Search

Start Over Subject infrared astronomy
841. NIR polarimetry in the Central Molecular Zone
ID:
ivo://CDS.VizieR/J/ApJS/213/22
Title:
NIR polarimetry in the Central Molecular Zone
Short Name:
J/ApJS/213/22
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have carried out near-infrared polarimetry toward the boundary of the Central Molecular Zone, in the field of (-1.{deg}4<~l<~-0.{deg}3 and 1.{deg}0<~l<~2.{deg}9,|b|<~0.{deg}1), using the near-infrared polarimetric camera SIRPOL on the 1.4m Infrared Survey Facility telescope. We have selected 112 intrinsically polarized sources on the basis of the estimate of interstellar polarization on Stokes Q/I-U/I planes. The selected sources are brighter than K_S_=14.5mag and have polarimetric uncertainty {delta}P<1%. Ten of these distinctive polarized sources are fit well with spectral energy distributions of young stellar objects when using the photometry in the archive of the Spitzer Space Telescope mid-infrared data. However, many sources have spectral energy distributions of normal stars suffering from heavy interstellar extinction; these might be stars behind dark clouds. Due to the small number of distinctive polarized sources and candidates of young stellar objects, we cannot judge if they are declining in number outside the Central Molecular Zone. Many massive candidates for young stellar objects in the literature have only small intrinsic polarization. This might suggest that their masses are 4-15M_{sun}_, whose intrinsic polarization has been expected to be small.
842. NIR polarimetry of sources near SgrA*
ID:
ivo://CDS.VizieR/J/A+A/534/A117
Title:
NIR polarimetry of sources near SgrA*
Short Name:
J/A+A/534/A117
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Galactic Center offers unique opportunities to study stellar and bow-shock polarization effects in a dusty environment. The goals of this work are to provide near-infrared (NIR) polarimetry of the stellar sources in the central parsec at the resolution of an 8m telescope for the first time, along with new insights into the nature of the known bright bow-shock sources. We use adaptive-optics assisted observations obtained at the ESO VLT in the H- and Ks-band, applying both high-precision photometric methods specifically developed for crowded fields and a newly established polarimetric calibration for NACO to produce polarization maps of the central 3"x10", in addition to spatially resolved polarimetry and a flux variability analysis on the extended sources in this region.
843. NIR proper motion catalogue from UKIDSS-LAS
ID:
ivo://CDS.VizieR/J/MNRAS/437/3603
Title:
NIR proper motion catalogue from UKIDSS-LAS
Short Name:
J/MNRAS/437/3603
Date:
21 Oct 2021
Publisher:
CDS
Description:
The United Kingdom Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS) began in 2005, with the start of the UKIDSS programme as a 7 year effort to survey roughly 4000deg^2^ at high Galactic latitudes in Y, J, H and K bands. The survey also included a significant quantity of two epoch J band observations, with an epoch baseline greater than 2 years to calculate proper motions. We present a near-infrared proper motion catalogue for the 1500deg^2^ of the two epoch LAS data, which includes 135625 stellar sources and a further 88324 with ambiguous morphological classifications, all with motions detected above the 5{sigma} level. We developed a custom proper motion pipeline which we describe here. Our catalogue agrees well with the proper motion data supplied for a 300deg^2^ subset in the current Wide Field Camera Science Archive (WSA) 10th data release (DR10) catalogue, and in various optical catalogues, but it benefits from a larger matching radius and hence a larger upper proper motion detection limit. We provide absolute proper motions, using LAS galaxies for the relative to absolute correction. By using local second-order polynomial transformations, as opposed to linear transformations in the WSA, we correct better for any local distortions in the focal plane, not including the radial distortion that is removed by the UKIDSS pipeline. We present the results of proper motion searches for new brown dwarfs and white dwarfs. We discuss 41 sources in the WSA DR10 overlap with our catalogue with proper motions >300mas/yr, several of which are new detections. We present 15 new candidate ultracool dwarf binary systems.
844. NIR spectral analysis of star-forming galaxies
ID:
ivo://CDS.VizieR/J/ApJ/796/7
Title:
NIR spectral analysis of star-forming galaxies
Short Name:
J/ApJ/796/7
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this paper, we follow up on our previous detection of nuclear ionized outflows in the most massive (log(M_*_/M_{sun}_)>=10.9) z~1-3 star-forming galaxies (SFGs) by increasing the sample size by a factor of six (to 44 galaxies above log(M_*_/M_{sun}_)>=10.9) from a combination of the SINS/zC-SINF, LUCI, GNIRS, and KMOS^3D^ spectroscopic surveys.
845. NIR spectral of M-T dwarfs
ID:
ivo://CDS.VizieR/J/A+A/503/639
Title:
NIR spectral of M-T dwarfs
Short Name:
J/A+A/503/639
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present complete near-infrared (0.85-2.45um), low-resolution (R~100) spectra of a sample of 54 disk M-, L-, and T-dwarfs with reliable optical or near infrared spectral-type classification from the literature. The observations were obtained with a prism-based optical element, the Amici device, which provides a complete spectrum of the source on the detector. Our observations indicate that low-resolution near-infrared spectroscopy can be used to determine the spectral classification of late-type field dwarfs in a fast but accurate way. We derive a set of near-infrared spectral indices that are useful to the classification of field dwarfs not seriously affected by reddening. Finally, we show that the comparison of Amici spectra with model atmospheres allows us to obtain a reliable estimate of the dwarf effective temperatures
846. NIR spectra of Centaurs and Kuiper Belt objects
ID:
ivo://CDS.VizieR/J/AJ/135/55
Title:
NIR spectra of Centaurs and Kuiper Belt objects
Short Name:
J/AJ/135/55
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present here an extensive survey of near-infrared (NIR) spectra of Kuiper belt objects (KBOs) and Centaurs taken with the Keck I Telescope. We find that most spectra in our sample are well characterized by a combination of water ice and a featureless continuum. A comparative analysis reveals that the NIR spectral properties have little correlation to the visible colors or albedo, with the exception of the fragment KBOs produced from the giant impact on 2003 E
847. NIR spectra of 2 extreme T-type subdwarfs
ID:
ivo://CDS.VizieR/J/ApJ/898/77
Title:
NIR spectra of 2 extreme T-type subdwarfs
Short Name:
J/ApJ/898/77
Date:
21 Mar 2022 08:47:02
Publisher:
CDS
Description:
We present the discoveries of WISEAJ041451.67-585456.7 and WISEAJ181006.18-101000.5, two low-temperature (1200-1400K), high proper motion T-type subdwarfs. Both objects were discovered via their high proper motion (>0.5yr^-1^); WISEA J181006.18-101000.5 as part of the NEOWISE proper motion survey and WISEA J041451.67-585456.7 as part of the citizen science project Backyard Worlds; Planet 9. We have confirmed both as brown dwarfs with follow-up near-infrared spectroscopy. Their spectra and near-infrared colors are unique among known brown dwarfs, with some colors consistent with L-type brown dwarfs and other colors resembling those of the latest-type T dwarfs. While no forward model consistently reproduces the features seen in their near-infrared spectra, the closest matches suggest very low metallicities ([Fe/H]<=-1), making these objects likely the first examples of extreme subdwarfs of the T spectral class (esdT). WISEAJ041451.67-585456.7 and WISEA J181006.18-101000.5 are found to be part of a small population of objects that occupy the "substellar transition zone", and have the lowest masses and effective temperatures of all objects in this group.
848. NIR spectra of 10 PNe in LMC and SMC
ID:
ivo://CDS.VizieR/J/ApJ/831/L3
Title:
NIR spectra of 10 PNe in LMC and SMC
Short Name:
J/ApJ/831/L3
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present near-infrared spectra of 10 planetary nebulae (PNe) in the Large and Small Magellanic Clouds (LMC and SMC), acquired with the FIRE and GNIRS spectrometers on the 6.5 m Baade and 8.1 m Gemini South Telescopes, respectively. We detect Se and/or Kr emission lines in eight of these objects, the first detections of n-capture elements in Magellanic Cloud PNe. Our abundance analysis shows large s-process enrichments of Kr (0.6-1.3 dex) in the six PNe in which it was detected, and Se is enriched by 0.5-0.9 dex in five objects. We also estimate upper limits to Rb and Cd abundances in these objects. Our abundance results for the LMC are consistent with the hypothesis that PNe with 2-3 M_{\sun}_ progenitors dominate the bright end of the PN luminosity function in young gas-rich galaxies. We find no significant correlations between s-process enrichments and other elemental abundances, central star temperature, or progenitor mass, though this is likely due to our small sample size. We determine S abundances from our spectra and find that [S/H] agrees with [Ar/H] to within 0.2 dex for most objects, but is lower than [O/H] by 0.2-0.4 dex in some PNe, possibly due to O enrichment via third dredge-up. Our results demonstrate that n-capture elements can be detected in PNe belonging to nearby galaxies with ground-based telescopes, allowing s-process enrichments to be studied in PN populations with well-determined distances.
849. NIR spectra of 5 red quasars at 0.5<z<0.9
ID:
ivo://CDS.VizieR/J/ApJ/812/66
Title:
NIR spectra of 5 red quasars at 0.5<z<0.9
Short Name:
J/ApJ/812/66
Date:
21 Oct 2021
Publisher:
CDS
Description:
Red quasars are thought to be an intermediate population between merger-driven star-forming galaxies in dust-enshrouded phase and normal quasars. If so, they are expected to have high accretion ratios, but their intrinsic dust extinction hampers reliable determination of Eddington ratios. Here, we compare the accretion rates of 16 red quasars at z~0.7 to those of normal type 1 quasars at the same redshift range. The red quasars are selected by their red colors in optical through near-infrared (NIR) and radio detection. The accretion rates of the red quasars are derived from the P{beta} line in NIR spectra, which is obtained by the SpeX on the Infrared Telescope Facility in order to avoid the effects of dust extinction. We find that the measured Eddington ratios (L_bol_/L_Edd_~=0.69) of red quasars are significantly higher than those of normal type 1 quasars, which is consistent with a scenario in which red quasars are the intermediate population and the black holes of red quasars grow very rapidly during such a stage.
850. NIR spectroscopy of COSMOS FIR galaxies
ID:
ivo://CDS.VizieR/J/ApJ/806/L35
Title:
NIR spectroscopy of COSMOS FIR galaxies
Short Name:
J/ApJ/806/L35
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have used FMOS on Subaru to obtain near-infrared spectroscopy of 123 far-infrared-selected galaxies in COSMOS and the key rest-frame optical emission lines. This is the largest sample of infrared galaxies with near-infrared spectroscopy at these redshifts. The far-infrared selection results in a sample of galaxies that are massive systems that span a range of metallicities in comparison with previous optically selected surveys, and thus has a higher active galactic nucleus (AGN) fraction and better samples the AGN branch. We establish the presence of AGNs and starbursts in this sample of (U)LIRGs selected as Herschel-PACS and Spitzer-MIPS detections in two redshift bins (z~0.7 and z~1.5) and test the redshift dependence of diagnostics used to separate AGNs from star formation dominated galaxies. In addition, we construct a low-redshift (z~0.1) comparison sample of infrared-selected galaxies and find that the evolution from z~1.5 to today is consistent with an evolving AGN selection line and a range of ISM conditions and metallicities from the models of Kewley et al. (2013ApJ...774L..10K). We find that a large fraction of (U)LIRGs are BPT-selected AGNs using their new redshift-dependent classification line. We compare the position of known X-ray-detected AGNs (67 in total) with the BPT selection and find that the new classification line accurately selects most of these objects (>70%). Furthermore, we identify 35 new (likely obscured) AGNs not selected as such by their X-ray emission. Our results have direct implications for AGN selection at higher redshift with either current (MOSFIRE, KMOS) or future (PFS, MOONS) spectroscopic efforts with near-infrared spectral coverage.