = 4.1 (spin 3/2 or spin 5/2). It is shown here that at around 150 K the state responsible for the multiline signal is converted to that responsible for the g = 4.1 signal upon the absorption of infrared light. This conversion is fully reversible at 200 K. The action spectrum of this conversion has its maximum at 820 nm (12 200 cm-1) and is similar to the intervalence charge transfer band in di-mu-oxo-(MnIIIMnIV) model systems. It is suggested that the conversion of the multiline signal to the g = 4.1 signal results from absorption of infrared light by the Mn cluster itself, resulting in electron transfer from MnIII to MnIV. The g = 4.1 signal is thus proposed to arise from a state which differs from that which gives rise to the multiline signal only in terms of this change in its valence distribution. The near-infrared light effect was observed in the S2 state of Sr(2+)-reconstituted photosystem II and in Ca(2+)-depleted, EGTA (or citrate-)-treated photosystem II but not in ammonia-treated photosystem II. Earlier results in the literature which showed that the g = 4.1 state was preferentially formed by illumination at 130 K are reinterpreted as being the result of two photochemical events: the first being photosynthetic charge separation resulting in an S2 state which gives rise to the multiline signal and the second being the conversion of this state to the g = 4.1 state due to the simultaneous and inadvertent presence of 820 nm light in the broad-band illumination given. There is therefore no reason to consider the state responsible for the g = 4.1 signal as a precursor of that which gives rise to the multiline signal.

  7. SYSTEMATIC VARIATIONS IN CO{sub 2}/H{sub 2}O ICE ABUNDANCE RATIOS IN NEARBY GALAXIES FOUND WITH AKARI NEAR-INFRARED SPECTROSCOPY

    SciTech Connect

    Yamagishi, M.; Kaneda, H.; Ishihara, D.; Oyabu, S.; Onaka, T.; Shimonishi, T.; Suzuki, T.

    2015-07-01

    We report CO{sub 2}/H{sub 2}O ice abundance ratios in seven nearby star-forming galaxies based on the AKARI near-infrared (2.5–5.0 μm) spectra. The CO{sub 2}/H{sub 2}O ice abundance ratios show clear variations between 0.05 and 0.2 with the averaged value of 0.14 ± 0.01. The previous study on M82 revealed that the CO{sub 2}/H{sub 2}O ice abundance ratios strongly correlate with the intensity ratios of the hydrogen recombination Brα line to the polycyclic aromatic hydrocarbon (PAH) 3.3 μm feature. In the present study, however, we find no correlation for the seven galaxies as a whole due to systematic differences in the relation between CO{sub 2}/H{sub 2}O ice abundance and Brα/PAH 3.3 μm intensity ratios from galaxy to galaxy. This result suggests that there is another parameter that determines the CO{sub 2}/H{sub 2}O ice abundance ratios in a galaxy in addition to the Brα/PAH 3.3 μm ratios. We find that the CO{sub 2}/H{sub 2}O ice abundance ratios positively correlate with the specific star formation rates of the galaxies. From these results, we conclude that CO{sub 2}/H{sub 2}O ice abundance ratios tend to be high in young star-forming galaxies.

  8. Spitzer/Infrared Array Camera near-infrared features in the outer parts of S4G galaxies

    NASA Astrophysics Data System (ADS)

    Laine, Seppo; Knapen, Johan H.; Muñoz-Mateos, Juan-Carlos; Kim, Taehyun; Comerón, Sébastien; Martig, Marie; Holwerda, Benne W.; Athanassoula, E.; Bosma, Albert; Johansson, Peter H.; Erroz-Ferrer, Santiago; Gadotti, Dimitri A.; Gil de Paz, Armando; Hinz, Joannah; Laine, Jarkko; Laurikainen, Eija; Menéndez-Delmestre, Karín; Mizusawa, Trisha; Regan, Michael W.; Salo, Heikki; Sheth, Kartik; Seibert, Mark; Buta, Ronald J.; Cisternas, Mauricio; Elmegreen, Bruce G.; Elmegreen, Debra M.; Ho, Luis C.; Madore, Barry F.; Zaritsky, Dennis

    2014-11-01

    We present a catalogue and images of visually detected features, such as asymmetries, extensions, warps, shells, tidal tails, polar rings, and obvious signs of mergers or interactions, in the faint outer regions (at and outside of R25) of nearby galaxies. This catalogue can be used in future quantitative studies that examine galaxy evolution due to internal and external factors. We are able to reliably detect outer region features down to a brightness level of 0.03 MJy sr-1 pixel-1 at 3.6 μm in the Spitzer Survey of Stellar Structure in Galaxies (S4G). We also tabulate companion galaxies. We find asymmetries in the outer isophotes in 22 ± 1 per cent of the sample. The asymmetry fraction does not correlate with galaxy classification as an interacting galaxy or merger remnant, or with the presence of companions. We also compare the detected features to similar features in galaxies taken from cosmological zoom re-simulations. The simulated images have a higher fraction (33 per cent) of outer disc asymmetries, which may be due to selection effects and an uncertain star formation threshold in the models. The asymmetries may have either an internal (e.g. lopsidedness due to dark halo asymmetry) or external origin.

  9. The COSMOS-WIRCam Near-Infrared Imaging Survey. I. BzK-Selected Passive and Star-Forming Galaxy Candidates at z gsim 1.4

    NASA Astrophysics Data System (ADS)

    McCracken, H. J.; Capak, P.; Salvato, M.; Aussel, H.; Thompson, D.; Daddi, E.; Sanders, D. B.; Kneib, J.-P.; Willott, C. J.; Mancini, C.; Renzini, A.; Cook, R.; Le Fèvre, O.; Ilbert, O.; Kartaltepe, J.; Koekemoer, A. M.; Mellier, Y.; Murayama, T.; Scoville, N. Z.; Shioya, Y.; Tanaguchi, Y.

    2010-01-01

    We present a new near-infrared survey covering the 2 deg2 COSMOS field conducted using WIRCam at the Canada-France-Hawaii Telescope. By combining our near-infrared data with Subaru B and z images, we construct a deep, wide-field optical-infrared catalog. At K s < 23 (AB magnitudes), our survey completeness is greater than 90% and 70% for stars and galaxies, respectively, and contains 143,466 galaxies and 13,254 stars. Using the BzK diagram, we divide our galaxy catalog into quiescent and star-forming galaxy candidates. At z ~ 2, our catalogs contain 3931 quiescent and 25,757 star-forming galaxies representing the largest and most secure sample at these depths and redshifts to date. Our counts of quiescent galaxies turns over at K s ~ 22, an effect that we demonstrate cannot be due to sample incompleteness. Both the number of faint and bright quiescent objects in our catalogs exceed the predictions of a recent semi-analytic model of galaxy formation, indicating potentially the need for further refinements in the amount of merging and active galactic nucleus feedback at z ~ 2 in these models. We measure the angular correlation function for each sample and find that the slope of the field galaxy correlation function flattens to 1.5 by K s ~ 23. At small angular scales, the angular correlation function for passive BzK galaxies is considerably in excess of the clustering of dark matter. We use precise 30-band photometric redshifts to derive the spatial correlation length and the redshift distributions for each object class. At K s < 22, we find r γ/1.8 0 = 7.0 ± 0.5h -1 Mpc for the passive BzK candidates and 4.7 ± 0.8 h -1 Mpc for the star-forming BzK galaxies. Our pBzK galaxies have an average photometric redshift of zp ~ 1.4, in approximate agreement with the limited spectroscopic information currently available. The stacked K s image will be made publicly available from IRSA. Based on data collected at the Subaru Telescope, which is operated by the National

  10. RECONSTRUCTING THE NEAR-INFRARED BACKGROUND FLUCTUATIONS FROM KNOWN GALAXY POPULATIONS USING MULTIBAND MEASUREMENTS OF LUMINOSITY FUNCTIONS

    SciTech Connect

    Helgason, Kari; Ricotti, Massimo; Kashlinsky, Alexander

    2012-06-20

    We model fluctuations in the cosmic infrared background (CIB) arising from known galaxy populations using 233 measured UV, optical, and near-IR luminosity functions (LFs) from a variety of surveys spanning a wide range of redshifts. We compare best-fit Schechter parameters across the literature and find clear indication of evolution with redshift. Providing fitting formulae for the multi-band evolution of the LFs out to z {approx} 5, we calculate the total emission redshifted into the near-IR bands in the observer frame and recover the observed optical and near-IR galaxy counts to good accuracy. Our empirical approach, in conjunction with a halo model describing the clustering of galaxies, allows us to compute the fluctuations of the unresolved CIB and compare the models to current measurements. We find that fluctuations from known galaxy populations are unable to account for the large-scale CIB clustering signal seen by Spitzer/IRAC and AKARI/IRC and continue to diverge out to larger angular scales. This holds true even if the LFs are extrapolated out to faint magnitudes with a steep faint-end slope all the way to z = 8. We also show that removing resolved sources to progressively fainter magnitude limits isolates CIB fluctuations to increasingly higher redshifts. Our empirical approach suggests that known galaxy populations are not responsible for the bulk of the fluctuation signal seen in the measurements and favors a very faint population of highly clustered sources.

  11. The optical and near-infrared distribution of light in the edge-on galaxy IC 2531

    NASA Technical Reports Server (NTRS)

    Wainscoat, R. J.; Freeman, K. C.; Hyland, A. R.

    1989-01-01

    Optical and near-IR imaging of the edge-on galaxy IC 2531 is presented, and an attempt is made to derive the true distributions of stars and dust in this galaxy. The results suggest that the z dependence of the light distribution is better fitted by an exponential than by the isothermal sech-squared distribution. The dynamical implication of such a distribution is that the vertical velocity dispersion near the galactic plane should increase with z. A simple model for the light and dust distribution in IC 2531 employing three exponential components is constructed: an old disk, a young disk, and dust. Vertical scale heights of h(zd) = h(z)/4 and h(zy) = h(z)/8 and an absorption equivalent to about half of that in the Galaxy are found to produce the best fits.

  12. Faint Submillimeter Galaxies Identified through Their Optical/Near-infrared Colors. I. Spatial Clustering and Halo Masses

    NASA Astrophysics Data System (ADS)

    Chen, Chian-Chou; Smail, Ian; Swinbank, A. M.; Simpson, James M.; Almaini, Omar; Conselice, Christopher J.; Hartley, Will G.; Mortlock, Alice; Simpson, Chris; Wilkinson, Aaron

    2016-11-01

    The properties of submillimeter galaxies (SMGs) that are fainter than the confusion limit of blank-field single-dish surveys ({S}850 ≲ 2 mJy) are poorly constrained. Using a newly developed color selection technique, Optical-Infrared Triple Color (OIRTC), that has been shown to successfully select such faint SMGs, we identify a sample of 2938 OIRTC-selected galaxies, dubbed Triple Color Galaxies (TCGs), in the UKIDSS-UDS field. We show that these galaxies have a median 850 μm flux of {S}850=0.96+/- 0.04 mJy (equivalent to a star formation rate SFR ˜ 60{--}100 {M}⊙ yr-1 based on spectral energy distribution fitting), representing the first large sample of faint SMGs that bridges the gap between bright SMGs and normal star-forming galaxies in S 850 and L IR. We assess the basic properties of TCGs and their relationship with other galaxy populations at z˜ 2. We measure the two-point autocorrelation function for this population and derive a typical halo mass of log10({M}{halo}) = {12.9}-0.3+0.2, {12.7}-0.2+0.1, and {12.9}-0.3+0.2 {h}-1 {M}⊙ at z=1{--}2, 2-3, and 3-5, respectively. Together with the bright SMGs ({S}850≳ 2 mJy) and a comparison sample of less far-infrared luminous star-forming galaxies, we find a lack of dependence between spatial clustering and S 850 (or SFR), suggesting that the difference between these populations may lie in their local galactic environment. Lastly, on the scale of ˜ 8{--}17 {kpc} at 1\\lt z\\lt 5 we find a tentative enhancement of the clustering of TCGs over the comparison star-forming galaxies, suggesting that some faint SMGs are physically associated pairs, perhaps reflecting a merging origin in their triggering.

  13. Hot molecular hydrogen in the central parsec of the Galaxy through near-infrared 3D fitting

    NASA Astrophysics Data System (ADS)

    Ciurlo, A.; Paumard, T.; Rouan, D.; Clénet, Y.

    2016-10-01

    Aims: We have investigated neutral gas in the central cavity of the circumnuclear disk (CND) at the Galactic center, where the ionized minispiral lies, to describe the H2 distribution and properties in this ionized environment. Methods: This study was carried out through a spectro-imaging data cube of the central cavity obtained with SPIFFI on the VLT. The observed field of view is 36″ × 29″, with a spectral resolution R = 1300 in the near-infrared. These observations cover several H2 lines. To preserve the spatial resolution and avoid edge effects, we applied a new line-fitting method that consists of a regularized 3D fitting. We also applied a more classical 1D fitting to compare the relative strength of the H2 lines. Results: We present high spatial and spectral resolution maps of the intensity, velocity, and width of five H2 lines and an extinction map derived from H2. Molecular gas is detected everywhere in the field. In particular, in addition to the known CND features, we detected an emission from the northern arm cloud and from the minicavity. The excitation diagrams allow us to estimate the temperature, mass, and density of these features. Conclusions: We interpret the CND emission as coming from a hot, thermalized, thin layer at the surface of the clouds. The observed H2 corresponds only to a small fraction of the total H2 mass. The emission remains fairly strong in the whole central cavity, but it is not thermalized. A strong deviation from thermal equilibrium is detected near the minicavity. We suggest that this emission is caused by constantly forming H2 that is destroyed again before it reaches ortho/para equilibrium.

  14. Detection and measurement of the Wing-Ford band in the near-infrared spectra of elliptical galaxies

    NASA Astrophysics Data System (ADS)

    Hardy, Edouardo; Couture, Jean

    1988-02-01

    An absorption feature was detected at the location of the Wing-Ford band near 9916 A in high-quality CCD spectra of five elliptical galaxies taken with the Cerro Tololo 4-m RC spectrograph. Measurements reveal that the mean strength is 0.013 mag (1 sigma of the mean) and individual galaxy strengths have 1 sigma errors of the order 0.002 mag. The (3-4) band of the delta system of TiO with band head at 9986 A was also detected, suggesting that the observed Wing-Ford feature is affected by the (2-3) band of the delta system of TiO at 9899 A which is present in late giants. Therefore, this feature is not due exclusively to the FeH molecule strong in late M dwarfs.

  15. Near Infrared Observations of a Redshift 5.34 Galaxy: Further Evidence for Significant Dust Absorption in the Early Universe

    NASA Technical Reports Server (NTRS)

    Armus, L.; Matthews, K.; Neugebauer, G.; Soifer, B. T.

    1998-01-01

    In the last several years, the combination of new wavelength dropout discovery techniques coupled with the incredible power of deep imaging of the Hubble Space Telescope and the spectroscopic capabilities of a new generation of large ground-based telescopes, has lead to an astonishing blossoming of the study of galaxies at redshifts of z=2-4, when the Universe was less than 10-20% of its current age.

  16. The host galaxies and explosion sites of long-duration gamma ray bursts: Hubble Space Telescope near-infrared imaging

    NASA Astrophysics Data System (ADS)

    Lyman, J. D.; Levan, A. J.; Tanvir, N. R.; Fynbo, J. P. U.; McGuire, J. T. W.; Perley, D. A.; Angus, C. R.; Bloom, J. S.; Conselice, C. J.; Fruchter, > A. S.; Hjorth, J.; Jakobsson, P.; Starling, R. L. C.

    2017-01-01

    We present the results of a Hubble Space Telescope WFC3/F160W SNAPSHOT survey of the host galaxies of 39 long-duration gamma-ray bursts (LGRBs) at z < 3. We have non-detections of hosts at the locations of 4 bursts. Sufficient accuracy to astrometrically align optical afterglow images and determine the location of the LGRB within its host was possible for 31/35 detected hosts. In agreement with other work, we find the luminosity distribution of LGRB hosts is significantly fainter than that of a star formation rate-weighted field galaxy sample over the same redshift range, indicating LGRBs are not unbiasedly tracing the star formation rate. Morphologically, the sample of LGRB hosts are dominated by spiral-like or irregular galaxies. We find evidence for evolution of the population of LGRB hosts towards lower-luminosity, higher concentrated hosts at lower redshifts. Their half-light radii are consistent with other LGRB host samples where measurements were made on rest-frame UV observations. In agreement with recent work, we find their 80 per cent enclosed flux radii distribution to be more extended than previously thought, making them intermediate between core-collapse supernova (CCSN) and super-luminous supernova (SLSN) hosts. The galactocentric projected-offset distribution confirms LGRBs as centrally concentrated, much more so than CCSNe and similar to SLSNe. LGRBs are strongly biased towards the brighter regions in their host light distributions, regardless of their offset. We find a correlation between the luminosity of the LGRB explosion site and the intrinsic column density, NH, towards the burst.

  17. AN ALMA SURVEY OF SUBMILLIMETER GALAXIES IN THE EXTENDED CHANDRA DEEP FIELD SOUTH: NEAR-INFRARED MORPHOLOGIES AND STELLAR SIZES

    SciTech Connect

    Chen, Chian-Chou; Smail, Ian; Swinbank, A. M.; Simpson, J. M.; Ma, Cheng-Jiun; Alexander, D. M.; Danielson, A. L. R.; Edge, A. C.; Biggs, A. D.; Ivison, R. J.; Brandt, W. N.; Chapman, S. C.; Coppin, K. E. K.; Dannerbauer, H.; Greve, T. R.; Karim, A.; Menten, Karl M.; Schinnerer, E.; Walter, F.; Wardlow, J. L.; and others

    2015-02-01

    We analyze Hubble Space Telescope WFC3/H {sub 160}-band observations of a sample of 48 Atacama Large Millimeter/submillimeter Array detected submillimeter galaxies (SMGs) in the Extended Chandra Deep Field South field, to study their stellar morphologies and sizes. We detect 79% ± 17% of the SMGs in the H {sub 160}-band imaging with a median sensitivity of 27.8 mag, and most (80%) of the nondetections are SMGs with 870 μm fluxes of S {sub 870} < 3 mJy. With a surface brightness limit of μ {sub H} ∼ 26 mag arcsec{sup –2}, we find that 82% ± 9% of the H {sub 160}-band-detected SMGs at z = 1-3 appear to have disturbed morphologies, meaning they are visually classified as either irregulars or interacting systems, or both. By determining a Sérsic fit to the H {sub 160} surface brightness profiles, we derive a median Sérsic index of n = 1.2 ± 0.3 and a median half-light radius of r{sub e} = 4.4{sub −0.5}{sup +1.1} kpc for our SMGs at z = 1-3. We also find significant displacements between the positions of the H {sub 160} component and 870 μm emission in these systems, suggesting that the dusty starburst regions and less-obscured stellar distribution are not colocated. We find significant differences in the sizes and the Sérsic index between our z = 2-3 SMGs and z ∼ 2 quiescent galaxies, suggesting that a major transformation of the stellar light profile is needed in the quenching processes if SMGs are progenitors of the red-and-dead z ∼ 2 galaxies. Given the short-lived nature of SMGs, we postulate that the majority of the z = 2-3 SMGs with S {sub 870} ≳ 2 mJy are early/mid-stage major mergers.

  18. Near-infrared to near-infrared upconverting NaYF4:Yb3+,Tm3+ nanoparticles-aptamer-Au nanorods light resonance energy transfer system for the detection of mercuric(II) ions in solution.

    PubMed

    Chen, Hong-Qi; Yuan, Fei; Wang, Shao-Zhen; Xu, Juan; Zhang, Yi-Yan; Wang, Lun

    2013-04-21

    A new luminescence resonant energy transfer (LRET) system has been designed that utilizes near-infrared (NIR)-to-NIR upconversion lanthanide nanophosphors (UCNPs) as the donor, and Au nanorods (Au NRs) as the acceptor. The UCNPs were excited by a near-infrared (980 nm) wavelength and also emitted at a near-infrared wavelength (804 nm) using an inexpensive infrared continuous wave laser diode. The Au NRs showed a high absorption band around 806 nm, which provided large spectral overlap between the donor and the acceptor. Hg(2+) ions were added to an aqueous solution containing the UCNPs and Au NRs that were modified with a Hg(2+) aptamer. Then, a sandwich-type LRET system was developed for the detection of Hg(2+) ions that had high sensitivity and selectivity in the NIR region. The method was successfully applied to the sensing of Hg(2+) ions in water and human serum samples.

  19. High-Resolution Near-Infrared Spectroscopy of an Equivalent Width-Selected Sample of Starbursting Dwarf Galaxies

    NASA Technical Reports Server (NTRS)

    Maseda, Michael V.; VanDerWeL, Arjen; DaChuna, Elisabete; Rix, Hans-Walter; Pacafichi, Camilla; Momcheva, Ivelina; Brammer, Gabriel B.; Franx, Marijn; VanDokkum, Pieter; Bell, Eric F.; Ferguson, Harry C.; Fumagalli, Mattia; Grogin, Norman A.; Kocevski, Dale D.; Koekemoer, Anton M.; Lundgren, Britt F.; Marchesini, Danilo; Nelson, Erica J.; Patel, Shannon; Skelton, Rosalind E.; Straughn, Amber N.; Trump, Jonathan R.; Weiner, Benjamin J.; Whitaker, Katherine E.; Wuyts, Stijn

    2013-01-01

    Spectroscopic observations from the Large Binocular Telescope and the Very Large Telescope reveal kinematically narrow lines (approx. 50 km/s) for a sample of 14 Extreme Emission Line Galaxies (EELGs) at redshifts 1.4 < zeta < 2.3. These measurements imply that the total dynamical masses of these systems are low ( 3 × 10(exp 9) M). Their large [O III]5007 equivalent widths (500 - 1100 A) and faint blue continuum emission imply young ages of 10-100 Myr and stellar masses of 10(exp 8)-10(exp 9) M, confirming the presence of a violent starburst. The stellar mass formed in this vigorous starburst phase thus represents a large fraction of the total (dynamical) mass, without a significantly massive underlying population of older stars. The occurrence of such intense events in shallow potentials strongly suggests that supernova-driven winds must be of critical importance in the subsequent evolution of these systems.

  20. K'-band observations of the evil eye galaxy: Are the optical and near-infrared dust albedos identical?

    NASA Technical Reports Server (NTRS)

    Witt, Adolf N.; Lindell, Rebecca S.; Block, David L.; Evans, Rhodri

    1994-01-01

    New measurements of the reduction of the V-band surface brightness across the prominent dust feature in the galaxy NGC 4826 are compared with corresponding increases in the V-K' color within the context of radiative transfer models invoking both absorption and scattering. The K'-band surface brightness is found to be higher than expected from standard dust models. We interpret the difference as resulting from a high effective dust albedo at K', with a likely value in excess of 0.8, provided the near-IR extinction curve in NGC 4826 is identical to the Galactic one. The high effective albedo may result from scattering by dust with a maximum grain size at least twice as large as assumed by standard models, a conclusion already indirectly hinted at by recent studies of dust star-forming regions and reflection nebulae. At least part of the high effective albedo at K' may result from near-IR nonequilibrium continuum emission attributable to very small grains.

  1. A search for Low Surface Brightness galaxies in the near-infrared. III. Nançay H I line observations

    NASA Astrophysics Data System (ADS)

    Monnier Ragaigne, D.; van Driel, W.; Schneider, S. E.; Balkowski, C.; Jarrett, T. H.

    2003-09-01

    A total of 334 Low Surface Brightness galaxies detected in the 2MASS all-sky near-infrared survey have been observed in the 21 cm H I line using the Nançay telescope. All have a Ks-band mean central surface brightness, measured within a 5'' radius, fainter than 18 mag arcsec-2 and a Ks-band isophotal radius at the 20 mag arcsec-2 level larger than 20''. We present global H I line parameters for the 171 clearly detected objects and the 23 marginal detections, as well as upper limits for the undetected objects. The 171 clear detections comprise 50 previously uncatalogued objects and 41 objects with a PGC entry only. Tables 3-5 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/408/465 Figures 1 and 2 are only available in electronic form at http://www.edpsciences.org

  2. NEAR-INFRARED SURVEY OF THE GOODS-NORTH FIELD: SEARCH FOR LUMINOUS GALAXY CANDIDATES AT z {approx}> 6.5 {sup ,}

    SciTech Connect

    Hathi, Nimish P.; Mobasher, Bahram; Capak, Peter; Wang, Wei-Hao; Ferguson, Henry C.

    2012-09-20

    We present near-infrared (NIR; J and K{sub s}) survey of the Great Observatories Origins Deep Survey-North (GOODS-N) field. The publicly available imaging data were obtained using the MOIRCS instrument on the 8.2 m Subaru and the WIRCam instrument on the 3.6 m Canada-France-Hawaii Telescope (CFHT). These observations fulfill a serious wavelength gap in the GOODS-N data, i.e., lack of deep NIR observations. We combine the Subaru/MOIRCS and CFHT/WIRCam archival data to generate deep J- and K{sub s}-band images, covering the full GOODS-N field ({approx}169 arcmin{sup 2}) to an AB magnitude limit of {approx}25 mag (3{sigma}). We applied z{sub 850}-band dropout color selection criteria, using the NIR data generated here. We have identified two possible Lyman break galaxy (LBG) candidates at z {approx}> 6.5 with J {approx}< 24.5. The first candidate is a likely LBG at z {approx_equal} 6.5 based on a weak spectral feature tentatively identified as Ly{alpha} line in the deep Keck/DEIMOS spectrum, while the second candidate is a possible LBG at z {approx_equal} 7 based on its photometric redshift. These z{sub 850}-dropout objects, if confirmed, are among the brightest such candidates found so far. At z {approx}> 6.5, their star formation rate is estimated as 100-200 M{sub Sun} yr{sup -1}. If they continue to form stars at this rate, they assemble a stellar mass of {approx}5 Multiplication-Sign 10{sup 10} M{sub Sun} after about 400 million years, becoming the progenitors of massive galaxies observed at z {approx_equal} 5. We study the implication of the z{sub 850}-band dropout candidates discovered here, in constraining the bright end of the luminosity function and understanding the nature of high-redshift galaxies.

  3. Near-Infrared Faint Galaxies in the Subaru Deep Field: Comparing the Theory with Observations for Galaxy Counts, Colors, and Size Distributions to K ~ 24.5

    NASA Astrophysics Data System (ADS)

    Totani, Tomonori; Yoshii, Yuzuru; Maihara, Toshinori; Iwamuro, Fumihide; Motohara, Kentaro

    2001-10-01

    Galaxy counts in the K band, (J-K) colors, and apparent size distributions of faint galaxies in the Subaru Deep Field (SDF) down to K~24.5 were studied in detail. Special attention has been paid to take into account various selection effects, including the cosmological dimming of surface brightness, to avoid any systematic bias that may be the origin of controversy in previously published results. We also tried to be very careful about systematic model uncertainties; we present a comprehensive survey of these systematic uncertainties and dependence on various parameters, and we have shown that the dominant factors to determine galaxy counts in this band are cosmology and number evolution. We found that the pure luminosity evolution (PLE) model is very consistent with all the SDF data down to K~22.5, without any evidence for number or size evolution in a low-density, Λ-dominated flat universe, which is now favored by various cosmological observations. On the other hand, a number evolution of galaxies with η~2, when invoked as the luminosity conserving mergers as φ*~(1+z)η and L*~(1+z)-η for all types of galaxies, is necessary to explain the data in the Einstein-de Sitter universe. If the popular Λ-dominated universe is taken for granted, our result then gives a strong constraint on the number evolution of giant elliptical or early-type galaxies to z~1-2 that must be met by any models in the hierarchically clustering universe, since such galaxies are the dominant population in this magnitude range (K<~22.5). A number evolution with η~1 is already difficult to reconcile with the data in this universe. On the other hand, number evolution of late-type galaxies and/or dwarf galaxies, which has been suggested by previous studies of optical galaxies, is allowed from the data. In the fainter magnitude range of K>~22.5, we found a slight excess of observed counts over the prediction of the PLE model when elliptical galaxies are treated as a single population. We

  4. Near-infrared spectroscopy of 3:1 Kirkwood Gap asteroids II: Probable and plausible parent bodies; primitive and differentiated

    NASA Astrophysics Data System (ADS)

    Fieber-Beyer, Sherry K.; Gaffey, Michael J.

    2014-02-01

    The 3:1 Kirkwood Gap asteroids are a mineralogically diverse set of asteroids located in a region that delivers meteoroids into Earth-crossing orbits. Mineralogical characterizations of asteroids in/near the 3:1 Kirkwood Gap can be used as a tool to “map” conditions and processes in the early Solar System. The chronological studies of the meteorite types provide a “clock” for the relative timing of those events and processes. By identifying the source asteroids of particular meteorite types, the “map” and “clock” can be combined to provide a much more sophisticated understanding of the history and evolution of the late solar nebula and the early Solar System. A mineralogical assessment of twelve 3:1 Kirkwood Gap asteroids has been carried out using near-infrared spectral data obtained from 2010 to 2011 combined with visible spectral data (when available) to cover the spectral interval of 0.4-2.5 μm. Eight of these asteroids have surfaces with basaltic-type silicate assemblages, indicating at least partial melting within their parent bodies. Although HED-like mineralogies are present these objects exhibit subdued features indicating the presence of an additional phase (e.g., NiFe metal) or process (e.g., space weathering). Four of these asteroids appear to be ordinary chondrite assemblages. Three of these are plausibly linked to the probable H-chondrite parent body, (6) Hebe.

  5. Near-infrared spectroscopic monitoring of the diffusion process of deuterium-labeled molecules in wood. Part II: hardwood.

    PubMed

    Tsuchikawa, Satoru; Siesler, H W

    2003-06-01

    Fourier transform near-infrared (FT-NIR) transmission spectroscopy was applied to monitor the diffusion process of deuterium-labeled molecules in hardwood (Beech). The results are compared with previous data obtained on softwood (Sitka spruce) in order to consistently understand the state of order in cellulose of wood. The saturation accessibility and diffusion rate varied characteristically with the OH groups in different states of order in the wood substance, the diffusants, and the wood species, respectively. The variation of saturation accessibility should be associated with the fundamental difference of the fine structure such as the microfibrils in the wood substance. The effect of the anatomical cellular structure on the accessibility was reflected in the variation of the diffusion rate with the wood species. The size effect of the diffusants also played an important role for the diffusion process in wood. Since the volumetric percentage of wood fibers and wood rays is relatively similar, the dichroic effects due to the anisotropy of the cellulose chains were apparently diminished. Finally, we proposed a new interpretation of the fine structure of the microfibrils in the cell wall by comparing a series of results from hardwood and softwood. Each elementary fibril in the hardwood has a more homogeneous arrangement in the microfibrils compared to that in the softwood.

  6. Near-infrared absorbing and emitting Ru(II)-Pt(II) heterodimetallic complexes of dpdpz (dpdpz = 2,3-di(2-pyridyl)-5,6-diphenylpyrazine).

    PubMed

    Wu, Si-Hai; Burkhardt, Stephen E; Yao, Jiannian; Zhong, Yu-Wu; Abruña, Héctor D

    2011-05-02

    The reaction of 2,3-di(2-pyridyl)-5,6-diphenylpyrazine (dpdpz) with K(2)PtCl(4) in a mixture of acetonitrile and water afforded mono-Pt complex (dpdpz)PtCl(2)4 in good yield, with two lateral pyridine nitrogen atoms binding to the metal center. Two types of Ru(II)-Pt(II) heterodimetallic complexes bridged by dpdpz, namely, [(bpy)(2)Ru(dpdpz)Pt(C≡CC(6)H(4)R)](2+) (7-9, R = H, NMe(2), or Cl, respectively) and [(tpy)Ru(dpdpz)Pt(C≡CPh)] (+) (12), were then designed and prepared, where bpy = 2,2'-bipyridine and tpy = 2,2';6',2''-terpyridine. In both cases, the platinum atom binds to dpdpz with a C(∧)N(∧)N tridentate mode. However, the coordination of the ruthenium atom with dpdpz could either be noncyclometalated (N(∧)N bidentate) or cyclometalated (C(∧)N(∧)N tridentate). The electronic properties of these complexes were subsequently studied and compared by spectroscopic and electrochemical analyses and theoretical calculations. These complexes exhibit substantial absorption in the visible to NIR (near-infrared) region because of mixed MLCT (metal-to-ligand-charge-tranfer) transitions from both the ruthenium and the platinum centers. Complexes 7 and 9 were found to emit NIR light with higher quantum yields than those of the mono-Ru complex [(bpy)(2)Ru(dpdpz)](2+) (5) and bis-Ru complex [(bpy)(2)Ru(dpdpz)Ru(bpy)(2)](4+) (13). However, no emission was detected from complex 8 or 12 at room temperature in acetonitrile.

  7. Novel calibrations of virial black hole mass estimators in active galaxies based on X-ray luminosity and optical/near-infrared emission lines

    NASA Astrophysics Data System (ADS)

    Ricci, F.; La Franca, F.; Onori, F.; Bianchi, S.

    2017-02-01

    Context. It is currently only possible to accurately weigh, through reverberation mapping (RM), the masses of super massive black holes (BHs) in active galactic nuclei (AGN) for a small group of local and bright broad line AGN. Statistical demographic studies can be carried out considering the empirical scaling relation between the size of the broad line region (BLR) and the AGN optical continuum luminosity. There are still biases, however, against low-luminosity or reddened AGN, in which the rest-frame optical radiation can be severely absorbed or diluted by the host galaxy and the BLR emission lines can be hard to detect. Aims: Our purpose is to widen the applicability of virial-based single-epoch (SE) relations to measure reliably the BH masses for low-luminosity or intermediate and type 2 AGN, which the current methodology misses. We achieve this goal by calibrating virial relations based on unbiased quantities: the hard X-ray luminosities in the 2-10 keV and 14-195 keV bands that are less sensitive to galaxy contamination, and the full width at half maximum (FWHM) of the most important rest-frame near-infrared (NIR) and optical BLR emission lines. Methods: We built a sample of RM AGN with both X-ray luminosity, broad optical and NIR FWHM measurements available to calibrate new virial BH mass estimators. Results: We found that the FWHM of the Hα, Hβ, and NIR lines (i.e. Paα, Paβ, and He iλ10830) all correlate with each other with negligible or small offsets. This result allowed us to derive virial BH mass estimators based on either the 2-10 keV or 14-195 keV luminosity. We also took into account the recent determination of the different virial coefficients, f, for pseudo- and classical bulges. By splitting the sample according to the bulge type and adopting separate f factors, we found that our virial relations predict BH masses of AGN hosted in pseudo-bulges 0.5 dex smaller than in classical bulges. Assuming the same average f factor for both populations

  8. Near-Infrared Properties of Moderate-Redshift Galaxy Clusters: Halo Occupation Number, Mass-to-Light Ratios and Omega(M)

    SciTech Connect

    Muzzin, Adam; Yee, H.K.C.; Hall, Patrick B.; Lin, Huan; /Fermilab

    2007-03-01

    Using K-band imaging for 15 of the Canadian Network for Observational Cosmology (CNOC1) clusters we examine the near-infrared properties of moderate-redshift (0.19 < z < 0.55) galaxy clusters. We find that the number of K-band selected cluster galaxies within R{sub 500} (the Halo Occupation Number, HON) is well-correlated with the cluster dynamical mass (M{sub 500}) and X-ray Temperature (T{sub x}); however, the intrinsic scatter in these scaling relations is 37% and 46% respectively. Comparison with clusters in the local universe shows that the HON-M{sub 500} relation does not evolve significantly between z = 0 and z {approx} 0.3. This suggests that if dark matter halos are disrupted or undergo significant tidal-stripping in high-density regions as seen in numerical simulations, the stellar mass within the halos is tightly bound, and not removed during the process. The total K-band cluster light (L{sub 200},K) and K-band selected richness (parameterized by B{sub gc,K}) are also correlated with both the cluster T{sub x} and M{sub 200}. The total (intrinsic) scatter in the L{sub 200,K}-M{sub 200} and B{sub gc,K}-M{sub 200} relations are 43%(31%) and 35%(18%) respectively and indicates that for massive clusters both L{sub 200,K} and B{sub gc,K} can predict M{sub 200} with similar accuracy as T{sub x}, L{sub x} or optical richness (B{sub gc}). Examination of the mass-to-light ratios of the clusters shows that similar to local clusters, the K-band mass-to-light ratio is an increasing function of halo mass. Using the K-band mass-to-light ratios of the clusters, we apply the Oort technique and find {Omega}{sub m,0} = 0.22 {+-} 0.02, which agrees well with recent combined concordance cosmology parameters, but, similar to previous cluster studies, is on the low-density end of preferred values.

  9. The gas-rich circumbinary disk of HR 4049. II. A detailed study of the near-infrared spectrum

    SciTech Connect

    Malek, S. E.; Cami, J. E-mail: jcami@uwo.ca

    2014-10-20

    HR 4049 is a peculiar evolved binary surrounded by a circumbinary disk. Mid-infrared observations show that the disk is rich in molecular gas and radially extended. To study the properties of this disk, we re-analyzed a set of near-infrared observations at high spectral resolution obtained with Gemini-Phoenix. These data cover absorption lines originating from the first overtone of CO and from H{sub 2}O in the 2.3 μm region as well as more complex emission-absorption profiles from H{sub 2}O and the fundamental mode of CO near 4.6 μm. By using an excitation diagram and from modeling the spectrum, we find that most of the CO overtone and H{sub 2}O absorption originates from hot gas (T {sub ex} ≈ 1000 K) with high column densities, consistent with the mid-infrared data. The strong emission in the wavelength range of the CO fundamental furthermore suggests that there is a significant quantity of gas in the inner cavity of the disk. In addition, there is a much colder component in the line of sight to the disk. A detailed analysis of the overtone line profiles reveals variations in the line widths that are consistent with a radially extended disk in Keplerian rotation with hotter gas closer to the central star. We estimate the mass of the primary to be ∼0.34 M {sub ☉} and discuss the implications for its evolutionary status.

  10. GROUND-BASED, NEAR-INFRARED EXOSPECTROSCOPY. II. TENTATIVE DETECTION OF EMISSION FROM THE EXTREMELY HOT JUPITER WASP-12b

    SciTech Connect

    Crossfield, Ian J. M.; Hansen, Brad M. S.; Barman, Travis

    2012-02-10

    We report the tentative detection of the near-infrared emission of the hot Jupiter WASP-12b with the low-resolution prism on Infrared Telescope Facility/SpeX. We find a K - H contrast color of 0.137% {+-} 0.054%, corresponding to a blackbody of temperature 2400{sup +1500}{sub -500} K and consistent with previous, photometric observations. We also revisit WASP-12b's energy budget on the basis of secondary eclipse observations: the dayside luminosity is a relatively poorly constrained (2.0-4.3) Multiplication-Sign 10{sup 30} erg s{sup -1}, but this still allows us to predict a day/night effective temperature contrast of 200-1000 K (assuming A{sub B} = 0). Thus, we conclude that WASP-12b probably does not have both a low albedo and low recirculation efficiency. Our results show the promise and pitfalls of using single-slit spectrographs for characterization of extrasolar planet atmospheres, and we suggest future observing techniques and instruments which could lead to further progress. Limiting systematic effects include the use of too narrow a slit on one night-which observers could avoid in the future-and chromatic slit losses (resulting from the variable size of the seeing disk) and variations in telluric transparency-which observers cannot control. Single-slit observations of the type we present remain the best option for obtaining {lambda} > 1.7 {mu}m spectra of transiting exoplanets in the brightest systems. Further and more precise spectroscopy is needed to better understand the atmospheric chemistry, structure, and energetics of this, and other, intensely irradiated planet.

  11. Investigating the Near-Infrared Properties of Planetary Nebulae II. Medium Resolution Spectra. 2; Medium Resolution Spectra

    NASA Technical Reports Server (NTRS)

    Hora, Joseph L.; Latter, William B.; Deutsch, Lynne K.

    1998-01-01

    We present medium-resolution (R approximately 700) near-infrared (lambda = 1 - 2.5 micrometers) spectra of a sample of planetary nebulae (PNe). A narrow slit was used which sampled discrete locations within the nebulae; observations were obtained at one or more positions in the 41 objects included in the survey. The PN spectra fall into one of four general categories: H1 emission line-dominated PNe, H1 and H2 emission line PNe, H2 emission line-dominated PNe, and continuum-dominated PNe. These categories correlate with morphological type, with the elliptical PNe falling into the first group, and the bipolar PNe primarily in the H2 and continuum emission groups. The categories also correlate with C/O ratio, with the O-rich objects falling into the first group and the C-rich objects in the groups. Other spectral features were observed in all catagories, such as continuum emission from the central star, and warm dust continuum emission towards the long wavelength end of the spectra. H2 was detected in four PNe in this survey for the first time. An analysis was performed using the H2 line ratios in all of the PN spectra in the survey where a sufficient number of lines were observed to determine the ortho-to-para ratio and the rotational and vibrational excitation temperatures of the H-2 in those objects. One unexpected result from this analysis is that the H-2 is excited by absorption of ultraviolet photons in most of the PNe, although there are several PNe in which collisional excitation plays an important role. The correlation between bipolar morphology and H2 emission has been strengthened with the new detections of H2 in this survey.

  12. Spectrum of excess partial molar absorptivity. Part II: a near infrared spectroscopic study of aqueous Na-halides.

    PubMed

    Sebe, Fumie; Nishikawa, Keiko; Koga, Yoshikata

    2012-04-07

    Our earlier thermodynamic studies suggested that F(-) and Cl(-) form hydration shells with the hydration number 14 ± 2 and 2.3 ± 0.6, respectively, and leave the bulk H(2)O away from hydration shells unperturbed. Br(-) and I(-), on the other hand, form hydrogen bonds directly with the momentarily existing hydrogen bond network of H(2)O, and retard the degree of entropy-volume cross fluctuation inherent in liquid H(2)O. The effect of the latter is stronger for I(-) than Br(-). Here we seek additional information about this qualitative difference between Cl(-) and (Br(-) and I(-)) pair by near infrared (NIR) spectroscopy. We analyze the ν(2) + ν(3) band of H(2)O in the range 4600-5500 cm(-1) of aqueous solutions of NaCl, NaBr and NaI, by a new approach. From observed absorbance, we calculate excess molar absorptivity, ε(E), excess over the additive contributions of solute and solvent. ε(E) thus contains information about the effect of inter-molecular interactions in the ν(2) + ν(3) spectrum. The spectrum of ε(E) shows three bands; two negative ones at 5263 and 4873 cm(-1), and the positive band at 5123 cm(-1). We then define and calculate the excess partial molar absorptivity of each salt, ε(E)(salt). From the behaviour of ε(E)(salt) we suggest that the negative band at 5263 cm(-1) represents free H(2)O without much hydrogen bonding under the influence of local electric field of ions. Furthermore, from a sudden change in the x(salt) (mole fraction of salt) dependence of ε(E)(salt), we suggest that there is an ion-pairing in x(salt) > 0.032, 0.036, and 0.04 for NaCl, NaBr and NaI respectively. The positive band of ε(E) at 5123 cm(-1) is attributed to a modestly organized hydrogen bond network of H(2)O (or liquid-likeness), and the x(salt) dependence of ε indicated a qualitative difference in the effect of Cl(-) from those of Br(-) and I(-). Namely, the values of ε(E)(salt) stay constant for Cl(-) but those for Br(-) and I(-) decrease smoothly on

  13. Near-infrared spectroscopy of M dwarfs. II. H2O molecule as an abundance indicator of oxygen†

    NASA Astrophysics Data System (ADS)

    Tsuji, Takashi; Nakajima, Tadashi; Takeda, Yoichi

    2015-04-01

    Based on the near-infrared spectra (R ≈ 20000) of M dwarfs, oxygen abundances are determined from the rovibrational lines of H2O. Although H2O lines in M dwarfs are badly blended with each other and the continuum levels are depressed appreciably by the collective effect of the numerous H2O lines themselves, quantitative analysis of H2O lines has been carried out by referring to the pseudo-continua, consistently defined on the observed and theoretical spectra. For this purpose, the pseudo-continuum on the theoretical spectrum has been evaluated accurately by the use of the recent high-precision H2O line-list. Then, we propose a simple and flexible method of analyzing the equivalent widths (EWs) of blended features (i.e., not necessarily limited to single lines) by the use of a mini-curve-of-growth (CG), which is a small portion of the usual CG around the observed EW. The mini-CG is generated by using the theoretical EWs evaluated from the synthetic spectrum in exactly the same way as the EWs are measured from the observed spectrum. The observed EW is converted to the abundance by the use of the mini-CG, and the process is repeated for all the observed EWs line-by-line or blend-by-blend. In cool M dwarfs, almost all the oxygen atoms left after CO formation are in stable H2O molecules, which suffer little change for the uncertainties due to imperfect modelling of the photospheres. Thus the numerous H2O lines are excellent abundance indicators of oxygen. The oxygen abundances are determined to be log AO (AO = NO/NH) between -3.5 and -3.0 in 38 M dwarfs, but cannot be determined in four early M dwarfs in which H2O lines are detected only marginally. The resulting log AO/AC values plotted against log AC appear to be systematically smaller in the carbon-rich M dwarfs, showing the different formation histories of oxygen and carbon in the chemical evolution of the Galactic disk. Also, AO/AFe ratios in most M dwarfs are closer to the solar AO/AFe ratio, based on the

  14. THE HIGH A{sub V} Quasar Survey: Reddened Quasi-Stellar Objects selected from optical/near-infrared photometry. II

    SciTech Connect

    Krogager, J.-K.; Fynbo, J. P. U.; Vestergaard, M.; Geier, S.; Venemans, B. P.; Ledoux, C.; Møller, P.; Noterdaeme, P.; Kangas, T.; Pursimo, T.; Smirnova, O.; Saturni, F. G.

    2015-03-15

    Quasi-stellar objects (QSOs) whose spectral energy distributions (SEDs) are reddened by dust either in their host galaxies or in intervening absorber galaxies are to a large degree missed by optical color selection criteria like the ones used by the Sloan Digital Sky Survey (SDSS). To overcome this bias against red QSOs, we employ a combined optical and near-infrared (near-IR) color selection. In this paper, we present a spectroscopic follow-up campaign of a sample of red candidate QSOs which were selected from the SDSS and the UKIRT Infrared Deep Sky Survey (UKIDSS). The spectroscopic data and SDSS/UKIDSS photometry are supplemented by mid-infrared photometry from the Wide-field Infrared Survey Explorer. In our sample of 159 candidates, 154 (97%) are confirmed to be QSOs. We use a statistical algorithm to identify sightlines with plausible intervening absorption systems and identify nine such cases assuming dust in the absorber similar to Large Magellanic Cloud sightlines. We find absorption systems toward 30 QSOs, 2 of which are consistent with the best-fit absorber redshift from the statistical modeling. Furthermore, we observe a broad range in SED properties of the QSOs as probed by the rest-frame 2 μm flux. We find QSOs with a strong excess as well as QSOs with a large deficit at rest-frame 2 μm relative to a QSO template. Potential solutions to these discrepancies are discussed. Overall, our study demonstrates the high efficiency of the optical/near-IR selection of red QSOs.

  15. SPIDER. IV. OPTICAL AND NEAR-INFRARED COLOR GRADIENTS IN EARLY-TYPE GALAXIES: NEW INSIGHT INTO CORRELATIONS WITH GALAXY PROPERTIES

    SciTech Connect

    La Barbera, F.; De Carvalho, R. R.; Gal, R. R.; Swindle, R.; Lopes, P. A. A.

    2010-11-15

    We present an analysis of stellar population gradients in 4546 early-type galaxies (ETGs) with photometry in grizYHJK along with optical spectroscopy. ETGs were selected as bulge-dominated systems, displaying passive spectra within the SDSS fibers. A new approach is described which utilizes color information to constrain age and metallicity gradients. Defining an effective color gradient, {nabla}{sub *}, which incorporates all of the available color indices, we investigate how {nabla}{sub *} varies with galaxy mass proxies, i.e., velocity dispersion, stellar (M{sub *}) and dynamical (M{sub dyn}) masses, as well as age, metallicity, and [{alpha}/Fe]. ETGs with M{sub dyn} larger than 8.5 x 10{sup 10} M{sub sun} have increasing age gradients and decreasing metallicity gradients with respect to mass, metallicity, and enhancement. We find that velocity dispersion and [{alpha}/Fe] are the main drivers of these correlations. ETGs with 2.5 x 10{sup 10} M{sub sun} {<=} M{sub dyn} {<=} 8.5 x 10{sup 10} M{sub sun} show no correlation of age, metallicity, and color gradients with respect to mass, although color gradients still correlate with stellar population parameters, and these correlations are independent of each other. In both mass regimes, the striking anti-correlation between color gradient and {alpha}-enhancement is significant at {approx}5{sigma} and results from the fact that metallicity gradient decreases with [{alpha}/Fe]. This anti-correlation may reflect the fact that star formation and metallicity enrichment are regulated by the interplay between the energy input from supernovae, and the temperature and pressure of the hot X-ray gas in ETGs. For all mass ranges, positive age gradients are associated with old galaxies (>5-7 Gyr). For galaxies younger than {approx}5 Gyr, mostly at low mass, the age gradient tends to be anti-correlated with the Age parameter, with more positive gradients at younger ages.

  16. Spitzer 24 Micron Observations of Optical/Near-Infrared-Selected Extremely Red Galaxies: Evidence for Assembly of Massive Galaxies at Z approximately equal to 1-2?

    NASA Technical Reports Server (NTRS)

    Yan, Lin; Choi, Philip I.; Fadda, D.; Marleau, F. R.; Soifer, B. T.; Im, M.; Armus, L.; Frayer, D. T.; Storrie-Lombardi, L. J.; Thompson, D. J.; Teplitz, H. I.; Helou, G.; Appleton, P. N.; Chapman, S.; Fan, F.; Heinrichsen, I.; Lacy, M.; Shupe, D. L.; Squires, G. K.; Surace, J.; Wilson, G.

    2004-01-01

    We carried out direct measurement of the fraction of dusty sources in a sample of extremely red galaxies with (R - Ks) >= 5.3 mag and Ks < 20:2 mag, using 24 micron data from the Spitzer Space Telescope. Combining deep 24 micron Ks- and R-band data over an area of 64 arcmin(sup 2) in ELAIS N1 of the Spitzer First Look Survey (FLS), we find that 50% +/- 6% of our extremely red object (ERO) sample have measurable 24 micron flux above the 3 (sigma) flux limit of 40 (micro)Jy. This flux limit corresponds to a star formation rate (SFR) of 12 solar masses per year 1, much more sensitive than any previous long-wavelength measurement. The 24 micron-detected EROs have 24 micron/2.2 micron and 24 micron/0.7 micron flux ratios consistent with infrared luminous, dusty sources at z >= 1, and are an order of magnitude too red to be explained by an infrared quiescent spiral or a pure old stellar population at any redshift. Some of these 24 micron-detected EROs could be active galactic nuclei; however, the fraction among the whole ERO sample is probably small, 10%-20%, as suggested by deep X-ray observations as well as optical spectroscopy. Keck optical spectroscopy of a sample of similarly selected EROs in the FLS field suggests that most of the EROs in ELAIS N1 are probably at z 1. The mean 24 micron flux (167 (micro)Jy) of the 24 micron-detected ERO sample roughly corresponds to the rest-frame 12 micron luminosity, (nu)L(nu)(12 micron, of 3x10(exp 10)(deg) solar luminosities at z 1. Using the c IRAS (nu)L(nu)(12 (micron) and infrared luminosity LIR(8-1000 (micron), we infer that the (LIR) of the 24 micron- detected EROs is 3 x 10(exp 11) and 1 x 10(exp 12) solar luminosities at z = 1.0 and similar to that of local luminous infrared galaxies (LIRGs) and ultraluminous infrared galaxies (ULIRGs). The corresponding SFR would be roughly 50-170 solar masses per year. If the timescale of this starbursting phase is on the order of 108 yr as inferred for the local LIRGs and ULIRGs, the

  17. Hydrothermal synthesis of high-quality type-II CdTe/CdSe quantum dots with near-infrared fluorescence.

    PubMed

    Wang, Jing; Han, Heyou

    2010-11-01

    A simple hydrothermal method is developed for the synthesis of high-quality, water-soluble, and near-infrared (NIR)-emitting type-II core/shell CdTe/CdSe quantum dots (QDs) by employing thiol-capped CdTe QDs as core templates and CdCl(2) and Na(2)SeO(3) as shell precursors. Compared with the original CdTe core QDs, the core/shell CdTe/CdSe QDs exhibit an obvious red-shifted emission, whose color can be tuned between visible and NIR regions (620-740 nm) by controlling the thickness of the CdSe shell. The photoluminescence quantum yield (PL QY) of CdTe/CdSe QDs with an optimized thickness of the CdSe shell can reach up to 44.2% without any post-preparative treatment. Through a thorough study of the core/shell structure by high-resolution transmission electron microscopy (HRTEM), ultraviolet-visible (UV-vis) absorption spectra, fluorescence spectra, X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), the as-prepared CdTe/CdSe QDs demonstrate good monodispersity, hardened lattice structure and excellent photostability, offering a great potential for biological application.

  18. Direct measurement of excited-state intervalence transfer in [(tpy)Ru(III)(tppz(*-))Ru(II)(tpy)](4+) by time-resolved near-infrared spectroscopy.

    PubMed

    Dattelbaum, Dana M; Hartshorn, Chris M; Meyer, Thomas J

    2002-05-08

    Extension of time-resolved infrared (TRIR) measurements into the near-infrared region has allowed the first direct measurement of a mixed-valence band in the metal-to-ligand charge transfer (MLCT) excited state of a symmetrical ligand-bridged complex. Visible laser flash excitation of [(tpy)Ru(tppz)Ru(tpy)]4+ (tppz is 2,3,5,6-tetrakis(2-pyridyl)pyrazine; tpy is 2,2':6',6' '-terpyridine) produces the mixed-valence, MLCT excited state [(tpy)RuIII(tppz*-)RuII(tpy)]4+* with the excited electron localized on the bridging tppz ligand. A mixed-valence band appears at numax = 6300 cm-1 with a bandwidth-at-half- maximum, Deltanu1/2 = 1070 cm-1. In the analogous ground-state complex, [(tpy)Ru(tppz)Ru(tpy)]5+, a mixed-valence band appears at numax = 6550 cm-1 with Deltanu1/2 = 970 cm-1 which allows a comparison to be made of electronic coupling across tppz0 and tppz*- as bridging ligands.

  19. Near infrared spectroscopy combined with multivariate analysis for monitoring the ethanol precipitation process of fraction I + II + III supernatant in human albumin separation

    NASA Astrophysics Data System (ADS)

    Li, Can; Wang, Fei; Zang, Lixuan; Zang, Hengchang; Alcalà, Manel; Nie, Lei; Wang, Mingyu; Li, Lian

    2017-03-01

    Nowadays, as a powerful process analytical tool, near infrared spectroscopy (NIRS) has been widely applied in process monitoring. In present work, NIRS combined with multivariate analysis was used to monitor the ethanol precipitation process of fraction I + II + III (FI + II + III) supernatant in human albumin (HA) separation to achieve qualitative and quantitative monitoring at the same time and assure the product's quality. First, a qualitative model was established by using principal component analysis (PCA) with 6 of 8 normal batches samples, and evaluated by the remaining 2 normal batches and 3 abnormal batches. The results showed that the first principal component (PC1) score chart could be successfully used for fault detection and diagnosis. Then, two quantitative models were built with 6 of 8 normal batches to determine the content of the total protein (TP) and HA separately by using partial least squares regression (PLS-R) strategy, and the models were validated by 2 remaining normal batches. The determination coefficient of validation (Rp2), root mean square error of cross validation (RMSECV), root mean square error of prediction (RMSEP) and ratio of performance deviation (RPD) were 0.975, 0.501 g/L, 0.465 g/L and 5.57 for TP, and 0.969, 0.530 g/L, 0.341 g/L and 5.47 for HA, respectively. The results showed that the established models could give a rapid and accurate measurement of the content of TP and HA. The results of this study indicated that NIRS is an effective tool and could be successfully used for qualitative and quantitative monitoring the ethanol precipitation process of FI + II + III supernatant simultaneously. This research has significant reference value for assuring the quality and improving the recovery ratio of HA in industrialization scale by using NIRS.

  20. Near infrared spectroscopy combined with multivariate analysis for monitoring the ethanol precipitation process of fraction I+II+III supernatant in human albumin separation.

    PubMed

    Li, Can; Wang, Fei; Zang, Lixuan; Zang, Hengchang; Alcalà, Manel; Nie, Lei; Wang, Mingyu; Li, Lian

    2017-03-15

    Nowadays, as a powerful process analytical tool, near infrared spectroscopy (NIRS) has been widely applied in process monitoring. In present work, NIRS combined with multivariate analysis was used to monitor the ethanol precipitation process of fraction I+II+III (FI+II+III) supernatant in human albumin (HA) separation to achieve qualitative and quantitative monitoring at the same time and assure the product's quality. First, a qualitative model was established by using principal component analysis (PCA) with 6 of 8 normal batches samples, and evaluated by the remaining 2 normal batches and 3 abnormal batches. The results showed that the first principal component (PC1) score chart could be successfully used for fault detection and diagnosis. Then, two quantitative models were built with 6 of 8 normal batches to determine the content of the total protein (TP) and HA separately by using partial least squares regression (PLS-R) strategy, and the models were validated by 2 remaining normal batches. The determination coefficient of validation (Rp(2)), root mean square error of cross validation (RMSECV), root mean square error of prediction (RMSEP) and ratio of performance deviation (RPD) were 0.975, 0.501g/L, 0.465g/L and 5.57 for TP, and 0.969, 0.530g/L, 0.341g/L and 5.47 for HA, respectively. The results showed that the established models could give a rapid and accurate measurement of the content of TP and HA. The results of this study indicated that NIRS is an effective tool and could be successfully used for qualitative and quantitative monitoring the ethanol precipitation process of FI+II+III supernatant simultaneously. This research has significant reference value for assuring the quality and improving the recovery ratio of HA in industrialization scale by using NIRS.

  1. He II-Emitting Galaxies

    NASA Astrophysics Data System (ADS)

    Heap, Sara R.

    2014-01-01

    A small fraction of star-forming galaxies at redshift, 3, show He II at 1640 A as a narrow emission line (Cassata et al. 2012), but the source of this emission is not understood. Does the He II emission arise in the stars or in the surrounding nebula? To answer this question, we use I Zw 18, a well studied blue compact dwarf galaxy showing narrow He II line emission as a test case. We consider if/how He II narrow emission lines could originate in the nearby nebulosity, or in the winds of hot, massive stars, both those on the main sequence and post-MS evolutionary phases.

  2. Dissymmetric Bis(dipyrrinato)zinc(II) Complexes: Rich Variety and Bright Red to Near-Infrared Luminescence with a Large Pseudo-Stokes Shift.

    PubMed

    Sakamoto, Ryota; Iwashima, Toshiki; Kögel, Julius F; Kusaka, Shinpei; Tsuchiya, Mizuho; Kitagawa, Yasutaka; Nishihara, Hiroshi

    2016-05-04

    Bis(dipyrrinato)metal(II) and tris(dipyrrinato)metal(III) complexes have been regarded as much less useful luminophores than their boron difluoride counterparts (4,4-difluoro-4-bora-3a,4a-diaza-s-indacenes, BODIPYs), especially in polar solvent. We proposed previously that dissymmetry in such metal complexes (i.e., two different dipyrrinato ligands in one molecule) improves their fluorescence quantum efficiencies. In this work, we demonstrate the universality and utility of our methodology by synthesizing eight new dissymmetric bis(dipyrrinato)zinc(II) complexes and comparing them with corresponding symmetric complexes. Single-crystal X-ray diffraction analysis, (1)H and (13)C NMR spectroscopy, and high-resolution mass spectrometry confirm the retention of dissymmetry in both solution and solid states. The dissymmetric complexes all show greater photoluminescence (PL) quantum yields (ϕPL) than the corresponding symmetric complexes, allowing red to near-infrared emissions with large pseudo-Stokes shifts. The best performance achieves a maximum PL wavelength of 671 nm, a pseudo-Stokes shift of 5400 cm(-1), and ϕPL of 0.62-0.72 in toluene (dielectric constant εs = 2.4), dichloromethane (εs = 9.1), acetone (εs = 21.4), and ethanol (εs = 24.3). The large pseudo-Stokes shift is distinctive considering BODIPYs with small Stokes shifts (∼500 cm(-1)), and the ϕPL values are higher than or comparable to those of BODIPYs fluorescing at similar wavelengths. Electrochemistry and density functional theory calculations illustrate that frontier orbital ordering in the dissymmetric complexes meets the condition for efficient PL proposed in our theory.

  3. RCSED—A Value-added Reference Catalog of Spectral Energy Distributions of 800,299 Galaxies in 11 Ultraviolet, Optical, and Near-infrared Bands: Morphologies, Colors, Ionized Gas, and Stellar Population Properties

    NASA Astrophysics Data System (ADS)

    Chilingarian, Igor V.; Zolotukhin, Ivan Yu.; Katkov, Ivan Yu.; Melchior, Anne-Laure; Rubtsov, Evgeniy V.; Grishin, Kirill A.

    2017-02-01

    We present RCSED, the value-added Reference Catalog of Spectral Energy Distributions of galaxies, which contains homogenized spectrophotometric data for 800,299 low- and intermediate-redshift galaxies (0.007< z< 0.6) selected from the Sloan Digital Sky Survey spectroscopic sample. Accessible from the Virtual Observatory (VO) and complemented with detailed information on galaxy properties obtained with state-of-the-art data analysis, RCSED enables direct studies of galaxy formation and evolution over the last 5 Gyr. We provide tabulated color transformations for galaxies of different morphologies and luminosities, and analytic expressions for the red sequence shape in different colors. RCSED comprises integrated k-corrected photometry in up to 11 ultraviolet, optical, and near-infrared bands published by the GALEX, SDSS, and UKIDSS wide-field imaging surveys; results of the stellar population fitting of SDSS spectra including best-fitting templates, velocity dispersions, parameterized star formation histories, and stellar metallicities computed for instantaneous starburst and exponentially declining star formation models; parametric and non-parametric emission line fluxes and profiles; and gas phase metallicities. We link RCSED to the Galaxy Zoo morphological classification and galaxy bulge+disk decomposition results of Simard et al. We construct the color–magnitude, Faber–Jackson, and mass–metallicity relations; compare them with the literature; and discuss systematic errors of the galaxy properties presented in our catalog. RCSED is accessible from the project web site and via VO simple spectrum access and table access services using VO-compliant applications. We describe several examples of SQL queries to the database. Finally, we briefly discuss existing and future scientific applications of RCSED and prospective catalog extensions to higher redshifts and different wavelengths. .

  4. Deriving the Extinction to Young Stellar Objects using [Fe II] Near-infrared Emission Lines: Prescriptions from GIANO High-resolution Spectra

    NASA Astrophysics Data System (ADS)

    Pecchioli, T.; Sanna, N.; Massi, F.; Oliva, E.

    2016-07-01

    The near-infrared (NIR) emission lines of Fe+ at 1.257, 1.321, and 1.644 μm share the same upper level; their ratios can then be exploited to derive the extinction to a line emitting region once the relevant spontaneous emission coefficients are known. This is commonly done, normally from low-resolution spectra, in observations of shocked gas from jets driven by Young Stellar Objects. In this paper we review this method, provide the relevant equations, and test it by analyzing high-resolution (R ∼ 50,000) NIR spectra of two young stars, namely the Herbig Be star HD 200775 and the Be star V1478 Cyg, which exhibit intense emission lines. The spectra were obtained with the new GIANO echelle spectrograph at the Telescopio Nazionale Galileo. Notably, the high-resolution spectra allowed checking the effects of overlapping telluric absorption lines. A set of various determinations of the Einstein coefficients are compared to show how much the available computations affect extinction derivation. The most recently obtained values are probably good enough to allow reddening determination within 1 visual mag of accuracy. Furthermore, we show that [Fe ii] line ratios from low-resolution pure emission-line spectra in general are likely to be in error due to the impossibility to properly account for telluric absorption lines. If low-resolution spectra are used for reddening determinations, we advice that the ratio 1.644/1.257, rather than 1.644/1.321, should be used, being less affected by the effects of telluric absorption lines.

  5. USING THE 1.6 {mu}m BUMP TO STUDY REST-FRAME NEAR-INFRARED-SELECTED GALAXIES AT REDSHIFT 2

    SciTech Connect

    Sorba, Robert; Sawicki, Marcin

    2010-10-01

    We explore the feasibility and limitations of using the 1.6 {mu}m bump as a photometric redshift indicator and selection technique, and use it to study the rest-frame H-band galaxy luminosity and stellar mass functions (SMFs) at redshift z {approx} 2. We use publicly available Spitzer/IRAC images in the GOODS fields and find that color selection in the IRAC bandpasses alone is comparable in completeness and contamination to BzK selection. We find that the shape of the 1.6 {mu}m bump is robust, and photometric redshifts are not greatly affected by choice of model parameters. Comparison with spectroscopic redshifts shows photometric redshifts to be reliable. We create a rest-frame NIR-selected catalog of galaxies at z {approx} 2 and construct a galaxy SMF. Comparisons with other SMFs at approximately the same redshift but determined using shorter wavelengths show good agreement. This agreement suggests that selection at bluer wavelengths does not miss a significant amount of stellar mass in passive galaxies. Comparison with SMFs at other redshifts shows evidence for the downsizing scenario of galaxy evolution. We conclude by pointing out the potential for using the 1.6 {mu}m bump technique to select high-redshift galaxies with the JWST, whose {lambda}>0.6 {mu}m coverage will not be well suited to selecting galaxies using techniques that require imaging at shorter wavelengths.

  6. HST-WFC3 Near-Infrared Spectroscopy of Quenched Galaxies at zeta approx 1.5 from the WISP Survey: Stellar Populations Properties

    NASA Technical Reports Server (NTRS)

    Bedregal, A. G.; Scarlata, C.; Henry, A. L.; Atek, H.; Rafelski, M.; Teplitz, H. I.; Dominguez, A.; Siana, B.; Colbert, J. W.; Malkan, M.; Ross, N. R.; Martin, C. L.; Dressler, A.; Bridge, C.; Hathi, N. P.; Masters, D.; McCarthy, P. J.; Rutkowski, M. J.

    2013-01-01

    We combine Hubble Space Telescope (HST) G102 and G141 near-IR (NIR) grism spectroscopy with HST/WFC3- UVIS, HST/WFC3-IR, and Spitzer/IRAC [3.6 microns] photometry to assemble a sample of massive (log(Mstar/M solar mass) at approx 11.0) and quenched (specific star formation rate < 0.01 G/yr(exp -1) galaxies at zeta approx 1.5. Our sample of 41 galaxies is the largest with G102+G141 NIR spectroscopy for quenched sources at these redshifts. In contrast to the local universe, zeta approx 1.5 quenched galaxies in the high-mass range have a wide range of stellar population properties. We find that their spectral energy distributions (SEDs) are well fitted with exponentially decreasing star formation histories and short star formation timescales (tau less than or equal to 100 M/yr). Quenched galaxies also show a wide distribution in ages, between 1 and 4 G/yr. In the (u - r)0-versus-mass space quenched galaxies have a large spread in rest-frame color at a given mass. Most quenched galaxies populate the zeta appro. 1.5 red sequence (RS), but an important fraction of them (32%) have substantially bluer colors. Although with a large spread, we find that the quenched galaxies on the RS have older median ages (3.1 G/yr) than the quenched galaxies off the RS (1.5 G/yr). We also show that a rejuvenated SED cannot reproduce the observed stacked spectra of (the bluer) quenched galaxies off the RS. We derive the upper limit on the fraction of massive galaxies on the RS at zeta approx 1.5 to be <43%.We speculate that the young quenched galaxies off the RS are in a transition phase between vigorous star formation at zeta > 2 and the zeta approx 1.5 RS. According to their estimated ages, the time required for quenched galaxies off the RS to join their counterparts on the z approx. 1.5 RS is of the order of approx. 1G/yr.

  7. HST/WFC3 near-infrared spectroscopy of quenched galaxies at z ∼ 1.5 from the WISP survey: Stellar population properties

    SciTech Connect

    Bedregal, A. G.; Scarlata, C.; Rutkowski, M. J.; Henry, A. L.; Martin, C. L.; Atek, H.; Colbert, J. W.; Rafelski, M.; Teplitz, H. I.; Dominguez, A.; Siana, B.; Masters, D.; Malkan, M.; Ross, N. R.; Dressler, A.; Bridge, C.; Hathi, N. P.; McCarthy, P. J.

    2013-12-01

    We combine Hubble Space Telescope (HST) G102 and G141 near-IR (NIR) grism spectroscopy with HST/WFC3-UVIS, HST/WFC3-IR, and Spitzer/IRAC [3.6 μm] photometry to assemble a sample of massive (log (M {sub star}/M {sub ☉}) ∼ 11.0) and quenched (specific star formation rate <0.01 Gyr{sup –1}) galaxies at z ∼ 1.5. Our sample of 41 galaxies is the largest with G102+G141 NIR spectroscopy for quenched sources at these redshifts. In contrast to the local universe, z ∼ 1.5 quenched galaxies in the high-mass range have a wide range of stellar population properties. We find that their spectral energy distributions (SEDs) are well fitted with exponentially decreasing star formation histories and short star formation timescales (τ ≤ 100 Myr). Quenched galaxies also show a wide distribution in ages, between 1 and 4 Gyr. In the (u – r){sub 0}-versus-mass space quenched galaxies have a large spread in rest-frame color at a given mass. Most quenched galaxies populate the z ∼ 1.5 red sequence (RS), but an important fraction of them (32%) have substantially bluer colors. Although with a large spread, we find that the quenched galaxies on the RS have older median ages (3.1 Gyr) than the quenched galaxies off the RS (1.5 Gyr). We also show that a rejuvenated SED cannot reproduce the observed stacked spectra of (the bluer) quenched galaxies off the RS. We derive the upper limit on the fraction of massive galaxies on the RS at z ∼ 1.5 to be <43%. We speculate that the young quenched galaxies off the RS are in a transition phase between vigorous star formation at z > 2 and the z ∼ 1.5 RS. According to their estimated ages, the time required for quenched galaxies off the RS to join their counterparts on the z ∼ 1.5 RS is of the order of ∼1 Gyr.

  8. A NEAR-INFRARED SPECTROSCOPIC SURVEY OF K-SELECTED GALAXIES AT z{approx} 2.3: COMPARISON OF STELLAR POPULATION SYNTHESIS CODES AND CONSTRAINTS FROM THE REST-FRAME NIR

    SciTech Connect

    Muzzin, Adam; Marchesini, Danilo; Van Dokkum, Pieter G.; Labbe, Ivo; Kriek, Mariska; Franx, Marijn

    2009-08-20

    We present spectral energy distribution (SED) modeling of a sample of 34 K-selected galaxies at z{approx} 2.3. These galaxies have near-infrared (NIR) spectroscopy that samples the rest-frame Balmer/4000 A break as well as deep photometry in 13 broadband filters. New to our analysis is Infrared Array Camera (IRAC) data that extend the SEDs into the rest-frame NIR. Comparing parameters determined from SED fits with and without the IRAC data we find that the IRAC photometry significantly improves the confidence intervals of {tau}, A{sub v} , M {sub star}, and SFR for individual galaxies, but does not systematically alter the mean parameters of the sample. We use the IRAC data to assess how well current stellar population synthesis codes describe the rest-frame NIR SEDs of young galaxies where discrepancies between treatments of the thermally pulsating asymptotic giant branch phase of stellar evolution are most pronounced. The models of Bruzual and Charlot, Maraston, and Charlot and Bruzual all successfully reproduce the SEDs of our galaxies with {<=}5% differences in the quality of fit; however, the best-fit masses from each code differ systematically by as much as a factor of 1.5, and other parameters vary more, up to factors of 2-3. A comparison of best-fit stellar population parameters from different stellar population synthesis (SPS) codes, dust laws, and metallicities shows that the choice of SPS code is the largest systematic uncertainty in most parameters, and that systematic uncertainties are typically larger than the formal random uncertainties. The SED fitting confirms our previous result that galaxies with strongly suppressed SF account for {approx}50% of the K-bright population at z{approx} 2.3; however, the uncertainty in this fraction is large due to systematic differences in the specific star formation rates derived from the three SPS models.

  9. A NEW SYNTHETIC LIBRARY OF THE NEAR-INFRARED Ca II TRIPLET INDICES. I. INDEX DEFINITION, CALIBRATION, AND RELATIONS WITH STELLAR ATMOSPHERIC PARAMETERS

    SciTech Connect

    Du, W.; Luo, A. L.; Zhao, Y. H. E-mail: lal@nao.cas.cn

    2012-02-15

    Adopting the SPECTRUM package, which is a stellar spectral synthesis program, we have synthesized a comprehensive set of 2890 near-infrared (NIR) synthetic spectra with a resolution and wavelength sampling similar to the Sloan Digital Sky Survey (SDSS) and the forthcoming Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) spectra. During the synthesis, we applied the 'New grids of ATLAS9 Model Atmosphere' to develop a grid of local thermodynamic equilibrium model atmospheres for effective temperatures (T{sub eff}) ranging from 3500 to 7500 K, for surface gravities (log g) from 0.5 to 5.0 dex, for metallicities ([Fe/H]) from -4.0 to 0.5 dex, and for solar ([{alpha}/Fe] = 0.0 dex) and non-solar ([{alpha}/Fe] = +0.4 dex) abundances. This synthetic stellar library is composed of 1350 solar scaled abundance (SSA) and 1530 non-solar scaled abundance (NSSA) spectra, grounding on which we have defined a new set of NIR Ca II triplet indices and an index CaT as the sum of the three. These defined indices were automatically measured on every spectrum of the synthetic stellar library and calibrated with the indices computed on the observational spectra from the INDO-U.S. stellar library. In order to check the effect of {alpha}-element enhancement on the so-defined Ca II indices, we compared indices measured on the SSA spectra with those on the NSSA ones at the same trine of stellar parameters (T{sub eff}, log g, [Fe/H]); luckily, little influences of {alpha}-element enhancement were found. Furthermore, comparisons of our synthetic indices with the observational ones from measurements on the INDO-U.S. stellar library, the SDSS-DR7 and SDSS-DR8 spectroscopic survey are presented, respectively, for dwarfs and giants in specific. For dwarfs, our synthetic indices could well reproduce the behaviors of the observational indices versus stellar parameters, which verifies the validity of our index definitions for dwarfs. For giants, the consistency between our synthetic

  10. Near infrared detectors for SNAP

    SciTech Connect

    Schubnell, M.; Barron, N.; Bebek, C.; Brown, M.G.; Borysow, M.; Cole, D.; Figer, D.; Lorenzon, W.; Mostek, N.; Mufson, S.; Seshadri, S.; Smith, R.; Tarle, G.

    2006-05-23

    Large format (1k x 1k and 2k x 2k) near infrared detectors manufactured by Rockwell Scientific Center and Raytheon Vision Systems are characterized as part of the near infrared R&D effort for SNAP (the Super-Nova/Acceleration Probe). These are hybridized HgCdTe focal plane arrays with a sharp high wavelength cut-off at 1.7 um. This cut-off provides a sufficiently deep reach in redshift while it allows at the same time low dark current operation of the passively cooled detectors at 140 K. Here the baseline SNAP near infrared system is briefly described and the science driven requirements for the near infrared detectors are summarized. A few results obtained during the testing of engineering grade near infrared devices procured for the SNAP project are highlighted. In particular some recent measurements that target correlated noise between adjacent detector pixels due to capacitive coupling and the response uniformity within individual detector pixels are discussed.

  11. UBVR and Hubble Space Telescope Mid-Ultraviolet and Near-Infrared Surface Photometry and Radial Color Gradients of Late-Type, Irregular, and Peculiar Galaxies

    NASA Astrophysics Data System (ADS)

    Taylor, Violet A.; Jansen, Rolf A.; Windhorst, Rogier A.; Odewahn, Stephen C.; Hibbard, John E.

    2005-09-01

    We introduce a data set of 142 mostly late-type spiral, irregular, and peculiar (interacting or merging) nearby galaxies observed in UBVR at the Vatican Advanced Technology Telescope (VATT), and we present an analysis of their radial color gradients. We confirm that nearby elliptical and early- to mid-type spiral galaxies show either no or only small color gradients, becoming slightly bluer with radius. In contrast, we find that late-type spiral, irregular, peculiar, and merging galaxies become on average redder with increasing distance from the center. The scatter in radial color gradient trends increases toward later Hubble type. As a preliminary analysis of a larger data set obtained with the Hubble Space Telescope (HST), we also analyze the color gradients of six nearby galaxies observed with NICMOS in the near-IR (H) and with WFPC2 in the mid-UV (F300W) and red (F814W). We discuss the possible implications of these results on galaxy formation and compare our nearby galaxy color gradients to those at high redshift. We present examples of images and UBVR radial surface brightness and color profiles, as well as of the tables of measurements; the full atlas and tables are published in the electronic edition only. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs 8645, 9124, and 9824.

  12. SINS/zC-SINF Survey of z ˜ 2 Galaxy Kinematics: Rest-frame Morphology, Structure, and Colors from Near-infrared Hubble Space Telescope Imaging

    NASA Astrophysics Data System (ADS)

    Tacchella, S.; Lang, P.; Carollo, C. M.; Förster Schreiber, N. M.; Renzini, A.; Shapley, A. E.; Wuyts, S.; Cresci, G.; Genzel, R.; Lilly, S. J.; Mancini, C.; Newman, S. F.; Tacconi, L. J.; Zamorani, G.; Davies, R. I.; Kurk, J.; Pozzetti, L.

    2015-04-01

    We present the analysis of Hubble Space Telescope (HST) J- and H-band imaging for 29 galaxies on the star-forming main sequence at z ˜ 2, which have adaptive optics Very Large Telescope SINFONI integral field spectroscopy from our SINS/zC-SINF program. The SINFONI Hα data resolve the ongoing star formation and the ionized gas kinematics on scales of 1-2 kpc; the near-IR images trace the galaxies’ rest-frame optical morphologies and distributions of stellar mass in old stellar populations at a similar resolution. The global light profiles of most galaxies show disk-like properties well described by a single Sérsic profile with n˜ 1, with only ˜ 15% requiring a high n\\gt 3 Sérsic index, all more massive than {{10}10} {{M}⊙ }. In bulge+disk fits, about 40% of galaxies have a measurable bulge component in the light profiles, with ˜ 15% showing a substantial bulge-to-total ratio (B/T) B/T≳ 0.3. This is a lower limit to the frequency of z ˜ 2 massive galaxies with a developed bulge component in stellar mass because it could be hidden by dust and/or outshined by a thick actively star-forming disk component. The galaxies’ rest-optical half-light radii range between 1 and 7 kpc, with a median of 2.1 kpc, and lie slightly above the size-mass relation at these epochs reported in the literature. This is attributed to differences in sample selection and definitions of size and/or mass measurements. The {{(u-g)}rest} color gradient and scatter within individual z ˜ 2 massive galaxies with ≳ {{10}11} {{M}⊙ } are as high as in z = 0 low-mass, late-type galaxies and are consistent with the high star formation rates of massive z ˜ 2 galaxies being sustained at large galactocentric distances. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute.

  13. Near-Infrared Photoluminescence Enhancement in Ge/CdS and Ge/ZnS Core/Shell Nanocrystals: Utilizing IV/II-VI Semiconductor Epitaxy

    SciTech Connect

    Guo, Yijun; Rowland, Clare E; Schaller, Richard D; Vela, Javier

    2014-08-26

    Ge nanocrystals have a large Bohr radius and a small, size-tunable band gap that may engender direct character via strain or doping. Colloidal Ge nanocrystals are particularly interesting in the development of near-infrared materials for applications in bioimaging, telecommunications and energy conversion. Epitaxial growth of a passivating shell is a common strategy employed in the synthesis of highly luminescent II–VI, III–V and IV–VI semiconductor quantum dots. Here, we use relatively unexplored IV/II–VI epitaxy as a way to enhance the photoluminescence and improve the optical stability of colloidal Ge nanocrystals. Selected on the basis of their relatively small lattice mismatch compared with crystalline Ge, we explore the growth of epitaxial CdS and ZnS shells using the successive ion layer adsorption and reaction method. Powder X-ray diffraction and electron microscopy techniques, including energy dispersive X-ray spectroscopy and selected area electron diffraction, clearly show the controllable growth of as many as 20 epitaxial monolayers of CdS atop Ge cores. In contrast, Ge etching and/or replacement by ZnS result in relatively small Ge/ZnS nanocrystals. The presence of an epitaxial II–VI shell greatly enhances the near-infrared photoluminescence and improves the photoluminescence stability of Ge. Ge/II–VI nanocrystals are reproducibly 1–3 orders of magnitude brighter than the brightest Ge cores. Ge/4.9CdS core/shells show the highest photoluminescence quantum yield and longest radiative recombination lifetime. Thiol ligand exchange easily results in near-infrared active, water-soluble Ge/II–VI nanocrystals. We expect this synthetic IV/II–VI epitaxial approach will lead to further studies into the optoelectronic behavior and practical applications of Si and Ge-based nanomaterials.

  14. THE LBT BOOeTES FIELD SURVEY. I. THE REST-FRAME ULTRAVIOLET AND NEAR-INFRARED LUMINOSITY FUNCTIONS AND CLUSTERING OF BRIGHT LYMAN BREAK GALAXIES AT Z {approx} 3

    SciTech Connect

    Bian Fuyan; Fan Xiaohui; Jiang Linhua; McGreer, Ian; Dave, Romeel; Dey, Arjun; Green, Richard F.; Maiolino, Roberto; Walter, Fabian; Lee, Kyoung-Soo

    2013-09-01

    We present a deep LBT/LBC U{sub spec}-band imaging survey (9 deg{sup 2}) covering the NOAO Booetes field. A total of 14,485 Lyman break galaxies (LBGs) at z {approx} 3 are selected, which are used to measure the rest-frame UV luminosity function (LF). The large sample size and survey area reduce the LF uncertainties due to Poisson statistics and cosmic variance by {>=}3 compared to previous studies. At the bright end, the LF shows excess power compared to the best-fit Schechter function, which can be attributed to the contribution of z {approx} 3 quasars. We compute the rest-frame near-infrared LF and stellar mass function (SMF) of z {approx} 3 LBGs based on the R-band and [4.5 {mu}m]-band flux relation. We investigate the evolution of the UV LFs and SMFs between z {approx} 7 and z {approx} 3, which supports a rising star formation history in the LBGs. We study the spatial correlation function of two bright LBG samples and estimate their average host halo mass. We find a tight relation between the host halo mass and the galaxy star formation rate (SFR), which follows the trend predicted by the baryonic accretion rate onto the halo, suggesting that the star formation in LBGs is fueled by baryonic accretion through the cosmic web. By comparing the SFRs with the total baryonic accretion rates, we find that cosmic star formation efficiency is about 5%-20% and it does not evolve significantly with redshift, halo mass, or galaxy luminosity.

  15. Near infrared leaf reflectance modeling

    NASA Technical Reports Server (NTRS)

    Parrish, J. B.

    1985-01-01

    Near infrared leaf reflectance modeling using Fresnel's equation (Kumar and Silva, 1973) and Snell's Law successfully approximated the spectral curve for a 0.25-mm turgid oak leaf lying on a Halon background. Calculations were made for ten interfaces, air-wax, wax-cellulose, cellulose-water, cellulose-air, air-water, and their inverses. A water path of 0.5 mm yielded acceptable results, and it was found that assignment of more weight to those interfaces involving air versus water or cellulose, and less to those involving wax, decreased the standard deviation of the error for all wavelengths. Data suggest that the air-cell interface is not the only important contributor to the overall reflectance of a leaf. Results also argue against the assertion that the near infrared plateau is a function of cell structure within the leaf.

  16. NEAR-INFRARED H{sub 2} AND CONTINUUM SURVEY OF EXTENDED GREEN OBJECTS. II. COMPLETE CENSUS FOR THE NORTHERN GALACTIC PLANE

    SciTech Connect

    Lee, Hsu-Tai; Karr, Jennifer; Su, Yu-Nung; Liu, Sheng-Yuan; Takami, Michihiro; Liao, Wei-Ting; Froebrich, Dirk; Ioannidis, Georgios; Lee, Yong-Hyun; Duan, Hao-Yuan

    2013-10-01

    We discuss 94 Extended Green Objects (EGOs) in the northern Galactic plane cataloged by Cyganowski et al., based on near-infrared narrow H{sub 2} (2.122 μm) and continuum observations from the United Kingdom Infrared Telescope. This data set is three times larger than the one in our previous study and is unbiased by preselection. As discussed in the previous paper, the morphologies of the 4.5 μm emission generally resemble those of the near-infrared continuum, but are different from those of the H{sub 2} emission. Of our sample, only 28% of EGOs with H{sub 2} emission show similar morphologies between 4.5 μm and H{sub 2} emission. These results suggest that the 4.5 μm emission mainly comes from scattered continuum from the embedded young stellar objects, and partially from H{sub 2} emission. About half of EGOs are associated with H{sub 2} outflows, if the H{sub 2} outflow incompleteness is considered. The H{sub 2} outflow detection rate for EGOs with K-band detections (61%) is significantly higher than for those without K-band detections (36%). This difference may be due to the fact that both H{sub 2} and K-band emissions are associated with outflows, i.e., H{sub 2} emission and K-band continuum are associated with shocks and outflow cavities, respectively. We also compared the correlation between the H{sub 2} outflows and Class I 44 GHz methanol masers from the literature. The methanol masers can be located upstream or downstream of the H{sub 2} outflows and some bright H{sub 2} spots or outflows are not associated with methanol masers, suggesting that methanol masers and H{sub 2} emission trace different excitation conditions.

  17. The VRI colours of H II galaxies

    NASA Astrophysics Data System (ADS)

    Telles, Eduardo; Terlevich, Roberto

    1997-03-01

    We present a high spatial resolution CCD surface photometry study in the optical V, R and I broad-band filters of a sample of 15 H II galaxies. Narrow-band imaging allows the separation of the emission-line region from the extended parts of the galaxy. The latter are assumed to represent the underlying galaxy in H II galaxies; thus the colours of the underlying galaxy are measured. The colours of the underlying stellar continuum within the starburst are also derived by subtracting the contribution of the emission lines falling in the broad-band filters. The distribution of colours of the underlying galaxy in H II galaxies is similar to the colours of other late-type low surface brightness galaxies, which suggests a close kinship of these with the quiescent phases of H II galaxies. However, comparison wtih recent evolutionary population synthesis models shows that the observational errors and the uncertainties in the models are still too large to put strict constraints on their past star formation history. Our analysis of the morphology and structural properties, from contour maps and luminosity profiles, of this sample of 15 H II galaxies agrees with what has been found by Telles and Telles, Melnick & Terlevich, namely that H II galaxies comprise two broad classes segregated by their luminosity; Type I H II galaxies are luminous and have disturbed and irregular outer shapes, while Type II H II galaxies are less luminous and have regular shapes. The outer parts of their profiles are well represented by an exponential, as in other types of known dwarf galaxy.

  18. STAR CLUSTER COMPLEXES AND THE HOST GALAXY IN THREE H II GALAXIES: Mrk 36, UM 408, AND UM 461

    SciTech Connect

    Lagos, P.; Telles, E.; Nigoche-Netro, A.

    2011-11-15

    We present a stellar population study of three H II galaxies (Mrk 36, UM 408, and UM 461) based on the analysis of new ground-based high-resolution near-infrared J, H, and K{sub p} broadband and Br{gamma} narrowband images obtained with Gemini/NIRI. We identify and determine the relative ages and masses of the elementary star clusters and/or star cluster complexes of the starburst regions in each of these galaxies by comparing the colors with evolutionary synthesis models that include the contribution of stellar continuum, nebular continuum, and emission lines. We found that the current star cluster formation efficiency in our sample of low-luminosity H II galaxies is {approx}10%. Therefore, most of the recent star formation is not in massive clusters. Our findings seem to indicate that the star formation mode in our sample of galaxies is clumpy, and that these complexes are formed by a few massive star clusters with masses {approx}>10{sup 4} M{sub Sun }. The age distribution of these star cluster complexes shows that the current burst started recently and likely simultaneously over short timescales in their host galaxies, triggered by some internal mechanism. Finally, the fraction of the total cluster mass with respect to the low surface brightness (or host galaxy) mass, considering our complete range in ages, is less than 1%.

  19. CRIRES-POP: a library of high resolution spectra in the near-infrared. II. Data reduction and the spectrum of the K giant 10 Leonis

    NASA Astrophysics Data System (ADS)

    Nicholls, C. P.; Lebzelter, T.; Smette, A.; Wolff, B.; Hartman, H.; Käufl, H.-U.; Przybilla, N.; Ramsay, S.; Uttenthaler, S.; Wahlgren, G. M.; Bagnulo, S.; Hussain, G. A. J.; Nieva, M.-F.; Seemann, U.; Seifahrt, A.

    2017-02-01

    Context. High resolution stellar spectral atlases are valuable resources to astronomy. They are rare in the 1-5 μm region for historical reasons, but once available, high resolution atlases in this part of the spectrum will aid the study of a wide range of astrophysical phenomena. Aims: The aim of the CRIRES-POP project is to produce a high resolution near-infrared spectral library of stars across the H-R diagram. The aim of this paper is to present the fully reduced spectrum of the K giant 10 Leo that will form the basis of the first atlas within the CRIRES-POP library, to provide a full description of the data reduction processes involved, and to provide an update on the CRIRES-POP project. Methods: All CRIRES-POP targets were observed with almost 200 different observational settings of CRIRES on the ESO Very Large Telescope, resulting in a basically complete coverage of its spectral range as accessible from the ground. We reduced the spectra of 10 Leo with the CRIRES pipeline, corrected the wavelength solution and removed telluric absorption with Molecfit, then resampled the spectra to a common wavelength scale, shifted them to rest wavelengths, flux normalised, and median combined them into one final data product. Results: We present the fully reduced, high resolution, near-infrared spectrum of 10 Leo. This is also the first complete spectrum from the CRIRES instrument. The spectrum is available online. Conclusions: The first CRIRES-POP spectrum has exceeded our quality expectations and will form the centre of a state-of-the-art stellar atlas. This first CRIRES-POP atlas will soon be available, and further atlases will follow. All CRIRES-POP data products will be freely and publicly available online. The spectrum 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/598/A79

  20. Comparative Variable Temperature Studies of Polyamide II with a Benchtop Fourier Transform and a Miniature Handheld Near-Infrared Spectrometer Using 2D-COS and PCMW-2D Analysis.

    PubMed

    Unger, Miriam; Pfeifer, Frank; Siesler, Heinz W

    2016-07-01

    The main objective of this communication is to compare the performance of a miniaturized handheld near-infrared (NIR) spectrometer with a benchtop Fourier transform near-infrared (FT-NIR) spectrometer. Generally, NIR spectroscopy is an extremely powerful analytical tool to study hydrogen-bonding changes of amide functionalities in solid and liquid materials and therefore variable temperature NIR measurements of polyamide II (PAII) have been selected as a case study. The information content of the measurement data has been further enhanced by exploiting the potential of two-dimensional correlation spectroscopy (2D-COS) and the perturbation correlation moving window two-dimensional (PCMW2D) evaluation technique. The data provide valuable insights not only into the changes of the hydrogen-bonding structure and the recrystallization of the hydrocarbon segments of the investigated PAII but also in their sequential order. Furthermore, it has been demonstrated that the 2D-COS and PCMW2D results derived from the spectra measured with the miniaturized NIR instrument are equivalent to the information extracted from the data obtained with the high-performance FT-NIR instrument.

  1. Near infrared laser ocular bioeffects

    SciTech Connect

    Lund, D.J.; Beatrice, E.S.

    1989-05-01

    Thresholds for laser chorioretinal injury in the red end of the visible spectrum and the near-infrared (IR-A) spectral regions are presented. An unpredicted wavelength dependence of the injury threshold for single Q-switched pulses is demonstrated. Four lasers were used to determine thresholds at 40 wavelengths between 532 nm and 1064 nm: a ruby laser, a neodymium:YAG-pumped dye laser, an erbium:YLF laser and an alexandrite laser. Despite many careful and repeated efforts to determine a cause for the variation due to possible variations in the lasers or other aspects of the experimental technique and due to biological absorption properties of the eye, there is no complete or obvious explanation for the significant variations of threshold with small changes in wavelength. The implications of these findings for laser safety standards are presented.

  2. Near infrared imaging with nanoparticles.

    PubMed

    Altinoğlu, Erhan I; Adair, James H

    2010-01-01

    Near infrared imaging has presented itself as a powerful diagnostic technique with potential to serve as a minimally invasive, nonionizing method for sensitive, deep tissue diagnostic imaging. This potential is further realized with the use of nanoparticle (NP)-based near infrared (NIR) contrast agents that are not prone to the rapid photobleaching and instability of their organic counterparts. This review discusses applications that have successfully demonstrated the utility of nanoparticles for NIR imaging, including NIR-emitting semiconductor quantum dots (QDs), resonant gold nanoshells, and dye-encapsulating nanoparticles. NIR QDs demonstrate superior optical performance with exceptional fluorescence brightness stability. However, the heavy metal composition and high propensity for toxicity hinder future application in clinical environments. NIR resonant gold nanoshells also exhibit brilliant signal intensities and likewise have none of the photo- or chemical-instabilities characteristic of organic contrast agents. However, concerns regarding ineffectual clearance and long-term accumulation in nontarget organs are a major issue for this technology. Finally, NIR dye-encapsulating nanoparticles synthesized from calcium phosphate (CP) also demonstrate improved optical performances by shielding the component dye from undesirable environmental influences, thereby enhancing quantum yields, emission brightness, and fluorescent lifetime. Calcium phosphate nanoparticle (CPNP) contrast agents are neither toxic, nor have issues with long-term sequestering, as they are readily dissolved in low pH environments and ultimately absorbed into the system. Though perhaps not as optically superior as QDs or nanoshells, these are a completely nontoxic, bioresorbable option for NP-based NIR imaging that still effectively improves the optical performance of conventional organic agents.

  3. CIBER : a near-infrared probe of the epoch of reionization

    NASA Astrophysics Data System (ADS)

    Sullivan, Ian Sorensen

    The Cosmic Infrared Background Experiment (CIBER) is a NASA sounding rocket payload that was first launched in February 2009. CIBER consists of four co-aligned instruments designed to study the near-Infrared background by measuring fluctuations and the absolute spectrum. The platform of a sounding rocket enables observations of the near-Infrared background outside of narrow atmospheric windows that are uncontaminated by airglow. CIBER uses two spectrometers to measure the absolute brightness spectrum of the extragalactic near-Infrared background. One, a high-resolution Fabry-Perot spectometer, is tuned to the 854.5 nm CaII line of the solar spectrum, and is designed to measure the absolute brightness of the Zodiacal Light directly, which is the source of greatest uncertainty in the near-Infrared background spectrum. The second spectrometer measures the near-Infrared background spectrum from 700 nm to 1800 nm, spanning the wavelength range where a Lyman limit cutoff feature from reionization could appear. CIBER also houses two Infrared imaging telescopes, which have identical optics that give 2 x 2 degree field of views with 7 arcsecond pixels, but have different band defining filters. The first imager has a wide band centered at 1600 nm, and images the background at the expected peak of the spectrum. The imagers?~@~Y wide field of view allows them to measure the distinctive power spectrum of first-light galaxy fluctuations peaking at 10 arcminutes. The second imager has a wide band centered at 1000 nm that is intended to image at wavelengths shorter than the Lyman cutoff, and provides a powerful systematic test for any detection made at 1600 nm. First-light fluctuations should have a distinctive spatial power spectrum with very red 1600 nm / 1000 nm color, distinctly redder than the approximately solar color of any residual fluctuations arising from Zodiacal light, Galactic starlight, or moderate-redshift galaxies. This work describes the design and

  4. A NEAR-INFRARED SURVEY OF THE INNER GALACTIC PLANE FOR WOLF-RAYET STARS. II. GOING FAINTER: 71 MORE NEW W-R STARS

    SciTech Connect

    Shara, Michael M.; Faherty, Jacqueline K.; Zurek, David; Moffat, Anthony F. J.; Doyon, Rene; Gerke, Jill; Artigau, Etienne; Drissen, Laurent E-mail: jfaherty@amnh.org E-mail: moffat@astro.umontreal.ca E-mail: gerke@astronomy.ohio-state.edu E-mail: ldrissen@phy.ulaval.ca

    2012-06-15

    We are continuing a J, K and narrowband imaging survey of 300 deg{sup 2} of the plane of the Galaxy, searching for new Wolf-Rayet (W-R) stars. Our survey spans 150 Degree-Sign in Galactic longitude and reaches 1 Degree-Sign above and below the Galactic plane. The survey has a useful limiting magnitude of K = 15 over most of the observed Galactic plane, and K = 14 (due to severe crowding) within a few degrees of the Galactic center. Thousands of emission-line candidates have been detected. In spectrographic follow-ups of 146 relatively bright W-R star candidates, we have re-examined 11 previously known WC and WN stars and discovered 71 new W-R stars, 17 of type WN and 54 of type WC. Our latest image analysis pipeline now picks out W-R stars with a 57% success rate. Star subtype assignments have been confirmed with the K-band spectra and distances approximated using the method of spectroscopic parallax. Some of the new W-R stars are among the most distant known in our Galaxy. The distribution of these new W-R stars is beginning to trace the locations of massive stars along the distant spiral arms of the Milky Way.

  5. Functional near-infrared neuroimaging.

    PubMed

    Izzetoglu, Kurtulus; Bunce, Scott; Izzetoglu, Meltem; Onaral, Banu; Pourrezaei, Kambiz

    2004-01-01

    Functional near-infrared (fNIR) spectroscopy is a wearable neuroimaging device that enables the continuous, non-invasive, and portable monitoring of changes in blood oxygen and blood volume related to human brain function. Over the last three years, studies in the laboratory and under field conditions have established the positive correlation between a participant's performance and oxygenation responses as a function of task load. Our findings indicate that fNIR can effectively monitor attention and working memory in real-life situations. These experimental outcomes compare favorably with functional magnetic resonance imaging (fMRI) studies, and in particular, with the blood oxygenation level dependent (BOLD) signal. The capacity to monitor brain hemodynamics with a wearable device holds promise for the use of fNIR in the creation of a symbiotic relationship between the user and his/her everyday environment. Moreover, under operational conditions, the fNIR system is amenable to integration with other established physiological and neurobehavioral measures, including EEG, eye tracking, pupil reflex, heart rate variability, respiration and electrodermal activity.

  6. Black-to-Transmissive Electrochromism with Visible-to-Near-Infrared Switching of a Co(II)-Based Metallo-Supramolecular Polymer for Smart Window and Digital Signage Applications.

    PubMed

    Hsu, Chih-Yu; Zhang, Jian; Sato, Takashi; Moriyama, Satoshi; Higuchi, Masayoshi

    2015-08-26

    Black-to-transmissive electrochromism has been obtained with a Co(II)-based metallo-supramolecular polymer (polyCo). Thin films of polyCo, based on bisterpyridine ligand assembled with Co(II) metal ion, were constructed by spray casting the polymer onto ITO glass. With such simple fabricating means to form good-quality films, polyCo films show stable switching at the central metal ion of the Co(II)/Co(I) redox reaction when immersed in aqueous solution. With an increase in the pH of the aqueous electrolyte solution from neutral, the film exhibits a color response due to the interaction between the d-orbital electron and hydroxide ions affecting the d-d* transition. As a result, a nearly transparent-to-black electrochromic performance can be achieved with a transmittance difference at 550 nm of 74.3% (81.9-7.6%) in pH 13 solution. The light absorption of the film can be tuned over light regions from visible to near-infrared with a large attenuation.

  7. The VVDS-VLA deep field. II. Optical and near infrared identifications of VLA S1.4 GHz > 80 μ Jy sources in the VIMOS VLT deep survey VVDS-02h field

    NASA Astrophysics Data System (ADS)

    Ciliegi, P.; Zamorani, G.; Bondi, M.; Pozzetti, L.; Bolzonella, M.; Gregorini, L.; Garilli, B.; Iovino, A.; McCracken, H. J.; Mellier, Y.; Radovich, M.; de Ruiter, H. R.; Parma, P.; Bottini, D.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Picat, J. P.; Scaramella, R.; Scodeggio, M.; Tresse, L.; Vettolani, G.; Zanichelli, A.; Adami, C.; Arnaboldi, M.; Arnouts, S.; Bardelli, S.; Cappi, A.; Charlot, S.; Contini, T.; Foucaud, S.; Franzetti, P.; Guzzo, L.; Ilbert, O.; Marano, B.; Marinoni, C.; Mathez, G.; Mazure, A.; Meneux, B.; Merighi, R.; Merluzzi, P.; Paltani, S.; Pollo, A.; Zucca, E.; Bongiorno, A.; Busarello, G.; Gavignaud, I.; Pellò, R.; Ripepi, V.; Rizzo, D.

    2005-10-01

    In this paper we present the optical and near-infrared identifications of the 1054 radio sources detected in the 20 cm deep radio survey down to a 5σ flux limit of ~80 μJy obtained with the VLA in the VIMOS VLT Deep Survey VVDS-02h deep field. Using U,B,V,R,I and K data, with limiting magnitudes of UAB˜25.4, BAB˜26.5, VAB˜26.2, RAB˜25.9 IAB˜25.0, JAB˜24.2, KAB˜23.9 (50% completeness) we identified 718 radio sources (~74% of the whole sample). The photometric redshift analysis shows that, in each magnitude bin, the radio sample has a higher median photometric redshift than the whole optical sample, while the median (V-I)AB color of the radio sources is redder than the median color of the whole optical sample. These results suggest that radio detection is preferentially selecting galaxies with higher intrinsic optical luminosity. From the analysis of the optical properties of the radio sources as function of the radio flux, we found that while about 35% of the radio sources are optically unidentified in the higher radio flux bin (S> 1.0 mJy), the percentage of unidentified sources decreases to about 25% in the faintest bins (S< 0.5 mJy). The median IAB magnitude for the total sample of radio sources, i.e. including also the unidentified ones, is brighter in the faintest radio bins than in the bin with higher radio flux. This suggests that most of the faintest radio sources are likely to be associated to relatively lower radio luminosity objects at relatively modest redshift, rather than radio-powerful, AGN type objects at high redshift. Using a classification in early-type and late-type galaxies based on the (B-I)AB color and the photometric redshift, we found that the majority of the radio sources below ~0.15 mJy are indeed late-type star forming galaxies. Finally, the radio sources without optical counterpart in our deep imaging have a median radio flux of 0.15 mJy, equal to that of identified sources. Given the very faint optical limits, these

  8. Bottled liquid explosive scanner by near infrared

    NASA Astrophysics Data System (ADS)

    Itozaki, Hideo

    2016-05-01

    A bottled liquid explosive scanner has been developed using near infrared technology for glass or PET bottles and ultrasound technology for metal cans. It has database of near infrared absorbance spectra and sound velocities of various liquids. Scanned liquids can be identified by using this database. This device has been certified by ECAC and installed at Japanese international airport.

  9. Near-infrared thermochromic diazapentalene dyes.

    PubMed

    Qian, Gang; Wang, Zhi Yuan

    2012-03-22

    A series of 2,5-diazapentalene containing dyes with tunable energy gaps are visible and near-infrared halochromic towards various acids and their protonated counterparts represent a new class of thermochromic materials with the near-infrared absorption being switched on at room temperature and off above 50 °C.

  10. Star formation in H II galaxies

    NASA Astrophysics Data System (ADS)

    Torres-Campos, A.; Díaz, A. I.; Terlevich, E.; Rosa-González, D.; Telles, E.; Terlevich, R.

    2013-05-01

    H II galaxies integrated properties have been widely studied. However, little is known about the individual H II regions and their photoionizing stellar clusters. To broaden our knowledge on star formation in low mass star-forming galaxies (like H II galaxies) it is necessary to answer questions like: How does the star formation distributes along the galaxy? Is it possible for them to form super stellar clusters? How does the star formation history on them looks like? To answer those questions the goal of this thesis work is to map (at tens of parsecs resolution) the recent star formation in six H II galaxies with extremely young star-forming bursts (Rosa-González et al. 2007, ApJ, 654, 226). The preliminary results obtained have allowed us to develop a catalog of H II regions (identified for the first time) in these galaxies and the characterization of the young stellar clusters responsible for their photoionization using POPSTAR (Mollá, García-Vargas, & Bressan 2009, MNRAS, 398, 451) stellar populations models.

  11. Near-infrared-emitting phthalocyanines. A combined experimental and density functional theory study of the structural, optical, and photophysical properties of Pd(II) and Pt(II) α-butoxyphthalocyanines.

    PubMed

    Soldatova, Alexandra V; Kim, Junhwan; Rizzoli, Corrado; Kenney, Malcolm E; Rodgers, Michael A J; Rosa, Angela; Ricciardi, Giampaolo

    2011-02-07

    The structural, optical, and photophysical properties of 1,4,8,11,15,18,22,25-octabutoxyphthalocyaninato-palladium(II), PdPc(OBu)(8), and the newly synthesized platinum analogue PtPc(OBu)(8) are investigated combining X-ray crystallography, static and transient absorption spectroscopy, and relativistic zeroth-order regular approximation (ZORA) Density Functional Theory (DFT)/Time Dependent DFT (TDDFT) calculations where spin-orbit coupling (SOC) effects are explicitly considered. The results are compared to those previously reported for NiPc(OBu)(8) (J. Phys. Chem. A 2005, 109, 2078) in an effort to highlight the effect of the central metal on the structural and photophysical properties of the group 10 transition metal octabutoxyphthalocyanines. Different from the nickel analogue, PdPc(OBu)(8) and PtPc(OBu)(8) show a modest and irregular saddling distortion of the macrocycle, but share with the first member of the group similar UV-vis spectra, with the deep red and intense Q-band absorption experiencing a blue shift down the group, as observed in virtually all tetrapyrrolic complexes of this triad. The blue shift of the Q-band along the MPc(OBu)(8) (M = Ni, Pd, Pt) series is interpreted on the basis of the metal-induced electronic structure changes. Besides the intense deep red absorption, the title complexes exhibit a distinct near-infrared (NIR) absorption due to a transition to the double-group 1E (π,π*) state, which is dominated by the lowest single-group (3)E (π,π*) state. Unlike NiPc(OBu)(8), which is nonluminescent, PdPc(OBu)(8) and PtPc(OBu)(8) show both deep red fluorescence emission and NIR phosphorescence emission. Transient absorption experiments and relativistic spin-orbit TDDFT calculations consistently indicate that fluorescence and phosphorescence emissions occur from the S(1)(π,π*) and T(1)(π,π*) states, respectively, the latter being directly populated from the former, and the triplet state decays directly to the S(0) surface (the triplet

  12. 21 CFR 882.1935 - Near Infrared (NIR) Brain Hematoma Detector.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Near Infrared (NIR) Brain Hematoma Detector. 882... Infrared (NIR) Brain Hematoma Detector. (a) Identification. A Near Infrared (NIR) Brain Hematoma Detector... evaluate suspected brain hematomas. (b) Classification. Class II (special controls). The special...

  13. 21 CFR 882.1935 - Near Infrared (NIR) Brain Hematoma Detector.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Near Infrared (NIR) Brain Hematoma Detector. 882... Infrared (NIR) Brain Hematoma Detector. (a) Identification. A Near Infrared (NIR) Brain Hematoma Detector... evaluate suspected brain hematomas. (b) Classification. Class II (special controls). The special...

  14. The Munich Near-Infrared Cluster Survey - IV. Biases in the completeness of near-infrared imaging data

    NASA Astrophysics Data System (ADS)

    Snigula, J.; Drory, N.; Bender, R.; Botzler, C. S.; Feulner, G.; Hopp, U.

    2002-11-01

    We present the results of completeness simulations for the detection of point sources as well as redshifted elliptical and spiral galaxies in the K'-band images of the Munich Near-Infrared Cluster Survey (MUNICS). The main focus of this work is to quantify the selection effects introduced by threshold-based object detection algorithms used in deep imaging surveys. Therefore, we simulate objects obeying the well-known scaling relations between effective radius and central surface brightness, for both de Vaucouleurs and exponential profiles. The results of these simulations, while presented for the MUNICS project, are applicable in a much wider context to deep optical and near-infrared selected samples. We investigate the detection probability as well as the reliability for recovering the true total magnitude with Kron-like (adaptive) aperture photometry. The results are compared with the predictions of the visibility theory of Disney and Phillipps in terms of the detection rate and the lost-light fraction. Additionally, the effects attributable to seeing are explored. The results show a bias against detecting high-redshifted massive elliptical galaxies in comparison to disc galaxies with exponential profiles, and that the measurements of the total magnitudes for intrinsically bright elliptical galaxies are systematically too faint. Disc galaxies, in contrast, show no significant offset in the magnitude measurement of luminous objects. Finally, we present an analytic formula to predict the completeness of point sources using only basic image parameters.

  15. Near-infrared IFU and MOS observations of supernova remnants

    NASA Astrophysics Data System (ADS)

    Lee, Ho-Gyu

    2016-06-01

    We present near-infrared IFU and MOS observations of two bright [Fe II] line emitting supernova remnants (SNRs). The two SNRs, G11.2-0.3 and RCW103, are selected from our near-infrared [Fe II] 1.64 um narrow band imaging survey of SNRs such as UKIRT unbiased [Fe II] imaging survey of the the Galactic plane and AAT [Fe II] imaging of some core-collapse SNRs. We detect several near-infrared hyperfine lines of [Fe II] at the southeastern shell of G11.2-0.3. We estimate the line strength and extinction-corrected density, which gives a clue to the origin of the iron-rich southeastern shell of G11.2-0.3. We obtain the MOS spectra of [Fe II]-emitting clumps inside RCW103. The observed clumps move about hundreds kilometers in radial direction, suggesting that they are shocked dense materials lost by stellar wind at the final stage of the evolution of the progenitor star.

  16. MOVPE growth of (GaIn)As/Ga(AsSb)/(GaIn)As type-II heterostructures on GaAs substrate for near infrared laser applications

    NASA Astrophysics Data System (ADS)

    Fuchs, C.; Beyer, A.; Volz, K.; Stolz, W.

    2017-04-01

    The growth of high quality (GaIn)As/Ga(AsSb)/(GaIn)As ;W;-quantum well heterostructures is discussed with respect to their application in 1300 nm laser devices. The structures are grown using metal organic vapor phase epitaxy and characterized using high-resolution X-ray diffraction, scanning transmission electron microscopy and photoluminescence measurements. The agreement between experimental high-resolution X-ray diffraction patterns and full dynamical simulations is verified for these structurally challenging heterostructures. Scanning transmission electron microscopy is used to demonstrate that the structure consists of well-defined quantum wells and forms the basis for future improvements of the optoelectronic quality of this materials system. By altering the group-V gas phase ratio, it is possible to cover a large spectral range between 1200 nm and 1470 nm using a growth temperature of 550 °C and a V/III ratio of 7.5. A comparison of a sample with a photoluminescence emission wavelength at 1360 nm with single quantum well material reference samples proves the type-II character of the emission. A further optimization of these structures for application in 1300 nm lasers by applying different V/III ratios yields a stable behavior of the photoluminescence intensity using a growth temperature of 550 °C.

  17. Construction of Identical [2 + 2] Schiff-Base Macrocyclic Ligands by Ln(III) and Zn(II) Template Ions Including Efficient Yb(III) Near-Infrared Sensitizers.

    PubMed

    Zhang, Kun; Zhang, Lei; Zhang, Song; Hu, Yong; Zheng, Youxuan; Huang, Wei

    2015-06-01

    Identical 34-membered [2 + 2] pendent-armed Schiff-base macrocyclic ligands (H4La and H4Lb) can be constructed via the condensation reactions between rigid o-phenylenediamine and extended dialdehydes (H2hpdd/H2pdd) in the presence of either Ln(III) or Zn(II) template with remarkable distinction on the ion radii and charge. X-ray single-crystal diffraction analyses reveal the formation of mononuclear Ln(III) complexes (1-4 and 7) and dinuclear Zn(II) complexes (5 and 6). It is noted that Ln(III) macrocyclic complexes have eight-coordinate sandwich-like mononuclear structures fully surrounded by flexible and large-sized macrocyclic ligands. Photophysical studies have demonstrated that both H4La and H4Lb can serve as effective sensitizers for the Yb(III) ion (2 and 7) exhibiting near-infrared emission at 974 nm with high quantum yields in solution (C2H5OH and CH3OH, ∼1%). Moreover, the quantum yields of two Yb(III) complexes 2 and 7 could be increased ∼15% in CH3OH under weak alkaline condition (pH = 8-9), while no significant changes are observed in C2H5OH by contrast. We think the unique sandwich-like macrocyclic structures of Yb(III) complexes 2 and 7 play important roles in simultaneously guaranteeing the effective match of the energy levels of Yb(III) centers as well as shielding from the solvent molecules and counterions.

  18. NIP: the near infrared imaging photometer for Euclid

    NASA Astrophysics Data System (ADS)

    Schweitzer, Mario; Bender, Ralf; Katterloher, Reinhard; Eisenhauer, Frank; Hofmann, Reiner; Saglia, Roberto; Holmes, Rory; Krause, Oliver; Rix, Hans-Walter; Booth, Jeff; Fagrelius, Parker; Rhodes, Jason; Seshadri, Suresh; Refregier, Alexandre; Amiaux, Jerome; Augueres, Jean-Louis; Boulade, Olivier; Cara, Christophe; Amara, Adam; Lilly, Simon; Atad-Ettedgui, Eli; di Giorgio, Anna-Maria; Duvet, Ludovic; Kuehl, Christopher; Syed, Mohsin

    2010-07-01

    The NIP is a near infrared imaging photometer that is currently under investigation for the Euclid space mission in context of ESA's 2015 Cosmic Vision program. Together with the visible camera (VIS) it will form the basis of the weak lensing measurements for Euclid. The NIP channel will perform photometric imaging in 3 near infrared bands (Y, J, H) covering a wavelength range from ~ 0.9 to 2 μm over a field of view (FoV) of ~ 0.5 deg2. With the required limiting point source magnitude of 24 mAB (5 sigma) the NIP channel will be used to determine the photometric redshifts of over 2 billion galaxies collected over a wide survey area of 20 000 deg2. In addition to the photometric measurements, the NIP channel will deliver unique near infrared (NIR) imaging data over the entire extragalactic sky, enabling a wide variety of ancillary astrophysical and cosmological studies. In this paper we will present the results of the study carried out by the Euclid Imaging Consortium (EIC) during the Euclid assessment phase.

  19. Near infrared lasers in flow cytometry.

    PubMed

    Telford, William G

    2015-07-01

    Technology development in flow cytometry has closely tracked laser technology, the light source that flow cytometers almost exclusively use to excite fluorescent probes. The original flow cytometers from the 1970s and 1980s used large water-cooled lasers to produce only one or two laser lines at a time. Modern cytometers can take advantage of the revolution in solid state laser technology to use almost any laser wavelength ranging from the ultraviolet to the near infrared. Commercial cytometers can now be equipped with many small solid state lasers, providing almost any wavelength needed for cellular analysis. Flow cytometers are now equipped to analyze 20 or more fluorescent probes simultaneously, requiring multiple laser wavelengths. Instrument developers are now trying to increase this number by designing fluorescent probes that can be excited by laser wavelength at the "edges" of the visible light range, in the near ultraviolet and near-infrared region. A variety of fluorescent probes have been developed that excite with violet and long wavelength ultraviolet light; however, the near-infrared range (660-800 nm) has yet seen only exploitation in flow cytometry. Fortunately, near-infrared laser diodes and other solid state laser technologies appropriate for flow cytometry have been in existence for some time, and can be readily incorporated into flow cytometers to accelerate fluorescent probe development. The near infrared region represents one of the last "frontiers" to maximize the number of fluorescent probes that can be analyzed by flow cytometry. In addition, near infrared fluorescent probes used in biomedical tracking and imaging could also be employed for flow cytometry with the correct laser wavelengths. This review describes the available technology, including lasers, fluorescent probes and detector technology optimal for near infrared signal detection.

  20. Near-infrared hyperspectral reflective confocal microscopy

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Zhang, Yunhai; Miao, Xin; Xue, Xiaojun; Xiao, Yun

    2016-10-01

    A Near-Infrared HyperSpectral Reflective Confocal Microscopy (NIHS-RCM) is proposed in order to get high resolution images of deep biological tissues such as skin. The microscopy system uses a super-continuum laser for illumination, an acousto-optic tunable filter (AOTF) for rapid selection of near-infrared spectrum, a resonant galvanometer scanner for high speed imaging (15f/s) and near-infrared avalanche diode as detector. Porcine skin and other experiments show that the microscopy system could get deep tissue images (180 μm), and show the different ingredients of tissue with different wavelength of illumination. The system has the ability of selectively imaging of multiple ingredients at deep tissue which can be used in skin diseases diagnosis and other fields.

  1. Optical absorption near infrared and EPR studies of mottramite

    NASA Astrophysics Data System (ADS)

    Lakshmi Reddy, S.; Reddy, K. N. M.; Siva Reddy, G.; Endo, Tamio; Frost, R. L.

    2010-06-01

    Mottramite mineral from Tsumeb Corporation Mine, Tsumeb, Otavi, Namibia, is investigated in this present work. The mineral contains vanadium and copper contents of 22.73% and 16.84% by weight, respectively, as V2O5 and CuO. An electron paramagnetic resonance (EPR) study confirmed the presence of Cu(II) with g = 2.2. The optical absorption spectrum of mottramite indicates that Cu(II) is present in a rhombic environment. Near infrared results are due to water fundamentals.

  2. Enhanced visible and near-infrared capabilities of the JET mirror-linked divertor spectroscopy system

    SciTech Connect

    Lomanowski, B. A. Sharples, R. M.; Meigs, A. G.; Conway, N. J.; Zastrow, K.-D.; Heesterman, P.; Kinna, D. [EURATOM Collaboration: JET-EFDA Team

    2014-11-15

    The mirror-linked divertor spectroscopy diagnostic on JET has been upgraded with a new visible and near-infrared grating and filtered spectroscopy system. New capabilities include extended near-infrared coverage up to 1875 nm, capturing the hydrogen Paschen series, as well as a 2 kHz frame rate filtered imaging camera system for fast measurements of impurity (Be II) and deuterium Dα, Dβ, Dγ line emission in the outer divertor. The expanded system provides unique capabilities for studying spatially resolved divertor plasma dynamics at near-ELM resolved timescales as well as a test bed for feasibility assessment of near-infrared spectroscopy.

  3. Enhanced visible and near-infrared capabilities of the JET mirror-linked divertor spectroscopy systema)

    NASA Astrophysics Data System (ADS)

    Lomanowski, B. A.; Meigs, A. G.; Conway, N. J.; Zastrow, K.-D.; Sharples, R. M.; Heesterman, P.; Kinna, D.

    2014-11-01

    The mirror-linked divertor spectroscopy diagnostic on JET has been upgraded with a new visible and near-infrared grating and filtered spectroscopy system. New capabilities include extended near-infrared coverage up to 1875 nm, capturing the hydrogen Paschen series, as well as a 2 kHz frame rate filtered imaging camera system for fast measurements of impurity (Be II) and deuterium Dα, Dβ, Dγ line emission in the outer divertor. The expanded system provides unique capabilities for studying spatially resolved divertor plasma dynamics at near-ELM resolved timescales as well as a test bed for feasibility assessment of near-infrared spectroscopy.

  4. Note: Near infrared interferometric silicon wafer metrology.

    PubMed

    Choi, M S; Park, H M; Joo, K N

    2016-04-01

    In this investigation, two near infrared (NIR) interferometric techniques for silicon wafer metrology are described and verified with experimental results. Based on the transparent characteristic of NIR light to a silicon wafer, the fiber based spectrally resolved interferometry can measure the optical thickness of the wafer and stitching low coherence scanning interferometry can reconstruct entire surfaces of the wafer.

  5. The Structure and Environment of H II Galaxies

    NASA Astrophysics Data System (ADS)

    Telles, Eduardo

    1996-05-01

    H II galaxies are dwarf star forming galaxies found in objective prism surveys through their strong emission lines. They have been targets of extensive studies of their spectroscopic properties such as chemical abundances, physical conditions and kinematics. Little surface photometry work has been done on H II galaxies up to now. This thesis is primarily a CCD surface photometry study of the structural properties, optical colors and a statistical analysis of the environment of H II galaxies. In the chapter "The Morphology of H II Galaxies" I have used a sample of 39 H II galaxies with CCD images for a study of their overall morphology and luminosity profiles. The results show that H II galaxies can be classified in two main types: type I H II galaxies are luminous and have disturbed and irregular outer shapes while type II H II galaxies are less luminous and have regular shapes. The outer parts of profiles of all HIi galaxies are well represented by an exponential as in other types of known dwarf galaxies. In "The Dynamics of H II Galaxies" I have investigated the relation between the linear size of the starburst, luminosity and velocity dispersion. It is found that H II galaxies have similar relations as virialized systems which supports the gravitational origin of their overall kinematics. The possible bi-parametric behavior ("fundamental plane") of H II galaxies is also investigated. However, a conclusive answer to this question still requires more and better data. In "The Colors of H II Galaxies" I have presented a high spatial resolution CCD surface photometry study. The colors of the underlying stellar continuum within the starburst are obtained by removing the flux contribution of the emission lines in the broad band filters. Comparison with recent evolutionary population synthesis models show that the observational errors and the uncertainties in the models are still too large to put strict constraints on their past star formation history. However, the

  6. Far Outer Galaxy H II Regions

    NASA Technical Reports Server (NTRS)

    Rudolph, A. L.; deGues, E. J.; Brand, J.; Wouterloot, J. G. A.; Gross, Anthony R. (Technical Monitor)

    1994-01-01

    We have made a multifrequency (6, 3.6, and 2 cm), high-resolution (3"-6"), radio continuum survey of IRAS selected sources from the catalogue of Wouterloot & Brand (1989) to search for and study H II regions in the far outer Galaxy. We identified 31 sources in this catalog with well determined galactocentric distances, and with R approx.. greater than 15 kpc and L(sub FIR) approx.greater than 10(exp 4) solar luminosity, indicating the presence of high-mass star-formation. We have observed 11 of these sources with the Very Large Array (VLA). We observed the sources at 6 and 2 cm using "scaled arrays", making possible a direct and reliable comparison of the data at these two wavelengths for the determination of spectral indices. We detected a total of 12 radio sources, of which 10 have spectral indices consistent with optically-thin free-free emission from H II regions. Combined with previous VLA observations by other investigators, we have data on a total of 15 H II regions at galactocentric distances of 15 to 18.2kpc, among the most remote H II regions found in our Galaxy. The sizes of the H II regions range from approx. less than 0.10 to 2.3 pc. Using the measured fluxes and sizes, we determine the electron densities, emission measures, and excitation parameters of the H II regions, as well as the fluxes of Lyman continuum photons needed to keep the nebulae ionized. The sizes and electron densities are consistent with most of the sources detected in this survey being compact or ultracompact H II regions. Seven of the fifteen H II regions have sizes approx. less than 0.20 pc. Assuming simple pressure-driven expansion of the H II regions, these sizes indicate ages approx. less than 5 x 10(exp 4) yr, or only 1% of the lifetime of an O star, which implies an unlikely overabundance of O stars in the outer Galaxy. Thus, the large number of compact H II regions suggests that the time these regions spend in a compact phase must be much longer than their dynamical

  7. [Near infrared light irradiator using halogen lamp].

    PubMed

    Ide, Yasuo

    2012-07-01

    The practical electric light bulb was invented by Thomas Alva Edison in 1879. Halogen lamp is the toughest and brightest electric light bulb. With light filter, it is used as a source of near infrared light. Super Lizer and Alphabeam are made as near infrared light irradiator using halogen lamp. The light emmited by Super Lizer is linear polarized near infrared light. The wave length is from 600 to 1,600 nm and strongest at about 1,000 nm. Concerning Super Lizer, there is evidence of analgesic effects and normalization of the sympathetic nervous system. Super Lizer has four types of probes. SG type is used for stellate ganglion irradiation. B type is used for narrow area irradiation. C and D types are for broad area irradiation. The output of Alphabeam is not polarized. The wave length is from 700 to 1,600 nm and the strongest length is about 1,000nm. Standard attachment is used for spot irradiation. Small attachment is used for stellate ganglion irradiation. Wide attachment is used for broad area irradiation. The effects of Alphabeam are thought to be similar to that of Super Lizer.

  8. Liquid explosive detection using near infrared LED

    NASA Astrophysics Data System (ADS)

    Itozaki, Hideo; Ito, Shiori; Sato-Akaba, Hideo; Miyato, Yuji

    2015-10-01

    A bottle scanner to detect liquid explosive has been developed using technologies of near infrared. Its detection rate of liquid explosive is quite high and its false alarm rate of safe liquids quite low. It uses a light source with wide spectrum such as a halogen lamp. Recently a variety of LEDs have been developed and some of them have near infrared spectrum. Here a near infrared LED is tested as a light source of the liquid explosive detector. Three infrared LEDs that have a main peak of spectrum at 901nm, 936nm, and 1028 nm have been used as a light source to scan liquids. Spectrum widths of these LEDs are quite narrow typically less than 100 nm. Ten typical liquids have been evaluated by these LEDs and the correlation coefficients of a spectrum by an LED and a tungsten lamp were more than 0.98. This experiment shows that the infrared LED can be used as a light source for the liquid scanner. An LED has some merits, such as long life of more than some ten thousand hours and small consumption electric power of less than 0.2 W. When the LED is used as a light source for the liquid scanner, it is also more compact and handy.

  9. Near-infrared peptide-coated quantum dots for small animal imaging

    NASA Astrophysics Data System (ADS)

    Iyer, Gopal; Li, Jack J.; Pinaud, Fabien; Tsay, James M.; Bentolila, Laurent A.; Michalet, Xavier; Weiss, Shimon

    2006-02-01

    We have synthesized high quality type-II CdTe/CdSe near infrared quantum dots using successive ion layer adsorption and reaction chemistry. Transmission electron microscopy reveals that CdTe/CdSe can be synthesized layer by layer yielding quantum dots of narrow size distribution. Excitation and photoluminescence spectra reveal discrete type-II transitions, which correspond to energy lower that type-I bandgap. We have used a peptide coating technique on type-II and commercial near infrared quantum dots for delivery in live animals and cultured cells.

  10. Near-Infrared Spectra of Uranian Satellites

    NASA Astrophysics Data System (ADS)

    Venturini, C. C.; Lynch, D. K.; Rudy, R. J.; Mazuk, S.; Puetter, R. C.

    2001-05-01

    We present 0.8 to 2.5 micron spectra taken on June 21 & 22, 1998 UT of the Uranian satellites Miranda, Titania, Ariel, Oberon, and Umbriel. The spectra were taken using The Aerospace Corporation's Near-Infrared Imaging Spectragraph (NIRIS) on the University of California's Lick Observatory 3 meter Shane telescope. These spectra will be compared with previous work including Brown, R.H. and Cruikshank, D.P. (1983) as well as more recent spectra and analysis by Grundy, W. et al. (1999). Support for this research was provided by The Aerospace Corporation's Independent Research and Development Program.

  11. Near-infrared scintillation of liquid argon

    SciTech Connect

    Alexander, T.; Escobar, C. O.; Lippincott, W. H.; Rubinov, P.

    2016-03-03

    Since the 1970s it has been known that noble gases scintillate in the near infrared (NIR) region of the spectrum (0.7 $\\mu$m < $\\lambda$; < 1.5$\\mu$m). More controversial has been the question of the NIR light yield for condensed noble gases. We first present the motivation for using the NIR scintillation in liquid argon detectors, then briefly review early as well as more recent efforts and finally show encouraging preliminary results of a test performed at Fermilab.

  12. Near-infrared spectroscopy of dark asteroids.

    PubMed

    Barucci, M A; Lazzarin, M; Owen, T; Barbieri, C; Fulchignoni, M

    1994-08-01

    Near-infrared (J, H and K bands) spectra of nine dark asteroids (chosen among a sample of supposed primitive objects between C and D classes) have been obtained at the Mauna Kea Observatory (Hawaii) with the 2.2-m telescope using KSPEC as spectrograph. The aim of this work was to search for evidence of the presence of organic materials in these objects as found in other planetary bodies as 5145 Pholus, and in some cometary nuclei. A careful analysis of the data has revealed flat or slightly redder spectra than the solar one for all observed asteroids. No evidence of distinct absorption features was found.

  13. The VIRMOS deep imaging survey. IV. Near-infrared observations

    NASA Astrophysics Data System (ADS)

    Iovino, A.; McCracken, H. J.; Garilli, B.; Foucaud, S.; Le Fèvre, O.; Maccagni, D.; Saracco, P.; Bardelli, S.; Busarello, G.; Scodeggio, M.; Zanichelli, A.; Paioro, L.; Bottini, D.; Le Brun, V.; Picat, J. P.; Scaramella, R.; Tresse, L.; Vettolani, G.; Adami, C.; Arnaboldi, M.; Arnouts, S.; Bolzonella, M.; Cappi, A.; Charlot, S.; Ciliegi, P.; Contini, T.; Franzetti, P.; Gavignaud, I.; Guzzo, L.; Ilbert, O.; Marano, B.; Marinoni, C.; Mazure, A.; Meneux, B.; Merighi, R.; Paltani, S.; Pellò, R.; Pollo, A.; Pozzetti, L.; Radovich, M.; Zamorani, G.; Zucca, E.; Bertin, E.; Bondi, M.; Bongiorno, A.; Cucciati, O.; Gregorini, L.; Mathez, G.; Mellier, Y.; Merluzzi, P.; Ripepi, V.; Rizzo, D.

    2005-11-01

    In this paper we present a new deep, wide-field near-infrared imaging survey. Our J- and K-band observations in four separate fields (0226-04, 2217+00, 1003+02, 1400+05) complement optical BVRI, ultraviolet and spectroscopic observations undertaken as part of the VIMOS-VLT deep survey (VVDS). In total, our survey spans ~400 arcmin2. Our catalogues are reliable in all fields to at least K˜20.75 and J˜21.50 (defined as the magnitude where object contamination is less than 10% and completeness greater than 90%). Taken together these four fields represents a unique combination of depth, wavelength coverage and area. Most importantly, our survey regions span a broad range of right ascension and declination which allow us to make a robust estimate of the effects of cosmic variance. We describe the complete data reduction process from raw observations to the construction of source lists and outline a comprehensive series of tests carried out to characterise the reliability of the final catalogues. From simulations we determine the completeness function of each final stacked image, and estimate the fraction of spurious sources in each magnitude bin. We compare the statistical properties of our catalogues with literature compilations. We find that our J- and K-selected galaxy counts are in good agreement with previously published works, as are our (J-K) versus K colour-magnitude diagrams. Stellar number counts extracted from our fields are consistent with a synthetic model of our galaxy. Using the location of the stellar locus in colour-magnitude space and the measured field-to-field variation in galaxy number counts we demonstrate that the absolute accuracy of our photometric calibration is at the 5% level or better. Finally, an investigation of the angular clustering of K-selected extended sources in our survey displays the expected scaling behaviour with limiting magnitude, with amplitudes in each magnitude bin in broad agreement with literature values. In summary

  14. Homo- and Heterobimetallic Ruthenium(II) and Osmium(II) Complexes Based on a Pyrene-Biimidazolate Spacer as Efficient DNA-Binding Probes in the Near-Infrared Domain.

    PubMed

    Mardanya, Sourav; Karmakar, Srikanta; Mondal, Debiprasad; Baitalik, Sujoy

    2016-04-04

    We report in this work a new family of homo- and heterobimetallic complexes of the type [(bpy)2M(Py-Biimz)M'(II)(bpy)2](2+) (M = M' = Ru(II) or Os(II); M = Ru(II) and M' = Os(II)) derived from a pyrenyl-biimidazole-based bridge, 2-imidazolylpyreno[4,5-d]imidazole (Py-BiimzH2). The homobimetallic Ru(II) and Os(II) complexes were found to crystallize in monoclinic form with space group P21/n. All the complexes exhibit strong absorptions throughout the entire UV-vis region and also exhibit luminescence at room temperature. For osmium-containing complexes (2 and 3) both the absorption and emission band stretched up to the NIR region and thus afford more biofriendly conditions for probable applications in infrared imaging and phototherapeutic studies. Detailed luminescence studies indicate that the emission originates from the respective (3)MLCT excited state mainly centered in the [M(bpy)2](2+) moiety of the complexes and is only slightly affected by the pyrene moiety. The bimetallic complexes show two successive one-electron reversible metal-centered oxidations in the positive potential window and several reduction processes in the negative potential window. An efficient intramolecular electronic energy transfer is found to occur from the Ru center to the Os-based component in the heterometallic dyad. The binding studies of the complexes with DNA were thoroughly studied through different spectroscopic techniques such as UV-vis absorption, steady-state and time-resolved emission, circular dichroism, and relative DNA binding study using ethidium bromide. The intercalative mode of binding was suggested to be operative in all cases. Finally, computational studies employing DFT and TD-DFT were also carried out to interpret the experimentally observed absorption and emission bands of the complexes.

  15. MAGIICAT I. THE Mg II ABSORBER-GALAXY CATALOG

    SciTech Connect

    Nielsen, Nikole M.; Churchill, Christopher W.; Kacprzak, Glenn G.; Murphy, Michael T.

    2013-10-20

    We describe the Mg II Absorber-Galaxy Catalog, MAGIICAT, a compilation of 182 spectroscopically identified intermediate redshift (0.07 ≤ z ≤ 1.1) galaxies with measurements of Mg II λλ2796, 2803 absorption from their circumgalactic medium within projected distances of 200 kpc from background quasars. In this work, we present 'isolated' galaxies, which are defined as having no spectroscopically identified galaxy within a projected distance of 100 kpc and a line of sight velocity separation of 500 km s{sup –1}. We standardized all galaxy properties to the ΛCDM cosmology and galaxy luminosities, absolute magnitudes, and rest-frame colors to the B- and K-band on the AB system. We present galaxy properties and rest-frame Mg II equivalent width, W{sub r} (2796), versus galaxy redshift. The well-known anti-correlation between W{sub r} (2796) and quasar-galaxy impact parameter, D, is significant to the 8σ level. The mean color of MAGIICAT galaxies is consistent with an Sbc galaxy for all redshifts. We also present B- and K-band luminosity functions for different W{sub r} (2796) and redshift subsamples: 'weak absorbing' [W{sub r} (2796) < 0.3 Å], 'strong absorbing' [W{sub r} (2796) ≥ 0.3 Å], low redshift (z < (z)), and high redshift (z ≥ (z)), where (z) = 0.359 is the median galaxy redshift. Rest-frame color B – K correlates with M{sub K} at the 8σ level for the whole sample but is driven by the strong absorbing, high-redshift subsample (6σ). Using M{sub K} as a proxy for stellar mass and examining the luminosity functions, we infer that in lower stellar mass galaxies, Mg II absorption is preferentially detected in blue galaxies and the absorption is more likely to be weak.

  16. MAGIICAT I. The Mg II Absorber-Galaxy Catalog

    NASA Astrophysics Data System (ADS)

    Nielsen, Nikole M.; Churchill, Christopher W.; Kacprzak, Glenn G.; Murphy, Michael T.

    2013-10-01

    We describe the Mg II Absorber-Galaxy Catalog, MAGIICAT, a compilation of 182 spectroscopically identified intermediate redshift (0.07 <= z <= 1.1) galaxies with measurements of Mg II λλ2796, 2803 absorption from their circumgalactic medium within projected distances of 200 kpc from background quasars. In this work, we present "isolated" galaxies, which are defined as having no spectroscopically identified galaxy within a projected distance of 100 kpc and a line of sight velocity separation of 500 km s-1. We standardized all galaxy properties to the ΛCDM cosmology and galaxy luminosities, absolute magnitudes, and rest-frame colors to the B- and K-band on the AB system. We present galaxy properties and rest-frame Mg II equivalent width, Wr (2796), versus galaxy redshift. The well-known anti-correlation between Wr (2796) and quasar-galaxy impact parameter, D, is significant to the 8σ level. The mean color of MAGIICAT galaxies is consistent with an Sbc galaxy for all redshifts. We also present B- and K-band luminosity functions for different Wr (2796) and redshift subsamples: "weak absorbing" [Wr (2796) < 0.3 Å], "strong absorbing" [Wr (2796) >= 0.3 Å], low redshift (z < langzrang), and high redshift (z >= langzrang), where langzrang = 0.359 is the median galaxy redshift. Rest-frame color B - K correlates with MK at the 8σ level for the whole sample but is driven by the strong absorbing, high-redshift subsample (6σ). Using MK as a proxy for stellar mass and examining the luminosity functions, we infer that in lower stellar mass galaxies, Mg II absorption is preferentially detected in blue galaxies and the absorption is more likely to be weak.

  17. The Origin of the Excess Near-Infrared Diffuse Sky Brightness: Population III Stars or Zodiacal Light?

    NASA Technical Reports Server (NTRS)

    Dwek, Eli

    2006-01-01

    The intensity of the diffuse 1 to 5 micron sky emission from which solar system and Galactic foregrounds have been subtracted is in excess of that expected from energy released by galaxies and stars that formed during the z < 5 redshift interval. The spectral signature of this excess near-infrared background light (NIRBL) component is almost identical to that of reflected sunlight from the interplanetary dust cloud, and could therefore be the result of the incomplete subtraction of this foreground emission component from the diffuse sky maps. Alternatively, this emission component could be extragalactic. Its spectral signature is consistent with that of redshifted continuum and recombination line emission from H-II regions formed by the first generation of very massive stars. In this talk I will present the implications of this excess emission for our understanding of the zodiacal dust cloud, the formation rate of Pop III stars, and the TeV gamma-ray opacity to nearby blazars.

  18. Jupiter in blue, ultraviolet and near infrared

    NASA Technical Reports Server (NTRS)

    2000-01-01

    These three images of Jupiter, taken through the narrow angle camera of NASA's Cassini spacecraft from a distance of 77.6 million kilometers (48.2 million miles) on October 8, reveal more than is apparent to the naked eye through a telescope.

    The image on the left was taken through the blue filter. The one in the middle was taken in the ultraviolet. The one on the right was taken in the near infrared.

    The blue-light filter is within the part of the electromagnetic spectrum detectable by the human eye. The appearance of Jupiter in this image is, consequently, very familiar. The Great Red Spot (below and to the right of center) and the planet's well-known banded cloud lanes are obvious. The brighter bands of clouds are called zones and are probably composed of ammonia ice particles. The darker bands are called belts and are made dark by particles of unknown composition intermixed with the ammonia ice.

    Jupiter's appearance changes dramatically in the ultraviolet and near infrared images. These images are near negatives of each other and illustrate the way in which observations in different wavelength regions can reveal different physical regimes on the planet.

    All gases scatter sunlight efficiently at short wavelengths; this is why the sky appears blue on Earth. The effect is even more pronounced in the ultraviolet. The gases in Jupiter's atmosphere, above the clouds, are no different. They scatter strongly in the ultraviolet, making the deep banded cloud layers invisible in the middle image. Only the very high altitude haze appears dark against the bright background. The contrast is reversed in the near infrared, where methane gas, abundant on Jupiter but not on Earth, is strongly absorbing and therefore appears dark. Again the deep clouds are invisible, but now the high altitude haze appears relatively bright against the dark background. High altitude haze is seen over the poles and the equator.

    The Great Red Spot, prominent in all images, is

  19. An Empirical Determination of the Intergalactic Background Light Using Near-Infrared Deep Galaxy Survey Data Out to 5 Micrometers and the Gamma-Ray Opacity of the Universe

    NASA Technical Reports Server (NTRS)

    Scully, Sean T.; Malkan, Matthew A.; Stecker, Floyd W.

    2014-01-01

    We extend our previous model-independent determination of the intergalactic background light, based purely on galaxy survey data, out to a wavelength of 5 micrometers. Our approach enables us to constrain the range of photon densities, based on the uncertainties from observationally determined luminosity densities and colors. We further determine a 68% confidence upper and lower limit on the opacity of the universe to gamma-rays up to energies of 1.6/(1 + z) terraelectron volts. A comparison of our lower limit redshift-dependent opacity curves to the opacity limits derived from the results of both ground-based air Cerenkov telescope and Fermi-LAT observations of PKS 1424+240 allows us to place a new upper limit on the redshift of this source, independent of IBL modeling.

  20. An empirical determination of the intergalactic background light using near-infrared deep galaxy survey data out to 5 μm and the gamma-ray opacity of the universe

    SciTech Connect

    Scully, Sean T.; Malkan, Matthew A.; Stecker, Floyd W.

    2014-04-01

    We extend our previous model-independent determination of the intergalactic background light, based purely on galaxy survey data, out to a wavelength of 5 μm. Our approach enables us to constrain the range of photon densities, based on the uncertainties from observationally determined luminosity densities and colors. We further determine a 68% confidence upper and lower limit on the opacity of the universe to γ-rays up to energies of 1.6/(1 + z) TeV. A comparison of our lower limit redshift-dependent opacity curves to the opacity limits derived from the results of both ground-based air Cerenkov telescope and Fermi-LAT observations of PKS 1424+240 allows us to place a new upper limit on the redshift of this source, independent of IBL modeling.

  1. Near-infrared absolute magnitudes of Type Ia Supernovae

    NASA Astrophysics Data System (ADS)

    Avelino, Arturo; Friedman, Andrew S.; Mandel, Kaisey; Kirshner, Robert; Challis, Peter

    2017-01-01

    Type Ia Supernovae light curves (SN Ia) in the near infrared (NIR) exhibit low dispersion in their peak luminosities and are less vulnerable to extinction by interstellar dust in their host galaxies. The increasing number of high quality NIR SNe Ia light curves, including the recent CfAIR2 sample obtained with PAIRITEL, provides updated evidence for their utility as standard candles for cosmology. Using NIR YJHKs light curves of ~150 nearby SNe Ia from the CfAIR2 and CSP samples, and from the literature, we determine the mean value and dispersion of the absolute magnitude in the range between -10 to 50 rest-frame days after the maximum luminosity in B band. We present the mean light-curve templates and Hubble diagram for YJHKs bands. This work contributes to a firm local anchor for supernova cosmology studies in the NIR which will help to reduce the systematic uncertainties due to host galaxy dust present in optical-only studies. This research is supported by NSF grants AST-156854, AST-1211196, Fundacion Mexico en Harvard, and CONACyT.

  2. PRIME: A Deep Near-infrared Survey Mission Concept

    NASA Astrophysics Data System (ADS)

    Zheng, W.; Ford, H. C.; Davidsen, A. F.; Kruk, J. W.; Tsvetanov, Z. I.; Szalay, A. S.; Hartig, G.; Postman, M.; Stockman, H. S.; Thompson, R.; Shu, P. K.; Lenzen, R.; Rix, H.-W.; Mark, D.; McGuffey, D.

    2000-12-01

    PRIME (The Primordial Explorer) is a proposed mission that has been selected for NASA SMEX concept study. It will carry out a deep sky survey from space in four near-infrared bands between 0.9-3.5 micron. The 0.75m telescope will survey a quarter of the sky to AB magnitude of approximately 24 in 1.5 years. Deeper surveys in selected sky regions are also planned. PRIME will reach an epoch during which the first quasars, galaxies and clusters of galaxies were formed in the early Universe, discover hundreds of Type-Ia supernovae to be used in measuring the acceleration of the expanding Universe, and detect hundreds of brown dwarfs and even Jupiter-size planets in the vicinity of the solar system. Most of these objects are so rare that they may be identified only in large and deep surveys. PRIME will serve as a pilot mission for the Next Generation Space Telescope (NGST) supplying rare targets for NGST spectroscopy and deep imaging. Combining PRIME with other surveys (SDSS, GALEX) will yield the largest astronomical database ever built.

  3. Precise Near-Infrared Radial Velocities

    NASA Astrophysics Data System (ADS)

    Plavchan, Peter; Gao, P.; Bottom, M.; Davison, C.; Mills, S.; Ciardi, D. R.; Brinkworth, C.; Tanner, A. M.; Beichman, C. A.; Catanzarite, J.; Crawford, S.; Wallace, J.; Mennesson, B.; Johnson, J. A.; White, R. J.; Anglada-Escudé, G.; von Braun, K.; Walp, B.; Vasisht, G.; Kane, S. R.; Prato, L. A.; NIRRVs

    2014-01-01

    We present precise radial velocity time-series from a 2.3 micron pilot survey to detect exoplanets around red, low mass, and young stars. We use the CSHELL spectrograph with an isotopic methane absorption gas cell for common optical path relative wavelength calibration at the NASA InfraRed Telescope Facility. We present an overview of our Nelder-Mead simplex optimization pipeline for extracting radial velocities. We will also present first light data at 1.6 microns from a near-infrared fiber scrambler used in tandem with our gas cell and CSHELL at IRTF. The fiber scrambler makes use of non-circular core fibers to stabilize the illumination of the slit and echelle grating against changes in seeing, focus, guiding and other sources of systematic radial velocity noise, complementing the wavelength calibration of a gas cell.

  4. Precise Near-Infrared Radial Velocities

    NASA Astrophysics Data System (ADS)

    Plavchan, Peter; Gao, Peter; Gagne, Jonathan; Furlan, Elise; Brinkworth, Carolyn; Bottom, Michael; Tanner, Angelle; Anglada-Escude, Guillem; White, Russel; Davison, Cassy; Mills, Sean; Beichman, Chas; Johnson, John Asher; Ciardi, David; Wallace, Kent; Mennesson, Bertrand; Vasisht, Gautam; Prato, Lisa; Kane, Stephen; Crawford, Sam; Crawford, Tim; Sung, Keeyoon; Drouin, Brian; Lin, Sean; Leifer, Stephanie; Catanzarite, Joe; Henry, Todd; von Braun, Kaspar; Walp, Bernie; Geneser, Claire; Ogden, Nick; Stufflebeam, Andrew; Pohl, Garrett; Regan, Joe

    2016-01-01

    We present the results of two 2.3 μm near-infrared (NIR) radial velocity (RV) surveys to detect exoplanets around 36 nearby and young M dwarfs. We use the CSHELL spectrograph (R ~ 46,000) at the NASA InfraRed Telescope Facility (IRTF), combined with an isotopic methane absorption gas cell for common optical path relative wavelength calibration. We have developed a sophisticated RV forward modeling code that accounts for fringing and other instrumental artifacts present in the spectra. With a spectral grasp of only 5 nm, we are able to reach long-term radial velocity dispersions of ~20-30 m s-1 on our survey targets.

  5. Detection of bottled explosives by near infrared

    NASA Astrophysics Data System (ADS)

    Itozaki, Hideo; Sato-Akaba, Hideo

    2013-10-01

    Bottled liquids are not allowed through the security gate in the airport, because liquid explosives have been used by the terrorists. However, passengers have a lot of trouble if they cannot bring their own bottles. For example, a mother would like to carry her own milk in the airplane for her baby. Therefore the detection technology of liquid explosives should be developed as soon as possible. This paper shows that near infrared spectroscopy can detect bottled explosives quickly. The transmission method cannot deal with milk in the sense of liquid inspection. Here we examined the reflection method to the test of milk. The inspection method with light cannot make test for the metal can. We also use ultrasonic method to check metal can simultaneously in order to expand test targets.

  6. Near-infrared light photoacoustic ophthalmoscopy

    PubMed Central

    Liu, Tan; Wei, Qing; Song, Wei; Burke, Janice M.; Jiao, Shuliang; Zhang, Hao F.

    2012-01-01

    We achieved photoacoustic ophthalmoscopy (PAOM) imaging of the retina with near-infrared (NIR) light illumination. A PAOM imaging system with dual-wavelength illumination at 1064 nm and 532 nm was built. We compared in vivo imaging results of both albino and pigmented rat eyes at the two wavelengths. The results show that the bulk optical absorption of the retinal pigment epithelium (RPE) is only slightly higher than that of the retinal vessels at 532 nm while it becomes more than an order of magnitude higher than that of the retinal vessels at 1064 nm. These studies suggest that although visible light illumination is suitable for imaging both the retinal vessels and the RPE, NIR light illumination, being more comfortable to the eye, is better suited for RPE melanin related investigations and diagnoses. PMID:22574266

  7. Near-Infrared Intraoperative Chemiluminescence Imaging.

    PubMed

    Büchel, Gabriel E; Carney, Brandon; Shaffer, Travis M; Tang, Jun; Austin, Christine; Arora, Manish; Zeglis, Brian M; Grimm, Jan; Eppinger, Jörg; Reiner, Thomas

    2016-09-20

    Intraoperative imaging technologies recently entered the operating room, and their implementation is revolutionizing how physicians plan, monitor, and perform surgical interventions. In this work, we present a novel surgical imaging reporter system: intraoperative chemiluminescence imaging (ICI). To this end, we have leveraged the ability of a chemiluminescent metal complex to generate near-infrared light upon exposure to an aqueous solution of Ce(4+) in the presence of reducing tissue or blood components. An optical camera spatially resolves the resulting photon flux. We describe the construction and application of a prototype imaging setup, which achieves a detection limit as low as 6.9 pmol cm(-2) of the transition-metal-based ICI agent. As a proof of concept, we use ICI for the in vivo detection of our transition metal tracer following both systemic and subdermal injections. The very high signal-to-noise ratios make ICI an interesting candidate for the development of new intraoperative imaging technologies.

  8. Evaluation of a near-infrared photomultiplier

    NASA Technical Reports Server (NTRS)

    Evans, W. E.

    1978-01-01

    A high performance near infrared sensitive photomultiplier tube was procured and evaluated with emphasis on those characteristics affecting its use over the very large amplitude range of signals encountered by an airborne lidar intended for mapping the distribution of stratospheric aerosols. A cathode quantum efficiency of 4.3 percent at 1.06 micrometer wavelength and a background count of less than 10,000 per second were realized. It is recommended that the tube be stored and operated at a temperature near -20 C, or cooler. Performance was found acceptable for the application in both pulse counting and analog modes, but careful design, probably including dynamic gain control, will be required to effectively utilize both modes on the same lidar shot.

  9. Near Infrared (nir) Imaging for Nde

    NASA Astrophysics Data System (ADS)

    Diamond, G. G.; Pallav, P.; Hutchins, D. A.

    2008-02-01

    A novel application of near infrared (NIR) signals is presented, which can be used to provide images of many different materials and objects. It is effectively a very low cost non-ionising alternative to many applications currently being investigated using electromagnetic waves at other frequencies, such as THz and X-ray imaging. This alternative technique can be realised by very simple and inexpensive electronics and is inherently far more portable and easy to use. Transmission imaging results from this technique are presented from examples industrial quality control, food inspection and various security applications, and the results compared to existing techniques. In addition, this technique can be used in through-transmission mode on biological and medical samples, and images are presented that differentiate between not only flesh and bone, but also various types of soft tissue.

  10. Near Infrared Astronomical Observing During the Daytime

    NASA Astrophysics Data System (ADS)

    Tinn Chee Jim, Kevin; Pier, Edward Alan; Cognion, Rita L.

    2015-08-01

    Ground-based, near-infrared astronomy has been mostly restriced to nighttime observing with occasional, bright solar system objects observed during the daytime. But for astronomical phenomena that are time-varying on timescales of less than a day, it would be advantageous to be able to gather data during the day and night. We explore some of the limitations of observing in the J, H, and K bands during the daytime. Atmospheric radiative transfer simulations show that K is the optimal common astronomical filter for daytime observations on Mauna Kea, but the J and H filters can also be used. Observations from Mauna Kea show that it is possible to observe objects at least as faint as K=15.5 during the early afternoon, with photometric accuracies only slightly worse than those obtained at night.

  11. Near-infrared absorptions of monomethylhydrazine

    NASA Technical Reports Server (NTRS)

    Murray, Mark; Kurtz, Joe

    1993-01-01

    The peak absorption coefficients for two near-infrared absorptions of monomethylhydrazine, CH3-N2H3, (MMH) were measured. Absorption bands located at 1.524 micrometers (6560/cm), 1.557 micrometers (6423/cm), and 1.583 micrometers (6316/cm) are assigned to the Delta upsilon = 2 overtones of the infared N-H stretching fundamentals at 3317, 3245 and 3177/cm. An absorption band located at 1.04 micrometers (9620 +/- 100/cm) is assigned to the Delta upsilon = 3 overtone of one of these fundamentals. The peak absorption coefficients (alpha(sub 10)) at 1.524 micrometers (6560 +/- 20/cm) and 1.04 micrometers (9620 +/- 100/cm) are 31 x 10(exp -3) and 0.97 x 10(exp -3)/(cm atm), respectively. Uncertainties in these coefficients were estimated to be less than +/- 20% due primarily to uncertainties in the partial vapor pressure of MMH.

  12. SPIRou -A Near-Infrared Spectropolarimeter @ CFHT

    NASA Astrophysics Data System (ADS)

    Malo, Lison; Moutou, Claire; Artigau, Etienne; Delfosse, Xavier; Donati, Jean-François; Doyon, Rene; Fouqué, Pascal; Morin, Julien; Martioli, Eder

    2015-12-01

    SPIRou is a near-infrared spectropolarimeter and a high-precision velocimeter optimized for both the detection and characterization of terrestrial planets orbiting nearby low-mass stars, and the study of the impact of magnetic field on the star-planet formation. The spectrograph is designed to record the whole near-infrared spectrum simultaneously in either circular or linear polarization and to reach a RV precision of 1 m/s at a resolving power of 75,000. It will be use to carry out the "SPIRou Legacy Survey" targeting two science objectives (habitable terrestrial planet detection & magnetic field impact on star-planet formation) and is intended to provide the community with an extensive, homogenous, well characterized and high-quality data. SPIRou is expected to make a major breakthrough in the field of telluric planets in the habitable zone of cool stars. Once implemented at CFHT in 2017, SPIRou is expected to be used extensively by the astronomical community - supporting in particular space missions such as TESS, JWST and PLATO. In this presentation, I will focus on the impact of the SPIRou future observing programs in the field of exoplanets: 1) the radial-velocity survey, its target selection of cool dwarfs, strategy and expectations; 2) the follow-up characterization of transiting candidates; 3) the search for giant planets around very young stars; 4) the importance of spectropolarimetry to filter out the intrinsic jitter of target stars at the sub m/s level; 5) the anticipated role in preparing further exoplanet characterization missions.

  13. Optical and Near-Infrared Imaging of Infrared-Excess Palomar-Green Quasars

    NASA Astrophysics Data System (ADS)

    Surace, Jason A.; Sanders, D. B.; Evans, A. S.

    2001-12-01

    Ground-based high spatial resolution (FWHM<0.3"-0.8") optical and near-infrared imaging (0.4-2.2 μm) is presented for a complete sample of optically selected Palomar-Green QSOs with far-infrared excesses at least as great as those of ``warm'' AGN-like ultraluminous infrared galaxies (Lir/LBBB>0.46). In all cases, the host galaxies of the QSOs were detected, and most have discernible two-dimensional structure. The QSO host galaxies and the QSO nuclei are similar in magnitude at H band. H-band luminosities of the hosts range from 0.5-7.5 L*, with a mean of 2.3 L*, and are consistent with those found in ultraluminous infrared galaxies. Both the QSO nuclei and the host galaxies have near-infrared excesses, which may be the result of dust associated with the nucleus and of recent dusty star formation in the host. These results suggest that some, but not all, optically selected QSOs may have evolved from an infrared active state triggered by the merger of two similarly sized L* galaxies, in a manner similar to that of the ultraluminous infrared galaxies.

  14. STELLAR POPULATIONS AND THE STAR FORMATION HISTORIES OF LOW SURFACE BRIGHTNESS GALAXIES. II. H II REGIONS

    SciTech Connect

    Schombert, James; McGaugh, Stacy; Maciel, Tamela E-mail: stacy.mcgaugh@case.edu

    2013-08-01

    The luminosities, colors, and H{alpha} emission for 429 H II regions in 54 low surface brightness (LSB) galaxies are presented. While the number of H II regions per galaxy is lower in LSB galaxies compared to star-forming irregulars and spirals, there is no indication that the size or luminosity function of H II regions differs from other galaxy types. The lower number of H II regions per galaxy is consistent with their lower total star formation rates. The fraction of the total L{sub H{alpha}} contributed by H II regions varies from 10% to 90% in LSB galaxies (the rest of the H{alpha} emission being associated with a diffuse component) with no correlation with galaxy stellar or gas mass. Bright H II regions have bluer colors, similar to the trend in spirals; their number and luminosities are consistent with the hypothesis that they are produced by the same H II luminosity function as spirals. Comparison with stellar population models indicates that the brightest H II regions in LSB galaxies range in cluster mass from a few 10{sup 3} M{sub Sun} (e.g., {rho} Oph) to globular-cluster-sized systems (e.g., 30 Dor) and that their ages are consistent with clusters from 2 to 15 Myr old. The faintest H II regions are comparable to those in the LMC powered by a single O or B star. Thus, star formation in LSB galaxies covers the full range of stellar cluster mass.

  15. Deep near-infrared survey of the Southern Sky (DENIS)

    NASA Technical Reports Server (NTRS)

    Deul, E.

    1992-01-01

    DENIS (Deep Near-Infrared Survey of the Southern Sky) will be the first complete census of astronomical sources in the near-infrared spectral range. The challenges of this novel survey are both scientific and technical. Phenomena radiating in the near-infrared range from brown dwarfs to galaxies in the early stages of cosmological evolution, the scientific exploitation of data relevant over such a wide range requires pooling expertise from several of the leading European astronomical centers. The technical challenges of a project which will provide an order of magnitude more sources than given by the IRAS space mission, and which will involve advanced data-handling and image-processing techniques, likewise require pooling of hardware and software resources, as well as of human expertise. The DENIS project team is composed of some 40 scientists, computer specialists, and engineers located in 5 European Community countries (France, Germany, Italy, The Netherlands, and Spain), with important contributions from specialists in Australia, Brazil, Chile, and Hungary. DENIS will survey the entire southern sky in 3 colors, namely in the I band at a wavelength of 0.8 micron, in the 1.25 micron J band, and in the 2.15 micron K' band. The sensitivity limits will be 18th magnitude in the I band, 16th in the J band, and 14.5th in the K' band. The angular resolution achieved will be 1 arcsecond in the I band, and 3.0 arcseconds in the J and K' bands. The European Southern Observatory 1 m telescope on La Silla will be dedicated to survey use during operations expected to last four years, commencing in late 1993. DENIS aims to provide the astronomical community with complete digitized infrared images of the full southern sky and a catalogue of extracted objects, both of the best quality and in readily accessible form. This will be achieved through dedicated software packages and specialized catalogues, and with assistance from the Leiden and Paris Data Analysis Centers. The data

  16. Process analytical technology case study: part II. Development and validation of quantitative near-infrared calibrations in support of a process analytical technology application for real-time release.

    PubMed

    Cogdill, Robert P; Anderson, Carl A; Delgado, Miriam; Chisholm, Robert; Bolton, Raymond; Herkert, Thorsten; Afnan, Ali M; Drennen, James K

    2005-10-06

    This article is the second of a series of articles detailing the development of near-infrared (NIR) methods for solid dosage-form analysis. Experiments were conducted at the Duquesne University Center for Pharmaceutical Technology to demonstrate a method for developing and validating NIR models for the analysis of active pharmaceutical ingredient (API) content and hardness of a solid dosage form. Robustness and cross-validation testing were used to optimize the API content and hardness models. For the API content calibration, the optimal model was determined as multiplicative scatter correction with Savitsky-Golay first-derivative preprocessing followed by partial least-squares (PLS) regression including 4 latent variables. API content calibration achieved root mean squared error (RMSE) and root mean square error of cross validation (RMSECV) of 1.48 and 1.80 mg, respectively. PLS regression and baseline-fit calibration models were compared for the prediction of tablet hardness. Based on robustness testing, PLS regression was selected for the final hardness model, with RMSE and RMSECV of 8.1 and 8.8 N, respectively. Validation testing indicated that API content and hardness of production-scale tablets is predicted with root mean square error of prediction of 1.04 mg and 8.5 N, respectively. Explicit robustness testing for high-flux noise and wavelength uncertainty demonstrated the robustness of the API concentration calibration model with respect to normal instrument operating conditions.

  17. Bioprocess monitoring using near-infrared spectroscopy.

    PubMed

    Suehara, Ken-ichiro; Yano, Takuo

    2004-01-01

    Near-infrared spectroscopy (NIR) is a nondestructive analytical technique that has been used for simultaneous prediction of the concentrations of several substrates, products and constructs in mixtures sampled from fermentation processes. In this chapter, we discuss applications of NIR for the monitoring of bioprocesses involving rice vinegar, compost, glycolipid, L-glutamic acid, lactic acid fermentation, mushroom cultivation, and Koji production. This includes detailed discussion of applications of NIR to process management of rice vinegar fermentation and compost fermentation. In the present study, absorbance at wavelengths between 400 and 2500 nm was measured at 2 nm intervals. To obtain calibration equations, multiple linear regression (MLR) was performed on NIR spectral data and conventional analysis values of a calibration sample set. To validate these calibration equations, they were used to calculate concentrations of a prediction sample set, which were then compared with concentrations measured by conventional methods. There was excellent agreement between the results of the conventional method and those of the NIR method, when both were used to analyze culture broth of rice vinegar fermentation and solid-state fermented compost. These results indicate that NIR is a useful method for monitoring and control of bioprocesses.

  18. Near-infrared fluorophores as biomolecular probes

    NASA Astrophysics Data System (ADS)

    Patonay, Gabor; Beckford, Garfield; Strekowski, Lucjan; Henary, Maged; Merid, Yonathan

    2010-02-01

    Near-Infrared (NIR) fluorescence has been valuable in analytical and bioanalytical chemistry. NIR probes and labels have been used for several applications, including hydrophobicity of protein binding sites, DNA sequencing, immunoassays, CE separations, etc. The NIR region (700-1100 nm) has advantages for the spectroscopist due to the inherently lower background interference from the biological matrix and the high molar absorptivities of NIR chromophores. During the studies we report here several NIR dyes were prepared to determine the role of the hydrophobicity of NIR dyes and their charge in binding to amino acids and proteins, e.g., serum albumins. We synthesized NIR dye homologs containing the same chromophore but substituents of varying hydrophobicity. Hydrophobic moieties were represented by alkyl and aryl groups. These NIR dyes of varying hydrophobicity exhibited varying degrees of H-aggregation in aqueous solution indicating that the degree of H-aggregation could be used as an indicator to predict binding characteristics to serum albumins. In order to understand what factors may be important in the binding process, spectral behavior of these varying hydrophobicity dyes were examined in the presence of amino acids. Typical dye structures that exhibit large binding constants to biomolecules were compared in order to optimize applications utilizing non-covalent interactions.

  19. The Euclid near-infrared calibration source

    NASA Astrophysics Data System (ADS)

    Holmes, Rory; Bizenberger, Peter; Krause, Oliver; Schweitzer, Mario; Glauser, Adrian M.

    2010-07-01

    The Euclid dark energy mission is currently competing in ESA's Cosmic Vision program. Its imaging instrument, which has one visible and one infrared channel, will survey the entire extragalactic sky during the 5 year mission. The near-infrared imaging photometer (NIP) channel, operating in the ~0.92 - 2.0 μm spectral range, will be used in conjunction with the visible imaging channel (VIS) to constrain the nature of dark energy and dark matter. To meet the stringent overall photometric requirement, the NIP channel requires a dedicated on-board flat-field source to calibrate the large, 18 detector focal plane. In the baseline concept a 170 mm Spectralon diffuser plate, mounted to a pre-existing shutter mechanism outside the channel, is used as a flat-field calibration target, negating the need for an additional single-point-failure mechanism. The 117 × 230 mm focal plane will therefore be illuminated through all of the channel's optical elements and will allow flat-field measurements to be taken in all wavelength bands. A ring of low power tungsten lamps, with custom reflecting elements optimized for optical performance, will be used to illuminate the diffuser plate. This paper details the end-to-end optical simulations of this concept, a potential mechanical implementation and the initial tests of the proposed key components.

  20. Near-Infrared Diffuse Optical Tomography

    PubMed Central

    Hielscher, A. H.; Bluestone, A. Y.; Abdoulaev, G. S.; Klose, A. D.; Lasker, J.; Stewart, M.; Netz, U.; Beuthan, J.

    2002-01-01

    Diffuse optical tomography (DOT) is emerging as a viable new biomedical imaging modality. Using near-infrared (NIR) light, this technique probes absorption as well as scattering properties of biological tissues. First commercial instruments are now available that allow users to obtain cross-sectional and volumetric views of various body parts. Currently, the main applications are brain, breast, limb, joint, and fluorescence/bioluminescence imaging. Although the spatial resolution is limited when compared with other imaging modalities, such as magnetic resonance imaging (MRI) or X-ray computerized tomography (CT), DOT provides access to a variety of physiological parameters that otherwise are not accessible, including sub-second imaging of hemodynamics and other fast-changing processes. Furthermore, DOT can be realized in compact, portable instrumentation that allows for bedside monitoring at relatively low cost. In this paper, we present an overview of current state-of-the -art technology, including hardware and image-reconstruction algorithms, and focus on applications in brain and joint imaging. In addition, we present recent results of work on optical tomographic imaging in small animals. PMID:14646043

  1. Near infrared photoimmunotherapy for lung metastases

    PubMed Central

    Sato, Kazuhide; Nagaya, Tadanobu; Mitsunaga, Makoto; Choyke, Peter L.; Kobayashi, Hisataka

    2015-01-01

    Lung metastases are a leading cause of cancer related deaths; nonetheless current treatments are limited. Near infrared photoimmunotherapy (NIR-PIT) is a new cancer treatment that combines the specificity of intravenously injected antibodies that target tumors with the toxicity induced by photosensitizers activated by NIR-light. Herein, we demonstrate the efficacy of NIR-PIT in a mouse model of lung metastases. Experiments were conducted with a HER2, luciferase and GFP expressing cell line (3T3/HER2-luc-GFP). An antibody-photosensitizer conjugate (APC) consisting of trastuzumab and a phthalocyanine dye, IRDye-700DX, was synthesized. In vitro NIR-PIT-induced cytotoxicity was light dose dependent. With 3D culture, repeated NIR-PIT could eradicate entire spheroids. In vivo anti-tumor effects of NIR-PIT included significant reductions in both tumor volume (p = 0.0141 vs. APC) and bioluminescence image (BLI) (p = 0.0086 vs. APC) in the flank model, and prolonged survival (p < 0.0001). BLI demonstrated a significant reduction in lung metastases volume (p = 0.0117 vs. APC). Multiple NIR-PIT doses significantly prolonged survival in the lung metastases model (p < 0.0001). These results suggested that NIR-PIT is a potential new therapy for the local control of lung metastases. PMID:26021765

  2. A New Near-Infrared Spectral Atlas of O and Early-B Stars.

    NASA Astrophysics Data System (ADS)

    Hanson, M. M.; Kenworthy, M. A.; Puls, J.; Kudritzki, R.-P.; Tokunaga, A. T.

    2004-05-01

    We present new, high-resolution, near-infrared spectroscopy of three dozen O and early-B stars. The spectra cover most of the wavelength range between 1.62 μ m to 2.2 μ m and includes the most prominent lines of Hydrogen, Helium (both neutral and ionized) as well as three important metal lines in the H- and K-band region. These spectra have more than 4 times the resolution and 2-3 times the signal-to-noise of the the original O and B star spectral atlases of Hanson, Conti, and Rieke (1996) and Hanson, Rieke, and Luhman (1998). Our interest in obtaining higher resolution and signal-to-noise spectra was to aide in the development of quantitative spectroscopic analysis at near-infrared wavelengths which members in our group are carrying out. The new spectra obtained in this study are of high enough quality to allow for direct modeling of the line profiles to constrain effective temperature, gravity, rotational velocity and general wind characteristics. The development of atmospheric modeling routines for the near-infrared regime is fundamental to constraining the nature of heavily embedded and distant O and B stars presently being located throughout the disk of our Galaxy via deep near-infrared imaging surveys (2MASS, DENIS, MSX, GLIMPSE, etc). These results are based upon work supported by the National Science Foundation under Grant No. 0094050 to the University of Cincinnati.

  3. MOONS: a multi-object optical and near-infrared spectrograph for the VLT

    NASA Astrophysics Data System (ADS)

    Cirasuolo, M.; Afonso, J.; Bender, R.; Bonifacio, P.; Evans, C.; Kaper, L.; Oliva, Ernesto; Vanzi, Leonardo; Abreu, Manuel; Atad-Ettedgui, Eli; Babusiaux, Carine; Bauer, Franz E.; Best, Philip; Bezawada, Naidu; Bryson, Ian R.; Cabral, Alexandre; Caputi, Karina; Centrone, Mauro; Chemla, Fanny; Cimatti, Andrea; Cioni, Maria-Rosa; Clementini, Gisella; Coelho, João.; Daddi, Emanuele; Dunlop, James S.; Feltzing, Sofia; Ferguson, Annette; Flores, Hector; Fontana, Adriano; Fynbo, Johan; Garilli, Bianca; Glauser, Adrian M.; Guinouard, Isabelle; Hammer, Jean-François; Hastings, Peter R.; Hess, Hans-Joachim; Ivison, Rob J.; Jagourel, Pascal; Jarvis, Matt; Kauffman, G.; Lawrence, A.; Lee, D.; Li Causi, G.; Lilly, S.; Lorenzetti, D.; Maiolino, R.; Mannucci, F.; McLure, R.; Minniti, D.; Montgomery, D.; Muschielok, B.; Nandra, K.; Navarro, R.; Norberg, P.; Origlia, L.; Padilla, N.; Peacock, J.; Pedicini, F.; Pentericci, L.; Pragt, J.; Puech, M.; Randich, S.; Renzini, A.; Ryde, N.; Rodrigues, M.; Royer, F.; Saglia, R.; Sánchez, A.; Schnetler, H.; Sobral, D.; Speziali, R.; Todd, S.; Tolstoy, E.; Torres, M.; Venema, L.; Vitali, F.; Wegner, M.; Wells, M.; Wild, V.; Wright, G.

    2012-09-01

    MOONS is a new conceptual design for a Multi-Object Optical and Near-infrared Spectrograph for the Very Large Telescope (VLT), selected by ESO for a Phase A study. The baseline design consists of ~1000 fibers deployable over a field of view of ~500 square arcmin, the largest patrol field offered by the Nasmyth focus at the VLT. The total wavelength coverage is 0.8μm-1.8μm and two resolution modes: medium resolution and high resolution. In the medium resolution mode (R~4,000-6,000) the entire wavelength range 0.8μm-1.8μm is observed simultaneously, while the high resolution mode covers simultaneously three selected spectral regions: one around the CaII triplet (at R~8,000) to measure radial velocities, and two regions at R~20,000 one in the J-band and one in the H-band, for detailed measurements of chemical abundances. The grasp of the 8.2m Very Large Telescope (VLT) combined with the large multiplex and wavelength coverage of MOONS - extending into the near-IR - will provide the observational power necessary to study galaxy formation and evolution over the entire history of the Universe, from our Milky Way, through the redshift desert and up to the epoch of re-ionization at z<8-9. At the same time, the high spectral resolution mode will allow astronomers to study chemical abundances of stars in our Galaxy, in particular in the highly obscured regions of the Bulge, and provide the necessary follow-up of the Gaia mission. Such characteristics and versatility make MOONS the long-awaited workhorse near-IR MOS for the VLT, which will perfectly complement optical spectroscopy performed by FLAMES and VIMOS.

  4. Study on near infrared technology for the measurement of moisture

    NASA Astrophysics Data System (ADS)

    Guo, Yong-cai; Chen, Zhao

    2006-02-01

    This paper studies near infrared technology for measuring moisture content in solid substance. After analyzing and improving traditional moisture instruments and discussing their disadvantages, we present a measuring scheme and instrument structure design with high performance and stability. The novel instrument utilizing near infrared range analysis (NIRA) technology possesses characteristics of on-line working, high accuracy, distribution and non-contact measurement.

  5. Near-infrared probes: design and applications

    NASA Astrophysics Data System (ADS)

    Patonay, G.; Strekowski, L.; Raszkiewicz, A.; Kim, J. S.

    2006-02-01

    Near-Infrared (NIR) absorbing chromophores have been valuable in analytical and bioanalytical chemistry. NIR probes and labels have been used for several applications, including solvent polarity, hydrophobicity, DNA sequencing, immunoassays, CE separations, etc. The NIR region (700-1100 nm) is more advantageous for the bioanalytical chemist due to the inherently lower background interference and the high molar absorptivities. NIR dyes can be used as simple probes to investigate biomolecule properties or just simply to detect the presence of biomolecules. Another typical application is the use of NIR fluorophores as labels. In these applications covalent labeling is the preferred method but it requires NIR dyes with appropriate reactive moieties. Due to the hydrophobic nature of NIR chromophores non-covalent labeling may be a viable alternative. For this purpose novel bis(carbocynines) have been developed in our laboratories. These dyes form intramolecular H-aggregates in polar solvents, even at very low concentrations. Spectral properties of this intramolecular dimer greatly depend on the properties of heterocyclic moieties and the length, the location and/or flexibility of the connecting chain. This form of the dye can be described as a clamshell complex with two interacting hydrophobic carbocyanine moieties. This intramolecular H-aggregate has a low extinction coefficient and fluorescence quantum yield. Upon opening the clamshell that can be facilitated by changing microhydrophobicity (i.e., binding to biomolecules) the H-and D- bands are decreased and the monomeric band is increased, with concomitant increase in fluorescence intensity. The main analytical utility of these bis(carbocyanines) is that the free dye (i.e., not complexed to an analyte) has negligible fluorescence in a typical aqueous buffer environment. Examples of different applications of these bis(carbocyanines) are given including forensic applications.

  6. Near-infrared imaging of FSC 10214+4724 with the W. M. Keck Telescope

    NASA Technical Reports Server (NTRS)

    Matthews, K.; Soifer, B. T.; Nelson, J.; Boesgaard, H.; Graham, J. R.; Harrison, W.; Irace, W.; Jernigan, G.; Larkin, J. E.; Lewis, H.

    1994-01-01

    Near-infrared observations of the z = 2.286 IRAS source FSC 10214+4724, made with the near-infrared camera on the W. M. Keck Telescope, are reported. Deep broad-band images at 2.15 and 1.27 micrometers, and narrow-band images at 2.165 and 2.125 micrometers with 0.6 sec to 0.9 sec seeing show that FSC 10214+4724 consists of at least three distinct components in a compact group of galaxies. The source of the infrared luminosity appears to be in a strongly interacting galaxy that has a luminosity of approximately 100 times that of a present-day L* galaxy. The interaction suggests and 'age' of this galaxy of approximately equal to 10(exp 9) yr. The H-alpha emission is resolved as a source of diameter approximately equal to 5 kpc, suggesting that a starburst contributes to the observed H-alpha emission. There is an excess of objects in the FSC 10214+4724 field that could represent galaxies in an associated cluster.

  7. Near-infrared imaging of Markarian 231: Evidence for a double nucleus

    NASA Technical Reports Server (NTRS)

    Armus, L.; Surace, J. A.; Soifer, B. T.; Matthews, K.; Graham, J. R.; Larkin, J. E.

    1994-01-01

    Near-infrared (1.2-2.4 micrometers) images are presented for the central 10 arcsec of the Seyfert 1 galaxy Markarian 231. We find a faint, but intrinsically luminous (M(sub k) approximately -20.7) secondary peak in the near-infrared light distribution approximately 3.5 arcsec (2.7 kpc) south of the primary Seyfert 1 nucleus. Since there is no optical or infrared evidence for ongoing star formation at the location of this secondary peak, and its near-infrared luminosity and color are comparable to slightly reddened spiral bulges or elliptical nuclei, we identify this peak with the stripped nucleus of the companion galaxy involved in the Mrk 231 merger event. Depending upon the exact ratio of the masses of the primary and secondary nucleus in the Mrk 231 system we estimate a merger time scale of less than or equal to 10(exp 9) yr. The morphology of the southern nucleus suggests that it may have recently survived a close passage (r less than 200 pc) with the Seyfert 1 nucleus on a highly elliptical orbit, in which case the merger time scale may be significantly shorter (approximately 10(exp 7) yr. We re-calculate the average merger time scale for the seven ultraluminous infrared galaxies with double nuclei in the Bright Galaxy Sample (the BGS) of Soifer et al. (AJ, 98, 766 (1989)) and derive a value of approximately 10(exp 8) yr. Since seven of ten of the ultraluminous infrared galaxies in the BGS are now known to be double, we estimate the ultraluminous 'phase' may be close to this value. Along with Arp 220 and Mrk 273, Mrk 231 is the third member of the class to possess a high brightness temperature non-thermal radio core and a double nucleus, suggesting the time scale for the generation or fueling of the active nucleus can be much less than the dynamical time scale for the merger of the progenitor nuclei.

  8. MOONS: the Multi-Object Optical and Near-infrared Spectrograph for the VLT

    NASA Astrophysics Data System (ADS)

    Cirasuolo, M.; Afonso, J.; Carollo, M.; Flores, H.; Maiolino, R.; Oliva, E.; Paltani, S.; Vanzi, Leonardo; Evans, Christopher; Abreu, M.; Atkinson, David; Babusiaux, C.; Beard, Steven; Bauer, F.; Bellazzini, M.; Bender, Ralf; Best, P.; Bezawada, N.; Bonifacio, P.; Bragaglia, A.; Bryson, I.; Busher, D.; Cabral, A.; Caputi, K.; Centrone, M.; Chemla, F.; Cimatti, A.; Cioni, M.-R.; Clementini, G.; Coelho, J.; Crnojevic, D.; Daddi, E.; Dunlop, J.; Eales, S.; Feltzing, S.; Ferguson, A.; Fisher, M.; Fontana, A.; Fynbo, J.; Garilli, B.; Gilmore, G.; Glauser, A.; Guinouard, I.; Hammer, F.; Hastings, P.; Hess, A.; Ivison, R.; Jagourel, P.; Jarvis, M.; Kaper, L.; Kauffman, G.; Kitching, A. T.; Lawrence, A.; Lee, D.; Lemasle, B.; Licausi, G.; Lilly, S.; Lorenzetti, D.; Lunney, D.; Maiolino, R.; Mannucci, F.; McLure, R.; Minniti, D.; Montgomery, D.; Muschielok, B.; Nandra, K.; Navarro, R.; Norberg, P.; Oliver, S.; Origlia, L.; Padilla, N.; Peacock, J.; Pedichini, F.; Peng, J.; Pentericci, L.; Pragt, J.; Puech, M.; Randich, S.; Rees, P.; Renzini, A.; Ryde, N.; Rodrigues, M.; Roseboom, I.; Royer, F.; Saglia, R.; Sanchez, A.; Schiavon, R.; Schnetler, H.; Sobral, D.; Speziali, R.; Sun, D.; Stuik, R.; Taylor, A.; Taylor, W.; Todd, S.; Tolstoy, E.; Torres, M.; Tosi, M.; Vanzella, E.; Venema, L.; Vitali, F.; Wegner, M.; Wells, M.; Wild, V.; Wright, G.; Zamorani, G.; Zoccali, M.

    2014-07-01

    MOONS is a new Multi-Object Optical and Near-infrared Spectrograph selected by ESO as a third generation instrument for the Very Large Telescope (VLT). The grasp of the large collecting area offered by the VLT (8.2m diameter), combined with the large multiplex and wavelength coverage (optical to near-IR: 0.8μm - 1.8μm) of MOONS will provide the European astronomical community with a powerful, unique instrument able to pioneer a wide range of Galactic, Extragalactic and Cosmological studies and provide crucial follow-up for major facilities such as Gaia, VISTA, Euclid and LSST. MOONS has the observational power needed to unveil galaxy formation and evolution over the entire history of the Universe, from stars in our Milky Way, through the redshift desert, and up to the epoch of very first galaxies and re-ionization of the Universe at redshift z>8-9, just few million years after the Big Bang. On a timescale of 5 years of observations, MOONS will provide high quality spectra for >3M stars in our Galaxy and the local group, and for 1-2M galaxies at z>1 (SDSS-like survey), promising to revolutionise our understanding of the Universe. The baseline design consists of ~1000 fibers deployable over a field of view of ~500 square arcmin, the largest patrol field offered by the Nasmyth focus at the VLT. The total wavelength coverage is 0.8μm-1.8μm and two resolution modes: medium resolution and high resolution. In the medium resolution mode (R~4,000-6,000) the entire wavelength range 0.8μm-1.8μm is observed simultaneously, while the high resolution mode covers simultaneously three selected spectral regions: one around the CaII triplet (at R~8,000) to measure radial velocities, and two regions at R~20,000 one in the J-band and one in the H-band, for detailed measurements of chemical abundances.

  9. The (C II) 158 micron line mapping of spiral galaxies

    NASA Technical Reports Server (NTRS)

    Stacey, Gordon J.; Geis, N.; Genzel, Reinhard; Jackson, J. M.; Poglitsch, Albrecht; Townes, Charles H.

    1990-01-01

    Large scale maps of the face of spiral galaxies M51, M83, and NGC 6946 in the 158 micron (C II) fine structure line. The maps are obtained from the Far-infrared Imaging Fabry-Perot Interferometer (FIFI) during its first series of flights on board the Kuiper Airborne Observatory. The (C II) line emission is ubiquitous and easily traced over the mapped regions of each of the galaxies. The (C II) maps are compared with those obtained with similar sized beams in the CO line. The data available from these maps is interpreted.

  10. [Drug release system controlled by near infrared light].

    PubMed

    Niidome, Takuro

    2013-01-01

    Gold nanorods have absorption bands in the near-infrared region; in this spectral range, light penetrates deeply into tissues. The absorbed light energy is converted into heat by gold nanorods. This is the so-called photothermal effect. Gold nanorods are therefore expected to act not only as thermal converters for photothermal therapy, but also as controllers for drug-release systems responding to irradiation with near-infrared light. To achieve a controlled-release system that could be triggered by light irradiation, the gold nanorods were modified with double-stranded DNA (dsDNA). When the dsDNA-modified gold nanorods were irradiated with near-infrared light, single-stranded DNA (ssDNA) was released from the gold nanorods because of the photothermal effect. The release of ssDNA was also observed in tumors grown on mice after near-infrared light irradiation. We also proposed a different controlled-release system responding to near-infrared light. Gold nanorods were modified with polyethylene glycol (PEG) through Diels-Alder cycloadducts. When the gold nanorods were irradiated with near-infrared light, the PEG chains were released from the gold nanorods because of the retro Diels-Alder reaction induced by the photothermal effect. Such controlled-release systems triggered by near-infrared light irradiation will be expanded for gold nanorod drug delivery system applications.

  11. Advances in Organic Near-Infrared Materials and Emerging Applications.

    PubMed

    Qi, Ji; Qiao, Wenqiang; Wang, Zhi Yuan

    2016-06-01

    Much progress has been made in the field of research on organic near-infrared materials for potential applications in photonics, communications, energy, and biophotonics. This account mainly describes our research work on organic near-infrared materials; in particular, donor-acceptor small molecules, organometallics, and donor-acceptor polymers with the bandgaps less than 1.2 eV. The molecular designs, structure-property relationships, unique near-infrared absorption, emission and color/wavelength-changing properties, and some emerging applications are discussed.

  12. Near-infrared line identification in type Ia supernovae during the transitional phase

    SciTech Connect

    Friesen, Brian; Baron, E.; Wisniewski, John P.; Miller, Timothy R.; Parrent, Jerod T.; Thomas, R. C.; Marion, G. H.

    2014-09-10

    We present near-infrared synthetic spectra of a delayed-detonation hydrodynamical model and compare them to observed spectra of four normal Type Ia supernovae ranging from day +56.5 to day +85. This is the epoch during which supernovae are believed to be undergoing the transition from the photospheric phase, where spectra are characterized by line scattering above an optically thick photosphere, to the nebular phase, where spectra consist of optically thin emission from forbidden lines. We find that most spectral features in the near-infrared can be accounted for by permitted lines of Fe II and Co II. In addition, we find that [Ni II] fits the emission feature near 1.98 μm, suggesting that a substantial mass of {sup 58}Ni exists near the center of the ejecta in these objects, arising from nuclear burning at high density.

  13. DERIVING METALLICITIES FROM THE INTEGRATED SPECTRA OF EXTRAGALACTIC GLOBULAR CLUSTERS USING THE NEAR-INFRARED CALCIUM TRIPLET

    SciTech Connect

    Foster, Caroline; Forbes, Duncan A.; Proctor, Robert N.; Spitler, Lee R.; Strader, Jay; Brodie, Jean P.

    2010-04-15

    The Ca II triplet (CaT) feature in the near-infrared has been employed as a metallicity indicator for individual stars as well as integrated light of Galactic globular clusters (GCs) and galaxies with varying degrees of success, and sometimes puzzling results. Using the DEIMOS multi-object spectrograph on Keck we obtain a sample of 144 integrated light spectra of GCs around the brightest group galaxy NGC 1407 to test whether the CaT index can be used as a metallicity indicator for extragalactic GCs. Different sets of single stellar population models make different predictions for the behavior of the CaT as a function of metallicity. In this work, the metallicities of the GCs around NGC 1407 are obtained from CaT index values using an empirical conversion. The measured CaT/metallicity distributions show unexpected features, the most remarkable being that the brightest red and blue GCs have similar CaT values despite their large difference in mean color. Suggested explanations for this behavior in the NGC 1407 GC system are (1) the CaT may be affected by a population of hot blue stars, (2) the CaT may saturate earlier than predicted by the models, and/or (3) color may not trace metallicity linearly. Until these possibilities are understood, the use of the CaT as a metallicity indicator for the integrated spectra of extragalactic GCs will remain problematic.

  14. Modeling the distribution of Mg II absorbers around galaxies using background galaxies and quasars

    SciTech Connect

    Bordoloi, R.; Lilly, S. J.; Kacprzak, G. G.; Churchill, C. W.

    2014-04-01

    We present joint constraints on the distribution of Mg II absorption around high redshift galaxies obtained by combining two orthogonal probes, the integrated Mg II absorption seen in stacked background galaxy spectra and the distribution of parent galaxies of individual strong Mg II systems as seen in the spectra of background quasars. We present a suite of models that can be used to predict, for different two- and three-dimensional distributions, how the projected Mg II absorption will depend on a galaxy's apparent inclination, the impact parameter b and the azimuthal angle between the projected vector to the line of sight and the projected minor axis. In general, we find that variations in the absorption strength with azimuthal angles provide much stronger constraints on the intrinsic geometry of the Mg II absorption than the dependence on the inclination of the galaxies. In addition to the clear azimuthal dependence in the integrated Mg II absorption that we reported earlier in Bordoloi et al., we show that strong equivalent width Mg II absorbers (W{sub r} (2796) ≥ 0.3 Å) are also asymmetrically distributed in azimuth around their host galaxies: 72% of the absorbers in Kacprzak et al., and 100% of the close-in absorbers within 35 kpc of the center of their host galaxies, are located within 50° of the host galaxy's projected semi minor axis. It is shown that either composite models consisting of a simple bipolar component plus a spherical or disk component, or a single highly softened bipolar distribution, can well represent the azimuthal dependencies observed in both the stacked spectrum and quasar absorption-line data sets within 40 kpc. Simultaneously fitting both data sets, we find that in the composite model the bipolar cone has an opening angle of ∼100° (i.e., confined to within 50° of the disk axis) and contains about two-thirds of the total Mg II absorption in the system. The single softened cone model has an exponential fall off with azimuthal

  15. Precise radial velocities in the near infrared

    NASA Astrophysics Data System (ADS)

    Redman, Stephen L.

    Since the first detection of a planet outside our Solar System byWolszczan & Frail (1992), over 500 exoplanets have been found to date2, none of which resemble the Earth. Most of these planets were discovered by measuring the radial velocity (hereafter, RV) of the host star, which wobbles under the gravitational influence of any existing planetary companions. However, this method has yet to achieve the sub-m/s precision necessary to detect an Earth-mass planet in the Habitable Zone (the region around a star that can support liquid water; hereafter, HZ) (Kasting et al. 1993) around a Solar-type star. Even though Kepler (Borucki et al. 2010) has announced several Earth-sized HZ candidates, these targets will be exceptionally difficult to confirm with current astrophysical spectrographs (Borucki et al. 2011). The fastest way to discover and confirm potentiallyhabitable Earth-mass planets is to observe stars with lower masses - in particular, late M dwarfs. While M dwarfs are readily abundant, comprising some 70% of the local stellar population, their low optical luminosity presents a formidable challenge to current optical RV instruments. By observing in the near-infrared (hereafter, NIR), where the flux from M dwarfs peaks, we can potentially reach low RV precisions with significantly less telescope time than would be required by a comparable optical instrument. However, NIR precision RV measurements are a relatively new idea and replete with challenges: IR arrays, unlike CCDs, are sensitive to the thermal background; modal noise is a bigger issue in the NIR than in the optical; and the NIR currently lacks the calibration sources like the very successful thorium-argon (hereafter, ThAr) hollow-cathode lamp and Iodine gas cell of the optical. The PSU Pathfinder (hereafter, Pathfinder) was designed to explore these technical issues with the intention of mitigating these problems for future NIR high-resolution spectrographs, such as the Habitable-Zone Planet Finder (HZPF

  16. [Identification of Metoprolol Tartrate Tablets from Different Manufacturers by Different Near Infrared Spectrometers].

    PubMed

    Li, Qi-lu; Wang, Fei; Wang, Jin-feng; Zang, Heng-chang; Zhang, Hui; Jiang, Wei

    2015-10-01

    To rapidly identify Metoprolol Tartrate tablets from different manufacturers, a qualitative analysis model can be established by near infrared spectroscopy. Firstly, AntarisII Fourier-transform near infrared (FT-NIR) spectroscopy and Micro NIR1700 Spectrometer were used to collect spectral data of 66 batches of samples which come from four different manufacturers, then 44 samples of calibration set and 22 samples of validation set were acquired by random sampling. In order to build up a PLS-DA model, the first derivative with Savitzky-Golay 15 points smoothing (1d+SG15) and standard normal vitiate transformation (SNV) was selected as the pretreatment method and according to the variation between different samples and the characteristic absorption band, 6 468-7 104 cm(-1) and 6 468-7 156 cm(-1) were chosen as the modeling spectra region. The confusion matrix indicated that Metoprolol Tartrate tablets could be rapidly and effectively identified by two analytical models, which were established using the spectral data collected from two instruments. For these two models, both of the sensitivity and specificity were 100%. This study confirmed that it is feasible to carry out the manufacturer identification of Metoprolol Tartrate tablets by near infrared spectroscopy. Besides, the use of Micro NIR1700 Spectrometer, which is the minimum and portable near infrared spectrometer, provides valuable insights for fast on-site drug screening.

  17. Applications Of Microspectroscopy In The Near-Infrared Region

    NASA Astrophysics Data System (ADS)

    Smith, Matthew J.; Carl, Richard T.

    1989-12-01

    The technique of infrared microspectroscopy has numerous applications in many fields including materials science, forensics, contamination analysis and biological science. The majority of these applications have been in the mid-infrared since using different spectral ranges in an FT-IR spectrometer often involve modifications to the interferometer, source and detector. However, recent advancements in infrared instrumentation have allowed rapid spectral range changes to become routine. As a result, near-infrared microspectroscopy is now a viable technique.1 The principle advantage of near-infrared microspectroscopy is the ability to analyze samples which are totally absorbing in the mid-infrared region. Most near-infrared absorbances are due to overtones or combination bands of fundamental bands and are typically one to two orders of magnitude weaker than their corresponding fundamental transitions. Thus, transmission analysis in the near-infrared can be carried out on many samples which are otherwise too thick for transmission analysis in the mid-infrared.

  18. Near-infrared branding efficiently correlates light and electron microscopy.

    PubMed

    Bishop, Derron; Nikić, Ivana; Brinkoetter, Mary; Knecht, Sharmon; Potz, Stephanie; Kerschensteiner, Martin; Misgeld, Thomas

    2011-06-05

    The correlation of light and electron microscopy of complex tissues remains a major challenge. Here we report near-infrared branding (NIRB), which facilitates such correlation by using a pulsed, near-infrared laser to create defined fiducial marks in three dimensions in fixed tissue. As these marks are fluorescent and can be photo-oxidized to generate electron contrast, they can guide re-identification of previously imaged structures as small as dendritic spines by electron microscopy.

  19. Nano-plasmonic antennas in the near infrared regime.

    PubMed

    Berkovitch, N; Ginzburg, P; Orenstein, M

    2012-02-22

    Plasmonic nano-antennas constitute a central research topic in current science and engineering with an enormous variety of potential applications. Here we review the recent progress in the niche of plasmonic nano-antennas operating in the near infrared part of the spectrum which is important for a variety of applications. Tuning of the resonance into the near infrared regime is emphasized in the perspectives of fabrication, measurement, modeling, and analytical treatments, concentrating on the vast recent achievements in these areas.

  20. Near-infrared photometric observations of Nova Ophiuchi 2012

    NASA Astrophysics Data System (ADS)

    Raj, Ashish; Ashok, N. M.; Banerjee, D. P. K.; Raman, V. Venkata

    2012-04-01

    Ashish Raj, N. M. Ashok, D. P. K. Banerjee and V. Venkata Raman, Physical Research Laboratory, report near-infrared J-, H-, and K-band photometry of the Nova Oph 2012 (cf. CBET 3072, 3081) obtained with the Mt. Abu 1.2-m telescope (+PRL Near-Infrared NICMOS3 Imager/Spectrometer). The preliminary reduction of these Mt. Abu observations, of Mar. 29, 31 and Apr. 2, 3 UT shows the brightening of the nova in the JHK bands.

  1. Near-Infrared Spectra of Type Ia Supernovae

    NASA Technical Reports Server (NTRS)

    Marion, G. H.; Hoeflich, P.; Vacca, W. D.; Wheeler, J. C.

    2003-01-01

    We report near-infrared (NIR) spectroscopic observations of 12 'branch-normal' Type Ia supernovae (SNe Ia) that cover the wavelength region from 0.8 to 2.5 microns. Our sample more than doubles the number of SNe Ia with published NIR spectra within 3 weeks of maximum light. The epochs of observation range from 13 days before maximum light to 18 days after maximum light. A detailed model for a Type Ia supernovae is used to identify spectral features. The Doppler shifts of lines are measured to obtain the velocity and thus the radial distribution of elements. The NIR is an extremely useful tool to probe the chemical structure in the layers of SNe Ia ejecta. This wavelength region is optimal for examining certain products of the SNe Ia explosion that may be blended or obscured in other spectral regions. We identify spectral features from Mg II, Ca II, Si II, Fe II, Co II, Ni II, and possibly Mn II. We find no indications for hydrogen, helium, or carbon in the spectra. The spectral features reveal important clues about the physical characteristics of SNe Ia. We use the features to derive upper limits for the amount of unburned matter, to identify the transition regions from explosive carbon to oxygen burning and from partial to complete silicon burning, and to estimate the level of mixing during and after the explosion. Elements synthesized in the outer layers during the explosion appear to remain in distinct layers. That provides strong evidence for the presence of a detonation phase during the explosion as it occurs in delayed detonation or merger models. Mg II velocities are found to exceed 11,000 - 15,000 km/s, depending on the individual SNe Ia. That result suggests that burning during the explosion reaches the outermost layers of the progenitor and limits the amount of unburned material to less than 10% of the mass of the progenitor. Small residuals of unburned material are predicted by delayed detonation models but are inconsistent with pure deflagration or

  2. Luminosity function of [O II] emission-line galaxies in the MassiveBlack-II simulation

    NASA Astrophysics Data System (ADS)

    Park, KwangHo; Di Matteo, Tiziana; Ho, Shirley; Croft, Rupert; Wilkins, Stephen M.; Feng, Yu; Khandai, Nishikanta

    2015-11-01

    We examine the luminosity function (LF) of [O II] emission-line galaxies in the high-resolution cosmological simulation MassiveBlack-II (MBII). From the spectral energy distribution of each galaxy, we select a sub-sample of star-forming galaxies at 0.06 ≤ z ≤ 3.0 using the [O II] emission line luminosity L([O II]). We confirm that the specific star formation rate matches that in the Galaxy And Mass Assembly survey. We show that the [O II] LF at z = 1.0 from the MBII shows good agreement with the LFs from several surveys below L([O II]) = 1043.0 erg s-1 while the low redshifts (z ≤ 0.3) show an excess in the prediction of bright [O II] galaxies, but still displaying a good match with observations below L([O II]) = 1041.6 erg s-1. Based on the validity in reproducing the properties of [O II] galaxies at low redshift (z ≤ 1), we forecast the evolution of the [O II] LF at high redshift (z ≤ 3), which can be tested by upcoming surveys such as the Hobby-Eberly Telescope Dark Energy Experiment and Dark Energy Spectroscopic Instrument. The slopes of the LFs at bright and faint ends range from -3 to -2 showing minima at z = 2. The slope of the bright end evolves approximately as (z + 1)-1 at z ≤ 2 while the faint end evolves as ˜3(z + 1)-1 at 0.6 ≤ z ≤ 2. In addition, a similar analysis is applied for the evolution of [O III] LFs, which is to be explored in the forthcoming survey Wide-Field InfraRed Survey Telescope-Astrophysics Focused Telescope Assets. Finally, we show that the auto-correlation function of [O II] and [O III] emitting galaxies shows a rapid evolution from z = 2 to 1.

  3. Near-infrared spectroscopy of Type Ia supernovae

    NASA Astrophysics Data System (ADS)

    Hsiao, Eric; Phillips, Mark; Burns, Christopher R.; Contreras, Carlos; Gall, Christa; Hoeflich, Peter; Kirshner, Robert P.; Marion, Howie H.; Morrell, Nidia; Sand, David J.; Stritzinger, Maximillian; Carnegie Supernova Project

    2016-01-01

    Improving the cosmological experiments with Type Ia supernovae (SNe Ia) is now not simply a question of observing more supernovae, since any survey, no matter how large, will ultimately be limited by the systematic errors. It has been clearly demonstrated in a number of studies that SNe Ia are better distance indicators in the near-infrared compared to the optical. As exciting as these new results are, SNe Ia in the NIR are expected to be even better than these studies indicate. A key ingredient for improving SN Ia in the NIR as distance indicators is to obtain NIR spectroscopy to determine precise k-corrections, which account for the effect of cosmological expansion upon the measured magnitudes. Better knowledge of the NIR spectroscopic behaviors, akin to that in the optical, is necessary to reach the distance precision required to identify viable models for dark energy. Carnegie Supernova Project II has built a definitive data set, much improved from previous samples, both in size and quality. With this previously unavailable window, we are also beginning to gain new insight on the physics of these events.

  4. Keck Near-Infrared AO Observation of Io in 2011

    NASA Astrophysics Data System (ADS)

    Cantrall, C.; De Pater, I.; Nelson, D. M.; Williams, D. A.; de Kleer, K.

    2015-12-01

    We report observation and analysis of 23 distinct hot spots on Io from images taken in November of 2011 on the 10-m W.M. Keck II telescope. The observations were obtained with 8 different near-infrared (1-5 μm) filters, although no hot spots were detected at the smallest wavelength filters of Hc (1.58 μm) and Kc (2.27 μm). The radiant flux of each hot spot at the different wavelengths was found, which allowed for 1-T and 2-T blackbody fits to obtain estimates of the temperature, emission area, and subsequently, the total radiant output. Global maps over a cylindrical coordinate system were also constructed at each wavelength. In general, Io appeared to be fairly quiescent compared to datasets obtained between 2001 and 2010, with no significant outburst at any particular hot spot. Using GIS software it was possible to create surface maps that display the changes in some of the major hot spots observed between 2001 and 2011. The analysis of these maps and comparison to observations at different time periods will help to further construct a timeline of Io's volcanic activity, which will lead to a better understanding of the variations in surface heat flow over time, the global distribution of hot spots, and the style of eruptions.

  5. Low-metallicity Young Clusters in the Outer Galaxy. II. Sh 2-208

    NASA Astrophysics Data System (ADS)

    Yasui, Chikako; Kobayashi, Naoto; Saito, Masao; Izumi, Natsuko

    2016-05-01

    We obtained deep near-infrared images of Sh 2-208, one of the lowest-metallicity H ii regions in the Galaxy, [O/H] = -0.8 dex. We detected a young cluster in the center of the H ii region with a limiting magnitude of K = 18.0 mag (10σ), which corresponds to a mass detection limit of ˜0.2 M⊙. This enables the comparison of star-forming properties under low metallicity with those of the solar neighborhood. We identified 89 cluster members. From the fitting of the K-band luminosity function (KLF), the age and distance of the cluster are estimated to be ˜0.5 Myr and ˜4 kpc, respectively. The estimated young age is consistent with the detection of strong CO emission in the cluster region and the estimated large extinction of cluster members (AV ˜ 4-25 mag). The observed KLF suggests that the underlying initial mass function (IMF) of the low-metallicity cluster is not significantly different from canonical IMFs in the solar neighborhood in terms of both high-mass slope and IMF peak (characteristic mass). Despite the very young age, the disk fraction of the cluster is estimated at only 27% ± 6%, which is significantly lower than those in the solar metallicity. Those results are similar to Sh 2-207, which is another star-forming region close to Sh 2-208 with a separation of 12 pc, suggesting that their star-forming activities in low-metallicity environments are essentially identical to those in the solar neighborhood, except for the disk dispersal timescale. From large-scale mid-infrared images, we suggest that sequential star formation is taking place in Sh 2-207, Sh 2-208, and the surrounding region, triggered by an expanding bubble with a ˜30 pc radius.

  6. In Vivo Fluorescence Imaging in the Second Near-Infrared Window Using Carbon Nanotubes.

    PubMed

    Hong, Guosong; Dai, Hongjie

    2016-01-01

    In vivo fluorescence imaging in the second near-infrared window (NIR-II window, 1000-1700 nm) is a powerful imaging technique that emerged in recent years. This imaging tool allows for noninvasive, deep-tissue visualization and interrogation of anatomical features and functions with improved imaging resolution and contrast at greater tissue penetration depths than traditional fluorescence imaging. Here, we present the detailed protocol for conducting NIR-II fluorescence imaging in live animals, including the procedures for preparation of biocompatible and NIR-II fluorescent carbon nanotube solution, live animal administration and NIR-II fluorescence image acquisition.

  7. Encapsulation and sensitization of UV-vis and near infrared lanthanide hydrate emitters for dual- and bimodal-emissions in both air and aqueous media based on a porous heteroatom-rich Cd(II)-framework.

    PubMed

    Li, Yan-An; Ren, Shu-Kui; Liu, Qi-Kui; Ma, Jian-Ping; Chen, Xueyuan; Zhu, Haomiao; Dong, Yu-Bin

    2012-09-17

    A porous heteroatom-rich Cd(II)-polymeric framework which is generated from an ethylene glycol ether-bridging dicarboxylate ligand L, 4,4'-bipy and Cd(II) ion is reported. It contains one-dimensional tubes (9-11 Å) which are able to trap cationic lanthanide hydrates such as Eu(H(2)O)(8)(3+), Tb(H(2)O)(8)(3+), and Nd(H(2)O)(8)(3+) under ambient conditions to generate Ln(H(2)O)(8)(3+)-loaded materials. In addition, the heteroatom-rich host material can effectively protect and sensitize the encapsulated Ln(3+) emitters in their hydrate form in both air and aqueous media. Furthermore, the dual- and bimodal-emissions are successfully realized by intercalation of the different Ln(3+)-hydrates based on a guest-driven approach.

  8. Observing Resolved Stellar Populations with the JWST Near-Infrared Spectrograph

    NASA Astrophysics Data System (ADS)

    Gilbert, K. M.; Beck, T. L.; Karakla, D. M.

    2016-10-01

    The James Webb Space Telescope's (JWST) Near Infrared Spectrograph (NIRSpec) will provide a multi-object spectroscopy (MOS) mode through the Micro-Shutter Array (MSA). Each MSA quadrant is a grid of contiguous shutters that can be configured to form slits on more than 100 astronomical targets simultaneously. The combination of JWST's sensitivity and superb resolution in the infrared and NIRSpec's full wavelength coverage over 0.6 to 5 μm will open new parameter space for studies of galaxies and resolved stellar populations alike. We describe a NIRSpec MSA observing scenario of spectroscopy of individual stars in an external galaxy, and investigate the technical challenges posed by this scenario. This use case and others, including a deep galaxy survey and observations of Galactic HII regions, are guiding development of the NIRSpec user interfaces including proposal planning and pipeline calibrations.

  9. The H II regions of the irregular galaxy, NGC 3239

    SciTech Connect

    Krienke, K.; Hodge, P. Washington, University, Seattle )

    1991-03-01

    The luminosities of the 88 H II regions of NGC 3239, very likely a merging galaxy system, were measured by digital analysis of a photographic plate (20 A bandwidth filter). Despite evidence for earlier starburst activity, the present H II luminosity function is very similar to that for the LMC, including a supergiant H II region of 0.76 the luminosity of 30 Dor. The measured H II regions of NGC 3239 have an H-alpha total luminosity of 1.3 x 10 to the 40th erg/s. 13 refs.

  10. AKARI OBSERVATION OF THE SUB-DEGREE SCALE FLUCTUATION OF THE NEAR-INFRARED BACKGROUND

    SciTech Connect

    Seo, H. J.; Lee, Hyung Mok; Lee, Myung Gyoon; Matsumoto, T.; Jeong, W.-S.; Pyo, J.

    2015-07-10

    We report spatial fluctuation analysis of the sky brightness in the near-infrared from observations toward the north ecliptic pole (NEP) by the AKARI at 2.4 and 3.2 μm. As a follow-up study of our previous work on the Monitor field of AKARI, we used NEP deep survey data, which covered a circular area of about 0.4 square degrees, in order to extend fluctuation analysis at angular scales up to 1000″. We found residual fluctuation over the estimated shot noise at larger angles than the angular scale of the Monitor field. The excess fluctuation of the NEP deep field smoothly connects with that of the Monitor field at angular scales of a few hundred arcseconds and extends without any significant variation to larger angular scales up to 1000″. By comparing excess fluctuations at two wavelengths, we confirm a blue spectral feature similar to the result of the Monitor field. We find that the result of this study is consistent with Spitzer Space Telescope observations at 3.6 μm. The origin of the excess fluctuation in the near-infrared background remains to be determined, but we could exclude zodiacal light, diffuse Galactic light, and unresolved faint galaxies at low redshift based on the comparison with mid- and far-infrared brightness, ground-based near-infrared images.

  11. Comparing [C II] , HI, and CO Dynamics of Nearby Galaxies

    NASA Astrophysics Data System (ADS)

    de Blok, W. J. G.; Walter, F.; Smith, J.-D. T.; Herrera-Camus, R.; Bolatto, A. D.; Requena-Torres, M. A.; Crocker, A. F.; Croxall, K. V.; Kennicutt, R. C.; Koda, J.; Armus, L.; Boquien, M.; Dale, D.; Kreckel, K.; Meidt, S.

    2016-08-01

    The H i and CO components of the interstellar medium (ISM) are usually used to derive the dynamical mass {M}{{dyn}} of nearby galaxies. Both components become too faint to be used as a tracer in observations of high-redshift galaxies. In those cases, the 158 μm line of atomic carbon ([C ii]) may be the only way to derive {M}{{dyn}}. As the distribution and kinematics of the ISM tracer affects the determination of {M}{{dyn}}, it is important to quantify the relative distributions of H i, CO, and [C ii]. H i and CO are well-characterized observationally, however, for [C ii] only very few measurements exist. Here we compare observations of CO, H i, and [C ii] emission of a sample of nearby galaxies, drawn from the HERACLES, THINGS, and KINGFISH surveys. We find that within R 25, the average [C ii] exponential radial profile is slightly shallower than that of the CO, but much steeper than the H i distribution. This is also reflected in the integrated spectrum (“global profile”), where the [C ii] spectrum looks more like that of the CO than that of the H i. For one galaxy, a spectrally resolved comparison of integrated spectra was possible; other comparisons were limited by the intrinsic line-widths of the galaxies and the coarse velocity resolution of the [C ii] data. Using high-spectral-resolution SOFIA [C ii] data of a number of star forming regions in two nearby galaxies, we find that their [C ii] linewidths agree better with those of the CO than the H i. As the radial extent of a given ISM tracer is a key input in deriving {M}{{dyn}} from spatially unresolved data, we conclude that the relevant length-scale to use in determining {M}{{dyn}} based on [C ii] data, is that of the well-characterized CO distribution. This length scale is similar to that of the optical disk.

  12. Galaxy counterparts of intervening high-z sub-DLAs/DLAs and Mg ii absorbers towards gamma-ray bursts

    NASA Astrophysics Data System (ADS)

    Schulze, S.; Fynbo, J. P. U.; Milvang-Jensen, B.; Rossi, A.; Jakobsson, P.; Ledoux, C.; De Cia, A.; Krühler, T.; Mehner, A.; Björnsson, G.; Chen, H.-W.; Vreeswijk, P. M.; Perley, D. A.; Hjorth, J.; Levan, A. J.; Tanvir, N. R.; Ellison, S.; Møller, P.; Worseck, G.; Chapman, R.; Dall'Aglio, A.; Letawe, G.

    2012-10-01

    We present the first search for galaxy counterparts of intervening high-z (2 < z < 3.6) sub-damped Lyα absorbers (sub-DLAs) and DLAs towards gamma-ray bursts (GRBs). Our final sample comprises five intervening sub-DLAs and DLAs in four GRB fields. To identify candidate galaxy counterparts of the absorbers we used deep optical- and near-infrared imaging, and low-, mid- and high-resolution spectroscopy acquired with 6-m to 10-m class telescopes, the Hubble and the Spitzer Space Telescopes. Furthermore, we used the spectroscopic information and spectral-energy-distribution fitting techniques to study them in detail. Our main result is the detection and spectroscopic confirmation of the galaxy counterpart of the intervening DLA at z = 3.096 in the field of GRB 070721B (zGRB = 3.6298) as proposed by other authors. We also identify good candidates for the galaxy counterparts of the two strong Mg ii absorbers at z = 0.6915 and 1.4288 towards GRB 050820A (zGRB = 2.615). The properties of the detected DLA galaxy are typical for Lyman-break galaxies (LBGs) at similar redshifts; a young, highly star-forming galaxy that shows evidence for a galactic outflow. This supports thehypothesis that a DLA can be the gaseous halo of an LBG. In addition, we report a redshift coincidence of different objects associated with metal lines in the same field, separated by 130-161 kpc. The high detection rate of three correlated structures on a length scale as short as ~150 kpc in two pairs of lines of sight is intriguing. The absorbers in each of these are most likely not part of the same gravitationally bound structure. They more likely represent groups of galaxies. Based in part on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, as part of the programs 075.A-0603, 075.A-0385, 077.A-0312, 084.A-0303, 177.A-0591 and 275.D-5022. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space

  13. A Near-infrared Survey of the Rosette Complex: Clues of Early Cluster Evolution

    NASA Astrophysics Data System (ADS)

    Román-Zúñiga, Carlos G.; Lada, Elizabeth A.; Ferreira, Bruno

    2008-05-01

    The majority of stars in our galaxy are born in embedded clusters, which can be considered the fundamental units of star formation. We have recently surveyed the star forming content of the Rosette Complex using FLAMINGOS in order to investigate the properties of its embedded clusters. We discuss the results of our near-infrared imaging survey. In particular, we on the first evidence for the early evolution and expansion of the embedded clusters. In addition we present data suggesting a temporal sequence of cluster formation across the cloud and discuss the influence of the HII region on the star forming history of the Rosette.

  14. Probing outflows in z = 1 ∼ 2 galaxies through Fe II/Fe II* multiplets

    SciTech Connect

    Tang, Yuping; Giavalisco, Mauro; Guo, Yicheng

    2014-10-01

    We report on a study of the 2300-2600 Å Fe II/Fe II* multiplets in the rest-UV spectra of star-forming galaxies at 1.0 < z < 2.6 as probes of galactic-scale outflows. We extracted a mass-limited sample of 97 galaxies at z ∼ 1.0-2.6 from ultra-deep spectra obtained during the GMASS spectroscopic survey in the GOODS South field with the Very Large Telescope and FORS2. We obtain robust measures of the rest equivalent width of the Fe II absorption lines down to a limit of W{sub r} > 1.5 Å and of the Fe II* emission lines to W{sub r} > 0.5 Å. Whenever we can measure the systemic redshift of the galaxies from the [O II] emission line, we find that both the Fe II and Mg II absorption lines are blueshifted, indicating that both species trace gaseous outflows. We also find, however, that the Fe II gas has generally lower outflow velocity relative to that of Mg II. We investigate the variation of Fe II line profiles as a function of the radiative transfer properties of the lines, and find that transitions with higher oscillator strengths are more blueshifted in terms of both line centroids and line wings. We discuss the possibility that Fe II lines are suppressed by stellar absorptions. The lower velocities of the Fe II lines relative to the Mg II doublet, as well as the absence of spatially extended Fe II* emission in two-dimensional stacked spectra, suggest that most clouds responsible for Fe II absorption lie close (3 ∼ 4 kpc) to the disks of galaxies. We show that the Fe II/Fe II* multiplets offer unique probes of the kinematic structure of galactic outflows.

  15. Near-infrared study of the stellar population of Sh2-152

    NASA Astrophysics Data System (ADS)

    Ramírez Alegría, S.; Herrero, A.; Marín-Franch, A.; Puga, E.; Najarro, F.; Acosta Pulido, J. A.; Hidalgo, S. L.; Simón-Díaz, S.

    2011-11-01

    Context. The discovery of new massive star clusters and massive stellar populations in previously known clusters in our Galaxy by means of infrared studies has changed our view of the Milky Way from an inactive to an active star-forming machine. Within this scenario, we present a near-infrared spectrophotometric study of the stellar content of the compact HII region Sh2-152. Aims: We aim to determine the distance, extinction, age, and mass of Sh2-152, using for the first time near-infrared stellar classification for several sources in the region. Methods: Using our near-infrared (J, H, and KS) photometry and the colour-magnitude diagram for the cluster field, we selected 13 bright stars, candidate members of the reddened cluster's main sequence, for H- and K-spectroscopy and spectral classification. This near-infrared information was complemented with an optical spectrum of the ionizing central star to confirm its spectral nature. Results: From the 13 spectroscopically observed stars, 5 were classified as B-type, 3 as G-type, 2 were young stellar objects (YSOs), and 3 remained unclassified (because of the poor data quality). The cluster's extinction varies from AKS = 0.5 to 2.6 mag (AV = 4.5 to 24 mag) and the distance is estimated to be 3.21 ± 0.21 kpc. The age of the cluster is younger than 9.4 Myr and the lower limit to the total mass of the cluster is (2.45 ± 0.79) × 103 M⊙. We compare the number of ionizing photons emitted from the OB-type stars with the Lyman continuum photons derived from the radio observations and conclude that both quantities are consistent for the central region of Sh2-152. In contrast, the main ionizing source of the lower region remains unidentified.

  16. New and Better Near-Infrared Detectors for JWST Near Infrared Spectrograph

    NASA Technical Reports Server (NTRS)

    Rauscher, Bernard J.; Mott, D. Brent; Wen, Yiting; Linder, Don; Greenhouse, Matthew A.; Hill, Robert J.

    2014-01-01

    ESA and NASA recently selected two 5 m cutoff Teledyne H2RG sensor chip assemblies (SCA) for flight on the James Webb Space Telescope (JWST) Near Infrared Spectrograph (NIRSpec). These HgCdTe SCAs incorporate Teledynes improved barrier layer design that eliminates the degradation that affected earlier JWST H2RGs(Rauscher et al. 2012a). The better indium barrier, together with other design changes, has improved the performance and reliability of JWSTs SCAs. In this article, we describe the measured performance characteristics that most directly affect scientific observations including read noise, total noise, dark current, quantum efficiency (QE), and image persistence. As part of measuring QE, we measured the quantum yield as a function of photon energy,, and found that it exceeds unity for photon energies E (2.65.2) Eg, where Eg is the HgCdTe bandgap energy. This corresponds to. 2 m for NIRSpecs 5 m cutoff HgCdTe. Our measurements agree well with a previous measurement by McCullough et al. (2008) for. 1.3. For 1.3, we find a slower increase in with photon energy than McCullough et al. did. However, and as McCullough et al. note, their two state model of the yield process is not valid for large 1.

  17. BAT AGN Spectroscopic Survey - IV: Near-Infrared Coronal Lines, Hidden Broad Lines, and Correlation with Hard X-ray Emission

    NASA Astrophysics Data System (ADS)

    Lamperti, Isabella; Koss, Michael; Trakhtenbrot, Benny; Schawinski, Kevin; Ricci, Claudio; Oh, Kyuseok; Landt, Hermine; Riffel, Rogério; Rodríguez-Ardila, Alberto; Gehrels, Neil; Harrison, Fiona; Masetti, Nicola; Mushotzky, Richard; Treister, Ezequiel; Ueda, Yoshihiro; Veilleux, Sylvain

    2017-01-01

    We provide a comprehensive census of the near-Infrared (NIR, 0.8-2.4 μm) spectroscopic properties of 102 nearby (z < 0.075) active galactic nuclei (AGN), selected in the hard X-ray band (14-195 keV) from the Swift-Burst Alert Telescope (BAT) survey. With the launch of the James Webb Space Telescope this regime is of increasing importance for dusty and obscured AGN surveys. We measure black hole masses in 68% (69/102) of the sample using broad emission lines (34/102) and/or the velocity dispersion of the Ca II triplet or the CO band-heads (46/102). We find that emission line diagnostics in the NIR are ineffective at identifying bright, nearby AGN galaxies because ([Fe II] 1.257μm/Paβ and H2 2.12μm/Brγ) identify only 25% (25/102) as AGN with significant overlap with star forming galaxies and only 20% of Seyfert 2 have detected coronal lines (6/30). We measure the coronal line emission in Seyfert 2 to be weaker than in Seyfert 1 of the same bolometric luminosity suggesting obscuration by the nuclear torus. We find that the correlation between the hard X-ray and the [Fe II] coronal line luminosity is significantly better than with the [O III] λ5007 luminosity. Finally, we find 3/29 galaxies (10%) that are optically classified as Seyfert 2 show broad emission lines in the NIR. These AGN have the lowest levels of obscuration among the Seyfert 2s in our sample (log NH < 22.43 cm-2), and all show signs of galaxy-scale interactions or mergers suggesting that the optical broad emission lines are obscured by host galaxy dust.

  18. Isodensitometry of selected interacting galaxies. II

    NASA Astrophysics Data System (ADS)

    Koroviakovskii, Iu. P.

    1984-09-01

    The morphology of 21 selected interacting galaxies from the Vorontsov-Vel'iaminov (VV) catalog has been investigated on the basis of several enhanced large scale photographs. The photographs were taken using the 6-meter telescope of the Special Astrophysical Observatory of the USSR Academy of Sciences. Digital filtering was used to reduce the high-frequency photoemulsion noise and to improve the angular resolution of the original photographs. The enhanced images are compared with isodensity charts and the original photographs, and the results are discussed in detail.

  19. Feeding versus feedback in active galactic nuclei from near-infrared integral field spectroscopy - XII. NGC 5548

    NASA Astrophysics Data System (ADS)

    Schönell, Astor J., Jr.; Storchi-Bergmann, Thaisa; Riffel, Rogemar A.; Riffel, Rogério

    2017-01-01

    We map the gas excitation and kinematics, and the stellar population properties of the Seyfert 1 galaxy NGC 5548 using Gemini Near Infrared Integral Field Spectrograph in the J and K bands at a spatial and velocity resolution of 105 pc and 45 km s-1, respectively. Emission-line flux distributions in ionized and molecular gas extend up to ≈400 pc from the nucleus, where they are found to peak. The mass of H II is 4.8±0.6 × 106 M⊙ and the mass of warm H2 is 1.1±0.2 × 103 M⊙, while the mass of cold H2 is estimated as 5.8±1.2 × 108 M⊙. The Pa β emission shows two kinematic components: one in blueshift, with velocity reaching ≈-300 km s-1 and another showing a velocity field characteristic of rotation in the galaxy plane. The blueshifted component is also observed in the coronal line [S IX]λ1.2523 μm, while the rotational component is also observed in the molecular gas. We interpret this velocity field as due to gas rotating in the galaxy plane plus an outflow, and estimate a mass outflow rate of 6.8±0.75 M⊙ yr-1. Spectral synthesis of the continuum shows nuclear emission dominated by a featureless AGN continuum combined with hot dust emission attributed to a dusty torus. The stellar population is dominated by an old (2 Gyr < t ≤ 15 Gyr) component between 160 and 300 pc, while closer to the nucleus, an intermediate age (50 Myr < t ≤ 2 Gyr) component contributes at levels ranging from ≈40 per cent to ≈100 per cent to the flux at 2.12 μm.

  20. The Dragonfly Nearby Galaxies Survey. II. Ultra-Diffuse Galaxies near the Elliptical Galaxy NGC 5485

    NASA Astrophysics Data System (ADS)

    Merritt, Allison; van Dokkum, Pieter; Danieli, Shany; Abraham, Roberto; Zhang, Jielai; Karachentsev, I. D.; Makarova, L. N.

    2016-12-01

    We present the unexpected discovery of four ultra-diffuse galaxies (UDGs) in a group environment. We recently identified seven extremely low surface brightness galaxies in the vicinity of the spiral galaxy M101, using data from the Dragonfly Telephoto Array. The galaxies have effective radii of 10″-38″ and central surface brightnesses of 25.6-27.7 mag arcsec-2 in the g-band. We subsequently obtained follow-up observations with HST to constrain the distances to these galaxies. Four remain persistently unresolved even with the spatial resolution of HST/ACS, which implies distances of D\\gt 17.5 Mpc. We show that the galaxies are most likely associated with a background group at ˜27 Mpc containing the massive ellipticals NGC 5485 and NGC 5473. At this distance, the galaxies have sizes of 2.6-4.9 kpc, and are classified as UDGs, similar to the populations that have been revealed in clusters such as Coma, Virgo, and Fornax, yet even more diffuse. The discovery of four UDGs in a galaxy group demonstrates that the UDG phenomenon is not exclusive to cluster environments. Furthermore, their morphologies seem less regular than those of the cluster populations, which may suggest a different formation mechanism or be indicative of a threshold in surface density below which UDGs are unable to maintain stability.

  1. Near infrared spectroscopy of stearic acid adsorbed on montmorillonite.

    PubMed

    Lu, Longfei; Cai, Jingong; Frost, Ray L

    2010-03-01

    The adsorption of stearic acid on both sodium montmorillonites and calcium montmorillonites has been studied by near infrared spectroscopy complimented with infrared spectroscopy. Upon adsorption of stearic acid on Ca-Mt additional near infrared bands are observed at 8236 cm(-1) and is assigned to an interaction of stearic acid with the water of hydration. Upon adsorption of the stearic acid on Na-Mt, the NIR bands are now observed at 5671, 5778, 5848 and 5912 cm(-1) and are assigned to the overtone and combination bands of the CH fundamentals. Additional bands at 4177, 4250, 4324, 4337, 4689 and 4809 cm(-1) are attributed to CH combination bands resulting from the adsorption of the stearic acid. Stearic acid is used as a model molecule for adsorption studies. The application of near infrared spectroscopy to the study of this adsorption proved most useful.

  2. [Study on near-infrared absorption mechanism of alkali lignin].

    PubMed

    Wu, Xin-sheng; Xie, Yi-min; Liu, Huan-bin; Wu, Hong

    2006-06-01

    The results showed that o-quinone and q-quinone had strong absorption while vanillin had nearly no absorption in the 800-900 nm range of near-infrared spectroscopy through the comparison of their near-infrared absorption spectra. It was proved that quinone structure of alkali lignin had strong absorption in the 800-900 nm range of near-infrared spectroscopy. The change in the absorbency of oleander milled wood lignin treated with NaOH and Na2 S before and after is greater than that in the absorbency of ginkgo milled wood lignin treated with NaOH and Na2 S before and after because more quinone structure was formed in the process of oleander milled wood lignin treated with NaOH and Na2 S. The finding well explained that cooking liquor of hardwood was much stronger than that of softwood while their pulp kappa number was very near.

  3. Near infrared reflectance analysis by Gauss-Jordan linear algebra

    NASA Astrophysics Data System (ADS)

    Honigs, D. E.; Freelin, J. M.; Hieftje, G. M.

    1983-02-01

    Near-infrared reflectance analysis (NIRA) is an analytical technique that uses the near-infrared diffuse reflectance of a sample at several discrete wavelengths to predict the concentration of one or more of the chemical species in that sample. However, because near-infrared bands from solid samples are both abundant and broad, the reflectance at a given wavelength usually contains contributions from several sample components, requiring extensive calculations on overlapped bands. In the present study, these calculations have been performed using an approach similar to that employed in multi-component spectrophotometry, but with Gauss-Jordan linear algebra serving as the computational vehicle. Using this approach, correlations for percent protein in wheat flour and percent benzene in hydrocarbons have been obtained and are evaluated. The advantages of a linear-algebra approach over the common one employing stepwise regression are explored.

  4. Dynamically hot galaxies. II - Global stellar populations

    NASA Technical Reports Server (NTRS)

    Bender, Ralf; Burstein, David; Faber, S. M.

    1993-01-01

    The global relationship between the stellar populations and the structural properties of dynamically hot galaxies (DHGs) is investigated using the same sample as was analyzed by Bender et al. (1992), which includes giant ellipticals, low-luminosity ellipticals, compact ellipticals, diffuse dwarf ellipticals, dwarf spheroidals, and bulges. It was found that all DHGs follow a single relationship between global stellar population (represented by Mg2 index or B-V color) and central velocity dispersion sigma(0), and that the Mg2-sigma(0) relation is significantly tighter than the relation between the Mg2 index and absolute luminosity. The relation between central Mg2 index and bulk B-V color was also found to be tight.

  5. Near-infrared spectra of the uranian ring system

    NASA Astrophysics Data System (ADS)

    de Kleer, Katherine; de Pater, Imke; Ádámkovics, Máté; Hammel, Heidi

    2013-09-01

    We present the first high-resolution near-infrared (1.18-2.38 μm) spectrum of the rings of Uranus, as observed with adaptive optics on the W.M. Keck II telescope in August 2010. We derive ring equivalent widths, as well as ring and particle reflectivities for the ɛ ring and ringlet groups based on H- and K-band data. We find the rings to be gray, indicating that they are dominated by large particles rather than dust, and we find no evidence for water ice. We present a reflectivity spectrum for the ɛ ring alone, which we also find to be consistent with a flat spectrum. We derive H-band ring particle reflectivities of 0.022 ± 0.010, 0.051 ± 0.009 0.042 ± 0.012, and 0.043 ± 0.001 and K-band ring particle reflectivities of 0.016 ± 0.010, 0.034 ± 0.012, 0.047 ± 0.008 and 0.041 ± 0.002 for the 456, αβ, ηγδ, and ɛ ring groups. Previous observations have found ring particle reflectivities in the 0.033-0.044 range (de Pater, I., Gibbard, S., Macintosh, B.A., Roe, H.G. [2002]. Icarus 160, 359-374; Gibbard, S.G., de Pater, I., Hammel, H.B. [2005]. Icarus 174, 253-262), and are generally consistent with our results.

  6. Near-infrared extinction with discretised stellar colours

    NASA Astrophysics Data System (ADS)

    Juvela, M.; Montillaud, J.

    2016-01-01

    Context. Near-infrared (NIR) extinction remains one of the most reliable methods of measuring the column density of dense interstellar clouds. Extinction can be estimated using the reddening of the light of background stars. Several methods exist (e.g., NICE, NICER, NICEST, GNICER) to combine observations of several NIR bands into extinction maps. Aims: We present a new method of estimating extinction based on NIR multiband observations and examine its performance. Methods: Our basic method uses a discretised version of the distribution of intrinsic stellar colours directly. The extinction of individual stars and the average over a resolution element are estimated with Markov chain Monte Carlo (MCMC) methods. Several variations of the basic method are tested, and the results are compared to NICER calculations. Results: In idealised settings or when photometric errors are large, the results of the new method are very close to those of NICER. Clear advantages can be seen when the distribution of intrinsic colours cannot be described well with a single covariance matrix. The MCMC framework makes it easy to consider additional effects such as those of completeness limits and contamination by galaxies or foreground stars. A priori information about relative column density variations at sub-beam scales can result in a significant increase in accuracy. For observations of high photometric precision, the results could be further improved by considering the magnitude dependence of the intrinsic colours. Conclusions: The MCMC computations are time-consuming, but the calculation of large extinction maps is already practical. The same methods can be used with direct optimisation, with significantly less computational work. Faster methods, like NICER, perform very well in many cases even when the basic assumptions no longer hold. The new methods are useful mostly when photometric errors are small, the distribution of intrinsic colours is well known, or one has prior knowledge

  7. Flamingos near-infrared study of the Serpens cloud

    NASA Astrophysics Data System (ADS)

    Hasan, Priya

    We present the results of a deep near-infrared imaging survey of the Serpens Cloud made with FLAMINGOS at the 2.1 m telescope at Kitt Peak National Observatory. We study the distribution of young embedded sources using the nearest neighbor method applied to a carefully selected sample of near-infrared excess (NIRX) stars that trace the latest episode of star formation in the complex. Our analysis finds the existence of six clusters, of which three are new in the molecular cloud. We determined a median age for the cluster to be 1-2 Myr at a mean distance of 300 pc.

  8. Breast phantom for mammary tissue characterization by near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Miranda, D. A.; Cristiano, K. L.; Gutiérrez, J. C.

    2013-11-01

    Breast cancer is a disease associated to a high morbidity and mortality in the entire world. In the study of early detection of breast cancer the development of phantom is so important. In this research we fabricate a breast phantom using a ballistic gel with special modifications to simulate a normal and abnormal human breast. Optical properties of woman breast in the near infrared region were modelled with the phantom we developed. The developed phantom was evaluated with near infrared spectroscopy in order to study its relation with breast tissue. A good optical behaviour was achieved with the model fabricated.

  9. A Search for a Near-Infrared Halo Around NGC 4565

    NASA Technical Reports Server (NTRS)

    Uemizu, Kazunori; Bock, James J.; Kawada, Mitsunobu; Lange, Andrew E.; Matsumoto, Toshio; Watabe, Toyoki; Yost, Sarah A.

    1998-01-01

    We present a near-infrared (3.5-5 micron) search for the integrated emission from low-mass stars and/or brown dwarfs in the halo of the nearby edge-on spiral galaxy NGC 4565. The observation was made with a liquid-helium-cooled rocket-borne telescope using a 256 x 256 InSb array with a pixel scale of 17". Images of NGC 4565 were successfully obtained with sensitivity near the natural background limit. Our search reveals no evidence of a faint halo around the galaxy, in contrast with the previous reports of a halo around NGC 5907. The lower limit of the mass-to-light ratio for the halo of NGC 4565 is 260 (2 delta) in solar units at 3.5-5 microns. This implies that hydrogen-burning stars do not contribute significantly to the mass of the dark halo in NGC 4565.

  10. HUBBLE SPACE TELESCOPE/NEAR-INFRARED CAMERA AND MULTI-OBJECT SPECTROMETER OBSERVATIONS OF THE GLIMPSE9 STELLAR CLUSTER

    SciTech Connect

    Messineo, Maria; Figer, Donald F.; Davies, Ben; Trombley, Christine; Kudritzki, R. P.; Rich, R. Michael; MacKenty, John

    2010-01-10

    We present Hubble Space Telescope/Near-Infrared Camera and Multi-Object Spectrometer photometry, and low-resolution K-band spectra of the GLIMPSE9 stellar cluster. The newly obtained color-magnitude diagram shows a cluster sequence with H - K{sub S} = approx1 mag, indicating an interstellar extinction A{sub K{sub s}} = 1.6 +- 0.2 mag. The spectra of the three brightest stars show deep CO band heads, which indicate red supergiants with spectral type M1-M2. Two 09-B2 supergiants are also identified, which yield a spectrophotometric distance of 4.2 +- 0.4 kpc. Presuming that the population is coeval, we derive an age between 15 and 27 Myr, and a total cluster mass of 1600 +- 400 M{sub sun}, integrated down to 1 M{sub sun}. In the vicinity of GLIMPSE9 are several H II regions and supernova remnants, all of which (including GLIMPSE9) are probably associated with a giant molecular cloud (GMC) in the inner galaxy. GLIMPSE9 probably represents one episode of massive star formation in this GMC. We have identified several other candidate stellar clusters of the same complex.

  11. Detecting Counterfeit Antimalarial Tablets by Near-Infrared Spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Counterfeit antimalarial drugs are found in many developing countries, but it is challenging to differentiate between genuine and fakes due to their increasing sophistication. Near-infrared spectroscopy (NIRS) is a powerful tool in pharmaceutical forensics, and we tested this technique for discrim...

  12. Comparative hazard evaluation of near-infrared diode lasers.

    PubMed

    Marshall, W J

    1994-05-01

    Hazard evaluation methods from various laser protection standards differ when applied to extended-source, near-infrared lasers. By way of example, various hazard analyses are applied to laser training systems, which incorporate diode lasers, specifically those that assist in training military or law enforcement personnel in the proper use of weapons by simulating actual firing by the substitution of a beam of near-infrared energy for bullets. A correct hazard evaluation of these lasers is necessary since simulators are designed to be directed toward personnel during normal use. The differences among laser standards are most apparent when determining the hazard class of a laser. Hazard classification is based on a comparison of the potential exposures with the maximum permissible exposures in the 1986 and 1993 versions of the American National Standard for the Safe Use of Lasers, Z136.1, and the accessible emission limits of the federal laser product performance standard. Necessary safety design features of a particular system depend on the hazard class. The ANSI Z136.1-1993 standard provides a simpler and more accurate hazard assessment of low-power, near-infrared, diode laser systems than the 1986 ANSI standard. Although a specific system is evaluated, the techniques described can be readily applied to other near-infrared lasers or laser training systems.

  13. Social Perception in Infancy: A Near Infrared Spectroscopy Study

    ERIC Educational Resources Information Center

    Lloyd-Fox, Sarah; Blasi, Anna; Volein, Agnes; Everdell, Nick; Elwell, Claire E.; Johnson, Mark H.

    2009-01-01

    The capacity to engage and communicate in a social world is one of the defining characteristics of the human species. While the network of regions that compose the social brain have been the subject of extensive research in adults, there are limited techniques available for monitoring young infants. This study used near infrared spectroscopy to…

  14. Cotton micronaire measurements by small portable near infrared (nir) analyzers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A key quality and processing parameter for cotton fiber is micronaire, which is a function of the fiber’s maturity and fineness. Near Infrared (NIR) spectroscopy has previously shown the ability to measure micronaire, primarily in the laboratory and using large, research-grade laboratory NIR instru...

  15. Near-infrared spectroscopic tissue imaging for medical applications

    DOEpatents

    Demos, Stavros; Staggs, Michael C.

    2006-12-12

    Near infrared imaging using elastic light scattering and tissue autofluorescence are explored for medical applications. The approach involves imaging using cross-polarized elastic light scattering and tissue autofluorescence in the Near Infra-Red (NIR) coupled with image processing and inter-image operations to differentiate human tissue components.

  16. Near-infrared spectroscopic tissue imaging for medical applications

    DOEpatents

    Demos; Stavros , Staggs; Michael C.

    2006-03-21

    Near infrared imaging using elastic light scattering and tissue autofluorescence are explored for medical applications. The approach involves imaging using cross-polarized elastic light scattering and tissue autofluorescence in the Near Infra-Red (NIR) coupled with image processing and inter-image operations to differentiate human tissue components.

  17. Near-infrared spectra of compact stellar wind sources at the Galactic center

    NASA Technical Reports Server (NTRS)

    Libonate, S.; Pipher, J. L.; Forrest, W. J.; Ashby, M. L. N.

    1995-01-01

    We present high- and low-resolution, H- and K-band spectra on nine compact 2.2 micrometers Galactic center sources in which we clearly detect He I 2.058 micrometers emission, including the AF source, IRS 13, IRS 1W, IRS 16NE, IRS 16NW, IRS 16C, IRS 16SW, IRS 34, and IRS 6E. We have also obtained comparison spectra of both a luminous blue variable (LBV) and a WR star (P Cygni and HD 192163, respectively). Our H- and K-band spectrum of the LBV P Cygni strongly resembles the near-infrared spectra of known WN9/Ofpe stars. Our spectra of the Galactic center sources share many characteristics in common with our spectrum of P Cygni. The spectra all show emission lines of H I and He I with large He I/H line flux ratios. Some have permitted and forbidden lines of Fe II. Brackett line widths and ratios indicate the presence of strong stellar winds. In contrast to the spectrum of the WR star, none of the Galactic center sources show evidence of He II emission lines in their spectra, suggesting that none of the Galactic center sources are WR stars. Our high-resolution H-band spectrum of the AF source differs from previously published low-resolution H-band spectra in that it is rich in emission lines. Furthermore, we find two distinct spectral components to the AF source separated in space by a few arcseconds. We identify both the emission-line component of the AF source and an exciting source of IRS 13 as an LBV or WN9/Ofpe star. Our results, when combined with the results of others, also suggest that IRS 16NE, IRS 16C, IRS 16NW, IRS 34, and a component of IRS 6E are early-type, emission-line stars. The argument for IRS 16SW, however, is less compelling. We find no evidence for a compact He I emission-line source at IRS 1W. This result contradicts previous findings, suggesting that the He I source at IRS 1W may be variable. If the He I lines in IRS 1W are truly variable, a stellar component of IRS 1W may be an LBV, because LBVs are known to have variable line emission on short

  18. Intraoperative Near-Infrared Imaging of Surgical Wounds after Tumor Resections Can Detect Residual Disease

    PubMed Central

    Madajewski, Brian; Judy, Brendan F.; Mouchli, Anas; Kapoor, Veena; Holt, David; Wang, May D.; Nie, Shuming; Singhal, Sunil

    2012-01-01

    Background Surgical resection remains the most effective therapy for solid tumors worldwide. The most important prognostic indicator for cure following cancer surgery is a complete resection with no residual disease. However, intraoperative detection of retained cancer cells after surgery is challenging, and residual disease continues to be the most common cause of local failure. We hypothesized visual enhancement of tumors using near-infrared imaging could potentially identify tumor deposits in the wound after resection. Methods A small animal model of surgery and retained disease was developed. Residual tumor deposits in the wound were targeted using an FDA approved imaging agent, indocyanine green, by the enhanced permeability and retention (EPR) effect. A novel hand-held spectrometer was used to optically visualize retained disease after surgery. Results We found residual disease using near-infrared imaging during surgery that was not visible to the naked eye or microCT. Furthermore, examination of tumor nodules was remarkably precise in delineating margins from normal surrounding tissues. This approach was most successful for tumors with increased neovasculature. Conclusions The results suggest that near-infrared examination of the surgical wound after curative resection can potentially enable the surgeon to locate residual disease. The data in this study is the basis of an ongoing Phase I/II clinical trial in patients who undergo resection for lung and breast cancer. PMID:22932668

  19. False-color image of the near-infrared sky as seen by the DIRBE

    NASA Technical Reports Server (NTRS)

    2002-01-01

    False-color image of the near-infrared sky as seen by the DIRBE. Data at 1.25, 2.2, and 3.5 Aum wavelengths are represented respectively as blue, green and red colors. The image is presented in Galactic coordinates, with the plane of the Milky Way Galaxy horizontal across the middle and the Galactic center at the center. The dominant sources of light at these wavelengths are stars within our Galaxy. The image shows both the thin disk and central bulge populations of stars in our spiral galaxy. Our Sun, much closer to us than any other star, lies in the disk (which is why the disk appears edge-on to us) at a distance of about 28,000 light years from the center. The image is redder in directions where there is more dust between the stars absorbing starlight from distant stars. This absorption is so strong at visible wavelengths that the central part of the Milky Way cannot be seen. DIRBE data will facilitate studies of the content, energetics and large scale structure of the Galaxy, as well as the nature and distribution of dust within the Solar System. The data also will be studied for evidence of a faint, uniform infrared background, the residual radiation from the first stars and galaxies formed following the Big Bang.

  20. Probing Reionization at z≥7 with HST's Near-Infrared Grisms

    NASA Astrophysics Data System (ADS)

    Borello Schmidt, Kasper

    2015-08-01

    The epoch of reionization, i.e. the transition of the IGM from neutral to fully ionized, is essential for our understanding of the evolution of the Universe and the formation of the first stars and galaxies. The first results at z≤ 7 suggest that the reionization happened in a patchy, rather than smooth, fashion. It is still unclear whether galaxies at z≥7 prefer a patchy reionization scenario as well. The Grism Lens-Amplified Survey from Space (GLASS) has obtained spectra of ten thousands of objects in and behind 10 massive galaxy clusters, including the six Hubble Frontier Fields. Coaming the Hubble grism spectroscopy from GLASS results in 100s of spectra of z≥7 galaxy candidates. Taking advantage of the lensing magnification from the foreground clusters, the GLASS spectra reaches unprecedented depths in the near-infrared with flux limits below 10-18 erg/s/cm2. This has resulted in several Lyα detections at z˜7, tight limits on the emission line fluxes for non-detections, and the equivalent width distribution of Lyα in the very earlier Universe. Taking advantage of the extensive spectroscopic samples of z≥7 galaxies from GLASS, I will show how these samples can give us and unprecedented view of the cosmic reionization at z≥7.

  1. STELLAR KINEMATICS OF THE ANDROMEDA II DWARF SPHEROIDAL GALAXY

    SciTech Connect

    Ho, Nhung; Geha, M.; Tollerud, E.; Munoz, R. R.; Guhathakurta, P.; Gilbert, K. M.; Bullock, J.; Beaton, R. L.; Majewski, S. R. E-mail: marla.geha@yale.edu

    2012-10-20

    We present kinematical profiles and metallicity for the M31 dwarf spheroidal (dSph) satellite galaxy Andromeda II (And II) based on Keck DEIMOS spectroscopy of 531 red giant branch stars. Our kinematical sample is among the largest for any M31 satellite and extends out to two effective radii (r {sub eff} = 5.'3 = 1.1 kpc). We find a mean systemic velocity of -192.4 {+-} 0.5 km s{sup -1} and an average velocity dispersion of {sigma} {sub v} = 7.8 {+-} 1.1 km s{sup -1}. While the rotation velocity along the major axis of And II is nearly zero (<1 km s{sup -1}), the rotation along the minor axis is significant with a maximum rotational velocity of v {sub max} = 8.6 {+-} 1.8 km s{sup -1}. We find a kinematical major axis, with a maximum rotational velocity of v {sub max} = 10.9 {+-} 2.4 km s{sup -1}, misaligned by 67 Degree-Sign to the isophotal major axis. And II is thus the first dwarf galaxy with evidence for nearly prolate rotation with a v {sub max}/{sigma} {sub v} = 1.1, although given its ellipticity of {epsilon} = 0.10, this object may be triaxial. We measured metallicities for a subsample of our data, finding a mean metallicity of [Fe/H] = -1.39 {+-} 0.03 dex and an internal metallicity dispersion of 0.72 {+-} 0.03 dex. We find a radial metallicity gradient with metal-rich stars more centrally concentrated, but do not observe a significant difference in the dynamics of the two metallicity populations. And II is the only known dwarf galaxy to show minor axis rotation, making it a unique system whose existence offers important clues on the processes responsible for the formation of dSphs.

  2. The REFLEX II galaxy cluster survey: power spectrum analysis

    NASA Astrophysics Data System (ADS)

    Balaguera-Antolínez, A.; Sánchez, Ariel G.; Böhringer, H.; Collins, C.; Guzzo, L.; Phleps, S.

    2011-05-01

    We present the power spectrum of galaxy clusters measured from the new ROSAT-ESO Flux-Limited X-Ray (REFLEX II) galaxy cluster catalogue. This new sample extends the flux limit of the original REFLEX catalogue to 1.8 × 10-12 erg s-1 cm-2, yielding a total of 911 clusters with ≥94 per cent completeness in redshift follow-up. The analysis of the data is improved by creating a set of 100 REFLEX II-catalogue-like mock galaxy cluster catalogues built from a suite of large-volume Λ cold dark matter (ΛCDM) N-body simulations (L-BASICC II). The measured power spectrum is in agreement with the predictions from a ΛCDM cosmological model. The measurements show the expected increase in the amplitude of the power spectrum with increasing X-ray luminosity. On large scales, we show that the shape of the measured power spectrum is compatible with a scale-independent bias and provide a model for the amplitude that allows us to connect our measurements with a cosmological model. By implementing a luminosity-dependent power-spectrum estimator, we observe that the power spectrum measured from the REFLEX II sample is weakly affected by flux-selection effects. The shape of the measured power spectrum is compatible with a featureless power spectrum on scales k > 0.01 h Mpc-1 and hence no statistically significant signal of baryonic acoustic oscillations can be detected. We show that the measured REFLEX II power spectrum displays signatures of non-linear evolution.

  3. THE NEAR-INFRARED BACKGROUND INTENSITY AND ANISOTROPIES DURING THE EPOCH OF REIONIZATION

    SciTech Connect

    Cooray, Asantha; Gong Yan; Smidt, Joseph; Santos, Mario G.

    2012-09-01

    A fraction of the extragalactic near-infrared (near-IR) background light involves redshifted photons from the ultraviolet (UV) emission from galaxies present during reionization at redshifts above 6. The absolute intensity and the anisotropies of the near-IR background provide an observational probe of the first-light galaxies and their spatial distribution. We estimate the extragalactic background light intensity during reionization by accounting for the stellar and nebular emission from first-light galaxies. We require the UV photon density from these galaxies to generate a reionization history that is consistent with the optical depth to electron scattering from cosmic microwave background measurements. We also require the bright-end luminosity function (LF) of galaxies in our models to reproduce the measured Lyman-dropout LFs at redshifts of 6-8. The absolute intensity is about 0.1-0.4 nW m{sup -2} sr{sup -1} at the peak of its spectrum at {approx}1.1 {mu}m. We also discuss the anisotropy power spectrum of the near-IR background using a halo model to describe the galaxy distribution. We compare our predictions for the anisotropy power spectrum to existing measurements from deep near-IR imaging data from Spitzer/IRAC, Hubble/NICMOS, and AKARI. The predicted rms fluctuations at tens of arcminute angular scales are roughly an order of magnitude smaller than the existing measurements. While strong arguments have been made that the measured fluctuations do not have an origin involving faint low-redshift galaxies, we find that measurements in the literature are also incompatible with galaxies present during the era of reionization. The measured near-IR background anisotropies remain unexplained with an unknown origin.

  4. Globular clusters of NGC 3115 in the near-infrared. Demonstrating the correctness of two opposing scenarios

    NASA Astrophysics Data System (ADS)

    Cantiello, Michele; Blakeslee, John P.; Raimondo, Gabriella; Chies-Santos, Ana L.; Jennings, Zachary G.; Norris, Mark A.; Kuntschner, Harald

    2014-04-01

    We combined new near-infrared VLT/HAWK-I data of the globular clusters (GCs) in the isolated edge-on S0 galaxy NGC 3115 with optical and spectroscopic ones taken from the literature, with the aim of analyzing the multiband GC color distributions. A recent study from the SLUGGS survey has shown that the GCs in this galaxy follow a bimodal distribution of Ca II triplet indices. Thus, NGC 3115 presents a critical example of a GC system with multiple, distinct, metallicity subpopulations, and this may argue against the "projection" scenario, which posits that the ubiquitous color bimodality mainly results from nonlinearities in the color-metallicity relations. Using optical, NIR, and spectroscopic data, we found strong and consistent evidence of index bimodality, which independently confirms the metallicity bimodality in NGC 3115 GCs. At the same time, we also found evidence for some color-color nonlinearity. Taken in the broader context of previous studies, the multicolor consistency of the GC bimodality in NGC 3115 suggests that in cases where GC systems exhibit clear differences between their optical and optical-NIR color distributions (as in some giant ellipticals), the apparent inconsistencies most likely result from nonlinearities in the color-metallicity relations. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 60.A-9284.Full Table 2 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/564/L3Tables 3-5 are available in electronic form at http://www.aanda.org

  5. Chemical Abundances in the Stellar Populations of the Leo I and Leo II dSph Galaxies

    NASA Astrophysics Data System (ADS)

    Bosler, T. L.; Smecker-Hane, T. A.; Stetson, P. B.

    2002-05-01

    Our goal is to map the chemical abundance distribution of the stellar populations of the Leo I and Leo II dwarf spheroidal (dSph) galaxies to constrain the physical processes that regulate their evolution. The dSphs are particularly interesting galaxies because their star formation histories (SFHs) appear to be much more complicated than theory would predict for such low mass, low luminosity, low surface-brightness galaxies. Color-magnitude diagrams (CMDs) of these dSphs have shown that they formed stars over many Gyr. In order to understand the true spread in stellar ages and chemical abundances we need more precise abundance indicators than can be inferred from CMD analysis: abundances based upon the broad-band colors of red giants are subject to large systematic errors because of limitations in convection theory, and poorly determined color--effective temperature relations produce sizable uncertainties in the derived shapes of theoretical red giant branches. Therefore we are measuring the abundance distribution of the Leo I and Leo II dSphs from spectroscopy of individual red giant stars using the Ca II absorption lines in the near infrared (8498, 8542, and 8662 Å). Our observations are made on the Keck I 10-meter Telescope using the Low Resolution Imaging Spectrometer. One night of successful observations yielded spectra of approximately 40 stars in each dSph from which abundances with random uncertainties of ≈ 0.1 dex will be derived. Calibration of the Ca II strengths to [Fe/H] has been done by Rutledge, et al. (1997, PASP, 109, 907) using Galactic globular clusters. We are also deriving a new calibration for [Ca/H]. This new calibration will remove the dependence on SFH built into the Rutledge, et al. calibration, i.e., the assumptions of a unique age for the system and a Galactic [Ca/Fe]--[Fe/H] relationship. Financial support for this project was provided by NSF grant AST-0070985 to TSH, and an ARCS Foundation fellowship to TB.

  6. Feeding and feedback in the active nucleus of Mrk 1157 probed with the Gemini Near-Infrared Integral-Field Spectrograph

    NASA Astrophysics Data System (ADS)

    Riffel, Rogemar A.; Storchi-Bergmann, Thaisa

    2011-11-01

    We have mapped the stellar and gaseous kinematics, as well as the emission-line flux distributions and ratios, from the inner ≈450 pc radius of the Seyfert 2 galaxy Mrk 1157, using two-dimensional near-infrared J- and Kl-band spectra obtained with the Gemini Near-Infrared Integral-Field Spectrograph instrument at a spatial resolution of ≈35 pc and velocity resolution of ≈40 km s-1. The stellar velocity field shows a rotation pattern, with a discrete S-shaped zero velocity curve - a signature of a nuclear bar. The presence of a bar is also supported by the residual map between the observed rotation field and a model of circular orbits in a Plummer potential. The stellar velocity dispersion (σ*) map presents a partial ring of low-σ* values (50-60 km s-1) at 250 pc from the nucleus surrounded by higher σ* values from the galaxy bulge. We propose that this ring has origin in kinematically colder regions with recent star formation. The stellar velocity dispersion of the bulge (100 km s-1) implies in a black hole mass of MBH= 8.3+3.2- 2.2× 106 M⊙. Emission-line flux distributions are most extended along the position angle PA = 27°/153°, reaching at least 450 pc from the nucleus and following the orientation observed in previous optical emission-line [O III] imaging and radio jets. The molecular hydrogen gas has an excitation temperature Texc≈ 2300 K and its emission is dominated by thermal processes, mainly due to X-ray heating by the active nucleus, with a possible small contribution from shocks produced by the radio jet. The [Fe II] excitation has a larger contribution from shocks produced by the radio jet, as evidenced by the line-ratio maps and velocity dispersion maps, which show spatial correlation with the radio structures. The coronal lines are resolved, extending up to ≈150 pc and are also slightly more extended along PA = 27°/153°. The gaseous kinematics show two components: one due to the gas located in the galaxy plane, in similar rotation

  7. CANDELS: The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey

    NASA Astrophysics Data System (ADS)

    Grogin, Norman A.; Kocevski, Dale D.; Faber, S. M.; Ferguson, Henry C.; Koekemoer, Anton M.; Riess, Adam G.; Acquaviva, Viviana; Alexander, David M.; Almaini, Omar; Ashby, Matthew L. N.; Barden, Marco; Bell, Eric F.; Bournaud, Frédéric; Brown, Thomas M.; Caputi, Karina I.; Casertano, Stefano; Cassata, Paolo; Castellano, Marco; Challis, Peter; Chary, Ranga-Ram; Cheung, Edmond; Cirasuolo, Michele; Conselice, Christopher J.; Roshan Cooray, Asantha; Croton, Darren J.; Daddi, Emanuele; Dahlen, Tomas; Davé, Romeel; de Mello, Duília F.; Dekel, Avishai; Dickinson, Mark; Dolch, Timothy; Donley, Jennifer L.; Dunlop, James S.; Dutton, Aaron A.; Elbaz, David; Fazio, Giovanni G.; Filippenko, Alexei V.; Finkelstein, Steven L.; Fontana, Adriano; Gardner, Jonathan P.; Garnavich, Peter M.; Gawiser, Eric; Giavalisco, Mauro; Grazian, Andrea; Guo, Yicheng; Hathi, Nimish P.; Häussler, Boris; Hopkins, Philip F.; Huang, Jia-Sheng; Huang, Kuang-Han; Jha, Saurabh W.; Kartaltepe, Jeyhan S.; Kirshner, Robert P.; Koo, David C.; Lai, Kamson; Lee, Kyoung-Soo; Li, Weidong; Lotz, Jennifer M.; Lucas, Ray A.; Madau, Piero; McCarthy, Patrick J.; McGrath, Elizabeth J.; McIntosh, Daniel H.; McLure, Ross J.; Mobasher, Bahram; Moustakas, Leonidas A.; Mozena, Mark; Nandra, Kirpal; Newman, Jeffrey A.; Niemi, Sami-Matias; Noeske, Kai G.; Papovich, Casey J.; Pentericci, Laura; Pope, Alexandra; Primack, Joel R.; Rajan, Abhijith; Ravindranath, Swara; Reddy, Naveen A.; Renzini, Alvio; Rix, Hans-Walter; Robaina, Aday R.; Rodney, Steven A.; Rosario, David J.; Rosati, Piero; Salimbeni, Sara; Scarlata, Claudia; Siana, Brian; Simard, Luc; Smidt, Joseph; Somerville, Rachel S.; Spinrad, Hyron; Straughn, Amber N.; Strolger, Louis-Gregory; Telford, Olivia; Teplitz, Harry I.; Trump, Jonathan R.; van der Wel, Arjen; Villforth, Carolin; Wechsler, Risa H.; Weiner, Benjamin J.; Wiklind, Tommy; Wild, Vivienne; Wilson, Grant; Wuyts, Stijn; Yan, Hao-Jing; Yun, Min S.

    2011-12-01

    The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) is designed to document the first third of galactic evolution, over the approximate redshift (z) range 8-1.5. It will image >250,000 distant galaxies using three separate cameras on the Hubble Space Telescope, from the mid-ultraviolet to the near-infrared, and will find and measure Type Ia supernovae at z > 1.5 to test their accuracy as standardizable candles for cosmology. Five premier multi-wavelength sky regions are selected, each with extensive ancillary data. The use of five widely separated fields mitigates cosmic variance and yields statistically robust and complete samples of galaxies down to a stellar mass of 109 M ⊙ to z ≈ 2, reaching the knee of the ultraviolet luminosity function of galaxies to z ≈ 8. The survey covers approximately 800 arcmin2 and is divided into two parts. The CANDELS/Deep survey (5σ point-source limit H = 27.7 mag) covers ~125 arcmin2 within Great Observatories Origins Deep Survey (GOODS)-N and GOODS-S. The CANDELS/Wide survey includes GOODS and three additional fields (Extended Groth Strip, COSMOS, and Ultra-deep Survey) and covers the full area to a 5σ point-source limit of H >~ 27.0 mag. Together with the Hubble Ultra Deep Fields, the strategy creates a three-tiered "wedding-cake" approach that has proven efficient for extragalactic surveys. Data from the survey are nonproprietary and are useful for a wide variety of science investigations. In this paper, we describe the basic motivations for the survey, the CANDELS team science goals and the resulting observational requirements, the field selection and geometry, and the observing design. The Hubble data processing and products are described in a companion paper.

  8. CANDELS: THE COSMIC ASSEMBLY NEAR-INFRARED DEEP EXTRAGALACTIC LEGACY SURVEY

    SciTech Connect

    Grogin, Norman A.; Ferguson, Henry C.; Koekemoer, Anton M.; Brown, Thomas M.; Casertano, Stefano; Kocevski, Dale D.; Faber, S. M.; Acquaviva, Viviana; Alexander, David M.; Almaini, Omar; Ashby, Matthew L. N.; Barden, Marco; Bell, Eric F.; Bournaud, Frederic; Cassata, Paolo; Castellano, Marco; Challis, Peter; Chary, Ranga-Ram; and others

    2011-12-01

    The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) is designed to document the first third of galactic evolution, over the approximate redshift (z) range 8-1.5. It will image >250,000 distant galaxies using three separate cameras on the Hubble Space Telescope, from the mid-ultraviolet to the near-infrared, and will find and measure Type Ia supernovae at z > 1.5 to test their accuracy as standardizable candles for cosmology. Five premier multi-wavelength sky regions are selected, each with extensive ancillary data. The use of five widely separated fields mitigates cosmic variance and yields statistically robust and complete samples of galaxies down to a stellar mass of 10{sup 9} M{sub Sun} to z Almost-Equal-To 2, reaching the knee of the ultraviolet luminosity function of galaxies to z Almost-Equal-To 8. The survey covers approximately 800 arcmin{sup 2} and is divided into two parts. The CANDELS/Deep survey (5{sigma} point-source limit H = 27.7 mag) covers {approx}125 arcmin{sup 2} within Great Observatories Origins Deep Survey (GOODS)-N and GOODS-S. The CANDELS/Wide survey includes GOODS and three additional fields (Extended Groth Strip, COSMOS, and Ultra-deep Survey) and covers the full area to a 5{sigma} point-source limit of H {approx}> 27.0 mag. Together with the Hubble Ultra Deep Fields, the strategy creates a three-tiered 'wedding-cake' approach that has proven efficient for extragalactic surveys. Data from the survey are nonproprietary and are useful for a wide variety of science investigations. In this paper, we describe the basic motivations for the survey, the CANDELS team science goals and the resulting observational requirements, the field selection and geometry, and the observing design. The Hubble data processing and products are described in a companion paper.

  9. Structure of the Interacting Starburst Galaxy II Zw 23

    NASA Astrophysics Data System (ADS)

    Cigan, P. J.; Gallagher, J. S.; Rudie, G.; Wehner, E. H.

    2005-09-01

    II Zw 23 (UGC 3179) is a luminous (MB -21) nearby compact narrow emission line starburst galaxy with blue optical colors and strong emission lines. We present a photometric and morphological study of II Zw 23 and its interacting companion, PC016099, using data obtained with the WIYN 3.5-m telescope in combination with a WFPC2 image from the HST archives. II Zw 23 has a highly disturbed outer structure with long trails of debris that may be feeding tidal dwarfs. Its central regions appear disk-like, a structure that is consistent with the overall rotation pattern observed in the Hα emission line velocity field measured from Densepak observations obtained with WIYN. We discuss these results in terms of the different evolutionary paths followed by stars and gas during strong interactions and the possibility of rapid secondary galactic disk formation in such events.

  10. Near-infrared instrumentation for rapid-response astronomy

    NASA Astrophysics Data System (ADS)

    Capone, John Isaac

    gamma-ray bursts (GRBs) are the Universe's most luminous transient events. Since the discovery of GRBs was announced in 1973, efforts have been ongoing to obtain data over a broader range of the electromagnetic spectrum at the earliest possible times following the initial detection. The discovery of the theorized "afterglow'' emission in radio through X-ray bands in the late 1990s confirmed the cosmological nature of these events. At present, GRB afterglows are among the best probes of the early Universe (z ≥ 9). In addition to informing theories about GRBs themselves, observations of afterglows probe the circum-burst medium (CBM), properties of the host galaxies and the progress of cosmic reionization. To explore the early-time variability of afterglows, I have developed a generalized analysis framework which models near-infrared (NIR), optical, ultra-violet (UV) and X-ray light curves without assuming an underlying model. These fits are then used to construct the spectral energy distribution (SED) of afterglows at arbitrary times within the observed window. Physical models are then used to explore the evolution of the SED parameter space with time. I demonstrate that this framework produces evidence of the photodestruction of dust in the CBM of GRB 120119A, similar to the findings from a previous study of this afterglow. The framework is additionally applied to the afterglows of GRB 140419A and GRB 080607. In these cases the evolution of the SEDs appears consistent with the standard fireball model. Having introduced the scientific motivations for early-time observations, I introduce the Rapid Infrared Imager-Spectrometer (RIMAS). Once commissioned on the 4.3 meter Discovery Channel Telescope (DCT), RIMAS will be used to study the afterglows of GRBs through photometric and spectroscopic observations beginning within minutes of the initial burst. The instrument will operate in the NIR, from 0.97 microm to 2.37 microm, permitting the detection of very high

  11. THE LIFETIME AND POWERS OF FR IIs IN GALAXY CLUSTERS

    SciTech Connect

    Antognini, Joe; Bird, Jonathan; Martini, Paul E-mail: bird@astronomy.ohio-state.edu

    2012-09-10

    We have identified and studied a sample of 151 FR IIs found in brightest cluster galaxies (BCGs) in the MaxBCG cluster catalog with data from FIRST and NVSS. We have compared the radio luminosities and projected lengths of these FR IIs to the projected length distribution of a range of mock catalogs generated by an FR II model and estimate the FR II lifetime to be 1.9 Multiplication-Sign 10{sup 8} yr. The uncertainty in the lifetime calculation is a factor of two, primarily due to uncertainties in the intracluster medium (ICM) density and the FR II axial ratio. We furthermore measure the jet power distribution of FR IIs in BCGs and find that it is well described by a log-normal distribution with a median power of 1.1 Multiplication-Sign 10{sup 37} W and a coefficient of variation of 2.2. These jet powers are nearly linearly related to the observed luminosities, and this relation is steeper than many other estimates, although it is dependent on the jet model. We investigate correlations between FR II and cluster properties and find that galaxy luminosity is correlated with jet power. This implies that jet power is also correlated with black hole mass, as the stellar luminosity of a BCG should be a good proxy for its spheroid mass and therefore the black hole mass. Jet power, however, is not correlated with cluster richness, nor is FR II lifetime strongly correlated with any cluster properties. We calculate the enthalpy of the lobes to examine the impact of the FR IIs on the ICM and find that heating due to adiabatic expansion is too small to offset radiative cooling by a factor of at least six. In contrast, the jet power is approximately an order of magnitude larger than required to counteract cooling. We conclude that if feedback from FR IIs offsets cooling of the ICM, then heating must be primarily due to another mechanism associated with FR II expansion.

  12. Near-Infrared Quantum Cutting Long Persistent Luminescence

    NASA Astrophysics Data System (ADS)

    Zou, Zehua; Feng, Lin; Cao, Cheng; Zhang, Jiachi; Wang, Yuhua

    2016-05-01

    By combining the unique features of the quantum cutting luminescence and long persistent luminescence, we design a new concept called “near-infrared quantum cutting long persistent luminescence (NQPL)”, which makes it possible for us to obtain highly efficient (>100%) near-infrared long persistent luminescence in theory. Guided by the NQPL concept, we fabricate the first NQPL phosphor Ca2Ga2GeO7:Pr3+,Yb3+. It reveals that both the two-step energy transfer of model (I) and the one-step energy transfer of model (IV) occur in 3P0 levels of Pr3+. Although the actual efficiency is not sufficient for the practical application at this primitive stage, this discovery and the associated materials are still expected to have important implications for several fields such as crystalline Si solar cells and bio-medical imaging.

  13. Near-Infrared Quantum Cutting Long Persistent Luminescence

    PubMed Central

    Zou, Zehua; Feng, Lin; Cao, Cheng; Zhang, Jiachi; Wang, Yuhua

    2016-01-01

    By combining the unique features of the quantum cutting luminescence and long persistent luminescence, we design a new concept called “near-infrared quantum cutting long persistent luminescence (NQPL)”, which makes it possible for us to obtain highly efficient (>100%) near-infrared long persistent luminescence in theory. Guided by the NQPL concept, we fabricate the first NQPL phosphor Ca2Ga2GeO7:Pr3+,Yb3+. It reveals that both the two-step energy transfer of model (I) and the one-step energy transfer of model (IV) occur in 3P0 levels of Pr3+. Although the actual efficiency is not sufficient for the practical application at this primitive stage, this discovery and the associated materials are still expected to have important implications for several fields such as crystalline Si solar cells and bio-medical imaging. PMID:27143282

  14. Near-infrared uncaging or photosensitizing dictated by oxygen tension

    NASA Astrophysics Data System (ADS)

    Anderson, Erin D.; Gorka, Alexander P.; Schnermann, Martin J.

    2016-11-01

    Existing strategies that use tissue-penetrant near-infrared light for the targeted treatment of cancer typically rely on the local generation of reactive oxygen species. This approach can be impeded by hypoxia, which frequently occurs in tumour microenvironments. Here we demonstrate that axially unsymmetrical silicon phthalocyanines uncage small molecules preferentially in a low-oxygen environment, while efficiently generating reactive oxygen species in normoxic conditions. Mechanistic studies of the uncaging reaction implicate a photoredox pathway involving photoinduced electron transfer to generate a key radical anion intermediate. Cellular studies demonstrate that the biological mechanism of action is O2-dependent, with reactive oxygen species-mediated phototoxicity in normoxic conditions and small molecule uncaging in hypoxia. These studies provide a near-infrared light-targeted treatment strategy with the potential to address the complex tumour landscape through two distinct mechanisms that vary in response to the local O2 environment.

  15. Near-infrared Mueller matrix imaging for colonic cancer detection

    NASA Astrophysics Data System (ADS)

    Wang, Jianfeng; Zheng, Wei; Lin, Kan; Huang, Zhiwei

    2016-03-01

    Mueller matrix imaging along with polar decomposition method was employed for the colonic cancer detection by polarized light in the near-infrared spectral range (700-1100 nm). A high-speed (<5s) Muller matrix imaging system with dual-rotating waveplates was developed. 16 (4 by 4) full Mueller matrices of the colonic tissues (i.e., normal and caner) were acquired. Polar decomposition was further implemented on the 16 images to derive the diattentuation, depolarization, and the retardance images. The decomposed images showed clear margin between the normal and cancerous colon tissue samples. The work shows the potential of near-infrared Mueller matrix imaging for the early diagnosis and detection of malignant lesions in the colon.

  16. Image-guided cancer surgery using near-infrared fluorescence

    PubMed Central

    Vahrmeijer, Alexander L.; Hutteman, Merlijn; van der Vorst, Joost R.; van de Velde, C.J.H.; Frangioni, John V.

    2013-01-01

    Paradigm shifts in surgery arise when surgeons are empowered to perform surgery faster, better, and/or less expensively. Optical imaging that exploits invisible near-infrared fluorescent light has the potential to improve cancer surgery outcomes while minimizing anesthesia time and lowering healthcare costs. Because of this, the last few years have witnessed an explosion of proof-of-concept clinical trials in the field. In this review, we introduce the concept of near-infrared fluorescence imaging for cancer surgery, review the clinical trial literature to date, outline the key issues pertaining to imaging system and contrast agent optimization, discuss limitations and leverage, and provide a framework for making the technology available for the routine care of cancer patients in the near future. PMID:23881033

  17. [Progress in noninvasive biochemical examination by near infrared spectroscopy].

    PubMed

    Ding, Hai-quan; Lu, Qi-peng; Peng, Zhong-qi; Chen, Xing-dan

    2010-08-01

    In the early nineties of last century, great importance had been gradually attached to the potential of near-infrared spectroscopy (NIRS) in the human body noninvasive biochemical examination. However, the human body is extremely complex. Although research teams have made some achievements in experimental simulations and in-vitro analysis, there is still no substantive breakthrough in clinical application now. The present paper discusses the key problems which prevent NIRS from achieving human noninvasive clinical biochemical examination, such as weak signal, the interference of human tissue background and the problem of blood volume change. The thoughts of noninvasive biomedical examination using NIRS are divided into two categories in terms of analytical method, that is classical near-infrared analysis and issue background interference elimination analysis. This paper also introduces in detail the current status of the two categories in the world, and believes that the second category is more promising to be successful in clinical application under the existing conditions.

  18. Near-infrared photodetector with reduced dark current

    DOEpatents

    Klem, John F; Kim, Jin K

    2012-10-30

    A photodetector is disclosed for the detection of near-infrared light with a wavelength in the range of about 0.9-1.7 microns. The photodetector, which can be formed as either an nBp device or a pBn device on an InP substrate, includes an InGaAs light-absorbing layer, an InAlGaAs graded layer, an InAlAs or InP barrier layer, and an InGaAs contact layer. The photodetector can detect near-infrared light with or without the use of an applied reverse-bias voltage and is useful as an individual photodetector, or to form a focal plane array.

  19. Near-infrared optical-resolution photoacoustic microscopy.

    PubMed

    Hai, Pengfei; Yao, Junjie; Maslov, Konstantin I; Zhou, Yong; Wang, Lihong V

    2014-09-01

    Compared with visible light (380-700 nm), near-infrared light (700-1400 nm) undergoes weaker optical attenuation in biological tissue; thus, it can penetrate deeper. Herein, we demonstrate near-infrared optical-resolution photoacoustic microscopy (NIR-OR-PAM) with 1046 nm illumination. A penetration depth of 3.2 mm was achieved in chicken breast tissue ex vivo using optical fluence within the American National Standards Institute (ANSI) limit (100  mJ/cm2). Beyond ∼0.6  mm deep in chicken breast tissue, NIR-OR-PAM has shown finer resolution than the visible counterpart with 570 nm illumination. The deep imaging capability of NIR-OR-PAM was validated in both a mouse ear and a mouse brain. NIR-OR-PAM of possible lipid contrast was explored as well.

  20. [Near infrared spectroscopy study on water content in turbine oil].

    PubMed

    Chen, Bin; Liu, Ge; Zhang, Xian-Ming

    2013-11-01

    Near infrared (NIR) spectroscopy combined with successive projections algorithm (SPA) was investigated for determination of water content in turbine oil. Through the 57 samples of different water content in turbine oil scanned applying near infrared (NIR) spectroscopy, with the water content in the turbine oil of 0-0.156%, different pretreatment methods such as the original spectra, first derivative spectra and differential polynomial least squares fitting algorithm Savitzky-Golay (SG), and successive projections algorithm (SPA) were applied for the extraction of effective wavelengths, the correlation coefficient (R) and root mean square error (RMSE) were used as the model evaluation indices, accordingly water content in turbine oil was investigated. The results indicated that the original spectra with different water content in turbine oil were pretreated by the performance of first derivative + SG pretreatments, then the selected effective wavelengths were used as the inputs of least square support vector machine (LS-SVM). A total of 16 variables selected by SPA were employed to construct the model of SPA and least square support vector machine (SPA-LS-SVM). There is 9 as The correlation coefficient was 0.975 9 and the root of mean square error of validation set was 2.655 8 x 10(-3) using the model, and it is feasible to determine the water content in oil using near infrared spectroscopy and SPA-LS-SVM, and an excellent prediction precision was obtained. This study supplied a new and alternative approach to the further application of near infrared spectroscopy in on-line monitoring of contamination such as water content in oil.

  1. Discovery in translation: near-infrared fluorescence imaging

    NASA Astrophysics Data System (ADS)

    Sevick-Muraca, Eva M.

    2012-01-01

    When translating new imaging modalities into the clinic, one can expect new discoveries. Owing to the high photon count rates, near-infrared fluorescence (NIRF) offers exquisite sensitivity and high temporal resolution that enable new insights into human disorders. Herein, the physics of NIRF are highlighted and compared to those involved in nuclear medicine techniques. The initial application of investigational NIRF involving characterization of the lymphatics in humans and animal models of human disease yields discoveries not otherwise attainable with conventional imaging.

  2. Near-infrared sensitive organic-inorganic photorefractive device

    NASA Astrophysics Data System (ADS)

    Marinova, Vera; Liu, Ren-Chung; Lin, Shiuan-Huei; Chen, Ming-Syuan; Lin, Yi-Hsin; Hsu, Ken-Yuh

    2016-10-01

    Organic-inorganic hybrid structure, assembled by Rh-doped Bi12TiO20 crystal and liquid crystal (LC) layer, operating at near-infrared range is proposed and demonstrated. Due to the photorefractive properties of inorganic substrate, light illumination caused a space charge field which acts as a driving force for LC molecules re-alignment and subsequent refractive index modulation. All optically controlled phase retardation ability has been demonstrated supporting possibilities for further infrared applications.

  3. Near-infrared emission from mesoporous crystalline germanium

    SciTech Connect

    Boucherif, Abderraouf; Aimez, Vincent; Arès, Richard; Korinek, Andreas

    2014-10-15

    Mesoporous crystalline germanium was fabricated by bipolar electrochemical etching of Ge wafer in HF-based electrolyte. It yields uniform mesoporous germanium layers composed of high density of crystallites with an average size 5-7 nm. Subsequent extended chemical etching allows tuning of crystallites size while preserving the same chemical composition. This highly controllable nanostructure exhibits photoluminescence emission above the bulk Ge bandgap, in the near-infrared range (1095-1360nm) with strong evidence of quantum confinement within the crystallites.

  4. Near-Infrared Reflectance of Snow-Covered Substrates,

    DTIC Science & Technology

    1981-11-01

    I - NEAR-INFRA RED RFETANCE OF SNOW-COVERED SUBSTRATES.IU) INoV SL H B RIEN, . KOH UNCLASSIF IED CRREL-8-21N L ~~LEVE REPORT 81-21 Near-infrared...that more than half of the radiant The condition of the snow cover at the time energy transmitted by the so-called 1.3-,um filter may explain the shape

  5. Near-infrared fundus autoflorescence imaging in solar retinopathy

    PubMed Central

    Czepita, Maciej; Machalińska, Anna; Czepita, Damian

    2017-01-01

    Solar retinopathy is a rare clinical entity caused by photochemical damage to the retinal pigment epithelium layer and photoreceptors of the fovea. Here we describe a case of a 33-year-old female patient diagnosed by near-infrared fundus autofluorescence imaging for signs of damage to the melanosomes of the retinal pigment epithelium of the fovea. The patient was advised to discontinue looking at the sun with the naked eye. PMID:28293534

  6. Near-Infrared Fluorescent Nanoprobes for in Vivo Optical Imaging

    PubMed Central

    Quek, Chai-Hoon; Leong, Kam W.

    2012-01-01

    Near-infrared (NIR) fluorescent probes offer advantages of high photon penetration, reduced light scattering and minimal autofluorescence from living tissues, rendering them valuable for noninvasive mapping of molecular events, assessment of therapeutic efficacy, and monitoring of disease progression in animal models. This review provides an overview of the recent development of the design and optical property of the different classes of NIR fluorescent nanoprobes associated with in vivo imaging applications.

  7. Tunable Near-Infrared Luminescence in Tin Halide Perovskite Devices.

    PubMed

    Lai, May L; Tay, Timothy Y S; Sadhanala, Aditya; Dutton, Siân E; Li, Guangru; Friend, Richard H; Tan, Zhi-Kuang

    2016-07-21

    Infrared emitters are reasonably rare in solution-processed materials. Recently, research into hybrid organo-lead halide perovskite, originally popular in photovoltaics,1-3 has gained traction in light-emitting diodes (LED) due to their low-cost solution processing and good performance.4-9 The lead-based electroluminescent materials show strong colorful emission in the visible region, but lack emissive variants further in the infrared. The concerns with the toxicity of lead may, additionally, limit their wide-scale applications. Here, we demonstrate tunable near-infrared electroluminescence from a lead-free organo-tin halide perovskite, using an ITO/PEDOT:PSS/CH3NH3Sn(Br1-xIx)3/F8/Ca/Ag device architecture. In our tin iodide (CH3NH3SnI3) LEDs, we achieved a 945 nm near-infrared emission with a radiance of 3.4 W sr(-1) m(-2) and a maximum external quantum efficiency of 0.72%, comparable with earlier lead-based devices. Increasing the bromide content in these tin perovskite devices widens the semiconductor bandgap and leads to shorter wavelength emissions, tunable down to 667 nm. These near-infrared LEDs could find useful applications in a range of optical communication, sensing and medical device applications.

  8. IR CMOS: near infrared enhanced digital imaging (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Pralle, Martin U.; Carey, James E.; Joy, Thomas; Vineis, Chris J.; Palsule, Chintamani

    2015-08-01

    SiOnyx has demonstrated imaging at light levels below 1 mLux (moonless starlight) at video frame rates with a 720P CMOS image sensor in a compact, low latency camera. Low light imaging is enabled by the combination of enhanced quantum efficiency in the near infrared together with state of the art low noise image sensor design. The quantum efficiency enhancements are achieved by applying Black Silicon, SiOnyx's proprietary ultrafast laser semiconductor processing technology. In the near infrared, silicon's native indirect bandgap results in low absorption coefficients and long absorption lengths. The Black Silicon nanostructured layer fundamentally disrupts this paradigm by enhancing the absorption of light within a thin pixel layer making 5 microns of silicon equivalent to over 300 microns of standard silicon. This results in a demonstrate 10 fold improvements in near infrared sensitivity over incumbent imaging technology while maintaining complete compatibility with standard CMOS image sensor process flows. Applications include surveillance, nightvision, and 1064nm laser see spot. Imaging performance metrics will be discussed. Demonstrated performance characteristics: Pixel size : 5.6 and 10 um Array size: 720P/1.3Mpix Frame rate: 60 Hz Read noise: 2 ele/pixel Spectral sensitivity: 400 to 1200 nm (with 10x QE at 1064nm) Daytime imaging: color (Bayer pattern) Nighttime imaging: moonless starlight conditions 1064nm laser imaging: daytime imaging out to 2Km

  9. A near-infrared SETI experiment: instrument overview

    NASA Astrophysics Data System (ADS)

    Wright, Shelley A.; Werthimer, Dan; Treffers, Richard R.; Maire, Jérôme; Marcy, Geoffrey W.; Stone, Remington P. S.; Drake, Frank; Meyer, Elliot; Dorval, Patrick; Siemion, Andrew

    2014-07-01

    We are designing and constructing a new SETI (Search for Extraterrestrial Intelligence) instrument to search for direct evidence of interstellar communications via pulsed laser signals at near-infrared wavelengths. The new instrument design builds upon our past optical SETI experiences, and is the first step toward a new, more versatile and sophisticated generation of very fast optical and near-infrared pulse search devices. We present our instrumental design by giving an overview of the opto-mechanical design, detector selection and characterization, signal processing, and integration procedure. This project makes use of near-infrared (950 - 1650 nm) discrete amplification Avalanche Photodiodes (APD) that have > 1 GHz bandwidths with low noise characteristics and moderate gain (~104). We have investigated the use of single versus multiple detectors in our instrument (see Maire et al., this conference), and have optimized the system to have both high sensitivity and low false coincidence rates. Our design is optimized for use behind a 1m telescope and includes an optical camera for acquisition and guiding. A goal is to make our instrument relatively economical and easy to duplicate. We describe our observational setup and our initial search strategies for SETI targets, and for potential interesting compact astrophysical objects.

  10. Near-infrared image filtering for pedestrian surveillance

    NASA Astrophysics Data System (ADS)

    Rodhouse, Kathryn N.; Watkins, Steve E.

    2012-04-01

    An image processing approach is investigated which has low computational complexity and which uses nearinfrared imaging. The target application is a surveillance system for pedestrian traffic. Near-infrared light has potential benefits including non-visible illumination requirements. An image-processing algorithm for monitoring pedestrians is implemented in outdoor and indoor environments with frequent traffic. The image sets consist of persons walking in the presence of foreground as well as background objects at different times during the day. The complex, cluttered environments are highly variable, e.g. shadows and moving foliage. The approach consists of thresholding an image and creating a silhouette of selected objects in the scene. Filtering is used to eliminate noise. The computational results using MATLABshow that the algorithm can effectively manipulate near-infrared images and that effective filtering is possible even in the presence of system noise and environmental clutter. The potential for automated surveillance based on near-infrared imaging and neural-network based feature processing is discussed.

  11. Near-infrared camera for the Clementine mission

    SciTech Connect

    Priest, R.E.; Lewis, I.T.; Sewall, N.R.; Park, H.S.; Shannon, M.J.; Ledebuhr, A.G.; Pleasance, L.D.; Massie, M.A.; Metschuleit, K.

    1995-04-01

    The Clementine mission provided the first ever complete, systematic surface mapping of the moon from the ultra-violet to the near-infrared regions. More than 1.7 million images of the moon, earth and space were returned from this mission. The near-infrared (NIR) multi-spectral camera, one of two workhorse lunar mapping cameras (the other being the UV/visible camera), provided {approximately}200 in spatial resolution at 400 km periselene, and a 39 km across-track swath. This 1.9 kg infrared camera using a 256 x 256 InSb FPA viewed reflected solar illumination from the lunar surface and lunar horizon in the 1 to 3 {micro}m wavelength region, extending lunar imagery and mineralogy studies into the near infrared. A description of this light-weight, low power NIR camera along with a summary of lessons learned is presented. Design goals and preliminary on-orbit performance estimates are addressed in terms of meeting the mission`s primary objective for flight qualifying the sensors for future Department of Defense flights.

  12. Near-infrared imaging spectrometer onboard NEXTSat-1

    NASA Astrophysics Data System (ADS)

    Jeong, Woong-Seob; Park, Sung-Joon; Moon, Bongkon; Lee, Dae-Hee; Pyo, Jeonghyun; Park, Won-Kee; Park, Youngsik; Kim, Il-Joong; Ko, Kyeongyeon; Lee, Dukhang; Kim, Min Gyu; Kim, Minjin; Ko, Jongwan; Shin, Goo-Hwan; Chae, Jangsoo; Matsumoto, Toshio

    2016-07-01

    The NISS (Near-infrared Imaging Spectrometer for Star formation history) is the near-infrared instrument optimized to the first next generation of small satellite (NEXTSat-1) in Korea. The spectro-photometric capability in the near-infrared range is a unique function of the NISS. The major scientific mission is to study the cosmic star formation history in local and distant universe. For those purposes, the NISS will perform the large areal imaging spectroscopic survey for astronomical objects and low background regions. We have paid careful attention to reduce the volume and to increase the total throughput. The newly implemented off-axis optics has a wide field of view (2° x 2°) and a wide wavelength range from 0.9 to 3.8μm. The mechanical structure is designed to consider launching conditions and passive cooling of the telescope. The compact dewar after relay-lens module is to operate the infrared detector and spectral filters at 80K stage. The independent integration of relay-lens part and primary-secondary mirror assembly alleviates the complex alignment process. We confirmed that the telescope and the infrared sensor can be cooled down to around 200K and 80K, respectively. The engineering qualification model of the NISS was tested in the space environment including the launch-induced vibration and shock. The NISS will be expected to demonstrate core technologies related to the development of the future infrared space telescope in Korea.

  13. Near-infrared Characterization of the Atmospheres of Alien Worlds

    NASA Astrophysics Data System (ADS)

    Croll, Bryce

    In this thesis I present near-infrared detections of the thermal emission of a number of hot Jupiters and likely transit depth differences from different wavelength observations of a super-Earth. I have pioneered "Staring Mode" using the Wide-field Infrared Camera on the Canada-France-Hawaii Telescope to achieve the most accurate photometry to-date in the near- infrared from the ground. I also discuss avenues that should allow one to achieve even more accurate photometry in the future. Using WIRCam on CFHT my collaborators and I have detected the thermal emission of the following hot Jupiters: TrES-2b and TrES-3b in Ks-band, WASP-12b in the J, H & Ks-bands, and WASP-3b in the Ks-band on two occasions. Near- infrared detections of the thermal emission of hot Jupiters are important, because the majority of these planets' blackbodies peak in this wavelength range; near-infrared detections allow us to obtain the most model-independent constraints on these planets' atmospheric characteristics, their temperature-pressure profiles with depth and an estimate of their bolometric luminosities. With these detections we are able to answer such questions as: how efficiently these planets redistribute heat to their nightsides, if they're being inflated by tidal heating, whether there's any evidence that one of these planets is precessing, and whether another experiences extreme weather and violent storms? My collaborators and I have also observed several transits of the super-Earth GJ 1214b. We find a deeper transit depth in one of our near-infrared bands than the other. This is likely indicative of a spectral absorption feature. For the differences in the transit depth to be as large as we observed, the atmosphere of GJ 1214b must have a large scale height, low mean molecular weight and thus have a hydrogen/helium dominated atmosphere. Given that other researchers have not found similar transit depth differences, we also discuss the most likely atmospheric makeup for this

  14. Star formation thresholds in H II galaxies with H I companions

    NASA Technical Reports Server (NTRS)

    Taylor, Christopher L.; Brinks, Elias; Pogge, Richard W.; Skillman, Evan D.

    1994-01-01

    We present high resolution Very Large Array (VLA) 21 cm line observations of five H II galaxies combined with previous lower resolution data from Taylor et al. (1993) and optical broadband R and H-alpha Charge Coupled Device (CCD) images of the systems. Following Kennicutt (1989) we calculated the threshold H I surface density for star formation for the H II galaxies and compared the location and shape of this predicted threshold density contour with the optical shape of the galaxies. We find generally a good correlation between these two, although a constant density contour of 10(exp 21)/sq cm fits the images of the optical galaxies equally as well. The H I synthesis observations have revealed that the H II galaxies have sharply peaked H I radial profiles, in contrast to the relatively flattened profiles of low surface brightness (LSB) galaxies, suggesting that large central concentrations of gas are a necessary condition for the occurrence of bursts of massive star formation seen in H II galaxies. These observations are consistent with the hypothesis that LSB galaxies represent the quiescent phase of H II galaxies, if a suitable mechanism exists (such as galaxy interactions) to cause H I to concentrate at the center of LSB galaxies prior to the onset of the burst of star formation. However, it is noted that the H II galaxies (and dwarf galaxies in general) span a relatively large range in mass. Since many properties correlate with mass (e.g., gas mass fraction), we point out that great care needs to be taken in choosing the proper comparison samples of LSB and H II galaxies.

  15. A phase II randomized clinical trial on cerebral near-infrared spectroscopy plus a treatment guideline versus treatment as usual for extremely preterm infants during the first three days of life (SafeBoosC): study protocol for a randomized controlled trial

    PubMed Central

    2013-01-01

    Background Every year in Europe about 25,000 infants are born extremely preterm. These infants have a 20% mortality rate, and 25% of survivors have severe long-term cerebral impairment. Preventative measures are key to reduce mortality and morbidity in an extremely preterm population. The primary objective of the SafeBoosC phase II trial is to examine if it is possible to stabilize the cerebral oxygenation of extremely preterm infants during the first 72 hours of life through the application of cerebral near-infrared spectroscopy (NIRS) oximetry and implementation of an clinical treatment guideline based on intervention thresholds of cerebral regional tissue saturation rStO2. Methods/Design SafeBoosC is a randomized, blinded, multinational, phase II clinical trial. The inclusion criteria are: neonates born more than 12 weeks preterm; decision to conduct full life support; parental informed consent; and possibility to place the cerebral NIRS oximeter within 3 hours after birth. The infants will be randomized into one of two groups. Both groups will have a cerebral oximeter monitoring device placed within three hours of birth. In the experimental group, the cerebral oxygenation reading will supplement the standard treatment using a predefined treatment guideline. In the control group, the cerebral oxygenation reading will not be visible and the infant will be treated according to the local standards. The primary outcome is the multiplication of the duration and magnitude of rStO2 values outside the target ranges of 55% to 85%, that is, the ‘burden of hypoxia and hyperoxia’ expressed in ‘%hours’. To detect a 50% difference between the experimental and control group in %hours, 166 infants in total must be randomized. Secondary outcomes are mortality at term date, cerebral ultrasound score, and interburst intervals on an amplitude-integrated electroencephalogram at 64 hours of life and explorative outcomes include neurodevelopmental outcome at 2 years corrected

  16. Effects of interaction on the properties of spiral galaxies. II. Isolated galaxies: The zero point

    NASA Astrophysics Data System (ADS)

    Márquez, I.; Moles, M.

    1999-04-01

    We analyse the properties of a sample of 22 bright isolated spiral galaxies on the basis of Johnson B,V,I images and optical rotation curves. The fraction of early morphological types in our sample of isolated galaxies (or in other samples of non-interacting spiral galaxies) appears to be smaller than in samples including interacting systems. The overall morphological aspect is regular and symmetric, but all the galaxies present non-axisymmetric components in the form of bars or rings. We find that the color indices become bluer towards the outer parts and that their central values are well correlated with the total colors. The properties of the bulges span a larger range than those of the disks, that thus are more alike between them. None of the galaxies shows a truncated, type II disk profile. It is found that the relation between surface brightness and size for the bulges, the Kormendy relation, is tighter when only isolated galaxies are considered. We find a similar relation for the disk parameters with an unprecedented low scatter. A Principal Component Analysis of the measured parameters shows that 2 eigenvectors suffice to explain more than 95 % of the total variance. These are, as found for other samples including spiral galaxies in different environmental situations, a scale parameter given by the mass or, equivalently, the luminosity or the size; and a form parameter given by the bulge to disk luminosity ratio, B/D, or, equivalently, by the gradient of the solid-body rotation region of the rotation curve, the G-parameter. We report here a tight correlation between G and B/D for our sample of isolated spirals that could be used as a new distance indicator. Based on data obtained at the 1.5m telescope of the Estacion de Observacion de Calar Alto, Instituto Geografico Nacional, which is jointly operated by the Instituto Geografico Nacional and the Consejo Superior de Investigaciones Cientificas through the Instituto de Astrofisica de Andalucia

  17. Near-Infrared Absolute Photometric Imaging of the Uranian System

    NASA Astrophysics Data System (ADS)

    Baines, Kevin H.; Yanamandra-Fisher, Padmavati A.; Lebofsky, Larry A.; Momary, Thomas W.; Golisch, William; Kaminski, Charles; Wild, Walter J.

    1998-04-01

    We report the first multifilter set of absolutely calibrated near-infrared images of Uranus, its rings, and three major satellites-Titania, Ariel, and Miranda. Along with imagery utilizing the canonical K filter bandpass (effective wavelength 2.20 μm), absolutely calibrated images of the uranian system are presented for the first time for three additional filter bandpasses: J (1.27 μm), H (1.62 μm), and in a narrow bandpass (0.1 μm full-width-at-half-maximum) centered at 1.73 μm (hereafter designated H‧) particularly diagnostic of C-H stretch vibrational absorptions common in hydrocarbons. Multifilter-derived spectra of the southern ring ansa including the bright apoapse of the dominant ɛ ring show no absorptions due to condensable volatiles, including water, ammonia, and light (high H:C) hydrocarbons. Plausible near-infrared spherical geometric and single-scattering particle albedos consistent with Voyager-derived phase functions range from 0.069 to 0.102 and from 0.030 to 0.037, respectively. These are approximately 50% greater than visible values, consistent with the optical properties of charcoal, carbonaceous chondrite material, and the darkside of Iapetus, and consistent with the hypothesis that a primary component of the ring particles is high stoichiometric ratio C:H organics produced by charged-particle and/or photochemical weathering of methane clathrate and/or hydrocarbon ice material originating from nearby moonlets. Additional components consistent with the ring spectrum include silicates such as pyroxene, but not olivine. Analytical modeling of the ring structure indicates ɛ-ring near-infrared opacities of 0.37 ± 0.05 and 1.8 ± 0.3 at apoapsis and periapsis, respectively. Ariel is more than 25% brighter than Miranda and 15% brighter than Titania at all near-infrared wavelengths. Comparisons with UV-visible spectra by Karkoschka (1997,Icarus125, 348-363) show consistency with the hypothesis that the water-ice surfaces of Titania and Ariel

  18. A near-infrared survey of old novae. I - The discovery of a candidate recurrent nova

    NASA Astrophysics Data System (ADS)

    Harrison, Thomas E.

    1992-12-01

    We report on a near-infrared survey of old novae in an attempt to discover previously unidentified members of the RS Oph family of recurrent novae. An RS Oph-type system contains a red giant, and is easily identified using infrared photometry. Two objects in our survey have infrared colors and luminosities that suggest that they may be recurrent novae: V723 Sco and AR Cir. We use a model of the Galaxy to rule out the possibility of source confusion in either case. The light curve of the 1952 outburst of V723 Sco was very similar to those of the other members of the RS Oph group of recurrent novae, and we conclude that it is a previously unidentified member of this family. The light curve of the 1906 outburst of AR Cir, however, more closely resembles those of the outbursts of symbiotic stars, and we classify it as such.

  19. NEAR-INFRARED (JHK) PHOTOMETRY OF 131 NORTHERN GALACTIC CLASSICAL CEPHEIDS

    SciTech Connect

    Monson, Andrew J.; Pierce, Michael J.

    2011-03-15

    Near-infrared photometric measurements for 131 Northern Galactic Cepheids are presented. The Cepheid light curves are sampled with an average of 22 measurements per star fully covering the phase of each Cepheid. The J, H, and K light curves for each Cepheid were uniformly interpolated to find the intensity mean magnitudes within each band. The results are consistent within {+-}1% for 26 stars in common with previous studies. This paper is the first in a projected series of two papers which will provide additional fundamental data for Cepheids in the Galaxy, namely, NIR photometry and line-of-sight extinction. In the course of this project, 93 additional variables were fortuitously observed within the Cepheid program fields, 82 of which have previously not been identified.

  20. REANALYSIS OF THE NEAR-INFRARED EXTRAGALACTIC BACKGROUND LIGHT BASED ON THE IRTS OBSERVATIONS

    SciTech Connect

    Matsumoto, T.; Kim, M. G.; Pyo, J.; Tsumura, K.

    2015-07-01

    We reanalyze data of the near-infrared background taken by IRTS using up-to-date observational results of zodiacal light (ZL), integrated star light, and diffuse Galactic light. We confirm the existence of residual isotropic emission, which is slightly lower but almost the same as previously reported. At wavelengths longer than 2 μm, the result is fairly consistent with the recent observation with AKARI. We also perform the same analysis using a different ZL model by Wright and detect residual isotropic emission that is slightly lower than that based on the original Kelsall model. Both models show residual isotropic emission that is significantly brighter than the integrated light of galaxies.

  1. The Hubble Space Telescope: UV, Visible, and Near-Infrared Pursuits

    NASA Technical Reports Server (NTRS)

    Wiseman, Jennifer

    2010-01-01

    The Hubble Space Telescope continues to push the limits on world-class astrophysics. Cameras including the Advanced Camera for Surveys and the new panchromatic Wide Field Camera 3 which was installed nu last year's successful servicing mission S2N4,o{fer imaging from near-infrared through ultraviolet wavelengths. Spectroscopic studies of sources from black holes to exoplanet atmospheres are making great advances through the versatile use of STIS, the Space Telescope Imaging Spectrograph. The new Cosmic Origins Spectrograph, also installed last year, is the most sensitive UV spectrograph to fly io space and is uniquely suited to address particular scientific questions on galaxy halos, the intergalactic medium, and the cosmic web. With these outstanding capabilities on HST come complex needs for laboratory astrophysics support including atomic and line identification data. I will provide an overview of Hubble's current capabilities and the scientific programs and goals that particularly benefit from the studies of laboratory astrophysics.

  2. HUBBLE SPACE TELESCOPE Near-infrared and Optical Imaging of Faint Radio Sources in the Distant Cluster CL 0939+4713

    NASA Astrophysics Data System (ADS)

    Smail, Ian; Morrison, G.; Gray, M. E.; Owen, F. N.; Ivison, R. J.; Kneib, J.-P.; Ellis, R. S.

    1999-11-01

    We present deep Hubble Space Telescope Near-Infrared Camera and Multiobject Spectrograph (NICMOS) and Wide Field and Planetary Camera 2 (WFPC2) optical imaging of a small region in the core of the distant rich cluster Cl 0939+4713 (z=0.41). We compare the optical and near-infrared morphologies of cluster members and find apparent small-scale optical structures within the galaxies that are absent in the near-infrared. We conclude that strong dust obscuration is a common feature in the late-type galaxies in distant clusters. We then concentrate on a sample of 10 faint radio galaxies lying within our NICMOS field and selected from a very deep 1.4 GHz VLA map of the cluster with a 1 σ flux limit of 9 μJy. Using published data we focus on the spectral properties of the eight radio-selected cluster members and show that these comprise a large fraction of the poststarburst population in the cluster. The simplest interpretation of the radio emission from these galaxies is that they are currently forming massive stars, contradicting their classification as poststarburst systems based on the optical spectra. We suggest that this star formation is hidden from view in the optical by the same obscuring dust that is apparent in our comparison on the optical and near-infrared morphologies of these galaxies. We caution that even in the rest-frame optical the effects of dust cannot be ignored when comparing samples of distant galaxies to low-redshift systems, particularly if dust is as prevalent in distant galaxies as appears to be the case in our study.

  3. EARLY-TYPE HOST GALAXIES OF TYPE II AND Ib SUPERNOVAE

    SciTech Connect

    Suh, Hyewon; Jeong, Hyunjin; Yi, Sukyoung K.; Yoon, Sung-chul

    2011-04-01

    Recent studies find that some early-type galaxies host Type II or Ibc supernovae (SNe II, Ibc). This may imply recent star formation activities in these SNe host galaxies, but a massive star origin of the SNe Ib so far observed in early-type galaxies has been questioned because of their intrinsic faintness and unusually strong Ca lines shown in the nebular phase. To address the issue, we investigate the properties of early-type SNe host galaxies using the data with Galaxy Evolution Explorer (GALEX) ultraviolet photometry and the Sloan Digital Sky Survey optical data. Our sample includes eight SNe II and one peculiar SN Ib (SN 2000ds) host galaxies as well as 32 SN Ia host galaxies. The host galaxy of SN 2005cz, another peculiar SN Ib, is also analyzed using the GALEX data and the NASA/IPAC Extragalactic Database optical data. We find that the NUV-optical colors of SN II/Ib host galaxies are systematically bluer than those of SN Ia host galaxies, and some SN II/Ib host galaxies with NUV - r colors markedly bluer than the others exhibit strong radio emission. We perform a stellar population synthesis analysis and find a clear signature of recent star formation activities in most of the SN II/Ib host galaxies. Our results generally support the association of the SNe II/Ib hosted in early-type galaxies with core collapse of massive stars. We briefly discuss implications for the progenitors of the peculiar SNe Ib 2000ds and 2005cz.

  4. Penetrating the Homunculus -- Near-Infrared Adaptive Optics Images of Eta Carinae

    NASA Astrophysics Data System (ADS)

    Martin, John C.; Artigau, E.; Davidson, K.; Humphreys, R. M.; Chesneau, O.; Smith, N.

    2010-01-01

    We present the extraordinary near-infrared images of Eta Carinae obtained with the Near-Infrared Coronagraphic Camera (NICI) with adaptive optics on the Gemini South telescope just after Eta Car's 2009 spectroscopic event. The K-band continuum and continuum-subtracted narrow-band Br-gamma and H2 images show a three-winged pattern outlined by bright emitting dust in the innermost region of the ejecta around the central star. This intriguing pattern was first noticed by Chesneau et al. (2005) from earlier VLT/NaCO images and was named the "butterfly nebula.” In contrast the with the Br-gamma and H2 images, the [Fe II] image does not follow the outline of the "butterfly wings,” but instead shows a much broader, bipolar distribution traced to about 2 arcsec from the star. We suggest that the [Fe II] emission is tracing the "little Homunculus" previously observed only spectroscopically, and attributed to a bipolar outflow from Eta Car's second eruption in the 1890's. The nature of the "butterfly nebula" is debated and may be due to an ouflow or to an equatorial torus. Kinematic data is needed to measure or set limits on its expansion, age and orientation within the larger Homunculus. In this poster we also report the results of our measurements of the transverse motions of the knots and filaments that outline the "butterfly."

  5. 77 FR 16925 - Medical Devices; Neurological Devices; Classification of the Near Infrared Brain Hematoma Detector

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-23

    ...; Classification of the Near Infrared Brain Hematoma Detector AGENCY: Food and Drug Administration, HHS. ACTION: Final rule. SUMMARY: The Food and Drug Administration (FDA) is classifying the Near Infrared (NIR) Brain... generic name Near Infrared (NIR) Brain Hematoma Detector, and it is identified as a noninvasive...

  6. Use of Near-Infrared Spectroscopy in Early Determination of Irreversible Hemorrhagic Shock

    DTIC Science & Technology

    2004-09-01

    infrared light. Unlike “pulse-oximetry,” NIR spectroscopy measures not only arterial, but...carotid artery. 2.2 Near- infrared spectroscopic methodology/ measurements : Near- infrared spectroscopy probes (Hutchinson Technology, Inc... Measurements 3rd resuscitation bolus (resus 3) 4th resuscitation bolus (resus 4) Measurements Measurements Use of Near- Infrared Spectroscopy

  7. [Detection of Adulteration in Milk Powder with Starch Near Infrared].

    PubMed

    Wang, Ning-ning; Shen, Bing-hui; Guan, Jian-jun; Zhao, Zhong-rui; Zhu, Ye-wei; Zhang, Lu-da; Yan, Yan-lu; Zheng, Yu-yan; Dong, Cheng-yu; Kang, Ding-ming

    2015-08-01

    Three China trademarks of milk powder called Mengniu, Yili, Wandashan were taken as testing samples. Each of them mixed varied amount of starch in different gradient, which were consisted of 32 adulterated milk powder samples mixed with starch, was taken as standard samples for constructing predicted model. To those 32 samples, the reflecting spectrum characteristics in middle wave of near infrared spectrum with Near Infrared Spectrum Analyzer (Micro NIR 1700) produced by JDSU Ltd. USA were collected for five repeats in five different days. The time span was nearly two months. Firstly, we build the model used the reflecting spectrum characteristics of those samples with biomimetic pattern recognition (BPR) arithmetic to do the qualitative analysis. The analysis included the reliability of testing result and stability of the model. When we took ninety percent as the evaluation threshold of testing result of CAR (Correct Acceptance Rate) and CRR (Correct Rejection Rate), the lowest starch content of adulterate milk powder in all tested samples which the tested result were bigger than that abovementioned threshold was designated CAR threshold (CAR-T) and CRR threshold (CRR-T). CAR means the correct rate of accepting a sample which is belong to itself, CRR means correct rate of refusing to accept a sample which is not belong to itself. The results were shown that, when we constructed a model based on the near infrared spectrum data from each of three China trademark milk powders, respectively, if we constructed a model with infrared spectrum data tested in a same day, both the CAR-T and CRR-T of adulterate starch content of a sample can reach 0.1% in predicting the remainder infrared spectrum data tested within a same day. The three China trademarks of milk powder had the same result. In addition, when we ignored the trademarks, put the spectrum data of adulterate milk powder samples mixed with the same content of starch of three China trademarks milk powder together

  8. Visible/near-infrared spectra of experimentally shocked plagioclase feldspars

    USGS Publications Warehouse

    Johnson, J. R.; Horz, F.

    2003-01-01

    High shock pressures cause structural changes in plagioclase feldspars such as mechanical fracturing and disaggregation of the crystal lattice at submicron scales, the formation of diaplectic glass (maskelynite), and genuine melting. Past studies of visible/ near-infrared spectra of shocked feldspars demonstrated few spectral variations with pressure except for a decrease in the depth of the absorption feature near 1250-1300 nm and an overall decrease in reflectance. New visible/near-infrared spectra (400-2500 nm) of experimentally shocked (17-56 GPa) albite- and anorthite-rich rock powders demonstrate similar trends, including the loss of minor hydrated mineral bands near 1410, 1930, 2250, and 2350 nm. However, the most interesting new observations are increases in reflectance at intermediate pressures, followed by subsequent decreases in reflectance at higher pressures. The amount of internal scattering and overall sample reflectance is controlled by the relative proportions of micro-fractures, submicron grains, diaplectic glass, and melts formed during shock metamorphism. We interpret the observed reflectance increases at intermediate pressures to result from progressively larger proportions of submicron feldspar grains and diaplectic glass. The ensuing decreases in reflectance occur after diaplectic glass formation is complete and the proportion of genuine melt inclusions increases. The pressure regimes over which these reflectance variations occur differ between albite and anorthite, consistent with thermal infrared spectra of these samples and previous studies of shocked feldspars. These types of spectral variations associated with different peak shock pressures should be considered during interpretation and modeling of visible/near-infrared remotely sensed spectra of planetary and asteroidal surfaces.

  9. Diffuse reflectance near infrared-chemometric methods development and validation of amoxicillin capsule formulations

    PubMed Central

    Khan, Ahmed Nawaz; Khar, Roop Krishen; Ajayakumar, P. V.

    2016-01-01

    Objective: The aim of present study was to establish near infrared-chemometric methods that could be effectively used for quality profiling through identification and quantification of amoxicillin (AMOX) in formulated capsule which were similar to commercial products. In order to evaluate a large number of market products easily and quickly, these methods were modeled. Materials and Methods: Thermo Scientific Antaris II near infrared analyzer with TQ Analyst Chemometric Software were used for the development and validation of the identification and quantification models. Several AMOX formulations were composed with four excipients microcrystalline cellulose, magnesium stearate, croscarmellose sodium and colloidal silicon dioxide. Development includes quadratic mixture formulation design, near infrared spectrum acquisition, spectral pretreatment and outlier detection. According to prescribed guidelines by International Conference on Harmonization (ICH) and European Medicine Agency (EMA) developed methods were validated in terms of specificity, accuracy, precision, linearity, and robustness. Results: On diffuse reflectance mode, an identification model based on discriminant analysis was successfully processed with 76 formulations; and same samples were also used for quantitative analysis using partial least square algorithm with four latent variables and 0.9937 correlation of coefficient followed by 2.17% root mean square error of calibration (RMSEC), 2.38% root mean square error of prediction (RMSEP), 2.43% root mean square error of cross-validation (RMSECV). Conclusion: Proposed model established a good relationship between the spectral information and AMOX identity as well as content. Resulted values show the performance of the proposed models which offers alternate choice for AMOX capsule evaluation, relative to that of well-established high-performance liquid chromatography method. Ultimately three commercial products were successfully evaluated using developed

  10. Near-Infrared Fluorescence-Enhanced Optical Tomography

    PubMed Central

    2016-01-01

    Fluorescence-enhanced optical imaging using near-infrared (NIR) light developed for in vivo molecular targeting and reporting of cancer provides promising opportunities for diagnostic imaging. The current state of the art of NIR fluorescence-enhanced optical tomography is reviewed in the context of the principle of fluorescence, the different measurement schemes employed, and the mathematical tools established to tomographically reconstruct the fluorescence optical properties in various tissue domains. Finally, we discuss the recent advances in forward modeling and distributed memory parallel computation to provide robust, accurate, and fast fluorescence-enhanced optical tomography. PMID:27803924

  11. Transrectal Near-Infrared Optical Tomography for Prostate Imaging

    DTIC Science & Technology

    2011-03-01

    2009. CA Cancer J Clin. 2009;59:225-249. 2. Hodge KK, McNeal JE, Stamey TA. Ultrasound guided transrectal core biopsies of the palpably abnormal...near-infrared spectroscopy: pilot results in the breast," Radiology 218, 261-266 (2001). [4] Tara Yates, Jeremy C Hebden, Adam Gibson, Nick ...digital rectal examination as screening tests for prostate carcinoma,” J Am Board Fam Pract.; 16(2):95- 101 (2003). 3. Hodge KK, McNeal JE, Stamey TA

  12. Monitoring Key Parameters in Bioprocesses Using Near-Infrared Technology

    PubMed Central

    Tamburini, Elena; Marchetti, Maria Gabriella; Pedrini, Paola

    2014-01-01

    Near-infrared spectroscopy (NIRS) is known to be a rapid and non-destructive technique for process monitoring. Bioprocesses are usually complex, from both the chemical (ill-defined medium composition) and physical (multiphase matrix) aspects, which poses an additional challenge to the development of robust calibrations. We investigated the use of NIRS for on-line and in-line monitoring of cell, substrate and product concentrations, during aerobic and anaerobic bacterial fermentations, in different fermentation strategies. Calibration models were built up, then validated and used for the automated control of fermentation processes. The capability of NIR in-line to discriminate among differently shaped bacteria was tested. PMID:25313494

  13. Monitoring key parameters in bioprocesses using near-infrared technology.

    PubMed

    Tamburini, Elena; Marchetti, Maria Gabriella; Pedrini, Paola

    2014-10-13

    Near-infrared spectroscopy (NIRS) is known to be a rapid and non-destructive technique for process monitoring. Bioprocesses are usually complex, from both the chemical (ill-defined medium composition) and physical (multiphase matrix) aspects, which poses an additional challenge to the development of robust calibrations. We investigated the use of NIRS for on-line and in-line monitoring of cell, substrate and product concentrations, during aerobic and anaerobic bacterial fermentations, in different fermentation strategies. Calibration models were built up, then validated and used for the automated control of fermentation processes. The capability of NIR in-line to discriminate among differently shaped bacteria was tested.

  14. Near Infrared Spectral Determination of Human Tissue pH.

    DTIC Science & Technology

    1995-10-01

    Continuous Tissue pH Monitory in the Human Fetus During Labor", Obstet . Gynecol ., 55:523, 1980. 23. [Lemer 82] Lemer, H., et al., "Measurement of Glucose...Umbilical Blood pH", Am. J. Obstet . Gynecol ., 128: 901-903, 1977. 38. [Weyer 85] Weyer, L G., "Near Infrared Spectroscopy of Organic Substances," Applied...Patterns and Tissue pH in the Human Fetus", Am. J. Obstet . Gynecol ., 134:685-690, 1979. 24 Appendix I An Estimation Extension of the FKNN Algorithm In

  15. Near-infrared spectra of Jupiter, Saturn, and Uranus

    NASA Technical Reports Server (NTRS)

    Potter, A. E.

    1974-01-01

    Near infrared spectra of Jupiter, Saturn, and Uranus were measured at resolutions higher than previously available in the range from 6,000 to 10,750/cm. The resolution was 0.5/cm for Jupiter and Saturn, and 32/cm for Uranus. The spectra are presented both individually and as ratio spectra, in which the planetary spectra are divided by the solar spectrum. The Uranus spectrum is shown with Saturn, Jupiter, and Sun spectra reduced to the same resolution so that Uranus can be compared with the other outer planets. The high resolution Saturn, Jupiter, and Sun spectra are presented in parallel plots to simplify comparisons between them.

  16. Near-Infrared Absolute Photometry of the Uranian Satellites

    NASA Astrophysics Data System (ADS)

    Momary, T. W.; Baines, K. H.; Yanamandra-Fisher, P.; Lebofsky, L. A.; Golisch, W.

    1996-09-01

    We report the first absolutely-calibrated photometry of the Uranian satellites Miranda, Ariel, and Titania, in canonical near-infrared filters. These satellites were observed in July, August, and September of 1995, with the NSFCAM instrument at the NASA/IRTF. Results are reported for J, H, and K filters near 1.26, 1.62, and 2.21 mu m, and two special ~ 0.15-mu m-wide filters placed at 1.73 and 2.27 mu m. We measure an opposition surge for Miranda in the near-infrared of at least 0.48 mag/deg between phase angles of 1.0deg and 0.6deg , compared to a much shallower 0.015 +/- 0.006 mag/deg surge reported by Buratti et al. (Icarus 84, 203-214, 1990) for the visible. Miranda, which is brighter than Titania throughout the visible (Karkoschka et al., Icarus submitted), becomes the darker of the two satellites in the near- infrared, being some 20.5% dimmer than Titania in H, 8.8% dimmer in 1.73 mu m, and 9.1% dimmer in K. All three satellites are brightest at 1.73 mu m, with Ariel being fully 1/3 brighter than Miranda or Titania, whereas the three satellites are evenly spaced in albedo at 0.7 mu m, in the visible (Ariel being 15% brighter than Miranda, which is in turn 15% brighter than Titania). Specifically, Ariel reaches a peak full disk albedo of 0.4161 +/- 0.0125 for 1.0deg phase at 1.73 mu m. By comparison, the peak albedos of Miranda and Titania are only 0.2730 +/- 0.0082 and 0.2969 +/- 0.0089, respectively, at this wavelength (though these latter observations were at 2.4deg phase). Continuing the trend seen in the visible, Ariel is the brightest of the Uranian satellites throughout the near-infrared. Finally, all three satellites show a distinct increase in full-disk albedo between H and 1.73 mu m filters, on the order of 20%, which is the expected signature of water ice, in agreement with spectra taken by Brown and Cruikshank (Icarus 55, 83-92, 1983).

  17. Feasibility of near-infrared markers for guiding surgical robots

    NASA Astrophysics Data System (ADS)

    Shademan, Azad; Dumont, Matthieu F.; Leonard, Simon; Krieger, Axel; Kim, Peter C. W.

    2013-09-01

    Automating surgery using robots requires robust visual tracking. The surgical environment often has poor light conditions where several organs have similar visual appearances. In addition, the field of view might be occluded by blood or tissue. In this paper, the feasibility of near-infrared (NIR) fluorescent marking and imaging for vision-based robot control is studied. The NIR region of the spectrum has several useful properties including deep tissue penetration. We study the optical properties of a clinically-approved NIR fluorescent dye, indocyanine green (ICG), with different concentrations and quantify image positioning error of ICG marker when obstructed by tissue.

  18. Near infrared fluorescence for image-guided surgery

    PubMed Central

    2012-01-01

    Near infrared (NIR) image-guided surgery holds great promise for improved surgical outcomes. A number of NIR image-guided surgical systems are currently in preclinical and clinical development with a few approved for limited clinical use. In order to wield the full power of NIR image-guided surgery, clinically available tissue and disease specific NIR fluorophores with high signal to background ratio are necessary. In the current review, the status of NIR image-guided surgery is discussed along with the desired chemical and biological properties of NIR fluorophores. Lastly, tissue and disease targeting strategies for NIR fluorophores are reviewed. PMID:23256079

  19. Review of near-infrared methods for wound assessment

    NASA Astrophysics Data System (ADS)

    Sowa, Michael G.; Kuo, Wen-Chuan; Ko, Alex C.-T.; Armstrong, David G.

    2016-09-01

    Wound management is a challenging and costly problem that is growing in importance as people are living longer. Instrumental methods are increasingly being relied upon to provide objective measures of wound assessment to help guide management. Technologies that employ near-infrared (NIR) light form a prominent contingent among the existing and emerging technologies. We review some of these technologies. Some are already established, such as indocyanine green fluorescence angiography, while we also speculate on others that have the potential to be clinically relevant to wound monitoring and assessment. These various NIR-based technologies address clinical wound management needs along the entire healing trajectory of a wound.

  20. Near-infrared spectroscopy of comet Bradfield 1979l

    NASA Astrophysics Data System (ADS)

    Danks, A. C.; Dennefeld, M.

    1981-02-01

    Spectroscopic observations using an unintensified reticon detector are presented of comet Bradfield 1979l, covering the spectral region from 6100 to 11,000 A. The red CN 2-0, 3-1, and 1-0 bands are easily identified in the nuclear region and their intensity ratios are used to determine that the vibrational transition probability for the ground electronic state lies between 0.32 and 1/sec. The CN 2-0 and 1-0 bands are also present in the coma. The interest in simultaneous measurements of the near-infrared and space UV of future comets is pointed out.

  1. Near-infrared spectral imaging Michelson interferometer for astronomical applications

    NASA Technical Reports Server (NTRS)

    Wells, C. W.; Potter, A. E.; Morgan, T. H.

    1980-01-01

    The design and operation of an imaging Michelson interferometer-spectrometer used for near-infrared (0.8 micron to 2.5 microns) spectral imaging are reported. The system employs a rapid scan interferometer modified for stable low resolution (250/cm) performance and a 42 element PbS linear detector array. A microcomputer system is described which provides data acquisition, coadding, and Fourier transformation for near real-time presentation of the spectra of all 42 scene elements. The electronic and mechanical designs are discussed and telescope performance data presented.

  2. Cartilage-Specific Near-Infrared Fluorophores for Biomedical Imaging.

    PubMed

    Hyun, Hoon; Owens, Eric A; Wada, Hideyuki; Levitz, Andrew; Park, GwangLi; Park, Min Ho; Frangioni, John V; Henary, Maged; Choi, Hak Soo

    2015-07-20

    A novel class of near-infrared fluorescent contrast agents was developed. These agents target cartilage with high specificity and this property is inherent to the chemical structure of the fluorophore. After a single low-dose intravenous injection and a clearance time of approximately 4 h, these agents bind to all three major types of cartilage (hyaline, elastic, and fibrocartilage) and perform equally well across species. Analysis of the chemical structure similarities revealed a potential pharmacophore for cartilage targeting. Our results lay the foundation for future improvements in tissue engineering, joint surgery, and cartilage-specific drug development.

  3. Near-infrared spectroscopy. Innovative technology summary report

    SciTech Connect

    Not Available

    1999-07-01

    A near-infrared (NIR) spectroscopy system with a remote fiber-optic probe was developed and demonstrated to measure the water content of high-level radioactive wastes from the underground storage tanks at the Hanford Site in richland Washington. The technology was developed as a cost-effective and safer alternative to the thermogravimetric analysis (TGA) technique in use as the baseline. This work was supported by the Tanks Focus Area (TFA) within the Department of Energy`s (DOE) Office of Science and Technology (OST) in cooperation with the Hanford Tank Waste Remediation System (TWRS) Program.

  4. JWST Near-Infrared Detectors: Latest Test Results

    NASA Technical Reports Server (NTRS)

    Smith, Erin C.; Rauscher, Bernard J.; Alexander, David; Brambora, Clifford K.; Chiao, Meng; Clemons, Brian L.; Derro, Rebecca; Engler, Chuck; Fox, Ori; Garrison, Matthew B.; Greenhouse, Matthew A.; Henegar, Greg; Hill, Robert J.; Johnson, Thomas; Lavaque, Dodolfo J.; Lindler, Don J.; Manthripragada, Sridhar S.; Marshall, Cheryl; Mott, Brent; Parr, Thomas M.; Roher, Wayne D.; Shakoorzadeh, Kamdin B.; Schnurr, Richard; Smith, Miles; Waczynski, Augustyn

    2009-01-01

    The James Webb Space Telescope, an infrared-optimized space telescope being developed by NASA for launch in 2013, will utilize cutting-edge detector technology in its investigation of fundamental questions in astrophysics. JWST's near infrared spectrograph, NIRSpec utilizes two 2048 x 2048 HdCdTe arrays with Sidecar ASIC readout electronics developed by Teledyne to provide spectral coverage from 0.6 microns to 5 microns. We present recent test and calibration results for the NIRSpec flight arrays as well as data processing routines for noise reduction and cosmic ray rejection.

  5. [Application of near infrared spectroscopy in analysis of wood properties].

    PubMed

    Yao, Sheng; Pu, Jun-wen

    2009-04-01

    There is substantial interest in the improvement of wood properties through genetic selection or a change in silviculture prescription. Tree breeding purpose requires measurement of a large number of samples. However, traditional methods of assessing wood properties are both time consuming and destructive, limiting the numbers of samples that can be processed, so new method would be needed to find. Near infrared spectroscopy (NIR) is an advanced spectroscopic tool for nondestructive evaluation of wood and it can quickly, accurately estimate the properties of increment core, solid wood or wood meal. The present paper reviews the advances in the research on the wood chemistry properties and anatomical properties using NIR.

  6. Investigation of a near-infrared-ray computed tomography scanner

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Oda, Yasuyuki; Satoi, Yuichi; Yamaguchi, Satoshi; Ishii, Tomotaka; Hagiwara, Osahiko; Matsukiyo, Hiroshi; Watanabe, Manabu; Kusachi, Shinya

    2016-10-01

    In the near-infrared-ray computed tomography (NIR-CT) scanner, NIR rays are produced from a light-emitting diode (LED) and detected using an NIR phototransistor (PT). The wavelengths of the LED peak intensity and the PT high sensitivity in the data table are both 940 nm. The photocurrents flowing through the PTR are converted into voltages using an emitter-follower circuit, and the output voltages are sent to a personal computer through an analog-digital converter. The NIR projection curves for tomography are obtained by repeated linear scans and rotations of the object, and the scanning is conducted in both directions of its movement.

  7. Near-infrared spectroscopy as a tool for driving research.

    PubMed

    Liu, Tao; Pelowski, Matthew; Pang, Changle; Zhou, Yuanji; Cai, Jianfeng

    2016-03-01

    Driving a motor vehicle requires various cognitive functions to process surrounding information, to guide appropriate actions, and especially to respond to or integrate with numerous contextual and perceptual hindrances or risks. It is, thus, imperative to examine driving performance and road safety from a perspective of cognitive neuroscience, which considers both the behaviour and the functioning of the brain. However, because of technical limitations of current brain imaging approaches, studies have primarily adopted driving games or simulators to present participants with simulated driving environments that may have less ecological validity. Near-infrared spectroscopy (NIRS) is a relatively new, non-invasive brain-imaging technique allowing measurement of brain activations in more realistic settings, even within real motor vehicles. This study reviews current NIRS driving research and explores NIRS' potential as a new tool to examine driving behaviour, along with various risk factors in natural situations, promoting our understanding about neural mechanisms of driving safety. Practitioner Summary: Driving a vehicle is dependent on a range of neurocognitive processing abilities. Near-infrared spectroscopy (NIRS) is a non-invasive brain-imaging technique allowing measurement of brain activation even in on-road studies within real motor vehicles. This study reviews current NIRS driving research and explores the potential of NIRS as a new tool to examine driving behaviour.

  8. Using near infrared light for deep sea mining observation systems

    NASA Astrophysics Data System (ADS)

    Lu, Huimin; Li, Yujie; Li, Xin; Yang, Jianmin; Serikawa, Seiichi

    2015-10-01

    In this paper, we design a novel deep-sea near infrared light based imaging equipment for deep-sea mining observation systems. The spectral sensitivity peaks are in the red region of the invisible spectrum, ranging from 750nm to 900nm. In addition, we propose a novel underwater imaging model that compensates for the attenuation discrepancy along the propagation path. The proposed model fully considered the effects of absorption, scattering and refraction. We also develop a locally adaptive Laplacian filtering for enhancing underwater transmission map after underwater dark channel prior estimation. Furthermore, we propose a spectral characteristic-based color correction algorithm to recover the distorted color. In water tank experiments, we made a linear scale of eight turbidity steps ranging from clean to heavily scattered by adding deep sea soil to the seawater (from 500 to 2000 mg/L). We compared the results of different turbidity underwater scene, illuminated alternately with near infrared light vs. white light. Experiments demonstrate that the enhanced NIR images have a reasonable noise level after the illumination compensation in the dark regions and demonstrates an improved global contrast by which the finest details and edges are significantly enhanced. We also demonstrate that the effective distance of the designed imaging system is about 1.5 meters, which can meet the requirement of micro-terrain observation around the deep-sea mining systems. Remotely Operated Underwater Vehicle (ROV)-based experiments also certified the effectiveness of the proposed method.

  9. NIRS3: The Near Infrared Spectrometer on Hayabusa2

    NASA Astrophysics Data System (ADS)

    Iwata, Takahiro; Kitazato, Kohei; Abe, Masanao; Ohtake, Makiko; Arai, Takehiko; Arai, Tomoko; Hirata, Naru; Hiroi, Takahiro; Honda, Chikatoshi; Imae, Naoya; Komatsu, Mutsumi; Matsunaga, Tsuneo; Matsuoka, Moe; Matsuura, Shuji; Nakamura, Tomoki; Nakato, Aiko; Nakauchi, Yusuke; Osawa, Takahito; Senshu, Hiroki; Takagi, Yasuhiko; Tsumura, Kohji; Takato, Naruhisa; Watanabe, Sei-ichiro; Barucci, Maria Antonietta; Palomba, Ernesto; Ozaki, Masanobu

    2017-03-01

    NIRS3: The Near Infrared Spectrometer is installed on the Hayabusa2 spacecraft to observe the target C-type asteroid 162173 Ryugu at near infrared wavelengths of 1.8 to 3.2 μm. It aims to obtain reflectance spectra in order to detect absorption bands of hydrated and hydroxide minerals in the 3 μm-band. We adopted a linear-image sensor with indium arsenide (InAs) photo diodes and a cooling system with a passive radiator to achieve an optics temperature of 188 K ( -85°C), which enables to retaining sufficient sensitivity and noise level in the 3 μm wavelength region. We conducted ground performance tests for the NIRS3 flight model (FM) to confirm its baseline specifications. The results imply that the properties such as the signal-to-noise ratio (SNR) conform to scientific requirements to determine the degree of aqueous alteration, such as CM or CI chondrite, and the stage of thermal metamorphism on the asteroid surface.

  10. Near infrared photochemistry of pyruvic acid in aqueous solution.

    PubMed

    Larsen, Molly C; Vaida, Veronica

    2012-06-21

    Recent experimental and theoretical results have suggested that organic acids such as pyruvic acid, can be photolyzed in the ground electronic state by the excitation of the OH stretch vibrational overtone. These overtones absorb in the near-infrared and visible regions of the spectrum where the solar photons are plentiful and could provide a reaction pathway for the organic acids and alcohols that are abundant in the earth's atmosphere. In this paper the overtone initiated photochemistry of aqueous pyruvic acid is investigated by monitoring the evolution of carbon dioxide. In these experiments CO(2) is being produced by excitation in the near-infrared, between 850 nm and ∼1150 nm (11,765-8696 cm(-1)), where the second OH vibrational overtone (Δν = 3) of pyruvic acid is expected to absorb. These findings show not only that the overtone initiated photochemical decarboxylation reaction occurs but also that in the aqueous phase it occurs at a lower energy than was predicted for the overtone initiated reaction of pyruvic acid in the gas phase (13,380 cm(-1)). A quantum yield of (3.5 ± 1.0) × 10(-4) is estimated, suggesting that although this process does occur, it does so with a very low efficiency.

  11. Length-free near infrared measurement of newborn malnutrition

    NASA Astrophysics Data System (ADS)

    Mustafa, Fatin Hamimi; Bek, Emily J.; Huvanandana, Jacqueline; Jones, Peter W.; Carberry, Angela E.; Jeffery, Heather E.; Jin, Craig T.; McEwan, Alistair L.

    2016-11-01

    Under-nutrition in neonates can cause immediate mortality, impaired cognitive development and early onset adult disease. Body fat percentage measured using air-displacement-plethysmography has been found to better indicate under-nutrition than conventional birth weight percentiles. However, air-displacement-plethysmography equipment is expensive and non-portable, so is not suited for use in developing communities where the burden is often the greatest. We proposed a new body fat measurement technique using a length-free model with near-infrared spectroscopy measurements on a single site of the body - the thigh. To remove the need for length measurement, we developed a model with five discrete wavelengths and a sex parameter. The model was developed using air-displacement-plethysmography measurements in 52 neonates within 48 hours of birth. We identified instrumentation required in a low-cost LED-based screening device and incorporated a receptor device that can increase the amount of light collected. This near-infrared method may be suitable as a low cost screening tool for detecting body fat levels and monitoring nutritional interventions for malnutrition in neonates and young children in resource-constrained communities.

  12. Near infrared transmission through clothing: applications in sensing and screening

    NASA Astrophysics Data System (ADS)

    Hutchins, D. A.; Canal, C. M.; Saleem, A.; Davis, L. A. J.; Green, R. J.

    2011-11-01

    Experiments have been performed to demonstrate that near infrared (NIR) transmission through a wide range of clothing materials is possible. Studies have shown that the characteristics of NIR transmission are affected by both the type of fibre used, and the weave pattern. A series of experiments has indicated that NIR transmission is also dependent on other variables such as fabric porosity and dye colour. It is shown that, in many cases, transmission coefficients are sufficiently high that imaging and spectroscopy of objects hidden behind clothing samples should be possible. However, while transmission through clothing at NIR wavelengths in the 750-1,700 nm range is often more effective than in the visible or IR regions, the fabrics themselves will modify the transmitted signal in terms of spatial effects, intensity and spectral content. The paper also describes the possible use of near infrared signals to identify objects that are hidden behind clothing layers. This can be done using spectroscopy. It is important, however, to distinguish the various contributions that exist within the backscattered signal. A set of careful laboratory experiments have demonstrated that transmission through a set of different clothing fabrics does modify the spectral content of signals, but that the spectrum of a particular chemical can still be identified, provided certain steps are taken. These involve a set of careful calibration measurements, and the use of processing techniques for the retrieval of data. It will be shown that this is possible for both granular solids and selected liquids.

  13. Wavelet minimum description length detrending for near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Jang, Kwang Eun; Tak, Sungho; Jung, Jinwook; Jang, Jaeduck; Jeong, Yong; Ye, Jong Chul

    2009-05-01

    Near-infrared spectroscopy (NIRS) can be employed to investigate brain activities associated with regional changes of the oxy- and deoxyhemoglobin concentration by measuring the absorption of near-infrared light through the intact skull. NIRS is regarded as a promising neuroimaging modality thanks to its excellent temporal resolution and flexibility for routine monitoring. Recently, the general linear model (GLM), which is a standard method for functional MRI (fMRI) analysis, has been employed for quantitative analysis of NIRS data. However, the GLM often fails in NIRS when there exists an unknown global trend due to breathing, cardiac, vasomotion, or other experimental errors. We propose a wavelet minimum description length (Wavelet-MDL) detrending algorithm to overcome this problem. Specifically, the wavelet transform is applied to decompose NIRS measurements into global trends, hemodynamic signals, and uncorrelated noise components at distinct scales. The minimum description length (MDL) principle plays an important role in preventing over- or underfitting and facilitates optimal model order selection for the global trend estimate. Experimental results demonstrate that the new detrending algorithm outperforms the conventional approaches.

  14. A near-infrared genetically targetable and activatable photosensitizer

    PubMed Central

    He, Jianjun; Wang, Yi; Missinato, Maria A.; Onuoha, Ezenwa; Perkins, Lydia A.; Watkins, Simon C.; St. Croix, Claudette M.; Tsang, Michael; Bruchez, Marcel P.

    2016-01-01

    Upon illumination, photosensitizer molecules produce reactive oxygen species (ROS) that can be utilized for functional manipulation of living cells, including protein inactivation, targeted damage introduction, and cellular ablation. Photosensitizers used to date have been either exogenous, resulting in delivery and removal challenges, or genetically encoded proteins that form or bind a native photosensitizing molecule, resulting in a constitutively active photosensitizer inside the cell. By binding a heavy-atom substituted fluorogenic dye with a genetically encoded Fluorogen Activating Protein (FAP), we demonstrate an ‘on-demand’ activated photosensitizer that produces singlet oxygen and fluorescence only when FAP-bound and activated with near infrared light. This Targeted and Activated Photosensitizer (TAPs) approach enables protein inactivation and targeted cell killing in cultured cells and rapid targeted lineage ablation in living larval and adult zebrafish. The near-infrared excitation and emission of this FAP-TAPs photosensitizer module provides a new spectral range for photosensitizer proteins, useful for imaging, manipulation and cellular ablation deep within living organisms. PMID:26808669

  15. Ischemic stroke assessment with near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Chen, Weiguo; Li, Pengcheng; Zeng, Shaoqun; Luo, Qingming; Hu, Bo

    1999-09-01

    Many authors have elucidated the theory about oxygenated hemoglobin, deoxygenated hemoglobin absorption in near-infrared spectrum. And the theory has opened a window to measure the hemodynamic changes caused by stroke. However, no proper animal model still has established to confirm the theory. The aim of this study was to validate near-infrared cerebral topography (NCT) as a practical tool and to try to trace the focal hemodynamic changes of ischemic stroke. In the present study, middle cerebral artery occlusion model and the photosensitizer induced intracranial infarct model had been established. NCT and functional magnetic resonance image (fMRI) were obtained during pre- and post-operation. The geometric shape and infarct area of NCT image was compared with the fMRI images and anatomical samples of each rat. The results of two occlusion models in different intervene factors showed the NCT for infarct focus matched well with fMRI and anatomic sample of each rats. The instrument might become a practical tool for short-term prediction of stroke and predicting the rehabilitation after stroke in real time.

  16. Photothermal response of near-infrared-absorbing NanoGUMBOS.

    PubMed

    Dumke, Jonathan C; Qureshi, Ammar; Hamdan, Suzana; El-Zahab, Bilal; Das, Susmita; Hayes, Daniel J; Boldor, Dorin; Rupnik, Kresimir; Warner, Isiah M

    2014-01-01

    The photothermal properties of several near-infrared-absorbing nanoparticles derived from group of uniform materials based on organic salts (GUMBOS) and composed of cationic dyes coupled with biocompatible anions are evaluated. These nanoparticles were synthesized using a reprecipitation method performed at various pH values: 2.0, 5.0, 7.0, 9.0, and 11.0. The cations for the nanoparticles derived from GUMBOS (nanoGUMBOS), [1048] and [1061], have absorbance maxima at wavelengths overlapping with human soft tissue absorbance minima. Near-infrared-absorbing nanoGUMBOS excited with a 1064 nm continuous laser led to heat generation, with an average temperature increase of 20.4 ± 2.7 °C. Although the [1061][Deoxycholate] nanoGUMBOS generated the highest temperature increase (23.7 ± 2.4 °C), it was the least photothermally efficient compound (13.0%) due to its relatively large energy band gap of 0.892 eV. The more photothermally efficient compound [1048][Ascorbate] (64.4%) had a smaller energy band gap of 0.861 eV and provided an average photothermal temperature increase of 21.0 ± 2.1 °C.

  17. Near-infrared spectral methods for noninvasively measuring blood glucose

    NASA Astrophysics Data System (ADS)

    Fei, Sun; Kong, Deyi; Mei, Tao; Tao, Yongchun

    2004-05-01

    Determination of blood glucose concentrations in diabetic patients is a frequently occurring procedure and an important tool for diabetes management. Use of noninvasive detection techniques can relieve patients from the pain of frequent finger pokes and avoid the infection of disease via blood. This thesis discusses current research and analyzes the advantages and shortages of different measurement methods, including: optical methods (Transmission, Polarimetry and scattering), then, we give emphasis to analyze the technology of near-infrared (NIR) spectra. NIR spectral range 700 nm ~2300 nm was used because of its good transparency for biological tissue and presence of glucose absorption band. In this work, we present an outline of noninvasive blood glucose measurement. A near-infrared light beam is passed through the finger, and the spectral components of the emergent beam are measured using spectroscopic techniques. The device includes light sources having the wavelengths of 600 nm - 1800 nm to illuminate the tissue. Receptors associated with the light sources for receiving light and generating a transmission signal representing the light transmitted are also provided. Once a transmission signal is received by receptors, and the high and low values from each of the signals are stored in the device. The averaged values are then analyzed to determine the glucose concentration, which is displayed on the device.

  18. Length-free near infrared measurement of newborn malnutrition

    PubMed Central

    Mustafa, Fatin Hamimi; Bek, Emily J.; Huvanandana, Jacqueline; Jones, Peter W.; Carberry, Angela E.; Jeffery, Heather E.; Jin, Craig T.; McEwan, Alistair L.

    2016-01-01

    Under-nutrition in neonates can cause immediate mortality, impaired cognitive development and early onset adult disease. Body fat percentage measured using air-displacement-plethysmography has been found to better indicate under-nutrition than conventional birth weight percentiles. However, air-displacement-plethysmography equipment is expensive and non-portable, so is not suited for use in developing communities where the burden is often the greatest. We proposed a new body fat measurement technique using a length-free model with near-infrared spectroscopy measurements on a single site of the body - the thigh. To remove the need for length measurement, we developed a model with five discrete wavelengths and a sex parameter. The model was developed using air-displacement-plethysmography measurements in 52 neonates within 48 hours of birth. We identified instrumentation required in a low-cost LED-based screening device and incorporated a receptor device that can increase the amount of light collected. This near-infrared method may be suitable as a low cost screening tool for detecting body fat levels and monitoring nutritional interventions for malnutrition in neonates and young children in resource-constrained communities. PMID:27824061

  19. Infrared and Near-Infrared Spectroscopy of Acetylacetone and Hexafluoroacetylacetone.

    PubMed

    Howard, Daryl L; Kjaergaard, Henrik G; Huang, Jing; Meuwly, Markus

    2015-07-23

    The infrared and near-infrared spectra of acetylacetone, acetylacetone-d8, and hexafluoroacetylacetone are characterized from experiment and computations at different levels. In the fundamental region, the intramolecular hydrogen bonded OH-stretching transition is clearly observed as a very broad band with substantial structure and located at significantly lower frequency compared to common OH-stretching frequencies. There is no clear evidence for OH-stretching overtone transitions in the near-infrared region, which is dominated by the CH-stretching overtones of the methine and methyl CH bonds. From molecular dynamics (MD) simulations, with a potential energy surface previously validated for tunneling splittings, the infrared spectra are determined and used in assigning the experimentally measured ones. It is found that the simulated spectrum in the region associated with the proton transfer mode is exquisitely sensitive to the height of the barrier for proton transfer. Comparison of the experimental and the MD simulated spectra establishes that the barrier height is around 2.5 kcal/mol, which favorably compares with 3.2 kcal/mol obtained from high-level electronic structure calculations.

  20. Micro-electro-mechanically switchable near infrared complementary metamaterial absorber

    SciTech Connect

    Pitchappa, Prakash; Pei Ho, Chong; Kropelnicki, Piotr; Singh, Navab; Kwong, Dim-Lee; Lee, Chengkuo

    2014-05-19

    We experimentally demonstrate a micro-electro-mechanically switchable near infrared complementary metamaterial absorber by integrating the metamaterial layer to be the out of plane movable microactuator. The metamaterial layer is electrostatically actuated by applying voltage across the suspended complementary metamaterial layer and the stationary bottom metallic reflector. Thus, the effective spacing between the metamaterial layer and bottom metal reflector is varied as a function of applied voltage. With the reduction of effective spacing between the metamaterial and reflector layers, a strong spectral blue shift in the peak absorption wavelength can be achieved. With spacing change of 300 nm, the spectral shift of 0.7 μm in peak absorption wavelength was obtained for near infrared spectral region. The electro-optic switching performance of the device was characterized, and a striking switching contrast of 1500% was achieved at 2.1 μm. The reported micro-electro-mechanically tunable complementary metamaterial absorber device can potentially enable a wide range of high performance electro-optical devices, such as continuously tunable filters, modulators, and electro-optic switches that form the key components to facilitate future photonic circuit applications.

  1. Airborne laser systems for atmospheric sounding in the near infrared

    NASA Astrophysics Data System (ADS)

    Sabatini, Roberto; Richardson, Mark A.; Jia, Huamin; Zammit-Mangion, David

    2012-06-01

    This paper presents new techniques for atmospheric sounding using Near Infrared (NIR) laser sources, direct detection electro-optics and passive infrared imaging systems. These techniques allow a direct determination of atmospheric extinction and, through the adoption of suitable inversion algorithms, the indirect measurement of some important natural and man-made atmospheric constituents, including Carbon Dioxide (CO2). The proposed techniques are suitable for remote sensing missions performed by using aircraft, satellites, Unmanned Aerial Vehicles (UAV), parachute/gliding vehicles, Roving Surface Vehicles (RSV), or Permanent Surface Installations (PSI). The various techniques proposed offer relative advantages in different scenarios. All are based on measurements of the laser energy/power incident on target surfaces of known geometric and reflective characteristics, by means of infrared detectors and/or infrared cameras calibrated for radiance. Experimental results are presented relative to ground and flight trials performed with laser systems operating in the near infrared (NIR) at λ = 1064 nm and λ = 1550 nm. This includes ground tests performed with 10 Hz and 20 KHz PRF NIR laser systems in a variety of atmospheric conditions, and flight trials performed with a 10 Hz airborne NIR laser system installed on a TORNADO aircraft, flying up to altitudes of 22,000 ft above ground level. Future activities are planned to validate the atmospheric retrieval algorithms developed for CO2 column density measurements, with emphasis on aircraft related emissions at airports and other high air-traffic density environments.

  2. Near-infrared stimulation on globus pallidus and subthalamus

    NASA Astrophysics Data System (ADS)

    Yoo, Minsu; Koo, Ho; Kim, Minsun; Kim, Hyoung-Ihl; Kim, Sohee

    2013-12-01

    Near-infrared stimulation (NIS) is an emerging technique used to evoke action potentials in nervous systems. Its efficacy of evoking action potentials has been demonstrated in different nerve tissues. However, few studies have been performed using NIS to stimulate the deep brain structures, such as globus pallidus (GP) and subthalamic nucleus (STN). Male Sprague-Dawley rats were randomly divided into GP stimulation group (n=11) and STN stimulation group (n=6). After introducing optrodes stereotaxically into the GP or STN, we stimulated neural tissue for 2 min with continuous near-infrared light of 808 nm while varying the radiant exposure from 40 to 10 mW. The effects were investigated with extracellular recordings and the temperature rises at the stimulation site were also measured. NIS was found to elicit excitatory responses in eight out of 11 cases (73%) and inhibitory responses in three cases in the GP stimulation group, whereas it predominantly evoked inhibitory responses in seven out of eight cases (87.5%) and an excitatory response in one case in STN stimulation group. Only radiation above 20 mW, accompanying temperature increases of more than 2°C, elicited a statistically significant neural response (p<0.05). The responsiveness to NIS was linearly dependent on the power of radiation exposure.

  3. Detection of faint broad emission lines in type 2 AGN - I. Near-infrared observations and spectral fitting

    NASA Astrophysics Data System (ADS)

    Onori, F.; La Franca, F.; Ricci, F.; Brusa, M.; Sani, E.; Maiolino, R.; Bianchi, S.; Bongiorno, A.; Fiore, F.; Marconi, A.; Vignali, C.

    2017-01-01

    We present medium resolution near-infrared spectroscopic observations of 41 obscured and intermediate class active galactic nuclei (AGN; type 2, 1.9 and 1.8; AGN2) with redshift z ≲ 0.1, selected from the Swift/Burst Alert Telescope 70-month catalogue. The observations have been carried out in the framework of a systematic study of the AGN2 near-infrared spectral properties and have been executed using Infrared Spectrometer And Array Camera/VLT, X-shooter/VLT and LUCI/LBT, reaching an average S/N ratio of ˜30 per resolution element. For those objects observed with X-shooter, we also obtained simultaneous optical and UV spectroscopy. We have identified a component from the broad line region in 13 out of 41 AGN2, with full width at half-maximum (FWHM) > 800 km s-1. We have verified that the detection of the broad line region components does not significantly depend on selection effects due to the quality of the spectra, the X-ray or near-infrared fluxes, the orientation angle of the host galaxy or the hydrogen column density measured in the X-ray band. The average broad line region components found in AGN2 has a significantly (a factor 2) smaller FWHM if compared with a control sample of type 1 AGN.

  4. Herschel-ATLAS: VISTA VIKING near-infrared counterparts in the Phase 1 GAMA 9-h data

    NASA Astrophysics Data System (ADS)

    Fleuren, S.; Sutherland, W.; Dunne, L.; Smith, D. J. B.; Maddox, S. J.; González-Nuevo, J.; Findlay, J.; Auld, R.; Baes, M.; Bond, N. A.; Bonfield, D. G.; Bourne, N.; Cooray, A.; Buttiglione, S.; Cava, A.; Dariush, A.; De Zotti, G.; Driver, S. P.; Dye, S.; Eales, S.; Fritz, J.; Gunawardhana, M. L. P.; Hopwood, R.; Ibar, E.; Ivison, R. J.; Jarvis, M. J.; Kelvin, L.; Lapi, A.; Liske, J.; Michałowski, M. J.; Negrello, M.; Pascale, E.; Pohlen, M.; Prescott, M.; Rigby, E. E.; Robotham, A.; Scott, D.; Temi, P.; Thompson, M. A.; Valiante, E.; van der Werf, P.

    2012-07-01

    We identify near-infrared Ks-band counterparts to Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) submillimetre (submm) sources, using a preliminary object catalogue from the VISTA Kilo-degree Infrared Galaxy (VIKING) survey. The submm sources are selected from the H-ATLAS Phase 1 catalogue of the Galaxy and Mass Assembly 9-h field, which includes all objects detected at 250, 350 or ? with the instrument. We apply and discuss a likelihood ratio method for VIKING candidates within a search radius of 10 arcsec of the 22 000 SPIRE sources with a 5σ detection at ?. We estimate the fraction of SPIRE sources with a counterpart above the magnitude limit of the VIKING survey to be Q0≈ 0.73. We find that 11 294 (51 per cent) of the SPIRE sources have a best VIKING counterpart with a reliability R≥ 0.8, and the false identification rate of these is estimated to be 4.2 per cent. We expect to miss ˜5 per cent of true VIKING counterparts. There is evidence from Z-J and J-Ks colours that the reliable counterparts to SPIRE galaxies are marginally redder than the field population. We obtain photometric redshifts for ˜68 per cent of all (non-stellar) VIKING candidates with a median redshift of ?. We have spectroscopic redshifts for 3147 (˜28 per cent) of the reliable counterparts from existing redshift surveys. Comparing to the results of the optical identifications supplied with the Phase 1 catalogue, we find that the use of medium-deep near-infrared data improves the identification rate of reliable counterparts from 36 to 51 per cent. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. VISTA is an ESO near-infrared telescope in Chile.

  5. Observations of Mg II Absorption near z ~ 1 Galaxies Selected from the DEEP2 Redshift Survey

    NASA Astrophysics Data System (ADS)

    Lovegrove, Elizabeth; Simcoe, Robert A.

    2011-10-01

    We study the frequency of Mg II absorption in the outer halos of galaxies at z = 0.6-1.4 (with median z = 0.87), using new spectra obtained of 10 background quasars with galaxy impact parameters of b < 100 kpc. The quasar sight lines were selected from the Sloan Digital Sky Survey DR6 QSO catalog based on proximity to galaxies in the DEEP2 redshift survey. In addition to the 10 small impact systems, we examine 40 additional galaxies at 100 kpc < b < 500 kpc serendipitously located in the same fields. We detect Mg II absorbers with equivalent width Wr = 0.15-1.0 Å, though not all absorbers correlate with DEEP galaxies. We find five unique absorbers within Δv = 500 km s-1 and b < 100 kpc of a DEEP galaxy; this small sample contains both early- and late-type galaxies and has no obvious trends with star formation rate. No Mg II is detected more than 100 kpc from galaxies; inside this radius the covering fraction scales with impact parameter and galaxy luminosity in a very similar fashion to samples studied at lower redshift. In all but one case, when Mg II is detected without a spectroscopically confirmed galaxy, there exists a plausible photometric candidate which was excluded because of slit collision or apparent magnitude. We do not detect any strong absorbers with Wr > 1.0 Å, consistent with other samples of galaxy-selected Mg II systems. We speculate that Mg II systems with 0.3 < Wr < 1.0 trace old relic material from galactic outflows and/or the halo assembly process, and that in contrast, systems with large Wr are more likely to reflect the more recent star-forming history of their associated galaxies. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

  6. Synthesis of Non-blinking Semiconductor Quantum Dots Emitting in the Near-Infrared

    SciTech Connect

    Dennis, Allison M.; Mangum, Benjamin D.; Piryatinski, Andrei; Park, Young-Shin; Htoon, Han; Hollingsworth, Jennifer A.

    2012-06-21

    Our previous work demonstrates that Quasi-Type II CdSe/CdS core-shell quantum dots with thick shells (3-5 nm) exhibit unique photophysical characteristics, including improved chemical robustness over typical thin-shelled core/shell systems and the elimination of blinking through suppression of nonradiative Auger recombination. Here we describe a new thick-shelled heterostructure, InP/CdS, which exhibits a Type II bandgap alignment producing near-infrared (NIR) emission. Samples with a range of shell thicknesses were synthesized, enabling shell-thickness-dependent study of the absorbance and emission spectra, fluorescence lifetimes, and quantum yields. InP/CdS/ZnS core/shell/shell structures were also synthesized to reduce cadmium exposure for applications in the biological environment. Single particle spectroscopy indicates reduced blinking and improved photostability with increasing shell thickness, resulting in thick-shelled dots that are appropriate for single-particle tracking measurements with NIR emission.

  7. Optical and Near-infrared Study of Nova V2676 Oph 2012

    NASA Astrophysics Data System (ADS)

    Raj, A.; Das, R. K.; Walter, F. M.

    2017-02-01

    We present optical spectrophotometric and near-infrared (NIR) photometric observations of the nova V2676 Oph covering the period from 2012 March 29 through 2015 May 8. The optical spectra and photometry of the nova have been taken from SMARTS and Asiago; the NIR photometry was obtained from SMARTS and Mt. Abu. The spectra were dominated by strong H i lines from the Balmer series, Fe ii, N i, and [O i] lines in the initial days, typical of an Fe ii type nova. The measured FWHM for the Hβ and Hα lines was 800–1200 km s‑1. There was pronounced dust formation starting 90 days after the outburst. The J ‑ K color was the largest among recent dust-forming novae.

  8. High-Contrast Near-Infrared Imaging Polarimetry of the Protoplanetary Disk around RY Tau

    NASA Technical Reports Server (NTRS)

    Takami, Michihiro; Karr, Jennifer L.; Hashimoto, Jun; Kim, Hyosun; Wisenewski, John; Henning, Thomas; Grady, Carol; Kandori, Ryo; Hodapp, Klaus W.; Kudo, Tomoyuki; Kusakabe, Nobuhiko; Chou, Mei-yin; Itoh, Yoichi; Momose, Mumetake; Mayama, Satoshi; Currie, Thayne; Follette, Katherine B.; Kwon, Jungmi; Abe, Lyu; Brandner, Wolfgang; Brandt, Timothy D.; Carson, Joseph; Egner, Sebastian E.; McElwain, Michael W.; Serabyn, Eugene

    2013-01-01

    We present near-infrared coronagraphic imaging polarimetry of RY Tau. The scattered light in the circumstellar environment was imaged at H-band at a high resolution (approx. 0.05) for the first time, using Subaru-HiCIAO. The observed polarized intensity (PI) distribution shows a butterfly-like distribution of bright emission with an angular scale similar to the disk observed at millimeter wavelengths. This distribution is offset toward the blueshifted jet, indicating the presence of a geometrically thick disk or a remnant envelope, and therefore the earliest stage of the Class II evolutionary phase. We perform comparisons between the observed PI distribution and disk models with: (1) full radiative transfer code, using the spectral energy distribution (SED) to constrain the disk parameters; and (2) monochromatic simulations of scattered light which explore a wide range of parameters space to constrain the disk and dust parameters. We show that these models cannot consistently explain the observed PI distribution, SED, and the viewing angle inferred by millimeter interferometry. We suggest that the scattered light in the near-infrared is associated with an optically thin and geometrically thick layer above the disk surface, with the surface responsible for the infrared SED. Half of the scattered light and thermal radiation in this layer illuminates the disk surface, and this process may significantly affect the thermal structure of the disk.

  9. PENETRATING THE HOMUNCULUS-NEAR-INFRARED ADAPTIVE OPTICS IMAGES OF ETA CARINAE

    SciTech Connect

    Artigau, Etienne; Martin, John C.; Humphreys, Roberta M.; Davidson, Kris; Chesneau, Olivier; Smith, Nathan

    2011-06-15

    Near-infrared adaptive optics imaging with the Near-Infrared Coronagraphic Imager (NICI) and NaCO reveal what appears to be a three-winged or lobed pattern, the 'butterfly nebula', outlined by bright Br{gamma} and H{sub 2} emission and light scattered by dust. In contrast, the [Fe II] emission does not follow the outline of the wings, but shows an extended bipolar distribution which is tracing the Little Homunculus ejected in {eta} Car's second or lesser eruption in the 1890s. Proper motions measured from the combined NICI and NaCO images together with radial velocities show that the knots and filaments that define the bright rims of the butterfly were ejected at two different epochs corresponding approximately to the great eruption and the second eruption. Most of the material is spatially distributed 10{sup 0}-20{sup 0} above and below the equatorial plane apparently behind the Little Homunculus and the larger SE lobe. The equatorial debris either has a wide opening angle or the clumps were ejected at different latitudes relative to the plane. The butterfly is not a coherent physical structure or equatorial torus but spatially separate clumps and filaments ejected at different times, and now 2000-4000 AU from the star.

  10. HIGH-CONTRAST NEAR-INFRARED IMAGING POLARIMETRY OF THE PROTOPLANETARY DISK AROUND RY TAU

    SciTech Connect

    Takami, Michihiro; Karr, Jennifer L.; Kim, Hyosun; Chou, Mei-Yin; Hashimoto, Jun; Kandori, Ryo; Kusakabe, Nobuhiko; Kwon, Jungmi; Wisniewski, John; Henning, Thomas; Brandner, Wolfgang; Grady, Carol A.; Hodapp, Klaus W.; Kudo, Tomoyuki; Itoh, Yoichi; Momose, Munetake; Mayama, Satoshi; Currie, Thayne; Follette, Katherine B.; Abe, Lyu; and others

    2013-08-01

    We present near-infrared coronagraphic imaging polarimetry of RY Tau. The scattered light in the circumstellar environment was imaged at the H band at a high resolution ({approx}0.''05) for the first time, using Subaru/HiCIAO. The observed polarized intensity (PI) distribution shows a butterfly-like distribution of bright emission with an angular scale similar to the disk observed at millimeter wavelengths. This distribution is offset toward the blueshifted jet, indicating the presence of a geometrically thick disk or a remnant envelope, and therefore the earliest stage of the Class II evolutionary phase. We perform comparisons between the observed PI distribution and disk models with (1) full radiative transfer code, using the spectral energy distribution (SED) to constrain the disk parameters; and (2) monochromatic simulations of scattered light which explore a wide range of parameters space to constrain the disk and dust parameters. We show that these models cannot consistently explain the observed PI distribution, SED, and the viewing angle inferred by millimeter interferometry. We suggest that the scattered light in the near-infrared is associated with an optically thin and geometrically thick layer above the disk surface, with the surface responsible for the infrared SED. Half of the scattered light and thermal radiation in this layer illuminates the disk surface, and this process may significantly affect the thermal structure of the disk.

  11. Gemini near-infrared observations of Europa's Hydrated Surface Materials

    NASA Astrophysics Data System (ADS)

    Tsang, C.; Spencer, J. R.; Grundy, W. M.; Dalton, J. B.

    2012-12-01

    Europa is a highly dynamic icy moon of Jupiter. It is thought the moon harbors a subsurface ocean, with the potential to sustain life, with Europa being a key target of ESA's forthcoming Jupiter Icy Moons Orbiter (JUICE) mission. However, much is not known concerning the chemistry of the subsurface ocean. The surface is dominated by water ice, with a hydrated non-ice material component providing the distinctive albedo contrasts seen at visible and near-infrared wavelengths. These non-ice materials are concentrated at disrupted surface regions, providing a diagnostic probe for the chemistry and characteristics of the liquid ocean beneath. Leading but potentially competing theories on the composition of these hydrated non-ice materials suggest either sulfuric acid-water mixtures (Carlson et al., 1999) or hydrated magnesium/sodium salts (McCord et al., 1999). Recent reanalysis of Galileo-NIMS observations suggest a mixture of both - hydrated salts are present at all longitudes but the sulfuric acid hydrates are localized on the trailing side. We present preliminary analysis of new ground-based Gemini disk-resolved spectroscopy of Europa using the Near-Infrared Integrated Field Spectrometer (NIFS), taken in late 2011, at H (1.49 - 1.80 μm) and K bands (1.99 - 2.40 μm) with spectral resolving powers of ~ 5300. At these NIR wavelengths, with spectral resolution much better than Galileo-NIMS, the spectral absorption and continuum characteristics of these ice and non-ice materials can be separated out. In addition, the spatial resolution potentially allows identification of localized materials whose signature would be diluted in disk-integrated spectra. These observations of the trailing hemisphere use Altair adaptive optics to achieve spatial resolutions of 0.1" (~310 km per pixel) or better, potentially leading to better identification of the non-ice materials and their spatial distributions. References Carlson, R.W., R.E. Johnson, and M.S. Anderson 1999. Sulfuric acid

  12. Near-infrared studies of embedded star clusters

    NASA Astrophysics Data System (ADS)

    Park, Chan

    The Fan Mountain Near-Infrared Camera, FanCam, features an 8.7'x8.7' field of view on a 1024x1024 Teledyne Imaging Sensors HAWAII-1 detector array. The instrument mounts at the f/15.5 focus of the 31 inch telescope. Its seeing-limited optical design, optimized for the JHK atmospheric bands, includes a field stop at the telescope focus, a doublet collimator, two 8-position filterwheels straddling a Lyot stop, and a doublet reimager. The 0.51''pixel-1 plate scale leads to a slightly oversampled point spread function for the typical seeing of 1.5''. The entire optical train is encased in a cryogenic dewar cooled by a closed-loop cooling system. Chapter 2 describes the camera design and some early results of camera performance test. Long term near-infrared, J, H, and Ks, photometric monitoring of the embedded cluster NGC 1333 is presented in Chapter 3. We employ the Stetson variability index and reduced chi 2 to identify variable objects. Color-magnitude and color-color diagrams demonstrate that NGC 1333 is extremely young and highly extincted. Light curves in all three bands are well correlated. The spatial distribution of variable stars shows a strong correlation with the peak of the extinction map while non-variable stars are evenly spread over the whole field of view. Spitzer-2MASS-identified IR excess YSOs and Chandra X-ray sources were compared with our variable stars. A total of 25 previously-unknown member candidates are presented, with 15 objects in the mass range of brown dwarfs. The IMF and mass distribution of the cluster are presented. We discuss the implication of Ks vs. H--Ks color-magnitude diagram slope statistics in view of the evolutionary sequence of young star-forming embedded clusters. Another long term near-infrared, J, H, and Ks, photometric monitoring performed with FanCam for the embedded cluster NGC 7129 is presented in Chapter 4.

  13. Optical and near infrared photometry of Butcher-Oemler clusters

    NASA Technical Reports Server (NTRS)

    Shier, Lisa M.; Rieke, Marcia J.

    1993-01-01

    Rich clusters of galaxies at moderate redshifts (z approx. .3) have a larger proportion of optically blue galaxies than their low redshift counterparts. Spectroscopic examination of the blue galaxies by various authors has shown that the blue galaxies are generally Seyferts, show evidence for recent star formation, or are foreground objects. Unfortunately, spectroscopy is too time consuming to be used on large samples. Thus, we have looked for a way to separate Seyferts, starbursts, ellipticals and nonmembers using photometry alone. Five moderate redshift clusters, Abell numbers 777, 963, 1758, 1961 and 2218, have been observed in the V, R and K bands. We model the spectral energy distributions of various kinds of galaxies found in clusters and derive observed colors. We have modeled the spectral energy distributions (SED) of several kinds of galaxies and compute their colors as a function of redshift. We expect to see ellipticals, spirals, starbursts, post-starburst and Seyfert galaxies. The SED of elliptical and Sbc galaxies was observed by Rieke and Rieke. The SEDs for the starburst galaxies was created by adding a reddened 10(exp 8) year old burst to a spiral galaxy SED. The post-starburst (E+A) galaxy SEDs are composed of a slightly reddened 10(exp 9) year old burst and elliptical galaxy SED. SEDs for the Seyferts were created by adding a v(exp -1.1) power law, and a hot dust thermal spectrum to the Sbc. From the SEDs the colors of galaxies at various redshifts with assorted filters were computed. Lilly & Gunn (1985) have optical and infrared photometry for a sample of galaxies in CL0024+1654 observed spectroscopically by Dressler, Gunn and Schneider (1985). We have used this data to choose the most appropriate SEDs for our starburst and post-starburst models. The most likely explanation for the optically blue colors in most cluster galaxies is star formation. Very few galaxies lie in the Seyfert locus. Abel 1758 has more Seyfert candidates than the other

  14. NIMBUS: the Near-infrared Multi-Band Ultraprecise Spectroimager for SOFIA

    NASA Astrophysics Data System (ADS)

    McElwain, Michael W.; Mandell, Avi; Woodgate, Bruce; Spiegel, David S.; Madhusudhan, Nikku; Amatucci, Edward; Blake, Cullen; Budinoff, Jason; Burgasser, Adam; Burrows, Adam; Clampin, Mark; Conroy, Charlie; Deming, L. Drake; Dunham, Edward; Foltz, Roger; Gong, Qian; Knutson, Heather; Muench, Theodore; Murray-Clay, Ruth; Peabody, Hume; Rauscher, Bernard; Rinehart, Stephen; Villanueva, Geronimo

    2012-09-01

    We present a new and innovative near-infrared multi-band ultraprecise spectroimager (NIMBUS) for SOFIA. This design is capable of characterizing a large sample of extrasolar planet atmospheres by measuring elemental and molecular abundances during primary transit and occultation. This wide-field spectroimager would also provide new insights into Trans-Neptunian Objects (TNO), Solar System occultations, brown dwarf atmospheres, carbon chemistry in globular clusters, chemical gradients in nearby galaxies, and galaxy photometric redshifts. NIMBUS would be the premier ultraprecise spectroimager by taking advantage of the SOFIA observatory and state of the art infrared technologies. This optical design splits the beam into eight separate spectral bandpasses, centered around key molecular bands from 1 to 4μm. Each spectral channel has a wide field of view for simultaneous observations of a reference star that can decorrelate time-variable atmospheric and optical assembly effects, allowing the instrument to achieve ultraprecise calibration for imaging and photometry for a wide variety of astrophysical sources. NIMBUS produces the same data products as a low-resolution integral field spectrograph over a large spectral bandpass, but this design obviates many of the problems that preclude high-precision measurements with traditional slit and integral field spectrographs. This instrument concept is currently not funded for development.

  15. Combining near-infrared illuminants to optimize venous imaging

    NASA Astrophysics Data System (ADS)

    Paquit, Vincent; Price, Jeffery R.; Mériaudeau, Fabrice; Tobin, Kenneth W., Jr.; Ferrell, Thomas L.

    2007-03-01

    The first and perhaps most important phase of a surgical procedure is the insertion of an intravenous (IV) catheter. Currently, this is performed manually by trained personnel. In some visions of future operating rooms, however, this process is to be replaced by an automated system. We previously presented work for localizing near-surface veins via near-infrared (NIR) imaging in combination with structured light ranging for surface mapping and robotic guidance. In this paper, we describe experiments to determine the best NIR wavelengths to optimize vein contrast for physiological differences such as skin tone and/or the presence of hair on the arm or wrist surface. For illumination, we employ an array of NIR LEDs comprising six different wavelength centers from 740nm to 910nm. We capture imagery of each subject under every possible combination of illuminants and determine the optimal combination of wavelengths for a given subject to maximize vein contrast using linear discriminant analysis.

  16. Study of surfaces using near infrared optical fiber spectrometry

    NASA Technical Reports Server (NTRS)

    Workman, G. L.; Arendale, W. A.; Hughes, C.

    1995-01-01

    The measurement and control of cleanliness for critical surfaces during manufacturing and in service provides a unique challenge for fulfillment of environmentally benign operations. Of particular interest has been work performed in maintaining quality in the production of bondline surfaces in propulsion systems and the identification of possible contaminants. This work requires an in-depth study of the possible sources of contamination, methodologies to identify contaminants, discrimination between contaminants and chemical species caused by environment, and the effect of particular contaminants on the bondline integrity of the critical surfaces. This presentation will provide an introduction to the use of optical fiber spectrometry in a nondestructive measurement system for process monitoring and how it can be used to help clarify issues concerning surface chemistry. Correlation of the Near Infrared (NIR) spectroscopic results with Optical Stimulated Electron Emission (OSEE) and ellipsometry will also be presented.

  17. Intravascular near-infrared fluorescence molecular imaging of atherosclerosis

    PubMed Central

    Thukkani, Arun K; Jaffer, Farouc A

    2013-01-01

    Novel imaging modalities are required to better identify vulnerable atherosclerotic plaques before their dire consequences of myocardial infarction, sudden death, and stroke. Moving beyond traditional diagnostic methods, the field of molecular imaging offers an innovative approach to report upon critical in vivo biological features of high-risk plaques. Molecular imaging employs engineered, targeted imaging agents in conjunction with sophisticated, high-resolution detection systems. While various modalities have been investigated for this purpose, intravascular near infrared fluorescence imaging (NIRF) strategies are uniquely poised to provide high-resolution readouts of human coronary artery plaques. To date, preclinical animal studies have demonstrated feasibility of both standalone NIRF intravascular imaging as well as dual-modality approaches detecting inflammation and fibrin deposition in coronary-sized arteries. This translatable catheter-based approach is positioned to advance the identification of biologically vulnerable coronary plaques and coronary stents at risk of thrombosis. PMID:23638334

  18. Near-infrared observations of the variable crab nebula

    NASA Astrophysics Data System (ADS)

    Yamamoto, M.; Mori, K.; Shibata, S.; Tsujimoto, M.; Misawa, T.; Burrows, D.; Kawai, N.

    We present three near-infrared NIR observations of the Crab Nebula obtained with CISCO on the Subaru Telescope and Quick Infrared Camera on the University of HAWAII 88 inch Telescope The observations were performed on 2004 September 2005 February and 2005 October and were coordinated with X-ray observations obtained with the Chandra X-ray observatory within 10 days As shown in previous optical and X-ray monitoring observations outward-moving wisps and variable knots are detected also in our NIR observations The NIR variations are closely correlated with variations in the X-ray observations indicating that both variations are driven by the same physical process We discuss the origin of NIR-emitting particles based on the temporal variations as well as the spectral energy distributions of each variable component

  19. Extended near infrared emission from visual reflection nebulae

    NASA Technical Reports Server (NTRS)

    Sellgren, K.; Werner, M. W.; Dinerstein, H. L.

    1982-01-01

    Extended near infrared (2 to 5 microns) emission was observed from three visual reflection nebulae, NGC 7023, 2023, and 2068. The emission from each nebula consists of a smooth continuum, which can be described by a greybody with a color temperature of 1000 K, and emission features at 3.3 and 3.4 microns. The continuum emission cannot be explained by free-free emission, reflected light, or field stars, or by thermal emission from grains, with commonly accepted ratios of infrared to ultraviolet emissivities, which are in equilibrium with the stellar radiation field. A possible explanation is thermal emission from grains with extremely low ratios of infrared to ultraviolet emissivities, or from grains with a temperature determined by mechanisms other than equilibrium radiative heating. Another possibility is continuum fluorescence.

  20. Functional Near Infrared Spectroscopy: Watching the Brain in Flight

    NASA Technical Reports Server (NTRS)

    Harrivel, Angela; Hearn, Tristan A.

    2012-01-01

    Functional Near Infrared Spectroscopy (fNIRS) is an emerging neurological sensing technique applicable to optimizing human performance in transportation operations, such as commercial aviation. Cognitive state can be determined via pattern classification of functional activations measured with fNIRS. Operational application calls for further development of algorithms and filters for dynamic artifact removal. The concept of using the frequency domain phase shift signal to tune a Kalman filter is introduced to improve the quality of fNIRS signals in real-time. Hemoglobin concentration and phase shift traces were simulated for four different types of motion artifact to demonstrate the filter. Unwanted signal was reduced by at least 43%, and the contrast of the filtered oxygenated hemoglobin signal was increased by more than 100% overall. This filtering method is a good candidate for qualifying fNIRS signals in real time without auxiliary sensors.

  1. Functional Near Infrared Spectroscopy: Watching the Brain in Flight

    NASA Technical Reports Server (NTRS)

    Harrivel, Angela; Hearn, Tristan

    2012-01-01

    Functional Near Infrared Spectroscopy (fNIRS) is an emerging neurological sensing technique applicable to optimizing human performance in transportation operations, such as commercial aviation. Cognitive state can be determined via pattern classification of functional activations measured with fNIRS. Operational application calls for further development of algorithms and filters for dynamic artifact removal. The concept of using the frequency domain phase shift signal to tune a Kalman filter is introduced to improve the quality of fNIRS signals in realtime. Hemoglobin concentration and phase shift traces were simulated for four different types of motion artifact to demonstrate the filter. Unwanted signal was reduced by at least 43%, and the contrast of the filtered oxygenated hemoglobin signal was increased by more than 100% overall. This filtering method is a good candidate for qualifying fNIRS signals in real time without auxiliary sensors

  2. Characteristic wavelength of textile fiber in near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Feng, Hongnian; Jin, Shangzhong; Gan, Bin

    2006-01-01

    Near Infrared (NIR) spectroscopy in the region from 1300 to 1700nm, coupled with multivariate analytic statistical techniques, have been used to predict the chemical properties of textile fiber. Molecule absorbs electromagnetic wave with especial wavelength, which leads to bring characteristic absorption spectrum. Characteristic wavelength is the most important parameter in NIR detection. How to select characteristic wavelength is the key to NIR measure. Different mathematical methods are used to find relationship between the NIR absorption spectrum and the chemical properties of the textile fiber. We adopt stepwise multiple linear regression (SMLR) to select characteristic wavelength. As objective condition is limited, this article only refers to cotton and terylene. By computing correlation coefficient, we establish calibration equation with the smoothed absorbance data. Finally, the bias was controlled under 6%. Then, we find that NIR can be used to carry on qualitative analysis and quantitative analysis of the textile.

  3. Detecting counterfeit antimalarial tablets by near-infrared spectroscopy.

    PubMed

    Dowell, Floyd E; Maghirang, Elizabeth B; Fernandez, Facundo M; Newton, Paul N; Green, Michael D

    2008-11-04

    Counterfeit antimalarial drugs are found in many developing countries, but it is challenging to differentiate between genuine and fakes due to their increasing sophistication. Near-infrared spectroscopy (NIRS) is a powerful tool in pharmaceutical forensics, and we tested this technique for discriminating between counterfeit and genuine artesunate antimalarial tablets. Using NIRS, we found that artesunate tablets could be identified as genuine or counterfeit with high accuracy. Multivariate classification models indicated that this discriminatory ability was based, at least partly, on the presence or absence of spectral signatures related to artesunate. This technique can be field-portable and requires little training after calibrations are developed, thus showing great promise for rapid and accurate fake detection.

  4. Near Infrared Excess Energy in Binary System V367 Cygni

    NASA Astrophysics Data System (ADS)

    Gunasekera, Saraj

    Spectral energy distribution of the Serpentid type binary V367 Cyg was obtained using several previous photometric measurements made on this system in different spectral bands. We found Near IR excess starting from 3μm and this excess flux is attributed to the free-free emission from the mass accretion disk of the binary system. We adopted the temperature of primary component as 8,000°K. We added the free-free emission flux of the circumstellar disk to the black body energy of the primary component to find a best fit for the observed near infrared excess flux. In this fitting we left the electron density of the circumstellar disk ne of the free-free emission as a free parameter. We found that volume emission measure of the circumstellar disk is ˜ 9 × 1059 cm-3.

  5. Near-infrared Spectroscopy in the Brewing Industry.

    PubMed

    Sileoni, Valeria; Marconi, Ombretta; Perretti, Giuseppe

    2015-01-01

    This article offers an exhaustive description of the use of Near-Infrared (NIR) Spectroscopy in the brewing industry. This technique is widely used for quality control testing of raw materials, intermediates, and finished products, as well as process monitoring during malting and brewing. In particular, most of the reviewed works focus on the assessment of barley properties, aimed at quickly selecting the best barley varieties in order to produce a high-quality malt leading to high-quality beer. Various works concerning the use of NIR in the evaluation of raw materials, such as barley, malt, hop, and yeast, are also summarized here. The implementation of NIR sensors for the control of malting and brewing processes is also highlighted, as well as the use of NIR for quality assessment of the final product.

  6. Aquaphotomics: Near Infrared Spectroscopy and Water States in Biological Systems.

    PubMed

    Tsenkova, Roumiana; Kovacs, Zoltan; Kubota, Yosuke

    2015-01-01

    Aquaphotomics is a new discipline that provides a framework for understanding changes in water molecular system presented as a water spectral pattern, to mirror the rest of the solution and to give a holistic description related to system functionality. One of its main purposes is to identify water bands as main coordinates of future absorbance patterns to be used as a system biomarker. This chapter presents the Aquaphotomics methodology and illustrates a way to identify specific water bands using temperature change and addition of solutions of different ionic strength as perturbations. Rapid and precise measurement of low concentration solutes has been given as a strong evidence of the vast information that "the water spectral pattern as molecular mirror" approach provides. Few applications using near infrared spectroscopy and multivariate analysis as main tools of Aquaphotomics have been presented.

  7. Transmission spectra of teeth in the visible to near infrared

    NASA Astrophysics Data System (ADS)

    Herr, Steven L.; Harbour, John D.; Sherwood, Timothy S.; Wist, Abund O.

    1994-05-01

    Investigations of new transillumination techniques have created a need for detailed transmission studies of teeth and tissues. Recent results have shown that light imaging of extracted teeth can identify small (1 mm2 cross-section) caries in teeth by raster scanning using helium-neon laser light and a post collimated in-line detector. Preliminary frequency (wavelength) dependent transmission studies have been carried out from the visible to the near infrared spectral regions on the dentin of a slice of an extracted tooth 1.85 mm thick. These preliminary results show that in the region from 5,000 to 20,000 cm-1 the dentin of an extracted, healthy, human tooth has a transmission of between 2.5 and 5.5 percent, indicating that the total attenuation coefficient is between 16 and 19.5 cm-1.

  8. Analysis of silage composition by near-infrared reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    Reeves, James B., III; Blosser, Timothy H.; Colenbrander, V. F.

    1991-02-01

    Two studies were performed to investigate the feasibility of using near infrared reflectance spectroscopy (NIRS) with undried silages. In the first study silages were analyzed for major components (e. g. dry matter crude protein and other forms of nitrogen fiber and in vitro digestible dry matter) and short chain fatty acids (SCFA). NIRS was found to operate satisfactorily except for some forms of nitrogen and SCFA. In study two various methods of grinding spectral regions and sample presentation were examined. Undried Wiley ground samples in a rectangular cell gave the best overall results for non-dry ice undried grinds with wavelengths between 1100 and 2498 nm. Silages scanned after drying however produced the best results. Intact samples did not perform as well as ground samples and wavelengths below 1100 nm were of little use. 2 .

  9. Near infrared reflectance measurement of nitrogen faecal losses.

    PubMed

    Benini, L; Caliari, S; Bonfante, F; Guidi, G C; Brentegani, M T; Castellani, G; Sembenini, C; Bardelli, E; Vantini, I

    1992-06-01

    Chemical methods of measuring nitrogen in stools are complex, unpleasant, and therefore rarely performed. Recently, near infrared reflectance (NIRA) has been suggested for stool analysis. The aim of this study was to evaluate the possible application of this method in routine faecal nitrogen measurement. Nitrogen concentration and daily output were measured in the stools of 83 patients using NIRA and, for comparison, the Kjeldahl method. Nitrogen concentration and output ranged between 0.4-2.72 g% and 0.45-8.96 g/day respectively. Correlation coefficients (r), of 0.89 and 0.97 were found between the two methods for concentration and output respectively, and similar values were found in patients on enteral nutrition. Repeated measurements from the same stool collection, requiring only a few minutes, allowed homogenisation to be avoided. NIRA seems to be an easy, fast, and reliable alternative to chemical assays of nitrogen measurement in the management of patients with digestive disorders.

  10. Near-infrared Molecular Probes for In Vivo Imaging

    PubMed Central

    Zhang, Xuan; Bloch, Sharon; Akers, Walter; Achilefu, Samuel

    2012-01-01

    Cellular and tissue imaging in the near-infrared (NIR) wavelengths between 700 and 900 nm is advantageous for in vivo because of the low absorption of biological molecules in this region. This Unit presents protocols for small animal imaging using planar and fluorescence lifetime imaging techniques. Included is an overview of NIR fluorescence imaging of cells and small animals using NIR organic fluorophores, nanoparticles, and multimodal imaging probes. The development, advantages, and application of NIR fluorescent probes that have been used for in vivo imaging are also summarized. The use of NIR agents in conjunction with visible dyes and considerations in selecting imaging agents are discussed. We conclude with practical considerations for the use of these dyes in cell and small animal imaging applications. PMID:22470154

  11. Visible and near infrared reflectances measured from laboratory ice clouds.

    PubMed

    Barkey, Brian; Liou, K N

    2008-05-01

    We present laboratory results of the 0.68 microm visible (VIS) and 1.617 microm near infrared (NIR) reflectances typically used for inferring optical depth and ice crystal size from satellite radiometers, from ice clouds generated in a temperature controlled column cloud chamber. Two types of ice crystals were produced in this experiment: small columns and dendrites with mean maximum dimensions of about 17 and 35 microm. Within experimental uncertainty, the measured reflectances from ice clouds at both wavelengths agree reasonably well with the theoretical results computed from the plane-parallel adding-doubling method for radiative transfer using the measured ice particle morphology. We demonstrate that laboratory scattering and reflectance data for thin ice clouds with optical depths less than 0.4 can be used for validation of the thin cirrus optical depth and ice crystal size that have been routinely retrieved from the satellite VIS-NIR two channel pair.

  12. Near Infrared Fluorescent NanoGUMBOS for Biomedical Imaging

    PubMed Central

    Bwambok, David K.; El-Zahab, Bilal; Challa, Santhosh K.; Li, Min; Chandler, Lin; Baker, Gary A.; Warner, Isiah M.

    2009-01-01

    Herein, we report on near infrared (NIR) fluorescent nanoparticles generated from an emergent class of materials we refer to as a Group of Uniform Materials Based on Organic Salts (GUMBOS). GUMBOS are largely frozen ionic liquids, although the concept is more general and is also easily applied to solid ionic materials with melting points in excess of 100 °C. Nanoparticles based on GUMBOS (nanoGUMBOS) derived from a NIR fluorophore are prepared using a reprecipitation method and evaluated for in vivo fluorescence imaging. Due to their uniformity, single-step preparation, and composite nature, nanoGUMBOS help to resolve issues with dye leakage problems innate to alternate cellular stains and unlock a myriad of applications for these materials, highlighting exciting possibilities for multifunctional nanoGUMBOS. PMID:19928781

  13. Design of planar chiral metamaterials for near-infrared regime

    NASA Astrophysics Data System (ADS)

    Kaya, Sabri; Turkmen, Mustafa; Topaktas, Omer

    2017-01-01

    Planar chiral metamaterials (PCMs) comprising double-layer dielectric-metal-dielectric resonant structures in the shape of a windmill are presented for near-infrared regime. The circular dichroism is retrieved from transmission spectra. Effects of used materials on circular dichroism characteristics of PCM arrays are investigated for the first time. The dependence of spectral characteristics on the geometrical parameters of the PCMs is analyzed by the finite-difference time-domain method. The observations indicated that the circular dichroism characteristics of the proposed PCM arrays are strongly dependent on the type of metal and dielectric materials. Due to the enhanced chiroptical near-field response and tunable spectral behavior, proposed PCM arrays may have potential for biosensing applications of chiral biomolecules.

  14. Non-invasive neuroimaging using near-infrared light

    NASA Technical Reports Server (NTRS)

    Strangman, Gary; Boas, David A.; Sutton, Jeffrey P.

    2002-01-01

    This article reviews diffuse optical brain imaging, a technique that employs near-infrared light to non-invasively probe the brain for changes in parameters relating to brain function. We describe the general methodology, including types of measurements and instrumentation (including the tradeoffs inherent in the various instrument components), and the basic theory required to interpret the recorded data. A brief review of diffuse optical applications is included, with an emphasis on research that has been done with psychiatric populations. Finally, we discuss some practical issues and limitations that are relevant when conducting diffuse optical experiments. We find that, while diffuse optics can provide substantial advantages to the psychiatric researcher relative to the alternative brain imaging methods, the method remains substantially underutilized in this field.

  15. Componential distribution analysis of food using near infrared ray image

    NASA Astrophysics Data System (ADS)

    Yamauchi, Hiroki; Kato, Kunihito; Yamamoto, Kazuhiko; Ogawa, Noriko; Ohba, Kimie

    2008-11-01

    The components of the food related to the "deliciousness" are usually evaluated by componential analysis. The component content and type of components in the food are determined by this analysis. However, componential analysis is not able to analyze measurements in detail, and the measurement is time consuming. We propose a method to measure the two-dimensional distribution of the component in food using a near infrared ray (IR) image. The advantage of our method is to be able to visualize the invisible components. Many components in food have characteristics such as absorption and reflection of light in the IR range. The component content is measured using subtraction between two wavelengths of near IR light. In this paper, we describe a method to measure the component of food using near IR image processing, and we show an application to visualize the saccharose in the pumpkin.

  16. Combining near-infrared illuminants to optimize venous imaging

    SciTech Connect

    Paquit, Vincent C; Price, Jeffery R; Meriaudeau, Fabrice; Tobin Jr, Kenneth William; Ferrell, Thomas L

    2007-01-01

    The first and perhaps most important phase of a surgical procedure is the insertion of an intravenous (IV) catheter. Currently, this is performed manually by trained personnel. In some visions of future operating rooms, however, this process is to be replaced by an automated system. We previously presented work for localizing near-surface veins via near-infrared (NIR) imaging in combination with structured light ranging for surface mapping and robotic guidance. In this paper, we describe experiments to determine the best NIR wavelengths to optimize vein contrast for physiological differences such as skin tone and/or the presence of hair on the arm or wrist surface. For illumination, we employ an array of NIR LEDs comprising six different wavelength centers from 740nm to 910nm. We capture imagery of each subject under every possible combination of illuminants and determine the optimal combination of wavelengths for a given subject to maximize vein contrast using linear discriminant analysis.

  17. Discrimination and content analysis of fritillaria using near infrared spectroscopy.

    PubMed

    Meng, Yu; Wang, Shisheng; Cai, Rui; Jiang, Bohai; Zhao, Weijie

    2015-01-01

    Fritillaria is a traditional Chinese herbal medicine which can be used to moisten the lungs. The objective of this study is to develop simple, accurate, and solvent-free methods to discriminate and quantify Fritillaria herbs from seven different origins. Near infrared spectroscopy (NIRS) methods are established for the rapid discrimination of seven different Fritillaria samples and quantitative analysis of their total alkaloids. The scaling to first range method and the partial least square (PLS) method are used for the establishment of qualitative and quantitative analysis models. As a result of evaluation for the qualitative NIR model, the selectivity values between groups are always above 2, and the mistaken judgment rate of fifteen samples in prediction sets was zero. This means that the NIR model can be used to distinguish different species of Fritillaria herbs. The established quantitative NIR model can accurately predict the content of total alkaloids from Fritillaria samples.

  18. Tailored Near-Infrared Contrast Agents for Image Guided Surgery

    PubMed Central

    Njiojob, Costyl N.; Owens, Eric A.; Narayana, Lakshminarayana; Hyun, Hoon; Choi, Hak Soo; Henary, Maged

    2015-01-01

    The success of near-infrared (NIR) fluorescence to be employed for intraoperative imaging relies on the ability to develop a highly stable, NIR fluorescent, nontoxic, biocompatible, and highly excreted compound that retains a reactive functionality for conjugation to a cancer-recognizing peptide. Herein, systematic modifications to previously detailed fluorophore ZW800-1 are explored. Specific modifications, including the isosteric replacement of the O atom of ZW800-1, include nucleophilic amine and sulfur species attached to the heptamethine core. These novel compounds have shown similar satisfactory results in biodistribution and clearance while also expressing increased stability in serum. Most importantly, all of the synthesized and evaluated compounds display a reactive functionality (either a free amino group or carboxylic acid moiety) for further bioconjugation. The results obtained from the newly prepared derivatives demonstrate that the central substitution with the studied linking agents retains the ultralow background in vivo performance of the fluorophores regardless of the total net charge. PMID:25711712

  19. Canopy near-infrared reflectance and terrestrial photosynthesis

    PubMed Central

    Badgley, Grayson; Field, Christopher B.; Berry, Joseph A.

    2017-01-01

    Global estimates of terrestrial gross primary production (GPP) remain highly uncertain, despite decades of satellite measurements and intensive in situ monitoring. We report a new approach for quantifying the near-infrared reflectance of terrestrial vegetation (NIRV). NIRV provides a foundation for a new approach to estimate GPP that consistently untangles the confounding effects of background brightness, leaf area, and the distribution of photosynthetic capacity with depth in canopies using existing moderate spatial and spectral resolution satellite sensors. NIRV is strongly correlated with solar-induced chlorophyll fluorescence, a direct index of photons intercepted by chlorophyll, and with site-level and globally gridded estimates of GPP. NIRV makes it possible to use existing and future reflectance data as a starting point for accurately estimating GPP. PMID:28345046

  20. Near-infrared imaging of demineralization under sealants

    NASA Astrophysics Data System (ADS)

    Tom, Henry; Simon, Jacob C.; Chan, Kenneth H.; Darling, Cynthia L.; Fried, Daniel

    2014-07-01

    Previous studies have shown that near-infrared (NIR) reflectance and transillumination imaging can be used to acquire high contrast images of early caries lesions and composite restorative materials. The aim of the study was to determine the optimum NIR wavelengths for imaging demineralized areas under dental sealants. Fifteen natural human premolars and molars with occlusal lesions were used in this in vitro study. Images before and after application of sealants were acquired using NIR reflectance and NIR transillumination at wavelengths of 1300, 1460, and 1500 to 1700 nm. Images were also acquired using polarization sensitive optical coherence tomography (OCT) for comparison. The highest contrast for NIR reflectance was at 1460 nm and 1500 to 1700 nm. These NIR wavelengths are coincident with higher water absorption. The clear Delton sealant investigated was not visible in either copolarization or cross-polarization OCT images. The wavelength region between 1500 and 1700 nm yielded the highest contrast of lesions under sealants for NIR reflectance measurements.

  1. Near infrared photodissociation spectra of the aniline +-argon ionic complexes

    NASA Astrophysics Data System (ADS)

    Pino, T.; Douin, S.; Boudin, N.; Bréchignac, Ph.

    2006-02-01

    The near infrared spectra of the ionic complexes aniline(NH 2) +-argon and aniline(ND 2) +-argon have been measured by laser photodissociation spectroscopy. The bands observed from 10 500 to 13 500 cm -1 have been assigned to the D1(A˜2A2)←D0(X˜2B1) electronic transition within the solvated chromophore. They are characterized by a long vibrational progression involving the 6a mode. On the basis of CASSCF calculations, a large change of geometry along this coordinate is found while the amino group remains in the ring plane. Therefore, a change of the conjugation of the ring rather than a charge transfer is inferred. This is thought to be the origin of the extent of the progression.

  2. Cardiac tissue characterization using near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Singh Moon, Rajinder; Hendon, Christine P.

    2014-03-01

    Cardiac tissue from swine and canine hearts were assessed using diffuse reflectance near-infrared spectroscopy (NIRS) ex vivo. Slope measured between 800-880 nm reflectance was found to reveal differences between epicardial fat and normal myocardium tissue. This parameter was observed to increase monotonically from measurements obtained from the onset of radiofrequency ablation (RFA). A sheathe-style fiber optic catheter was then developed to allow real-time sampling of the zone of resistive heating during RFA treatment. A model was developed and used to extract changes in tissue absorption and reduced scattering based on the steady-state diffusion approximation. It was found that key changes in tissue optical properties occur during application of RF energy and can be monitored using NIRS. These results encourage the development of NIRS integrated catheters for real-time guidance of the cardiac ablation treatment.

  3. Engineering adenylate cyclases regulated by near-infrared window light.

    PubMed

    Ryu, Min-Hyung; Kang, In-Hye; Nelson, Mathew D; Jensen, Tricia M; Lyuksyutova, Anna I; Siltberg-Liberles, Jessica; Raizen, David M; Gomelsky, Mark

    2014-07-15

    Bacteriophytochromes sense light in the near-infrared window, the spectral region where absorption by mammalian tissues is minimal, and their chromophore, biliverdin IXα, is naturally present in animal cells. These properties make bacteriophytochromes particularly attractive for optogenetic applications. However, the lack of understanding of how light-induced conformational changes control output activities has hindered engineering of bacteriophytochrome-based optogenetic tools. Many bacteriophytochromes function as homodimeric enzymes, in which light-induced conformational changes are transferred via α-helical linkers to the rigid output domains. We hypothesized that heterologous output domains requiring homodimerization can be fused to the photosensory modules of bacteriophytochromes to generate light-activated fusions. Here, we tested this hypothesis by engineering adenylate cyclases regulated by light in the near-infrared spectral window using the photosensory module of the Rhodobacter sphaeroides bacteriophytochrome BphG1 and the adenylate cyclase domain from Nostoc sp. CyaB1. We engineered several light-activated fusion proteins that differed from each other by approximately one or two α-helical turns, suggesting that positioning of the output domains in the same phase of the helix is important for light-dependent activity. Extensive mutagenesis of one of these fusions resulted in an adenylate cyclase with a sixfold photodynamic range. Additional mutagenesis produced an enzyme with a more stable photoactivated state. When expressed in cholinergic neurons in Caenorhabditis elegans, the engineered adenylate cyclase affected worm behavior in a light-dependent manner. The insights derived from this study can be applied to the engineering of other homodimeric bacteriophytochromes, which will further expand the optogenetic toolset.

  4. Investigation of graphene applied on near infrared photodetector (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Lien, I.-Chun; Chen, Sheng-Hui

    2016-10-01

    The particular Graphene-Germanium-Graphene photodetector (GSG PD) is investigated in this research. Germanium has good absorption coefficient in near infrared such as 850 nm, 1310 nm and 1550 nm which are commonly used in optics communication. Generally, the metal electrode was utilized for photodetector and there were lots of light being loss. In recent years, graphene is found to be a good conductive film. It is a two-dimensional monolayer of sp2-bonded carbon atoms. In cases where synthesized by chemical vapor deposition (CVD), graphene is especially a promising candidate for transparent conductive films (TCFs) due to its exceptional electrical conductivity and high optical transmittance which is almost transparent in the wide wavelength range, especially including near infrared. Therefore, the higher photo current and responsivity of the device can be achieved. In this investigation, interdigitated graphene electrodes are used on the devices with the purposes of a relatively easy process for high-speed devices and a comparable process for the integrated circuit. We used the n-type Germanium as the substrates for the absorption of photodetector and different layers of graphene as the interdigitated electrodes. The interdigitated graphene electrode is prepared by transferred the graphene which is grown by CVD on the substrate first and then pattern by O2 plasma. The most direct method of measuring the photo current is to be incident a laser source by fiber and give a DC bias then using KEITHLEY 2400 Source Meter to measure current from photodetectors. As the result of that, we can calculate the responsivity by formula.

  5. Preliminary status of POLICAN: A near-infrared imaging polarimeter

    NASA Astrophysics Data System (ADS)

    Devaraj, R.; Luna, A.; Carrasco, L.; Mayya, Y. D.

    2015-10-01

    POLICAN is a near-infrared (J, H, K) imaging polarimeter developed for the Cananea near infrared camera (CANICA) at the 2.1m telescope of the Guillermo Haro Astrophysical Observatory (OAGH) located at Cananea, Sonora, México. The camera has a 1024 x 1024 HgCdTe detector (HAWAII array) with a plate scale of 0.32 arcsec/pixel providing a field of view of 5.5 x 5.5 arcmin. POLICAN is mounted externally to CANICA for narrow-field (f/12) linear polarimetric observations. It consists of a rotating super achromatic (1-2.7μm) half waveplate and a fixed wire-grid polarizer as the analyzer. The light is modulated by setting the half waveplate at different angles (0°, 22.5°, 45°, 67.5°) and linear combinations of the Stokes parameters (I, Q and U) are obtained. Image reduction and removal of instrumental polarization consist of dark noise subtraction, polarimetric flat fielding and background sky subtraction. Polarimetric calibration is performed by observing polarization standards available in the literature. The astrometry correction is performed by matching common stars with the Two Micron All Sky Survey. POLICAN's bright and limiting magnitudes are approximately 6th and 16th magnitude, which correspond to saturation and photon noise, respectively. POLICAN currently achieves a polarimetric accuracy about 3.0% and polarization angle uncertainties within 3°. Preliminary observations of star forming regions are being carried out in order to study their magnetic field properties.

  6. Optimal hemodynamic response model for functional near-infrared spectroscopy

    PubMed Central

    Kamran, Muhammad A.; Jeong, Myung Yung; Mannan, Malik M. N.

    2015-01-01

    Functional near-infrared spectroscopy (fNIRS) is an emerging non-invasive brain imaging technique and measures brain activities by means of near-infrared light of 650–950 nm wavelengths. The cortical hemodynamic response (HR) differs in attributes at different brain regions and on repetition of trials, even if the experimental paradigm is kept exactly the same. Therefore, an HR model that can estimate such variations in the response is the objective of this research. The canonical hemodynamic response function (cHRF) is modeled by two Gamma functions with six unknown parameters (four of them to model the shape and other two to scale and baseline respectively). The HRF model is supposed to be a linear combination of HRF, baseline, and physiological noises (amplitudes and frequencies of physiological noises are supposed to be unknown). An objective function is developed as a square of the residuals with constraints on 12 free parameters. The formulated problem is solved by using an iterative optimization algorithm to estimate the unknown parameters in the model. Inter-subject variations in HRF and physiological noises have been estimated for better cortical functional maps. The accuracy of the algorithm has been verified using 10 real and 15 simulated data sets. Ten healthy subjects participated in the experiment and their HRF for finger-tapping tasks have been estimated and analyzed. The statistical significance of the estimated activity strength parameters has been verified by employing statistical analysis (i.e., t-value > tcritical and p-value < 0.05). PMID:26136668

  7. [Rapid determination of beet sugar content using near infrared spectroscopy].

    PubMed

    Yang, Yong; Ren, Jian; Zheng, Xi-Qun; Zhao, Li-Ying; Li, Mao-Mao

    2014-10-01

    In order to classify and set different prices on basis of difference of beet sugar content in the acquisition process and promote the development of beet sugar industry healthily, a fast, nondestructive, accurate method to detect sugar content of beet was determined by applying near infrared spectroscopy technology. Eight hundred twenty samples from 28 representative varieties of beet were collected as calibration set and 70 samples were chosen as prediction set. Then near infrared spectra of calibration set samples were collected by scanning, effective information was extracted from NIR spectroscopy, and the original spectroscopy data was optimized by data preprocessing methods appropriately. Then partial least square(PLS)regression was used to establish beet sugar quantitative prediction mathematical model. The performances of the models were evaluated by the root mean square of cross-validation (RMSECV), the coefficient of determination (R2) of the calibration model and the standard error of prediction (SEP), and the predicted results of these models were compared. Results show that the established mathematical model by using first derivative (FD) and standard normal variate transformation (SNV) coupled with partial least squares has good predictive ability. The R2 of calibration models of sugar content of beet is 0.908 3, and the RMSECV is 0.376 7. Using this model to forecast the prediction set including 70 samples, the correlation coefficient is 0.921 4 between predicted values and measured values, and the standard error of prediction (SEP) is 0.439, without significant difference (p > 0.05) between predicted values and measured values. These results demonstrated that NIRS can take advantage of simple, rapid, nondestructive and environmental detection method and could be applied to predict beet sugar content. This model owned high accuracy and can meet the precision need of determination of beet sugar content. This detection method could be used to classify

  8. Asteroid 951 Gaspra Near Infrared Mapping Spectrometer Radiance Data

    NASA Astrophysics Data System (ADS)

    Granahan, J. C., Jr.

    2015-12-01

    Five radiance spectra of asteroid 951 Gaspra have been archived in the Small Bodies Node of the NASA Planetary Data System [Granahan, 2014]. The radiance spectra were created from uncalibrated Galileo spacecraft Near Infrared Mapping Spectrometer files archived in the Imaging Node of the NASA Planetary Data System. The NASA Galileo spacecraft observed asteroid 951 Gaspra on October 29, 1991 with the Near Infrared Mapping Spectrometer (NIMS) at wavelengths ranging from 0.7 - 5.2 micrometers [Carlson et al., 1992]. The five radiance spectra consist of two 17, two 100, and one 329 spectral channel data sets. They record data that was acquired by NIMS at ranges between 27232.6 to 14723.8 kilometers from asteroid 951 Gaspra. The uncalibrated NIMS data were converted into radiance spectra using calibration coefficients obtained during the Galileo mission's first Earth encounter on December 8, 1990. The archived radiance spectral data is located at the URL (Universal Record Locator): http://sbn.psi.edu/pds/resource/gaspraspec.html and contains radiance, solar, incidence over flux, and data documentation. This archived data set contains a variety of spectral signatures. These signatures include absorptions near 1.0, 2.0, 2.8, 3.4, and 4.5 micrometers. The 1.0 and 2.0 micrometer features are indicators of olivine and pyroxene on the asteroid surface. The 2.8 micrometer feature has a shape similar to the combined spectra of multiple iron bearing phyllosilicates. The 3.4 micrometer feature is in the same location as absorptions created by a carbon-hydrogen bond. The 4.5 micrometer feature, present only in the 329 channel data set, corresponds in position to absorptions detected in sulfate minerals. Carlson, R. W., et al. (1992) Bull. of the A.A.S., 24, 932. Granahan, J. C. (2014), GO-A-NIMS-3-GASPRASPEC-V1.0, NASA Planetary Data System.

  9. THE EARLIEST NEAR-INFRARED TIME-SERIES SPECTROSCOPY OF A TYPE Ia SUPERNOVA

    SciTech Connect

    Hsiao, E. Y.; Phillips, M. M.; Morrell, N.; Contreras, C.; Roth, M.; Marion, G. H.; Kirshner, R. P.; Burns, C. R.; Freedman, W. L.; Persson, S. E.; Winge, C.; Gerardy, C. L.; Hoeflich, P.; Im, M.; Jeon, Y.; Pignata, G.; Stanishev, V.; and others

    2013-04-01

    We present ten medium-resolution, high signal-to-noise ratio near-infrared (NIR) spectra of SN 2011fe from SpeX on the NASA Infrared Telescope Facility (IRTF) and Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North, obtained as part of the Carnegie Supernova Project. This data set constitutes the earliest time-series NIR spectroscopy of a Type Ia supernova (SN Ia), with the first spectrum obtained at 2.58 days past the explosion and covering -14.6 to +17.3 days relative to B-band maximum. C I {lambda}1.0693 {mu}m is detected in SN 2011fe with increasing strength up to maximum light. The delay in the onset of the NIR C I line demonstrates its potential to be an effective tracer of unprocessed material. For the first time in a SN Ia, the early rapid decline of the Mg II {lambda}1.0927 {mu}m velocity was observed, and the subsequent velocity is remarkably constant. The Mg II velocity during this constant phase locates the inner edge of carbon burning and probes the conditions under which the transition from deflagration to detonation occurs. We show that the Mg II velocity does not correlate with the optical light-curve decline rate {Delta}m{sub 15}(B). The prominent break at {approx}1.5 {mu}m is the main source of concern for NIR k-correction calculations. We demonstrate here that the feature has a uniform time evolution among SNe Ia, with the flux ratio across the break strongly correlated with {Delta}m{sub 15}(B). The predictability of the strength and the onset of this feature suggests that the associated k-correction uncertainties can be minimized with improved spectral templates.

  10. The Earliest Near-infrared Time-series Spectroscopy of a Type Ia Supernova

    NASA Astrophysics Data System (ADS)

    Hsiao, E. Y.; Marion, G. H.; Phillips, M. M.; Burns, C. R.; Winge, C.; Morrell, N.; Contreras, C.; Freedman, W. L.; Kromer, M.; Gall, E. E. E.; Gerardy, C. L.; Höflich, P.; Im, M.; Jeon, Y.; Kirshner, R. P.; Nugent, P. E.; Persson, S. E.; Pignata, G.; Roth, M.; Stanishev, V.; Stritzinger, M.; Suntzeff, N. B.

    2013-04-01

    We present ten medium-resolution, high signal-to-noise ratio near-infrared (NIR) spectra of SN 2011fe from SpeX on the NASA Infrared Telescope Facility (IRTF) and Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North, obtained as part of the Carnegie Supernova Project. This data set constitutes the earliest time-series NIR spectroscopy of a Type Ia supernova (SN Ia), with the first spectrum obtained at 2.58 days past the explosion and covering -14.6 to +17.3 days relative to B-band maximum. C I λ1.0693 μm is detected in SN 2011fe with increasing strength up to maximum light. The delay in the onset of the NIR C I line demonstrates its potential to be an effective tracer of unprocessed material. For the first time in a SN Ia, the early rapid decline of the Mg II λ1.0927 μm velocity was observed, and the subsequent velocity is remarkably constant. The Mg II velocity during this constant phase locates the inner edge of carbon burning and probes the conditions under which the transition from deflagration to detonation occurs. We show that the Mg II velocity does not correlate with the optical light-curve decline rate Δm 15(B). The prominent break at ~1.5 μm is the main source of concern for NIR k-correction calculations. We demonstrate here that the feature has a uniform time evolution among SNe Ia, with the flux ratio across the break strongly correlated with Δm 15(B). The predictability of the strength and the onset of this feature suggests that the associated k-correction uncertainties can be minimized with improved spectral templates.

  11. THE L-{sigma} RELATION OF LOCAL H II GALAXIES

    SciTech Connect

    Bordalo, V.; Telles, E. E-mail: etelles@on.br

    2011-07-01

    For the first time we present a new data set of emission line widths for 118 star-forming regions in H II galaxies (HIIGs). This homogeneous set is used to investigate the L-{sigma} relation in conjunction with optical spectrophotometric observations. We were able to classify their nebular emission line profiles due to our high-resolution spectra. Peculiarities in the line profiles such as sharp lines, wings, asymmetries, and in some cases more than one component in emission were verified. From a new independent homogeneous set of spectrophotometric data, we derived physical condition parameters and performed statistical principal component analysis. We have investigated the potential role of metallicity (O/H), H{beta} equivalent width (W{sub H{beta}}), and ionization ratio [O III]/[O II] to account for the observational scatter of the L-{sigma} relation. Our results indicate that the L-{sigma} relation for HIIGs is more sensitive to the evolution of the current starburst event (short-term evolution) and dated by W{sub H}{beta} or even the [O III]/[O II] ratio. The long-term evolution measured by O/H also plays a potential role in determining the luminosity of the current burst for a given velocity dispersion and age as previously suggested. Additionally, galaxies showing Gaussian line profiles present tighter correlations indicating that they are the best targets for the application of the parametric relations as an extragalactic cosmological distance indicator. Best fits for a restricted homogeneous sample of 45 HIIGs provide us with a set of new extragalactic distance indicators with an rms scatter compatible with observational errors of {delta}log L{sub H}{alpha} = 0.2 dex or 0.5 mag. Improvements may still come from future optimized observational programs to reduce the observational uncertainties on the predicted luminosities of HIIGs in order to achieve the precision required for the application of these relations as tests of cosmological models.

  12. Saccharide substituted zinc phthalocyanines: optical properties, interaction with bovine serum albumin and near infrared fluorescence imaging for sentinel lymph nodes.

    PubMed

    Lu, Li; Lv, Feng; Cao, Bo; He, Xujun; Liu, Tianjun

    2014-01-03

    Saccharide-substituted zinc phthalocyanines, [2,9(10),16(17),23(24)-tetrakis((1-(β-D-glucose-2-yl)-1H-1,2,3-triazol-4-yl)methoxy)phthalocyaninato]zinc(II) and [2,9(10), 16(17),23(24)-tetrakis((1-(β-D-lactose-2-yl)-1H-1,2,3-triazol-4-yl)methoxy)phthalocyaninato] zinc(II), were evaluated as novel near infrared fluorescence agents. Their interaction with bovine serum albumin was investigated by fluorescence and circular dichroism spectroscopy and isothermal titration calorimetry. Near infrared imaging for sentinel lymph nodes in vivo was performed using nude mice as models. Results show that saccharide- substituted zinc phthalocyanines have favourable water solubility, good optical stability and high emission ability in the near infrared region. The interaction of lactose-substituted phthalocyanine with bovine serum albumin displays obvious differences to that of glucose- substituted phthalocyanine. Moreover, lactose-substituted phthalocyanine possesses obvious imaging effects for sentinel lymph nodes in vivo.

  13. Rocket-borne instrument for observations of near-infrared and far-infrared extended astrophysical emission

    NASA Technical Reports Server (NTRS)

    Matsuhara, Hideo; Kawada, Mitsunobu; Matsumoto, Toshio; Matsuura, Shuji; Tanaka, Masahiro; Bock, James J.; Hristov, Viktor V.; Lange, Andrew E.; Mauskopf, Philip D.; Richards, Paul L.

    1994-01-01

    We give a detailed description of the design and flight performance of an instrument onboard the S-520-15 rocket of the Institute of Space and Astronautical Science. The isntrument, consisting of a near-infrared spectrometer and a far-infrared photometer at the focus of a 10 cm liquid-helium cooled telescope, was designed to observe both the brightness and distribution of diffuse emission with high sensitivity. The rocket was successfully launched and the instrument observed near-infrared and far-infrared continuum emission, as well as (C II) 157.7 micrometer line emission from regions at high Galactic latitude. We also give a brief description of the design and performance of an onboard attitude control system.

  14. A near-infrared magnetic aptasensor for Ochratoxin A based on near-infrared upconversion nanoparticles and magnetic nanoparticles.

    PubMed

    Dai, Shaoliang; Wu, Shijia; Duan, Nuo; Wang, Zhouping

    2016-09-01

    A multiplexed, sensitive and specific detection method is highly desirable for the simultaneous detection of several pathogenic bacteria and bio-toxins. In our previous work, multicolor upconversion nanoparticles (UCNPs) via doping with various rare-earth ions to obtain well-separated emission peaks by means of a solvothermal method were synthesized and were successfully applied as luminescence labels in the detection of three pathogenic bacteria. One of the basic achievements of our group has been to establish that the key to increasing the number of simultaneous detection components is the preparation of more UCNPs, the emission peaks of which can be distinguished from each other. According to this vision, NaYF4:Yb0.2, Tm0.02 UCNPs were obtained via a thermal-decomposition protocol, which has a main near-infrared (NIR) UC emission at 804nm under 980nm excitation. The emission peak at 804nm was well-separated from the emission peaks of UCNPs we have reported at 477nm, 542nm, and 660nm. It means both the excitation and the emission of NaYF4:Yb0.2, Tm0.02 UCNPs are located in the NIR spectral range (NIR-to-NIR UC emission), the so-called biological window. This result establishes the basis of achieving simultaneous detection of four components. To confirm the analytical performance of this NaYF4:Yb0.2, Tm0.02 UCNPs, a novel near-infrared magnetic aptasensor for the detection of Ochratoxin A (OTA) was developed using the OTA aptamer-conjugated near-infrared upconversion nanoparticles (apt-UCNPs) and the complementary oligonucleotide-modified magnetic nanoparticles (cDNA-MNPs). The apt-UCNPs and cDNA-MNPs were hybridized to form a poly-network structure of MNP-UCNP nanocomposites. When the target OTA was introduced, the aptamer combined with the priority target and the cDNA-MNPs were replaced. The proposed method achieved a linear range between 0.01 and 100ngmL(-1), with a detection limit as low as 0.005ngmL(-1). Then, we successfully applied this method to measure

  15. Near-infrared organic light-emitting diodes with very high external quantum efficiency and radiance

    NASA Astrophysics Data System (ADS)

    Tuong Ly, Kiet; Chen-Cheng, Ren-Wu; Lin, Hao-Wu; Shiau, Yu-Jeng; Liu, Shih-Hung; Chou, Pi-Tai; Tsao, Cheng-Si; Huang, Yu-Ching; Chi, Yun

    2017-01-01

    Bright and efficient organic emitters of near-infrared light would be of use in applications ranging from biological imaging and medical therapy to night-vision devices. Here we report how a new class of Pt(II) complex phosphors have enabled the fabrication of organic light-emitting diodes that emit light at 740 nm with very high efficiency and radiance due to a high photoluminescence quantum yield of ∼81% and a highly preferred horizontal dipole orientation. The best devices exhibited an external quantum efficiency of 24 ± 1% in a normal planar organic light-emitting diode structure. The incorporation of a light out-coupling hemisphere structure further boosts the external quantum efficiency up to 55 ± 3%.

  16. Probing Reionization through Near-Infrared Background Fluctuations with CIBER

    NASA Astrophysics Data System (ADS)

    Sullivan, Ian S.

    2010-01-01

    The Cosmic Infrared Background Experiment (CIBER) is a NASA sounding rocket payload that was first launched in February 2009. CIBER consists of four co-aligned instruments designed with foreground subtraction and control of systematics in mind. In addition, the platform of a sounding rocket enables observations of the NIRB outside of narrow atmospheric windows that are uncontaminated by airglow. We will present preliminary results from the first flight. CIBER seeks to measure the absolute brightness spectrum of the extragalactic NIRB, and has two spectrometers dedicated to that purpose. One, a high-resolution Fabry-Perot spectometer, is tuned to the 8545 nm Ca II line of the solar spectrum, and is designed to measure the absolute brightness of the Zodiacal Light directly, which is the source of greatest uncertainty in the NIRB spectrum. The second spectrometer measures the NIRB spectrum from 700nm to 1800nm, which spans the wavelength range where a Lyman cutoff feature from Reionization could appear. CIBER also houses two Infrared imaging telescopes, which have identical optics that give 2º x 2º field of views with 7 arcsec pixels, but have different band defining filters. The first imager has a wide band centered at 1600nm, and images the background at the expected peak of the spectrum. The imagers’ wide field of view allows them to measure the distinctive power spectrum peaking at 10 arcminutes. The second imager has a wide band centered at 1000nm that is intended to image at wavelengths shorter than the Lyman cutoff, and provides a powerful systematic test for any detection made at 1600 nm. First-light fluctuations should have a distinctive spatial power spectrum with very red 1600nm / 1000nm color, distinctly redder than the approximately solar color of any residual fluctuations arising from Zodiacal light, Galactic starlight, or low-redshift galaxies.

  17. Non-thermal DNA damage of cancer cells using near-infrared irradiation.

    PubMed

    Tanaka, Yohei; Tatewaki, Naoto; Nishida, Hiroshi; Eitsuka, Takahiro; Ikekawa, Nobuo; Nakayama, Jun

    2012-08-01

    Previously, we reported that near-infrared irradiation that simulates solar near-infrared irradiation with pre- and parallel-irradiational cooling can non-thermally induce cytocidal effects in cancer cells. To explore these effects, we assessed cell viability, DNA damage response pathways, and the percentage of mitotic cancer cells after near-infrared treatment. Further, we evaluated the anti-cancer effects of near-infrared irradiation compared with doxorubicin in xenografts in nude mice by measuring tumor volume and assessing protein phosphorylation by immunoblot analysis. The cell viability of A549 lung adenocarcinoma cells was significantly decreased after three rounds of near-infrared irradiation at 20 J/cm(2). Apoptotic cells were observed in near-infrared treated cells. Moreover, near-infrared treatment increased the phosphorylation of ataxia-telangiectasia mutated (ATM) at Ser(1981), H2AX at Ser(139), Chk1 at Ser(317), structural maintenance of chromosome (SMC) 1 at Ser(966), and p53 at Ser(15) in A549 cells compared with control. Notably, near-infrared treatment induced the formation of nucleic foci of γH2AX. The percentage of mitotic A549 cells, as measured by histone H3 phosphorylation, decreased significantly after three rounds of near-infrared irradiation at 20 J/cm(2). Both near-infrared and doxorubicin inhibited the tumor growth of MDA-MB435 melanoma cell xenografts in nude mice and increased the phosphorylation of p53 at Ser(15), Chk1 at Ser(317), SMC1 at Ser(966), and H2AX at Ser(139) compared with control mice. These results indicate that near-infrared irradiation can non-thermally induce cytocidal effects in cancer cells as a result of activation of the DNA damage response pathway. The near-infrared irradiation schedule used here reduces discomfort and side effects. Therefore, this strategy may have potential application in the treatment of cancer.

  18. Gratings and Random Reflectors for Near-Infrared PIN Diodes

    NASA Technical Reports Server (NTRS)

    Gunapala, Sarath; Bandara, Sumith; Liu, John; Ting, David

    2007-01-01

    Crossed diffraction gratings and random reflectors have been proposed as means to increase the quantum efficiencies of InGaAs/InP positive/intrinsic/ negative (PIN) diodes designed to operate as near-infrared photodetectors. The proposal is meant especially to apply to focal-plane imaging arrays of such photodetectors to be used for near-infrared imaging. A further increase in quantum efficiency near the short-wavelength limit of the near-infrared spectrum of such a photodetector array could be effected by removing the InP substrate of the array. The use of crossed diffraction gratings and random reflectors as optical devices for increasing the quantum efficiencies of quantum-well infrared photodetectors (QWIPs) was discussed in several prior NASA Tech Briefs articles. While the optical effects of crossed gratings and random reflectors as applied to PIN photodiodes would be similar to those of crossed gratings and random reflectors as applied to QWIPs, the physical mechanisms by which these optical effects would enhance efficiency differ between the PIN-photodiode and QWIP cases: In a QWIP, the multiple-quantum-well layers are typically oriented parallel to the focal plane and therefore perpendicular or nearly perpendicular to the direction of incidence of infrared light. By virtue of the applicable quantum selection rules, light polarized parallel to the focal plane (as normally incident light is) cannot excite charge carriers and, hence, cannot be detected. A pair of crossed gratings or a random reflector scatters normally or nearly normally incident light so that a significant portion of it attains a component of polarization normal to the focal plane and, hence, can excite charge carriers. A pair of crossed gratings or a random reflector on a PIN photodiode would also scatter light into directions away from the perpendicular to the focal plane. However, in this case, the reason for redirecting light away from the perpendicular is to increase the length of the

  19. Intraoperative near-infrared fluorescent imaging during robotic operations.

    PubMed

    Macedo, Antonio Luiz de Vasconcellos; Schraibman, Vladimir

    2016-01-01

    The intraoperative identification of certain anatomical structures because they are small or visually occult may be challenging. The development of minimally invasive surgery brought additional difficulties to identify these structures due to the lack of complete tactile sensitivity. A number of different forms of intraoperative mapping have been tried. Recently, the near-infrared fluorescence imaging technology with indocyanine green has been added to robotic platforms. In addition, this technology has been tested in several types of operations, and has advantages such as safety, low cost and good results. Disadvantages are linked to contrast distribution in certain clinical scenarios. The intraoperative near-infrared fluorescent imaging is new and promising addition to robotic surgery. Several reports show the utility of this technology in several different procedures. The ideal dose, time and site for dye injection are not well defined. No high quality evidence-based comparative studies and long-term follow-up outcomes have been published so far. Initial results, however, are good and safe. RESUMO A identificação intraoperatória de certas estruturas anatômicas, por seu tamanho ou por elas serem ocultas à visão, pode ser desafiadora. O desenvolvimento da cirurgia minimamente invasiva trouxe dificuldades adicionais, pela falta da sensibilidade tátil completa. Diversas formas de detecção intraoperatória destas estruturas têm sido tentadas. Recentemente, a tecnologia de fluorescência infravermelha com verde de indocianina foi associada às plataformas robóticas. Além disso, essa tecnologia tem sido testada em uma variedade de cirurgias, e suas vantagens parecem estar ligadas a baixo custo, segurança e bons resultados. As desvantagens estão associadas à má distribuição do contraste em determinados cenários. A imagem intraoperatória por fluorescência infravermelha é uma nova e promissora adição à cirurgia robótica. Diversas séries mostram

  20. The near infrared camera for the Subaru Prime Focus Spectrograph

    NASA Astrophysics Data System (ADS)

    Smee, Stephen A.; Gunn, James E.; Golebiowski, Mirek; Barkhouser, Robert; Vivès, Sebastien; Pascal, Sandrine; Carr, Michael; Hope, Stephen C.; Loomis, Craig; Hart, Murdock; Sugai, Hajime; Tamura, Naoyuki; Shimono, Atsushi

    2014-08-01

    We present the detailed design of the near infrared camera for the SuMIRe (Subaru Measurement of Images and Redshifts) Prime Focus Spectrograph (PFS) being developed for the Subaru Telescope. The PFS spectrograph is designed to collect spectra from 2394 objects simultaneously, covering wavelengths that extend from 380 nm - 1.26 μm. The spectrograph is comprised of four identical spectrograph modules, with each module collecting roughly 600 spectra from a robotic fiber positioner at the telescope prime focus. Each spectrograph module will have two visible channels covering wavelength ranges 380 nm - 640 nm and 640 nm - 955 nm, and one near infrared (NIR) channel with a wavelength range 955 nm - 1.26 μm. Dispersed light in each channel is imaged by a 300 mm focal length, f/1.07, vacuum Schmidt camera onto a 4k x 4k, 15 µm pixel, detector format. For the NIR channel a HgCdTe substrate-removed Teledyne 1.7 μm cutoff device is used. In the visible channels, CCDs from Hamamatsu are used. These cameras are large, having a clear aperture of 300 mm at the entrance window, and a mass of ~ 250 kg. Like the two visible channel cameras, the NIR camera contains just four optical elements: a two-element refractive corrector, a Mangin mirror, and a field flattening lens. This simple design produces very good imaging performance considering the wide field and wavelength range, and it does so in large part due to the use of a Mangin mirror (a lens with a reflecting rear surface) for the Schmidt primary. In the case of the NIR camera, the rear reflecting surface is a dichroic, which reflects in-band wavelengths and transmits wavelengths beyond 1.26 μm. This, combined with a thermal rejection filter coating on the rear surface of the second corrector element, greatly reduces the out-of-band thermal radiation that reaches the detector. The camera optics and detector are packaged in a cryostat and cooled by two Stirling cycle cryocoolers. The first corrector element serves as the

  1. Galaxies at redshifts 5 to 6 with systematically low dust content and high [C II] emission.

    PubMed

    Capak, P L; Carilli, C; Jones, G; Casey, C M; Riechers, D; Sheth, K; Carollo, C M; Ilbert, O; Karim, A; LeFevre, O; Lilly, S; Scoville, N; Smolcic, V; Yan, L

    2015-06-25

    The rest-frame ultraviolet properties of galaxies during the first three billion years of cosmic time (redshift z > 4) indicate a rapid evolution in the dust obscuration of such galaxies. This evolution implies a change in the average properties of the interstellar medium, but the measurements are systematically uncertain owing to untested assumptions and the inability to detect heavily obscured regions of the galaxies. Previous attempts to measure the interstellar medium directly in normal galaxies at these redshifts have failed for a number of reasons, with two notable exceptions. Here we report measurements of the forbidden C ii emission (that is, [C II]) from gas, and the far-infrared emission from dust, in nine typical star-forming galaxies about one billion years after the Big Bang (z ≈ 5-6). We find that these galaxies have thermal emission that is less than 1/12 that of similar systems about two billion years later, and enhanced [C II] emission relative to the far-infrared continuum, confirming a strong evolution in the properties of the interstellar medium in the early Universe. The gas is distributed over scales of one to eight kiloparsecs, and shows diverse dynamics within the sample. These results are consistent with early galaxies having significantly less dust than typical galaxies seen at z < 3 and being comparable in dust content to local low-metallicity systems.

  2. The remnant of a merger between two dwarf galaxies in Andromeda II.

    PubMed

    Amorisco, N C; Evans, N W; van de Ven, G

    2014-03-20

    Driven by gravity, massive structures like galaxies and clusters of galaxies are believed to grow continuously through hierarchical merging and accretion of smaller systems. Observational evidence of accretion events is provided by the coherent stellar streams crossing the outer haloes of massive galaxies, such as the Milky Way or Andromeda. At similar mass scales, around 10(11) solar masses in stars, further evidence of merging activity is also ample. Mergers of lower-mass galaxies are expected within the hierarchical process of galaxy formation, but have hitherto not been seen for galaxies with less than about 10(9) solar masses in stars. Here we report the kinematic detection of a stellar stream in one of the satellite galaxies of Andromeda, the dwarf spheroidal Andromeda II, which has a mass of only 10(7) solar masses in stars. The properties of the stream show that we are observing the remnant of a merger between two dwarf galaxies. This had a drastic influence on the dynamics of the remnant, which is now rotating around its projected major axis. The stellar stream in Andromeda II illustrates the scale-free character of the formation of galaxies, down to the lowest galactic mass scales.

  3. Near-infrared light-responsive nanomaterials in cancer therapeutics.

    PubMed

    Shanmugam, Vijayakumar; Selvakumar, S; Yeh, Chen-Sheng

    2014-09-07

    Noninvasive techniques, such as breath tests (urea breath test), blood pressure measurements using a sphygmomanometer and electrocardiography, were employed by a physician to perform classical diagnosis. The use of state-of-the-art noninvasive therapies at the organ level in modern medicine has gradually become possible. However, cancer treatment demands spatially and temporally controlled noninvasive therapy at the cell level because nonspecific toxicity often causes complicated side effects. To increase survival in cancer patients further, combination therapy and combination drugs are explored which demand high specificity to avoid combined-drug side effects. We believe that high specificity could be obtained by implementing near-infrared (NIR) light-assisted nanoparticles in photothermal therapy, chemotherapy, and photodynamic therapy. To refine this therapy and subsequently achieve high efficiency, novel nanomaterials have been designed and modified either to enhance the uptake and drug delivery to the cancer site, or control treatment to administer therapy efficiently. These modifications and developments have been demonstrated to achieve spatial and temporal control when conducting an in vivo xenograft, because the NIR light penetrated effectively the biological tissue. The nanoplatforms discussed in this review are grouped under the following subheadings: Au nanorods (NRs), Au nanoshells, other Au-related nanomaterials, graphene oxide, upconversion nanoparticles, and other related materials (including materials such as CuS, Fe3O4-related systems, and carbon nanotubes (CNTs)).

  4. Bundled-Optode Method in Functional Near-Infrared Spectroscopy

    PubMed Central

    Nguyen, Hoang-Dung; Hong, Keum-Shik; Shin, Yong-Il

    2016-01-01

    In this paper, a theory for detection of the absolute concentrations of oxy-hemoglobin (HbO) and deoxy-hemoglobin (HbR) from hemodynamic responses using a bundled-optode configuration in functional near-infrared spectroscopy (fNIRS) is proposed. The proposed method is then applied to the identification of two fingers (i.e., little and thumb) during their flexion and extension. This experiment involves a continuous-wave-type dual-wavelength (760 and 830 nm) fNIRS and five healthy male subjects. The active brain locations of two finger movements are identified based on the analysis of the t- and p-values of the averaged HbOs, which are quite distinctive. Our experimental results, furthermore, revealed that the hemodynamic responses of two-finger movements are different: The mean, peak, and time-to-peak of little finger movements are higher than those of thumb movements. It is noteworthy that the developed method can be extended to 3-dimensional fNIRS imaging. PMID:27788178

  5. Near-infrared autofluorescence for the detection of parathyroid glands.

    PubMed

    Paras, Constantine; Keller, Matthew; White, Lisa; Phay, John; Mahadevan-Jansen, Anita

    2011-06-01

    A major challenge in endocrine surgery is the intraoperative detection of parathyroid glands during both thyroidectomies and parathyroidectomies. Current localization techniques such as ultrasound and sestamibi scan are mostly preoperative and rely on an abnormal parathyroid for its detection. In this paper, we present near-infrared (NIR) autofluorescence as a nonintrusive, real-time, automated in vivo method for the detection of the parathyroid gland. A pilot in vivo study was conducted to assess the ability of NIR fluorescence to identify parathyroid glands during thyroid and parathyroidectomies. Fluorescence measurements at 785 nm excitation were obtained intra-operatively from the different tissues exposed in the neck region in 21 patients undergoing endocrine surgery. The fluorescence intensity of the parathyroid gland was found to be consistently greater than that of the thyroid and all other tissues in the neck of all patients. In particular, parathyroid fluorescence was two to eleven times higher than that of the thyroid tissues with peak fluorescence occurring at 820 to 830 nm. These results indicate that NIR fluorescence has the potential to be an excellent optical tool to locate parathyroid tissue during surgery.

  6. Retinal-Based Proton Pumping in the Near Infrared.

    PubMed

    Ganapathy, Srividya; Venselaar, Hanka; Chen, Que; de Groot, Huub J M; Hellingwerf, Klaas J; de Grip, Willem J

    2017-02-15

    Proteorhodopsin (PR) and Gloeobacter rhodopsin (GR) are retinal-based light-driven proton pumps that absorb visible light (maxima at 520-540 nm). Shifting the action spectra of these proton pumps beyond 700 nm would generate new prospects in optogenetics, membrane sensor technology, and complementation of oxygenic phototrophy. We therefore investigated the effect of red-shifting analogues of retinal, combined with red-shifting mutations, on the spectral properties and pump activity of the resulting pigments. We investigated a variety of analogues, including many novel ones. One of the novel analogues we tested, 3-methylamino-16-nor-1,2,3,4-didehydroretinal (MMAR), produced exciting results. This analogue red-shifted all of the rhodopsin variants tested, accompanied by a strong broadening of the absorbance band, tailing out to 850-950 nm. In particular, MMAR showed a strong synergistic effect with the PR-D212N,F234S double mutant, inducing an astonishing 200 nm red shift in the absorbance maximum. To our knowledge, this is by far the largest red shift reported for any retinal protein. Very importantly, all MMAR-containing holoproteins are the first rhodopsins retaining significant pump activity under near-infrared illumination (730 nm light-emitting diode). Such MMAR-based rhodopsin variants present very promising opportunities for further synthetic biology modification and for a variety of biotechnological and biophysical applications.

  7. Graphene surface plasmons at the near-infrared optical regime

    PubMed Central

    Zhang, Qiming; Li, Xiangping; Hossain, Md Muntasir; Xue, Yunzhou; Zhang, Jie; Song, Jingchao; Liu, Jingying; Turner, Mark D.; Fan, Shanhui; Bao, Qiaoliang; Gu, Min

    2014-01-01

    Graphene has been identified as an emerging horizon for a nanoscale photonic platform because the Fermi level of intrinsic graphene can be engineered to support surface plasmons (SPs). The current solid back electrical gating and chemical doping methods cannot facilitate the demonstration of graphene SPs at the near-infrared (NIR) window because of the limited shift of the Fermi level. Here, we present the evidence for the existence of graphene SPs on a tapered graphene-silicon waveguide tip at a NIR wavelength, employing a surface carrier transfer method with molybdenum trioxides. The coupling between the graphene surface plasmons and the guiding mode in silicon waveguides allows for the observation of the concentrated field of the SPs in the tip by near-field scanning optical microscopy. Thus the hot spot from the concentrated SPs in the graphene layer can be used as a key experimental signature of graphene SPs. The NIR graphene SPs opens a new perspective for optical communications, optical sensing and imaging, and optical data storage with extreme spatial confinement, broad bandwidth and high tunability. PMID:25297570

  8. Broadband near-infrared metamaterial absorbers utilizing highly lossy metals

    PubMed Central

    Ding, Fei; Dai, Jin; Chen, Yiting; Zhu, Jianfei; Jin, Yi; Bozhevolnyi, Sergey I.

    2016-01-01

    Radiation absorbers have increasingly been attracting attention as crucial components for controllable thermal emission, energy harvesting, modulators, etc. However, it is still challenging to realize thin absorbers which can operate over a wide spectrum range. Here, we propose and experimentally demonstrate thin, broadband, polarization-insensitive and omnidirectional absorbers working in the near-infrared range. We choose titanium (Ti) instead of the commonly used gold (Au) to construct nano-disk arrays on the top of a silicon dioxide (SiO2) coated Au substrate, with the quality (Q) factor of the localized surface plasmon (LSP) resonance being decreased due to the intrinsic high loss of Ti. The combination of this low-Q LSP resonance and the propagating surface plasmon (PSP) excitation resonance, which occur at different wavelengths, is the fundamental origin of the broadband absorption. The measured (at normal light incidence) absorption is over 90% in the wavelength range from 900 nm to 1825 nm, with high absorption persisting up to the incident angle of ~40°. The demonstrated thin-film absorber configuration is relatively easy to fabricate and can be realized with other properly selected materials. PMID:28000718

  9. Retinal safety of near-infrared lasers in cataract surgery

    NASA Astrophysics Data System (ADS)

    Wang, Jenny; Sramek, Christopher; Paulus, Yannis M.; Lavinsky, Daniel; Schuele, Georg; Anderson, Dan; Dewey, David; Palanker, Daniel

    2012-09-01

    Femtosecond lasers have added unprecedented precision and reproducibility to cataract surgery. However, retinal safety limits for the near-infrared lasers employed in surgery are not well quantified. We determined retinal injury thresholds for scanning patterns while considering the effects of reduced blood perfusion from rising intraocular pressure and retinal protection from light scattering on bubbles and tissue fragments produced by laser cutting. We measured retinal damage thresholds of a stationary, 1030-nm, continuous-wave laser with 2.6-mm retinal spot size for 10- and 100-s exposures in rabbits to be 1.35 W (1.26 to 1.42) and 0.78 W (0.73 to 0.83), respectively, and 1.08 W (0.96 to 1.11) and 0.36 W (0.33 to 0.41) when retinal perfusion is blocked. These thresholds were input into a computational model of ocular heating to calculate damage threshold temperatures. By requiring the tissue temperature to remain below the damage threshold temperatures determined in stationary beam experiments, one can calculate conservative damage thresholds for cataract surgery patterns. Light scattering on microbubbles and tissue fragments decreased the transmitted power by 88% within a 12 deg angle, adding a significant margin for retinal safety. These results can be used for assessment of the maximum permissible exposure during laser cataract surgery under various assumptions of blood perfusion, treatment duration, and scanning patterns.

  10. Electro-optic sampling of near-infrared waveforms

    NASA Astrophysics Data System (ADS)

    Keiber, Sabine; Sederberg, Shawn; Schwarz, Alexander; Trubetskov, Michael; Pervak, Volodymyr; Krausz, Ferenc; Karpowicz, Nicholas

    2016-03-01

    Access to the complete electric field evolution of a laser pulse is essential for attosecond science in general, and for the scrutiny and control of electron phenomena in solid-state physics specifically. Time-resolved field measurements are routine in the terahertz spectral range, using electro-optic sampling (EOS), photoconductive switches and field-induced second harmonic generation. EOS in particular features outstanding sensitivity and ease of use, making it the basis of time-resolved spectroscopic measurements for studying charge carrier dynamics and active optical devices. In this Letter, we show that careful optical filtering allows the bandwidth of this technique to be extended to wavelengths as short as 1.2 μm (230 THz) with half-cycle durations 2.3 times shorter than the sampling pulse. In a proof-of-principle application, we measure the influence of optical parametric amplification (OPA) on the electric field dynamics of a few-cycle near-infrared (NIR) pulse.

  11. Near-infrared plasmonics with transparent conducting oxides (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kim, Jongbum; Kinsey, Nathaniel; DeVault, Clayton; Dutta, Aveek; Ferrera, Marcello; Shalaev, Vladimir; Boltasseva, Alexandra

    2016-04-01

    As a result of the significant attention in searching for alternative plasmonic materials for real-life nanophotonic devices, transparent conducting oxides (TCOs) have been proposed as promising constituent building blocks for telecommunication wavelengths. They are eminently practical materials because they are CMOS-compatible, can be grown on many different types of substrates, patterned by standard fabrication procedures, and integrated with many other standard technologies. Due to the ability of TCO nanostructures to support strong plasmonic resonance in the near infrared (NIR), metasurface devices, such as a quarter wave plate, have been demonstrated whose properties can be easily adjustable with post processing such as thermal annealing. Additionally, TCOs can be used as epsilon near zero (ENZ) materials in the NIR. From our recent study of the behavior of nanoantennae sitting upon a TCO substrate, we found that TCOs serve as an optical insulating media due to the high impedance of TCOs at the ENZ frequency, enabling emission shaping. Finally, the optical properties of TCOs can be varied by optical or electrical means. Current research is focused on studying the ultrafast carrier dynamics in doped zinc oxide films using pump-probe spectroscopy. We have shown that aluminum doped zinc oxide films can achieve a 40% change in reflection with ultrafast dynamics (<1ps) under a small fluence of 3mJ/cm2. Consequently, TCOs are shown to be extremely flexible materials, enabling fascinating physics and unique devices for applications in the NIR regime.

  12. Optically guided neuronal growth at near-infrared wavelengths

    NASA Astrophysics Data System (ADS)

    Stevenson, D. J.; Lake, T. K.; Agate, B.; Garcés-Chávez, V.; Dholakia, K.; Gunn-Moore, F.

    2006-08-01

    Recent work has indicated the potential of light to guide the growth cones of neuronal cells using a Ti:Sapphire laser at 800 nm (Ehrlicher et al, PNAS, 2002). We have developed an optical set-up that has allowed, for the first time, the direct comparison of this process at near infrared wavelengths. A high number of growth cones were studied in order to provide a detailed statistical analysis. Actively extending growth cones of the neuroblastoma cell-line, NG108, can be guided at not only 780 nm, but also at 1064 nm. These wavelengths are an appropriate choice for guidance experiments, as wavelengths in the visible spectrum and UV are highly absorbing by cells and lead to death by phototoxicity and thermal stress. At 780 nm, 47% of actively extending growth cones were found to turn towards the focused incident light by at least 30° (n=32 growth cones). At 1064 nm, 61% of cells were successfully guided (n=31 growth cones). This suggests that the light detection mechanism within the cell is not due a single protein with a defined activity wavelength as occurs for example with the photoreceptor family of opsin proteins in the mammalian eye. We present two novel mechanisms of light induced neuronal guidance which are not related to temperature increases, or optical tweezing of the growth cone. We are also now identifying the signaling pathways that mediate this phenomenon.

  13. Functional data analysis view of functional near infrared spectroscopy data.

    PubMed

    Barati, Zeinab; Zakeri, Issa; Pourrezaei, Kambiz

    2013-11-01

    Functional near infrared spectroscopy (fNIRS) is a powerful tool for the study of oxygenation and hemodynamics of living tissues. Despite the continuous nature of the processes generating the data, analysis of fNIRS data has been limited to discrete-time methods. We propose a technique, namely functional data analysis (fDA), that converts discrete samples to continuous curves. We used fNIRS data collected on forehead during a cold pressor test (CPT) from 20 healthy subjects. Using functional principal component analysis, oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) curves were decomposed into several components based on variability across the subjects. Each component corresponded to an experimental condition and provided qualitative and quantitative information of the shape and weight of that component. Furthermore, we applied functional canonical correlation analysis to investigate the interaction between Hb and HbO2 curves. We showed that the variation of Hb and HbO2 was positively correlated during the CPT, with a "far" channel on right forehead showing a smaller and faster HbO2 variation than Hb. This research suggests the fDA platform for the analysis of fNIRS data, which solves problem of high dimensionality, enables study of response dynamics, enhances characterization of the evoked response, and may improve design of future fNIRS experiments.

  14. A near-Infrared SETI Experiment: Alignment and Astrometric precision

    NASA Astrophysics Data System (ADS)

    Duenas, Andres; Maire, Jerome; Wright, Shelley; Drake, Frank D.; Marcy, Geoffrey W.; Siemion, Andrew; Stone, Remington P. S.; Tallis, Melisa; Treffers, Richard R.; Werthimer, Dan

    2016-06-01

    Beginning in March 2015, a Near-InfraRed Optical SETI (NIROSETI) instrument aiming to search for fast nanosecond laser pulses, has been commissioned on the Nickel 1m-telescope at Lick Observatory. The NIROSETI instrument makes use of an optical guide camera, SONY ICX694 CCD from PointGrey, to align our selected sources into two 200µm near-infrared Avalanche Photo Diodes (APD) with a field-of-view of 2.5"x2.5" each. These APD detectors operate at very fast bandwidths and are able to detect pulse widths extending down into the nanosecond range. Aligning sources onto these relatively small detectors requires characterizing the guide camera plate scale, static optical distortion solution, and relative orientation with respect to the APD detectors. We determined the guide camera plate scale as 55.9+- 2.7 milli-arcseconds/pixel and magnitude limit of 18.15mag (+1.07/-0.58) in V-band. We will present the full distortion solution of the guide camera, orientation, and our alignment method between the camera and the two APDs, and will discuss target selection within the NIROSETI observational campaign, including coordination with Breakthrough Listen.

  15. Near-infrared light activated delivery platform for cancer therapy.

    PubMed

    Lin, Min; Gao, Yan; Hornicek, Francis; Xu, Feng; Lu, Tian Jian; Amiji, Mansoor; Duan, Zhenfeng

    2015-12-01

    Cancer treatment using conventional drug delivery platforms may lead to fatal damage to normal cells. Among various intelligent delivery platforms, photoresponsive delivery platforms are becoming popular, as light can be easily focused and tuned in terms of power intensity, wavelength, and irradiation time, allowing remote and precise control over therapeutic payload release both spatially and temporally. This unprecedented controlled delivery manner is important to improve therapeutic efficacy while minimizing side effects. However, most of the existing photoactive delivery platforms require UV/visible excitation to initiate their function, which suffers from phototoxicity and low level of tissue penetration limiting their practical applications in biomedicine. With the advanced optical property of converting near infrared (NIR) excitation to localized UV/visible emission, upconversion nanoparticles (UCNPs) have emerged as a promising photoactive delivery platform that provides practical applications for remote spatially and temporally controlled release of therapeutic payload molecules using low phototoxic and high tissue penetration NIR light as the excitation source. This article reviews the state-of-the-art design, synthesis and therapeutic molecular payload encapsulation strategies of UCNP-based photoactive delivery platforms for cancer therapy. Challenges and promises for engineering of advanced delivery platforms are also highlighted.

  16. Fully Automated Lipid Pool Detection Using Near Infrared Spectroscopy

    PubMed Central

    Wojakowski, Wojciech

    2016-01-01

    Background. Detecting and identifying vulnerable plaque, which is prone to rupture, is still a challenge for cardiologist. Such lipid core-containing plaque is still not identifiable by everyday angiography, thus triggering the need to develop a new tool where NIRS-IVUS can visualize plaque characterization in terms of its chemical and morphologic characteristic. The new tool can lead to the development of new methods of interpreting the newly obtained data. In this study, the algorithm to fully automated lipid pool detection on NIRS images is proposed. Method. Designed algorithm is divided into four stages: preprocessing (image enhancement), segmentation of artifacts, detection of lipid areas, and calculation of Lipid Core Burden Index. Results. A total of 31 NIRS chemograms were analyzed by two methods. The metrics, total LCBI, maximal LCBI in 4 mm blocks, and maximal LCBI in 2 mm blocks, were calculated to compare presented algorithm with commercial available system. Both intraclass correlation (ICC) and Bland-Altman plots showed good agreement and correlation between used methods. Conclusions. Proposed algorithm is fully automated lipid pool detection on near infrared spectroscopy images. It is a tool developed for offline data analysis, which could be easily augmented for newer functions and projects. PMID:27610191

  17. NEAR-INFRARED LINEAR POLARIZATION OF ULTRACOOL DWARFS

    SciTech Connect

    Zapatero Osorio, M. R.; Bejar, V. J. S.; Rebolo, R.; Acosta-Pulido, J. A.; Manchado, A.; Pena Ramirez, K.; Caballero, J. A. E-mail: vbejar@iac.es E-mail: jaa@iac.es E-mail: karla@iac.es E-mail: caballero@cab.inta-csic.es

    2011-10-10

    We report on near-infrared J- and H-band linear polarimetric photometry of eight ultracool dwarfs (two late-M, five L0-L7.5, and one T2.5) with known evidence for photometric variability due to dust clouds, anomalous red infrared colors, or low-gravity atmospheres. The polarimetric data were acquired with the LIRIS instrument on the William Herschel Telescope. We also provide mid-infrared photometry in the interval 3.4-24 {mu}m for some targets obtained with Spitzer and WISE, which has allowed us to confirm the peculiar red colors of five sources in the sample. We can impose modest upper limits of 0.9% and 1.8% on the linear polarization degree for seven targets with a confidence of 99%. Only one source, 2MASS J02411151-0326587 (L0), appears to be strongly polarized (P {approx} 3%) in the J band with a significance level of P/{sigma}{sub P} {approx} 10. The likely origin of its linearly polarized light and rather red infrared colors may reside in a surrounding disk with an asymmetric distribution of grains. Given its proximity (66 {+-} 8 pc), this object becomes an excellent target for the direct detection of the disk.

  18. Rapid analysis of Radix puerariae by near-infrared spectroscopy.

    PubMed

    Lau, Ching-Ching; Chan, Chi-On; Chau, Foo-Tim; Mok, Daniel Kam-Wah

    2009-03-13

    A new, rapid analytical method using near-infrared spectroscopy (NIRS) was developed to differentiate two species of Radix puerariae (GG), Pueraria lobata (YG) and Pueraria thomsonii (FG), and to determine the contents of puerarin, daidzin and total isoflavonoid in the samples. Five isoflavonoids, puerarin, daidzin, daidzein, genistin and genistein were analyzed simultaneously by high-performance liquid chromatography-diode array detection (HPLC-DAD). The total isoflavonoid content was exploited as critical parameter for successful discrimination of the two species. Scattering effect and baseline shift in the NIR spectra were corrected and the spectral features were enhanced by several pre-processing methods. By using linear discriminant analysis (LDA) and soft independent modeling class analogy (SIMCA), samples were separated successfully into two different clusters corresponding to the two GG species. Furthermore, sensitivity and specificity of the classification models were determined to evaluate the performance. Finally, partial least squares (PLS) regression was used to build the correlation models. The results showed that the correlation coefficients of the prediction models are R=0.970 for the puerarin, R=0.939 for daidzin and R=0.969 for total isoflavonoid. The outcome showed that NIRS can serve as routine screening in the quality control of Chinese herbal medicine (CHM).

  19. Turbid Media Extinction Coefficient for Near-Infrared Laser Radiation

    NASA Astrophysics Data System (ADS)

    Dreischuh, T.; Gurdev, L.; Vankov, O.; Stoyanov, D.; Avramov, L.

    2015-03-01

    In this work, extended investigations are performed of the extinction coefficient of Intralipid-20% dilutions in distilled water depending on the Intralipid concentration, for laser radiation wavelengths in the red and near-infrared regions covering the so-called tissue optical window. The extinction is measured by using an approach we have developed recently based on the features of the spatial intensity distribution of laser-radiation beams propagating through semi-infinite turbid media. The measurements are conducted using separately two dilution- containing plexiglass boxes of different sizes and volumes, in order to prove the appropriateness of the assumption of semi-infinite turbid medium. The experimental results for the extinction are in agreement with our previous results and with empiric formulae found by other authors concerning the wavelength dependence of the scattering coefficient of Intralipid - 10% and Intralipid - 20%. They are also in agreement with known data of the water absorptance. It is estimated as well that the wavelengths around 1320 nm would be advantageous for deep harmless sensing and diagnostics of tissues.

  20. Near infrared light responsive hybrid nanoparticles for synergistic therapy.

    PubMed

    Liang, Yan; Gao, Wenxia; Peng, Xinyu; Deng, Xin; Sun, Changzhen; Wu, Huayue; He, Bin

    2016-09-01

    A near infrared (NIR) light responsive chromophore 7-(diethylamino)-4-(hydroxymethyl)-2H-chromen-2-one (DEACM) was synthesized and incorporated to β-cyclodextrins with cRGD functionalized poly(ethylene glycol), the amphiphiles were coordinated with Au nanorods or nanoparticles to load anticancer drug doxorubicin (DOX) for fabricating hybrid nanoparticles. The π-π stacking interaction between DEACM and DOX was formed in the hybrid nanoparticles, which contributed to the high drug loading content. The Au nanorods or nanoparticles enhanced the photosolvolysis of DEACM under the irradiation of NIR with 808 nm wavelength and triggered the accelerated drug release from the nanoparticles. The drug loaded hybrid nanoparticles with NIR irradiation exhibited efficient inhibition effect on the proliferation of 4T1 breast cancer cells in vitro. The in vivo anticancer activity study on breast cancer bearing mice revealed that the hybrid nanoparticles containing Au nanorods exhibited excellent anticancer activity under the irradiation of 808 nm wavelength NIR with 800 mW.

  1. Studying hot exozodiacal dust with near-infrared interferometry

    NASA Astrophysics Data System (ADS)

    Absil, Olivier; Defrère, Denis; Le Bouquin, Jean-Baptiste; Mollier, Benjamin; Augereau, Jean-Charles; Coudé du Foresto, Vincent; Di Folco, Emmanuel; Ertel, Steve; ten Brummelaar, Theo

    2012-07-01

    Since our first detection of a resolved near-infrared emission around the main sequence star Vega, which we identified as the signature of hot dust grains close to the sublimation limit, we have been systematically searching for similar signatures around a magnitude-limited sample of nearby main sequence stars with the FLUOR instrument at the CHARA array. About 40 targets with spectral types ranging from A to K have been observed within the last 6 years, leading to first statistical trends on the occurence of the bright exozodi phenomenon as a function of spectral type. Our target sample is balanced between stars known to harbour cold dust populations from space-based missions (e.g., Spitzer, Herschel) and stars without cold dust, so that the occurence of abundant hot dust can also be correlated with the presence of large reservoirs of cold planetesimals. In this paper, we present preliminary conclusions from the CHARA/FLUOR survey. We also discuss the first results obtained in 2011/2012 with the new PIONIER visiting instrument at the VLTI, which is now used to extend our survey sample to the Southern hemisphere and to fainter targets. A first measurement of the exozodi/star flux ratio as a function of wavelength within the H band is presented, thanks to the low spectral resolution capability of PIONIER. Finally, we also briefly discuss our plans for extending the survey to fainter targets in the Northern hemisphere with an upgraded version of the FLUOR beam combiner.

  2. Near-infrared mapping spectrometer optical subsystem development and testing

    NASA Technical Reports Server (NTRS)

    Macenka, S. A.

    1983-01-01

    The Near-Infrared Mapping Spectrometer (NIMS) is one of the four remote-sensing science instruments of the Galileo Orbiter scientific payload. The NIMS scientific objectives require operating the detector and optical subsystem at cryogenic temperatures. The necessity of assembling, aligning, and testing the optics at room temperature and meeting design specifications at the cryogenic operating temperature (130 K) presented a set of challenging technical problems. A systematic approach to the development of athermalized mounts and supporting structures for optical components is described. A technique utilizing the visible spectral range and supplementary ray-trace information for alignment of an infrared instrument is presented. The optical subsystem point-spread function and spatial and spectral resolution were determined at room temperature using selected spectral and spatial targets. Based on thermal-distortion analyses of the structure and mounts, compensators were selected, implemented, and verified at cryogenic temperatures. The selection of the compensator and the overall system performance were verified in a thermal vacuum chamber. Various external and internal calibration targets were used.

  3. Silicon photonic crystal thermal emitter at near-infrared wavelengths.

    PubMed

    O'Regan, Bryan J; Wang, Yue; Krauss, Thomas F

    2015-08-21

    Controlling thermal emission with resonant photonic nanostructures has recently attracted much attention. Most of the work has concentrated on the mid-infrared wavelength range and/or was based on metallic nanostructures. Here, we demonstrate the experimental operation of a resonant thermal emitter operating in the near-infrared (≈1.5 μm) wavelength range. The emitter is based on a doped silicon photonic crystal consisting of a two dimensional square array of holes and using silicon-on-insulator technology with a device-layer thickness of 220 nm. The device is resistively heated by passing current through the photonic crystal membrane. At a temperature of ≈1100 K, we observe relatively sharp emission peaks with a Q factor around 18. A support structure system is implemented in order to achieve a large area suspended photonic crystal thermal emitter and electrical injection. The device demonstrates that weak absorption together with photonic resonances can be used as a wavelength-selection mechanism for thermal emitters, both for the enhancement and the suppression of emission.

  4. Sensitivity analysis of near-infrared functional lymphatic imaging

    PubMed Central

    Weiler, Michael; Kassis, Timothy

    2012-01-01

    Abstract. Near-infrared imaging of lymphatic drainage of injected indocyanine green (ICG) has emerged as a new technology for clinical imaging of lymphatic architecture and quantification of vessel function, yet the imaging capabilities of this approach have yet to be quantitatively characterized. We seek to quantify its capabilities as a diagnostic tool for lymphatic disease. Imaging is performed in a tissue phantom for sensitivity analysis and in hairless rats for in vivo testing. To demonstrate the efficacy of this imaging approach to quantifying immediate functional changes in lymphatics, we investigate the effects of a topically applied nitric oxide (NO) donor glyceryl trinitrate ointment. Premixing ICG with albumin induces greater fluorescence intensity, with the ideal concentration being 150  μg/mL ICG and 60  g/L albumin. ICG fluorescence can be detected at a concentration of 150  μg/mL as deep as 6 mm with our system, but spatial resolution deteriorates below 3 mm, skewing measurements of vessel geometry. NO treatment slows lymphatic transport, which is reflected in increased transport time, reduced packet frequency, reduced packet velocity, and reduced effective contraction length. NIR imaging may be an alternative to invasive procedures measuring lymphatic function in vivo in real time. PMID:22734775

  5. Measurement of subcutaneous adipose tissue thickness by near-infrared.

    PubMed

    Wang, Yu; Yang, Zeqiang; Hao, Dongmei; Zhang, Song; Yang, Yimin; Zeng, Yanjun

    2013-06-01

    Obesity is strongly associated with the risks of diabetes and cardiovascular disease, and there is a need to measure the subcutaneous adipose tissue (SAT) layer thickness and to understand the distribution of body fat. A device was designed to illuminate the body parts by near-infrared (NIR), measure the backscattered light, and predict the SAT layer thickness. The device was controlled by a single-chip microcontroller (SCM), and the thickness value was presented on a liquid crystal display (LCD). There were 30 subjects in this study, and the measurements were performed on 14 body parts for each subject. The paper investigated the impacts of pressure and skin colour on the measurement. Combining with principal component analysis (PCA) and support vector regression (SVR), the measurement accuracy of SAT layer thickness was 89.1 % with a mechanical caliper as reference. The measuring range was 5-11 mm. The study provides a non-invasive and low-cost technique to detect subcutaneous fat thickness, which is more accessible and affordable compared to other conventional techniques. The designed device can be used at home and in community.

  6. GMTNIRS (Giant Magellan Telescope near-infrared spectrograph): design concept

    NASA Astrophysics Data System (ADS)

    Lee, Sungho; Yuk, In-Soo; Lee, Hanshin; Wang, Weisong; Park, Chan; Park, Kwi-Jong; Chun, Moo-Young; Pak, Soojong; Strubhar, Joseph; Deen, Casey; Gully-Santiago, Michael; Rand, Jared; Seo, Haingja; Kwon, Jungmi; Oh, Heeyoung; Barnes, Stuart; Lacy, John; Goertz, John; Park, Won-Kee; Pyo, Tae-Soo; Jaffe, Daniel T.

    2010-07-01

    We are designing a sensitive high resolution (R=60,000-100,000) spectrograph for the Giant Magellan Telescope (GMTNIRS, the GMT Near-Infrared Spectrograph). Using large-format IR arrays and silicon immersion gratings, this instrument will cover all of the J (longer than 1.1 μm), H, and K atmospheric windows or all of the L and M windows in a single exposure. GMTNIRS makes use of the GMT adaptive optics system for all bands. The small slits will offer the possibility of spatially resolved spectroscopy as well as superior sensitivity and wavelength coverage. The GMTNIRS team is composed of scientists and engineers at the University of Texas, the Korea Astronomy and Space Science Institute, and Kyung Hee University. In this paper, we describe the optical and mechanical design of the instrument. The principal innovative feature of the design is the use of silicon immersion gratings which are now being produced by our team with sufficient quality to permit designs with high resolving power and broad instantaneous wavelength coverage across the near-IR.

  7. Prototype Nerve-Specific Near-Infrared Fluorophores

    PubMed Central

    Park, Min Ho; Hyun, Hoon; Ashitate, Yoshitomo; Wada, Hideyuki; Park, GwangLi; Lee, Jeong Heon; Njiojob, Costyl; Henary, Maged; Frangioni, John V.; Choi, Hak Soo

    2014-01-01

    Nerve preservation is an important issue during most surgery because accidental transection or injury results in significant morbidity, including numbness, pain, weakness, or paralysis. Currently, nerves are still identified only by gross appearance and anatomical location during surgery, without intraoperative image guidance. Near-infrared (NIR) fluorescent light, in the wavelength range of 650-900 nm, has the potential to provide high-resolution, high-sensitivity, and real-time avoidance of nerve damage, but only if nerve-specific NIR fluorophores can be developed. In this study, we evaluated a series of Oxazine derivatives to highlight various peripheral nerve structures in small and large animals. Among the targeted fluorophores, Oxazine 4 has peak emission near into the NIR, which provided nerve-targeted signal in the brachial plexus and sciatic nerve for up to 12 h after a single intravenous injection. In addition, recurrent laryngeal nerves were successfully identified and highlighted in real time in swine, which could be preserved during the course of thyroid resection. Although optical properties of these agents are not yet optimal, chemical structure analysis provides a basis for improving these prototype nerve-specific NIR fluorophores even further. PMID:24955143

  8. Textile integrated sensors and actuators for near-infrared spectroscopy.

    PubMed

    Zysset, Christoph; Nasseri, Nassim; Büthe, Lars; Münzenrieder, Niko; Kinkeldei, Thomas; Petti, Luisa; Kleiser, Stefan; Salvatore, Giovanni A; Wolf, Martin; Tröster, Gerhard

    2013-02-11

    Being the closest layer to our body, textiles provide an ideal platform for integrating sensors and actuators to monitor physiological signals. We used a woven textile to integrate photodiodes and light emitting diodes. LEDs and photodiodes enable near-infrared spectroscopy (NIRS) systems to monitor arterial oxygen saturation and oxygenated and deoxygenated hemoglobin in human tissue. Photodiodes and LEDs are mounted on flexible plastic strips with widths of 4 mm and 2 mm, respectively. The strips are woven during the textile fabrication process in weft direction and interconnected with copper wires with a diameter of 71 μm in warp direction. The sensor textile is applied to measure the pulse waves in the fingertip and the changes in oxygenated and deoxygenated hemoglobin during a venous occlusion at the calf. The system has a signal-to-noise ratio of more than 70 dB and a system drift of 0.37% ± 0.48%. The presented work demonstrates the feasibility of integrating photodiodes and LEDs into woven textiles, a step towards wearable health monitoring devices.

  9. Application of near infrared spectroscopy to predict plant diseases

    NASA Astrophysics Data System (ADS)

    Xu, Huirong; Ying, Yibin; Ye, Zunzhong

    2005-11-01

    The objectives of this study were to characterize leaf reflectance spectra of tomato leaves damaged by leaf miner and to determine those leaf reflectance wavelengths that were most responsive to plant damage caused by the pest. Near infrared (NIR) Spectral characteristics of single tomato leaves at various levels of infestation by the leaf miner, were measured and analyzed using a spectrometer. Tomato leaf damage was classified into five scales, i.e., 0 (no damage), 1 (light damaged), 2 (10-25% damaged), 3 (more than 25% damaged), and 4 (severe damaged), based on the scale of infestation displayed on the surfaces of plant parts. Spectral parameter such as reflectance sensitivity was used to find the optimal wavelengths to determining and evaluating the damage level. Results showed that there were significant differences in reflectance among infestations at wavelengths of 1450nm and 1900 nm particularly. The determining coefficients (R2) for a linear relationship were 0.98 and 0.91 for the spectral-infestation levels relations. Thus, both of these wavelengths were good indicators of leaf senescence caused by the leaf miner.

  10. Near infrared spectroscopy based brain-computer interface

    NASA Astrophysics Data System (ADS)

    Ranganatha, Sitaram; Hoshi, Yoko; Guan, Cuntai

    2005-04-01

    A brain-computer interface (BCI) provides users with an alternative output channel other than the normal output path of the brain. BCI is being given much attention recently as an alternate mode of communication and control for the disabled, such as patients suffering from Amyotrophic Lateral Sclerosis (ALS) or "locked-in". BCI may also find applications in military, education and entertainment. Most of the existing BCI systems which rely on the brain's electrical activity use scalp EEG signals. The scalp EEG is an inherently noisy and non-linear signal. The signal is detrimentally affected by various artifacts such as the EOG, EMG, ECG and so forth. EEG is cumbersome to use in practice, because of the need for applying conductive gel, and the need for the subject to be immobile. There is an urgent need for a more accessible interface that uses a more direct measure of cognitive function to control an output device. The optical response of Near Infrared Spectroscopy (NIRS) denoting brain activation can be used as an alternative to electrical signals, with the intention of developing a more practical and user-friendly BCI. In this paper, a new method of brain-computer interface (BCI) based on NIRS is proposed. Preliminary results of our experiments towards developing this system are reported.

  11. Near-infrared spectroscopy for burning plasma diagnostic applications.

    PubMed

    Soukhanovskii, V A

    2008-10-01

    Ultraviolet and visible (UV-VIS, 200-750 nm) atomic spectroscopy of neutral and ionized fuel species (H, D, T, and Li) and impurities (e.g., He, Be, C, and W) is a key element of plasma control and diagnosis on International Thermonuclear Experimental Reactor and future magnetically confined burning plasma experiments (BPXs). Spectroscopic diagnostic implementation and performance issues that arise in the BPX harsh nuclear environment in the UV-VIS range, e.g., degradation of first mirror reflectivity under charge-exchange atom bombardment (erosion) and impurity deposition, permanent and dynamic loss of window, and optical fiber transmission under intense neutron and gamma-ray fluxes, are either absent or not as severe in the near-infrared (NIR, 750-2000 nm) range. An initial survey of NIR diagnostic applications has been undertaken on the National Spherical Torus Experiment. It is demonstrated that NIR spectroscopy can be used for machine protection and plasma control applications, as well as contribute to plasma performance evaluation and physics studies. Emission intensity estimates demonstrate that NIR measurements are possible in the BPX plasma operating parameter range. Complications in the NIR range due to the parasitic background emissions are expected to occur at very high plasma densities, low impurity densities, and at high plasma-facing component temperatures.

  12. Motion in Jupiter's Atmospheric Vortices (Near-infrared filters)

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Two frame 'movie' of a pair of vortices in Jupiter's southern hemisphere. The two frames are separated by ten hours. The right oval is rotating counterclockwise, like other anticyclonic bright vortices in Jupiter's atmosphere. The left vortex is a cyclonic (clockwise) vortex. The differences between them (their brightness, their symmetry, and their behavior) are clues to how Jupiter's atmosphere works. The frames span about fifteen degrees in latitude and longitude and are centered at 141 degrees west longitude and 36 degrees south planetocentric latitude. Both vortices are about 3500 kilometers in diameter in the north-south direction.

    The images were taken in near infrared light at 756 nanometers and show clouds that are at a pressure level of about 1 bar in Jupiter's atmosphere. North is at the top. The smallest resolved features are tens of kilometers in size. These images were taken on May 7, 1997, at a range of 1.5 million kilometers by the Solid State Imaging system on NASA's Galileo spacecraft.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  13. Fluorescence lifetime imaging with near-infrared dyes

    NASA Astrophysics Data System (ADS)

    Becker, Wolfgang; Shcheslavskiy, Vladislav

    2013-02-01

    Near-infrared (NIR) dyes are used as fluorescence markers in small-animal imaging and in diffuse optical tomography of the human brain. In these applications it is important to know whether the dyes bind to proteins or other tissue constituents, and whether their fluorescence lifetimes depend on the targets they are bound to. Unfortunately, neither the lasers nor the detectors of commonly used confocal and multiphoton laser scanning microscopes allow for excitation and detection of NIR fluorescence. We therefore upgraded existing confocal TCSPC FLIM systems with NIR lasers and NIR sensitive detectors. In multiphoton systems we used the Ti:Sa laser as a one-photon excitation source in combination with an NIR-sensitive detector in the confocal beam path. We tested a number of NIR dyes in biological tissue. Some of them showed clear lifetime changes depending on the tissue structures they are bound to. We therefore believe that NIR FLIM can deliver supplementary information on the tissue constitution and on local biochemical parameters.

  14. Near-infrared (NIR) up-conversion optogenetics

    NASA Astrophysics Data System (ADS)

    Hososhima, Shoko; Yuasa, Hideya; Ishizuka, Toru; Hoque, Mohammad Razuanul; Yamashita, Takayuki; Yamanaka, Akihiro; Sugano, Eriko; Tomita, Hiroshi; Yawo, Hiromu

    2015-11-01

    Non-invasive remote control technologies designed to manipulate neural functions have been long-awaited for the comprehensive and quantitative understanding of neuronal network in the brain as well as for the therapy of neurological disorders. Recently, it has become possible for the neuronal activity to be optically manipulated using biological photo-reactive molecules such as channelrhodopsin (ChR)-2. However, ChR2 and its relatives are mostly reactive to visible light, which does not effectively penetrate through biological tissues. In contrast, near-infrared (NIR) light (650-1450 nm) penetrates deep into the tissues because biological systems are almost transparent to light within this so-called ‘imaging window’. Here we used lanthanide nanoparticles (LNPs), composed of rare-earth elements, as luminous bodies to activate ChRs since they absorb low-energy NIR light to emit high-energy visible light (up-conversion). Here, we created a new type of optogenetic system which consists of the donor LNPs and the acceptor ChRs. The NIR laser irradiation emitted visible light from LNPs, then induced the photo-reactive responses in the near-by cells that expressed ChRs. However, there remains room for large improvements in the energy efficiency of the LNP-ChR system.

  15. Novel near infrared sensors for hybrid BCI applications

    NASA Astrophysics Data System (ADS)

    Almajidy, Rand K.; Le, Khang S.; Hofmann, Ulrich G.

    2015-07-01

    This study's goal is to develop a low cost, portable, accurate and comfortable NIRS module that can be used simultaneously with EEG in a dual modality system for brain computer interface (BCI). The sensing modules consist of electroencephalography (EEG) electrodes (at the positions Fp1, Fpz and Fp2 in the international 10-20 system) with eight custom made functional near infrared spectroscopy (fNIRS) channels, positioned on the prefrontal cortex area with two extra channels to measure and eliminate extra-cranial oxygenation. The NIRS sensors were designed to guarantee good sensor-skin contact, without causing subject discomfort, using springs to press them to the skin instead of pressing them by cap fixture. Two open source software packages were modified to carry out dual modality hybrid BCI experiments. The experimental paradigm consisted of a mental task (arithmetic task or text reading) and a resting period. Both oxygenated hemoglobin concentration changes (HbO), and EEG signals showed an increase during the mental task, but the onset, period and amount of that increase depends on each modality's characteristics. The subject's degree of attention played an important role especially during online sessions. The sensors can be easily used to acquire brain signals from different cerebral cortex parts. The system serves as a simple technological test bed and will be used for stroke patient rehabilitation purposes.

  16. Retinal-Based Proton Pumping in the Near Infrared

    PubMed Central

    2017-01-01

    Proteorhodopsin (PR) and Gloeobacter rhodopsin (GR) are retinal-based light-driven proton pumps that absorb visible light (maxima at 520–540 nm). Shifting the action spectra of these proton pumps beyond 700 nm would generate new prospects in optogenetics, membrane sensor technology, and complementation of oxygenic phototrophy. We therefore investigated the effect of red-shifting analogues of retinal, combined with red-shifting mutations, on the spectral properties and pump activity of the resulting pigments. We investigated a variety of analogues, including many novel ones. One of the novel analogues we tested, 3-methylamino-16-nor-1,2,3,4-didehydroretinal (MMAR), produced exciting results. This analogue red-shifted all of the rhodopsin variants tested, accompanied by a strong broadening of the absorbance band, tailing out to 850–950 nm. In particular, MMAR showed a strong synergistic effect with the PR-D212N,F234S double mutant, inducing an astonishing 200 nm red shift in the absorbance maximum. To our knowledge, this is by far the largest red shift reported for any retinal protein. Very importantly, all MMAR-containing holoproteins are the first rhodopsins retaining significant pump activity under near-infrared illumination (730 nm light-emitting diode). Such MMAR-based rhodopsin variants present very promising opportunities for further synthetic biology modification and for a variety of biotechnological and biophysical applications. PMID:28094925

  17. Optical bench assembly for the near-infrared camera

    NASA Astrophysics Data System (ADS)

    Nordt, Alison; Edinger, Derek

    2005-08-01

    The Near Infrared Camera is the primary imaging instrument on the James Webb Space Telescope. This instrument operates in the wavelength range of 0.6 to 5 microns and at a temperature of 35K. Two mirror-image optical paths or modules are utilized to provide two adjacent fields of view for science observations and redundancy for the purpose of wavefront sensing. All optical components are supported and aligned by an Optical Bench Assembly consisting of two benches mounted back to back. Each optical bench is a closed back Beryllium structure optimized for mass and stiffness. The closed back structure is achieved by bonding two machined parts together at the midplane of the structure. Each bench half is an open back structure consisting of a facesheet with machined ribs optimized to provide stiffness and to support along primary load paths. The two benches are integrated with optical components separately and are subsequently joined by bolts and pins to form the Optical Bench Assembly. The assembly is then mounted to interface struts, which are used to mount the instrument within the Integrated Science Instrument Module for integration into the JWST observatory. The design of the Optical Bench Assembly is describing including trade studies and analysis results.

  18. Near-infrared free carrier absorption in heavily doped silicon

    SciTech Connect

    Baker-Finch, Simeon C.; McIntosh, Keith R.; Yan, Di; Fong, Kean Chern; Kho, Teng C.

    2014-08-14

    Free carrier absorption in heavily doped silicon can have a significant impact on devices operating in the infrared. In the near infrared, the free carrier absorption process can compete with band to band absorption processes, thereby reducing the number of available photons to optoelectronic devices such as solar cells. In this work, we fabricate 18 heavily doped regions by phosphorus and boron diffusion into planar polished silicon wafers; the simple sample structure facilitates accurate and precise measurement of the free carrier absorptance. We measure and model reflectance and transmittance dispersion to arrive at a parameterisation for the free carrier absorption coefficient that applies in the wavelength range between 1000 and 1500 nm, and the range of dopant densities between ∼10{sup 18} and 3 × 10{sup 20} cm{sup −3}. Our measurements indicate that previously published parameterisations underestimate the free carrier absorptance in phosphorus diffusions. On the other hand, published parameterisations are generally consistent with our measurements and model for boron diffusions. Our new model is the first to be assigned uncertainty and is well-suited to routine device analysis.

  19. LED-based near infrared sensor for cancer diagnostics

    NASA Astrophysics Data System (ADS)

    Bogomolov, Andrey; Ageev, Vladimir; Zabarylo, Urszula; Usenov, Iskander; Schulte, Franziska; Kirsanov, Dmitry; Belikova, Valeria; Minet, Olaf; Feliksberger, E.; Meshkovsky, I.; Artyushenko, Viacheslav

    2016-03-01

    Optical spectroscopic technologies are increasingly used for cancer diagnostics. Feasibility of differentiation between malignant and healthy samples of human kidney using Fluorescence, Raman, MIR and NIR spectroscopy has been recently reported . In the present work, a simplification of NIR spectroscopy method has been studied. Traditional high-resolution NIR spectrometry was replaced by an optical sensor based on a set of light-emitting diodes at selected wavelengths as light sources and a photodiode. Two prototypes of the sensor have been developed and tested using 14 in-vitro samples of seven kidney tumor patients. Statistical evaluation of results using principal component analysis and partial least-squares discriminant analysis has been performed. Despite only partial discrimination between tumor and healthy tissue achieved by the presented new technique, the results evidence benefits of LED-based near-infrared sensing used for oncological diagnostics. Publisher's Note: This paper, originally published on 4 March, 2016, was replaced with a corrected/revised version on 7 April, 2016. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance.

  20. Visible and near infrared fluorescence spectral flow cytometry.

    PubMed

    Nolan, John P; Condello, Danilo; Duggan, Erika; Naivar, Mark; Novo, David

    2013-03-01

    There is a long standing interest in measuring complete emission spectra from individual cells in flow cytometry. We have developed flow cytometry instruments and analysis approaches to enable this to be done routinely and robustly. Our spectral flow cytometers use a holographic grating to disperse light from single cells onto a CCD for high speed, wavelength-resolved detection. Customized software allows the single cell spectral data to be displayed and analyzed to produce new spectra-derived parameters. We show that familiar reference and calibration beads can be employed to quantitatively assess instrument performance. We use microspheres stained with six different quantum dots to compare a virtual bandpass filter approach with classic least squares (CLS) spectral unmixing, and then use antibody capture beads and CLS unmixing to demonstrate immunophenotyping of peripheral blood mononuclear cells using spectral flow cytometry. Finally, we characterize and evaluate several near infrared (NIR) emitting fluorophores for use in spectral flow cytometry. Spectral flow cytometry offers a number of attractive features for single cell analysis, including a simplified optical path, high spectral resolution, and streamlined approaches to quantitative multiparameter measurements. The availability of robust instrumentation, software, and analysis approaches will facilitate the development of spectral flow cytometry applications.

  1. Near-Infrared Grating Spectrometer for Mobile Phone Applications.

    PubMed

    Pügner, Tino; Knobbe, Jens; Grüger, Heinrich

    2016-05-01

    Near-infrared (NIR) spectroscopy is a well-established technique for the chemical analysis of organic and inorganic matter. Accordingly, spectroscopic instrumentation of different complexity has been developed and is currently commercially available. However, there are an increasing number of new mobile applications that have come into focus and that cannot be addressed by the existing technology due to size and cost. Therefore, a new miniaturized scanning grating spectrometer for NIR spectroscopy has been developed at Fraunhofer IPMS. It is based on micro-electro-mechanical systems (MEMS) technology, and has been designed to meet the requirements for mobile application, regarding spectral range, resolution, overall size, robustness, and cost. The MEMS spectrometer covers a spectral range from 950 nm to 1900 nm at a resolution of 10 nm. The instrument is extremely small and has a volume of only 2.1 cm(3) Therefore, it is well suited for integration, even into a mobile phone. A first sample of the new spectrometer has been manufactured and put into operation. The results of a series of test measurements are in good agreement with the requirements and specifications.

  2. Standardization of near infrared spectra measured on multi-instrument.

    PubMed

    Liu, Yan; Cai, Wensheng; Shao, Xueguang

    2014-07-11

    Calibration model transfer is essential for practical applications of near infrared (NIR) spectroscopy because the measurements of the spectra may be performed on different instruments and the difference between the instruments must be corrected. An approach for calibration transfer based on alternating trilinear decomposition (ATLD) algorithm is proposed in this work. From the three-way spectral matrix measured on different instruments, the relative intensity of concentration, spectrum and instrument is obtained using trilinear decomposition. Because the relative intensity of instrument is a reflection of the spectral difference between instruments, the spectra measured on different instruments can be standardized by a correction of the coefficients in the relative intensity. Two NIR datasets of corn and tobacco leaf samples measured with three instruments are used to test the performance of the method. The results show that, for both the datasets, the spectra measured on one instrument can be correctly predicted using the partial least squares (PLS) models built with the spectra measured on the other instruments.

  3. Near-infrared spectroscopy: a methodology-focused review.

    PubMed

    Pellicer, Adelina; Bravo, María del Carmen

    2011-02-01

    Near infrared spectroscopy (NIRS) is a light-based technology used to monitor tissue oxygen status. Refinements to the method since it was first described have extended its applicability to different research and clinical settings due to its non-invasiveness, instrument portability and ease of use. Classic NIRS recordings, based in the Beer-Lambert law, can be used for the trend monitoring of changes in tissue perfusion-oxygenation parting from an arbitrary zero point. However, in order to derive intermittently quantitative values in absolute terms, certain manoeuvres must be performed. More recently, the evolution of the technique has led to the development of instruments that provide an absolute value of regional hemoglobin saturation in a continuous manner. This review will focus on the physical principles of tissue spectroscopy including a brief description of the different operating principles that are currently in use or under development. The theoretical details, experimental procedures and data analysis involved in the measurements of physiological variables using NIRS will be described. The future beyond the scope of NIRS and potential lines of research will also be discussed.

  4. Moisture influence on near-infrared prediction of wheat hardness

    NASA Astrophysics Data System (ADS)

    Windham, William R.; Gaines, Charles S.; Leffler, Richard G.

    1991-02-01

    Recently near infrared (NTR) reflectance instrumentation has been used to provide an empirical measure of wheat hardness. This hardness scale is based on the radiation scattering properties of meal particles at 1680 and 2230 nm. Hard wheats have a larger mean particles size (PS) after grinding than soft wheats. However wheat kernel moisture content can influence mean PS after grinding. The objective of this study was to determine the sensitivity of MR wheat hardness measurements to moisture content and to make the hardness score independent of moisture by correcting hardness measurements for the actual moisture content of measured samples. Forty wheat cultivars composed of hard red winter hard red spring soft red winter and soft white winter were used. Wheat kernel subsamples were stored at 20 40 60 and 80 relative humidity (RH). After equilibration samples were ground and the meal analyzed for hardness score (HS) and moisture. HS were 48 50 54 and 65 for 20 40 60 and 80 RH respectively. Differences in HS within each wheat class were the result of a moisture induced change in the PS of the meal. An algorithm was developed to correct HS to 11 moisture. This correction provides HS that are nearly independent of moisture content. 1.

  5. Sensitivity analysis of near-infrared functional lymphatic imaging

    NASA Astrophysics Data System (ADS)

    Weiler, Michael; Kassis, Timothy; Dixon, J. Brandon

    2012-06-01

    Near-infrared imaging of lymphatic drainage of injected indocyanine green (ICG) has emerged as a new technology for clinical imaging of lymphatic architecture and quantification of vessel function, yet the imaging capabilities of this approach have yet to be quantitatively characterized. We seek to quantify its capabilities as a diagnostic tool for lymphatic disease. Imaging is performed in a tissue phantom for sensitivity analysis and in hairless rats for in vivo testing. To demonstrate the efficacy of this imaging approach to quantifying immediate functional changes in lymphatics, we investigate the effects of a topically applied nitric oxide (NO) donor glyceryl trinitrate ointment. Premixing ICG with albumin induces greater fluorescence intensity, with the ideal concentration being 150 μg/mL ICG and 60 g/L albumin. ICG fluorescence can be detected at a concentration of 150 μg/mL as deep as 6 mm with our system, but spatial resolution deteriorates below 3 mm, skewing measurements of vessel geometry. NO treatment slows lymphatic transport, which is reflected in increased transport time, reduced packet frequency, reduced packet velocity, and reduced effective contraction length. NIR imaging may be an alternative to invasive procedures measuring lymphatic function in vivo in real time.

  6. Rapid Characterization of Tanshinone Extract Powder by Near Infrared Spectroscopy

    PubMed Central

    Luo, Gan; Xu, Bing; Shi, Xinyuan; Li, Jianyu; Dai, Shengyun; Qiao, Yanjiang

    2015-01-01

    Chemical and physical quality attributes of herbal extract powders play an important role in the research and development of Chinese medicine preparations. The active pharmaceutical ingredients have a direct impact on the herbal extract's efficacy, while the physical properties of raw material affect the pharmaceutical manufacturing process and the final products' quality. In this study, tanshinone extract powders from Salvia miltiorrhiza which are widely used for the treatment of cardiovascular diseases in the clinic are taken as the research object. Both the chemical information and physical information of tanshinone extract powders are analyzed by near infrared (NIR) spectroscopy. The partial least squares (PLS) and least square support vector machine (LS-SVM) models are investigated to build the relationship between NIR spectra and reference values. PLS models performed well for the content of crytotanshinone, tanshinone IIA, the moisture, and average median particle size, while, for specific surface area and tapped density, the LS-SVM models performed better than the PLS models. Results demonstrated NIR to be a valid and fast process analytical technology tool to simultaneously determine multiple quality attributes of herbal extract powders and indicated that there existed some nonlinear relationship between NIR spectra and physical quality attributes. PMID:25866511

  7. Constraining Type Ia Supernova Physics with Near-Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Sand, David; Valenti, Stefano; Howell, Andy; Graham, Melissa; Parrent, Jerod

    2014-02-01

    Despite their success as standardizable candles, relatively little is known about the exact progenitor(s) and explosion physics of type Ia supernovae -- a potential source of systematic uncertainty for future dark energy surveys, and a hole in our knowledge about stellar end-states. One promising route forward is the combination of dense optical time series and near-infrared (NIR) spectroscopic data sets. Recent work has suggested that the NIR can discern unburned carbon from the progenitor white dwarf more cleanly than in the optical, and its unique access to relatively unblended magnesium lines also probes the inner edge of carbon burning. Both measures provide a direct constraint for SN Ia explosion models, but only a handful of appropriate NIR spectroscopic time series exist. We propose to continue our campaign to roughly double the sample of SN Ia with such data (leveraging our access to a worldwide network of 1m imaging telescopes and twin robotic optical spectrographs) in order to begin to tackle our understanding of NIR spectral diagnostics and how they vary from supernova to supernova. Note that we were allocated time with Gemini South Flamingos-2 in 2013B, but have not triggered any ToO time yet, partially due to the persistent alignment issues with the On-Instrument Wave Front Sensor.

  8. Constraining Type Ia Supernova Physics with Near-Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Sand, David; Valenti, Stefano; Howell, Andy; Graham, Melissa; Parrent, Jerod

    2014-08-01

    Despite their success as standardizable candles, relatively little is known about the exact progenitor(s) and explosion physics of type Ia supernovae -- a potential source of systematic uncertainty for future dark energy surveys, and a hole in our knowledge about stellar end-states. One promising route forward is the combination of dense optical time series and near-infrared (NIR) spectroscopic data sets. Recent work has suggested that the NIR can discern unburned carbon from the progenitor white dwarf more cleanly than in the optical, and its unique access to relatively unblended magnesium lines also probes the inner edge of carbon burning. Both measures provide a direct constraint for SN Ia explosion models, but only a handful of appropriate NIR spectroscopic time series exist. We propose to continue our campaign to roughly double the sample of SN Ia with such data (leveraging our access to a worldwide network of 1m imaging telescopes and twin robotic optical spectrographs) in order to begin to tackle our understanding of NIR spectral diagnostics and how they vary from supernova to supernova. During our 2014A time thus far, we have been intensely following the nearest SN Ia in a generation -- SN 2014J -- and have already submitted our initial results.

  9. Quantitative analysis of ice films by near-infrared spectroscopy

    NASA Technical Reports Server (NTRS)

    Keiser, Joseph T.

    1990-01-01

    One of the outstanding problems in the Space Transportation System is the possibility of the ice buildup on the external fuel tank surface while it is mounted on the launch pad. During the T-2 hours (and holding) period, the frost/ice thickness on the external tank is monitored/measured. However, after the resumption of the countdown time, the tank surface can only be monitored remotely. Currently, remote sensing is done with a TV camera coupled to a thermal imaging device. This device is capable of identifying the presence of ice, especially if it is covered with a layer of frost. However, it has difficulty identifying transparent ice, and, it is not capable of determining the thickness of ice in any case. Thus, there is a need for developing a technique for measuring the thickness of frost/ice on the tank surface during this two hour period before launch. The external tank surface is flooded with sunlight (natural or simulated) before launch. It may be possible, therefore, to analyze the diffuse reflection of sunlight from the external tank to determine the presence and thickness of ice. The purpose was to investigate the feasibility of this approach. A near-infrared spectrophotometer was used to record spectra of ice. It was determined that the optimum frequencies for monitoring the ice films were 1.03 and 1.255 microns.

  10. Distributed Software for Observations in the Near Infrared

    NASA Astrophysics Data System (ADS)

    Gavryusev, V.; Baffa, C.; Giani, E.

    We have developed an integrated system that performs astronomical observations in Near Infrared bands operating two-dimensional instruments at the Italian National Infrared Facility's \\htmllink{ARNICA}{http://helios.arcetri.astro.it:/home/idefix/Mosaic/ instr/arnica/arnica.html} and \\htmllink{LONGSP}{http://helios.arcetri.astro.it:/home/idefix/Mosaic/ instr/longsp/longsp.html}. This software consists of several communicating processes, generally executed across a network, as well as on a single computer. The user interface is organized as widget-based X11 client. The interprocess communication is provided by sockets and uses TCP/IP. The processes denoted for control of hardware (telescope and other instruments) should be executed currently on a PC dedicated for this task under DESQview/X, while all other components (user interface, tools for the data analysis, etc.) can also work under UNIX\\@. The hardware independent part of software is based on the Athena Widget Set and is compiled by GNU C to provide maximum portability.

  11. Visible and Near Infrared Fluorescence Spectral Flow Cytometry

    PubMed Central

    Nolan, John P.; Condello, Danilo; Duggan, Erika; Naivar, Mark; Novo, David

    2013-01-01

    There is a long standing interest in measuring complete emission spectra from individual cells in flow cytometry. We have developed flow cytometry instruments and analysis approaches to enable this to be done routinely and robustly. Our spectral flow cytometers use a holographic grating to disperse light from single cells onto a CCD for high speed, wavelength-resolved detection. Customized software allows the single cell spectral data to be displayed and analyzed to produce new spectra-derived parameters. We show that familiar reference and calibration beads can be employed to quantitatively assess instrument performance. We use microspheres stained with six different quantum dots to compare a virtual bandpass filter approach with classic least squares (CLS) spectral unmixing, and then use antibody capture beads and CLS unmixing to demonstrate immunophenotyping of peripheral blood mononuclear cells using spectral flow cytometry. Finally, we characterize and evaluate several near infrared (NIR) emitting fluorophores for use in spectral flow cytometry. Spectral flow cytometry offers a number of attractive features for single cell analysis, including a simplified optical path, high spectral resolution, and streamlined approaches to quantitative multiparameter measurements. The availability of robust instrumentation, software, and analysis approaches will facilitate the development of spectral flow cytometry applications. PMID:23225549

  12. Near-infrared Photometry of the Open Cluster NGC 2420

    NASA Astrophysics Data System (ADS)

    Hejazi, Neda; De Robertis, Michael M.; Dawson, Peter C.

    2016-01-01

    Open clusters have been used in numerous studies of stellar formation and evolution and have provided important constraints on theoretical stellar models. In this study, we carried out deep near-infrared imaging (I, J, H and Ks bands) with the 1024×1024 CFHT-IR camera at the Cassegrain focus of the Canada-France-Hawaii 3.6 m telescope of two fields in the relatively old open cluster, NGC 2420. This cluster was selected due to its relatively low metallicity, [Fe/H] ˜ -0.5, and rather high Galactic latitude (for an open cluster), b ≈ 20°, reducing the effects of reddening as well as reducing the extent of contamination by non-members of the cluster. The empirical data were calibrated using 2MASS and Stetson standards in the field. Non-cluster stars were removed using a field-cluster decontamination algorithm. By fitting available theoretical isochrones to the observed color-magnitude diagrams, we have been able to estimate the age, metallicity and distance of the cluster which are compared to previous studies.

  13. Human skin detection in the visible and near infrared.

    PubMed

    Mendenhall, Michael J; Nunez, Abel S; Martin, Richard K

    2015-12-10

    Skin detection is a well-studied area in color imagery and is useful in a number of scenarios to include search and rescue and computer vision. Most approaches focus on color imagery due to cost and availability. Many of the visible-based approaches do well at detecting skin (above 90%) but they tend to have relatively high false-alarm rates (8%-15%). This article presents a novel feature space for skin detection in visible and near infrared portions of the electromagnetic spectrum. The features are derived from known spectral absorption of skin constituents to include hemoglobin, melanin, and water as well as scattering properties of the dermis. Fitting a Gaussian mixture to skin and background distributions and using a likelihood ratio test detector, the features presented here show dominating performance when comparing receiver-operating characteristic curves (ROCs) and statistically significant improvement when comparing equal error rates and area under the ROC (AUC). A detection/false-alarm probability of 98.6%/1.1% is achieved for the averaged equal error rate (EER). EER values for the proposed feature space show a 5.6%-11.2% increase in detection probability with a 6.0%-11.6% decrease in false-alarm probability compared to well performing color-based features. The AUC shows a 0.034-0.173 increase in total area under the curve compared to well performing color-based features.

  14. Near infrared hyperspectral imaging for forensic analysis of document forgery.

    PubMed

    Silva, Carolina S; Pimentel, Maria Fernanda; Honorato, Ricardo S; Pasquini, Celio; Prats-Montalbán, José M; Ferrer, Alberto

    2014-10-21

    Hyperspectral images in the near infrared range (HSI-NIR) were evaluated as a nondestructive method to detect fraud in documents. Three different types of typical forgeries were simulated by (a) obliterating text, (b) adding text and (c) approaching the crossing lines problem. The simulated samples were imaged in the range of 928-2524 nm with spectral and spatial resolutions of 6.3 nm and 10 μm, respectively. After data pre-processing, different chemometric techniques were evaluated for each type of forgery. Principal component analysis (PCA) was performed to elucidate the first two types of adulteration, (a) and (b). Moreover, Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) was used in an attempt to improve the results of the type (a) obliteration and type (b) adding text problems. Finally, MCR-ALS and Partial Least Squares-Discriminant Analysis (PLS-DA), employed as a variable selection tool, were used to study the type (c) forgeries, i.e. crossing lines problem. Type (a) forgeries (obliterating text) were successfully identified in 43% of the samples using both the chemometric methods (PCA and MCR-ALS). Type (b) forgeries (adding text) were successfully identified in 82% of the samples using both the methods (PCA and MCR-ALS). Finally, type (c) forgeries (crossing lines) were successfully identified in 85% of the samples. The results demonstrate the potential of HSI-NIR associated with chemometric tools to support document forgery identification.

  15. Near-Infrared Grating Spectrometer for Mobile Phone Applications

    PubMed Central

    Knobbe, Jens; Grüger, Heinrich

    2016-01-01

    Near-infrared (NIR) spectroscopy is a well-established technique for the chemical analysis of organic and inorganic matter. Accordingly, spectroscopic instrumentation of different complexity has been developed and is currently commercially available. However, there are an increasing number of new mobile applications that have come into focus and that cannot be addressed by the existing technology due to size and cost. Therefore, a new miniaturized scanning grating spectrometer for NIR spectroscopy has been developed at Fraunhofer IPMS. It is based on micro–electro–mechanical systems (MEMS) technology, and has been designed to meet the requirements for mobile application, regarding spectral range, resolution, overall size, robustness, and cost. The MEMS spectrometer covers a spectral range from 950 nm to 1900 nm at a resolution of 10 nm. The instrument is extremely small and has a volume of only 2.1 cm3. Therefore, it is well suited for integration, even into a mobile phone. A first sample of the new spectrometer has been manufactured and put into operation. The results of a series of test measurements are in good agreement with the requirements and specifications. PMID:27170776

  16. Dynamic causal modelling for functional near-infrared spectroscopy

    PubMed Central

    Tak, S.; Kempny, A.M.; Friston, K.J.; Leff, A.P.; Penny, W.D.

    2015-01-01

    Functional near-infrared spectroscopy (fNIRS) is an emerging technique for measuring changes in cerebral hemoglobin concentration via optical absorption changes. Although there is great interest in using fNIRS to study brain connectivity, current methods are unable to infer the directionality of neuronal connections. In this paper, we apply Dynamic Causal Modelling (DCM) to fNIRS data. Specifically, we present a generative model of how observed fNIRS data are caused by interactions among hidden neuronal states. Inversion of this generative model, using an established Bayesian framework (variational Laplace), then enables inference about changes in directed connectivity at the neuronal level. Using experimental data acquired during motor imagery and motor execution tasks, we show that directed (i.e., effective) connectivity from the supplementary motor area to the primary motor cortex is negatively modulated by motor imagery, and this suppressive influence causes reduced activity in the primary motor cortex during motor imagery. These results are consistent with findings of previous functional magnetic resonance imaging (fMRI) studies, suggesting that the proposed method enables one to infer directed interactions in the brain mediated by neuronal dynamics from measurements of optical density changes. PMID:25724757

  17. Broadband near-infrared metamaterial absorbers utilizing highly lossy metals

    NASA Astrophysics Data System (ADS)

    Ding, Fei; Dai, Jin; Chen, Yiting; Zhu, Jianfei; Jin, Yi; Bozhevolnyi, Sergey I.

    2016-12-01

    Radiation absorbers have increasingly been attracting attention as crucial components for controllable thermal emission, energy harvesting, modulators, etc. However, it is still challenging to realize thin absorbers which can operate over a wide spectrum range. Here, we propose and experimentally demonstrate thin, broadband, polarization-insensitive and omnidirectional absorbers working in the near-infrared range. We choose titanium (Ti) instead of the commonly used gold (Au) to construct nano-disk arrays on the top of a silicon dioxide (SiO2) coated Au substrate, with the quality (Q) factor of the localized surface plasmon (LSP) resonance being decreased due to the intrinsic high loss of Ti. The combination of this low-Q LSP resonance and the propagating surface plasmon (PSP) excitation resonance, which occur at different wavelengths, is the fundamental origin of the broadband absorption. The measured (at normal light incidence) absorption is over 90% in the wavelength range from 900 nm to 1825 nm, with high absorption persisting up to the incident angle of ~40°. The demonstrated thin-film absorber configuration is relatively easy to fabricate and can be realized with other properly selected materials.

  18. Development of a new diffuse near-infrared food measuring

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Piao, Renguan

    2006-11-01

    Industries from agriculture to petrochemistry have found near infrared (NIR) spectroscopic analysis useful for quality control and quantitative analysis of materials and products. The general chemical, polymer chemistry, petrochemistry, agriculture, food and textile industries are currently using NIR spectroscopic methods for analysis. In this study, we developed a new sort NIR instrument for food measuring. The instrument consists of a light source, 12 filters to the prismatic part. The special part is that we use a mirror to get two beams of light. And two PbS detectors were used. One detector collected the radiation of one light beam directly and the value was set as the standard instead the standard white surface. Another light beam irradiate the sample surface, and the diffuse light was collected by another detector. The value of the two detectors was compared and the absorbency was computed. We tested the performance of the NIR instrument in determining the protein and fat content of milk powder. The calibration showed the accuracy of the instrument in practice.

  19. Stratigraphy of snow profiles using near-infrared photography

    NASA Astrophysics Data System (ADS)

    Matzl, M.; Schneebeli, M.

    2002-12-01

    The detailed representation of the layers in snow profiles is extremly time consuming. Translucent profiles are used to reveal layer boundaries, however no method is known to relate the transmitted light intensity to morphologic parameters. We use digital near-infrared photography (NIP), centered at a wavelength of 890 nm, to determine optical grainsize on snow profiles. The reflectivity was calibrated with snow samples of different grain size and shape. The digital image of a snow profile is optically and geometrically corrected and the intensities are then converted to optical grainsize. The measured snow profiles on different slopes are compared to planar sections and classical snow profiles. In several cases the NIP image revealed thin layers, layer transitions and disturbances which are also visible in the planar section, but were not recorded in the snow profile. NIP profiles could be as large as 1 m high and 3 m long at very high spatial resolution by assembling several images. NIP of snow profiles is well suited to document and analyse snow stratigraphy and to determine optical diameter .

  20. Near-infrared (NIR) up-conversion optogenetics

    PubMed Central

    Hososhima, Shoko; Yuasa, Hideya; Ishizuka, Toru; Hoque, Mohammad Razuanul; Yamashita, Takayuki; Yamanaka, Akihiro; Sugano, Eriko; Tomita, Hiroshi; Yawo, Hiromu

    2015-01-01

    Non-invasive remote control technologies designed to manipulate neural functions have been long-awaited for the comprehensive and quantitative understanding of neuronal network in the brain as well as for the therapy of neurological disorders. Recently, it has become possible for the neuronal activity to be optically manipulated using biological photo-reactive molecules such as channelrhodopsin (ChR)-2. However, ChR2 and its relatives are mostly reactive to visible light, which does not effectively penetrate through biological tissues. In contrast, near-infrared (NIR) light (650–1450 nm) penetrates deep into the tissues because biological systems are almost transparent to light within this so-called ‘imaging window’. Here we used lanthanide nanoparticles (LNPs), composed of rare-earth elements, as luminous bodies to activate ChRs since they absorb low-energy NIR light to emit high-energy visible light (up-conversion). Here, we created a new type of optogenetic system which consists of the donor LNPs and the acceptor ChRs. The NIR laser irradiation emitted visible light from LNPs, then induced the photo-reactive responses in the near-by cells that expressed ChRs. However, there remains room for large improvements in the energy efficiency of the LNP-ChR system. PMID:26552717

  1. The application of near infrared spectroscopy in nutritional intervention studies

    PubMed Central

    Jackson, Philippa A.; Kennedy, David O.

    2013-01-01

    Functional near infrared spectroscopy (NIRS) is a non-invasive optical imaging technique used to monitor cerebral blood flow (CBF) and by proxy neuronal activation. The use of NIRS in nutritional intervention studies is a relatively novel application of this technique, with only a small, but growing, number of trials published to date. These trials—in which the effects on CBF following administration of dietary components such as caffeine, polyphenols and omega-3 polyunsaturated fatty acids are assessed—have successfully demonstrated NIRS as a sensitive measure of change in hemodynamic response during cognitive tasks in both acute and chronic treatment intervention paradigms. The existent research in this area has been limited by the constraints of the technique itself however advancements in the measurement technology, paired with studies endeavoring increased sophistication in number and locations of channels over the head should render the use of NIRS in nutritional interventions particularly valuable in advancing our understanding of the effects of nutrients and dietary components on the brain. PMID:23964231

  2. SIMP: A Near-Infrared Proper Motion Survey

    NASA Astrophysics Data System (ADS)

    Artigau, Étienne; Lafrenière, David; Doyon, René; Albert, Loïc; Robert, Jasmin; Malo, Lison

    2009-02-01

    SIMP is a proper motion (PM) survey made with the Observatoire du Mont Mégantic (OMM) wide-field near-infrared camera CPAPIR at the CTIO 1.5 m and OMM 1.6 m telescopes. The SIMP observations were initiated in early 2005, are still ongoing and, to date, have covered 28% of the sky at high galactic latitudes. The PMs of the sources detected are determined by comparing their measured positions with those listed in the 2MASS point source catalog, giving a time baseline of 4 to 10 years. The 5 σ uncertainty on the relative SIMP and 2MASS astrometry is 1'', equivalent to a PM lower limit of 0.125-0.250''/yr, or a tangential velocity limit of 15-30 km/s at 25 pc. Up to the 2MASS magnitude limit (J~16.5), T dwarfs are found out to ~25 pc, while L dwarfs may be found as far as 100 pc away.

  3. Near-infrared autofluorescence for the detection of parathyroid glands

    NASA Astrophysics Data System (ADS)

    Paras, Constantine; Keller, Matthew; White, Lisa; Phay, John; Mahadevan-Jansen, Anita

    2011-06-01

    A major challenge in endocrine surgery is the intraoperative detection of parathyroid glands during both thyroidectomies and parathyroidectomies. Current localization techniques such as ultrasound and sestamibi scan are mostly preoperative and rely on an abnormal parathyroid for its detection. In this paper, we present near-infrared (NIR) autofluorescence as a nonintrusive, real-time, automated in vivo method for the detection of the parathyroid gland. A pilot in vivo study was conducted to assess the ability of NIR fluorescence to identify parathyroid glands during thyroid and parathyroidectomies. Fluorescence measurements at 785 nm excitation were obtained intra-operatively from the different tissues exposed in the neck region in 21 patients undergoing endocrine surgery. The fluorescence intensity of the parathyroid gland was found to be consistently greater than that of the thyroid and all other tissues in the neck of all patients. In particular, parathyroid fluorescence was two to eleven times higher than that of the thyroid tissues with peak fluorescence occurring at 820 to 830 nm. These results indicate that NIR fluorescence has the potential to be an excellent optical tool to locate parathyroid tissue during surgery.

  4. Application of functional near-infrared spectroscopy in psychiatry.

    PubMed

    Ehlis, Ann-Christine; Schneider, Sabrina; Dresler, Thomas; Fallgatter, Andreas J

    2014-01-15

    Two decades ago, the introduction of functional near-infrared spectroscopy (fNIRS) into the field of neuroscience created new opportunities for investigating neural processes within the human cerebral cortex. Since then, fNIRS has been increasingly used to conduct functional activation studies in different neuropsychiatric disorders, most prominently schizophrenic illnesses, affective disorders and developmental syndromes, such as attention-deficit/hyperactivity disorder as well as normal and pathological aging. This review article provides a comprehensive overview of state of the art fNIRS research in psychiatry covering a wide range of applications, including studies on the phenomenological characterization of psychiatric disorders, descriptions of life-time developmental aspects, treatment effects, and genetic influences on neuroimaging data. Finally, methodological shortcomings as well as current research perspectives and promising future applications of fNIRS in psychiatry are discussed. We conclude that fNIRS is a valid addition to the range of neuroscientific methods available to assess neural mechanisms underlying neuropsychiatric disorders. Future research should particularly focus on expanding the presently used activation paradigms and cortical regions of interest, while additionally fostering technical and methodological advances particularly concerning the identification and removal of extracranial influences on fNIRS data as well as systematic artifact correction. Eventually, fNIRS might be a useful tool in practical psychiatric settings involving both diagnostics and the complementary treatment of psychological disorders using, for example, neurofeedback applications.

  5. [Near infrared Raman spectra analysis of rhizoma dioscoreae].

    PubMed

    Lin, Wen-Shuo; Chen, Rong; Li, Yong-Zeng; Feng, Shang-Yuan; Huang, Zu-Fang; Xie, Bing-Xian

    2008-05-01

    A novel and compact near-infrared (NIR) Raman system was developed using 785 nm diode laser, volume-phase technology holographic system, and NIR intensified charge-coupled device (CCD). The Raman spectra and first derivative spectra of rhizoma dioscoreae were obtained. The Raman spectra of rhizoma dioscoreae showed three strong characteristic peaks at 477, 863 and 936 cm(-1), respectively. The major ingredients are protein, amino acid, starch, polysaccharides and so on, matching the known basic biochemical composition of rhizoma dioscoreae. In the first derivative spectra of rhizoma dioscoreae, the distinguishing characteristic peaks appeared at 467, 484, 870 and 943 cm(-1). Contrasted with rhizoma dioscoreae Raman spectra in the ranges of 600 to 800 cm(-1) and 1 000 to 1 400 cm(-1), the changes in rhizoma dioscoreae Raman first derivative spectra are represented more clearly than the rhizoma dioscoreae Raman spectra. So the rhizoma dioscoreae Raman first derivative spectra can be an accurate supplementary analysis method to the rhizoma dioscoreae Raman spectra.

  6. A novel storage method for near infrared spectroscopy chemometric models.

    PubMed

    Zhang, Zhi-Min; Chen, Shan; Liang, Yi-Zeng

    2010-06-04

    Chemometric Modeling Markup Language (CMML) is developed by us for containing chemometrics models within one document through converting binary data into strings by base64 encode/decode algorithms to solve the interoperability issue in sharing chemometrics models. It provides a base functionality for storage of sampling, variable selection, pretreating, outlier and modeling parameters and data. With the help of base64 algorithm, the usability of CMML is in equilibrium with size by transforming the binary data into base64 encoded string. Due to the advantages of Extensible Markup Language (XML), models stored in CMML can be easily reused in various other software and programming languages as long as the programming language has XML parsing library. One can also use the XML Path Language (XPath) query language to select desired data from the CMML file effectively. The application of this language in near infrared spectroscopy model storage is implemented as a class in C++ language and available as open source software (http://code.google.com/p/cmml), and the implementations in other languages, such as MATLAB and R are in progress.

  7. Near-infrared spectroscopy for burning plasma diagnostic applicationsa)

    NASA Astrophysics Data System (ADS)

    Soukhanovskii, V. A.

    2008-10-01

    Ultraviolet and visible (UV-VIS, 200-750nm) atomic spectroscopy of neutral and ionized fuel species (H, D, T, and Li) and impurities (e.g., He, Be, C, and W) is a key element of plasma control and diagnosis on International Thermonuclear Experimental Reactor and future magnetically confined burning plasma experiments (BPXs). Spectroscopic diagnostic implementation and performance issues that arise in the BPX harsh nuclear environment in the UV-VIS range, e.g., degradation of first mirror reflectivity under charge-exchange atom bombardment (erosion) and impurity deposition, permanent and dynamic loss of window, and optical fiber transmission under intense neutron and γ-ray fluxes, are either absent or not as severe in the near-infrared (NIR, 750-2000nm) range. An initial survey of NIR diagnostic applications has been undertaken on the National Spherical Torus Experiment. It is demonstrated that NIR spectroscopy can be used for machine protection and plasma control applications, as well as contribute to plasma performance evaluation and physics studies. Emission intensity estimates demonstrate that NIR measurements are possible in the BPX plasma operating parameter range. Complications in the NIR range due to the parasitic background emissions are expected to occur at very high plasma densities, low impurity densities, and at high plasma-facing component temperatures.

  8. Photochemical effects in the lens from near infrared radiation?

    NASA Astrophysics Data System (ADS)

    Söderberg, Per G.; Al-Saqry, Riyadh; Schulmeister, Karl; Gallichanin, Konstantin; Kronschläger, Martin; Yu, Zhaohua

    2009-02-01

    Conclusion: The current data are consistent with a potential photochemical effect of in vivo exposure of the crystalline lens to near infrared radiation since the onset of cataract after in just above threshold dose was at least 18 hrs delayed after the exposure. Materials and methods: The eyes of 6 weeks old Sprague-Dawley rats were exposed unilaterally in vivo to 1090 nm, 6.2 W quasi-top hat spatial distribution with a 3 mm spot on the anterior lens surface within the dilated pupil. First, four exposure time groups of rats were exposed to increasing exposure times. At 24 hrs after exposure, the difference of light scattering between the lenses from the same animal was measured. Then, based on the first experiment, four post-exposure time groups were exposed unilaterally in vivo to 8 s of 1090 nm, 6.2 W quasi-top hat spatial distribution with a 3 mm spot on the anterior lens surface within the dilated pupil. After, the intended post-exposure time, the difference of light scattering between the lenses from the same animal was measured. Results: A 3 mm spot of 6.2 W induces light scattering in the lens with exposures of at least 8 s. Further, after 8 s of 6.2 W within a 3 mm spot on the lens surface, the light scattering increase in the lens was delayed at least 18 hrs after the exposure.

  9. NIFTE: The Near Infrared Faint-Object Telescope Experiment

    NASA Technical Reports Server (NTRS)

    Bock, James J.; Lange, Andrew E.; Matsumoto, T.; Eisenhardt, Peter B.; Hacking, Perry B.; Schember, Helene R.

    1994-01-01

    The high sensitivity of large format InSb arrays can be used to obtain deep images of the sky at 3-5 micrometers. In this spectral range cool or highly redshifted objects (e.g. brown dwarfs and protogalaxies) which are not visible at shorter wavelengths may be observed. Sensitivity at these wavelengths in ground-based observations is severly limited by the thermal flux from the telescope and from the earth's atmosphere. The Near Infrared Faint-Object Telescope Experiment (NIFTE), a 50 cm cooled rocket-borne telescope combined with large format, high performance InSb arrays, can reach a limiting flux less than 1 micro-Jy(1-sigma) over a large field-of-view in a single flight. In comparison, the Infrared Space Observatory (ISO) will require days of observation to reach a sensitivity more than one order of magnitude worse over a similar area of the sky. The deep 3-5 micrometer images obtained by the rocket-borne telescope will assist in determining the nature of faint red objects detected by ground-based telescopes at 2 micrometers, and by ISO at wavelengths longer than 5 micrometers.

  10. Simulation and measurement of transcranial near infrared light penetration