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- ID:
- ivo://CDS.VizieR/J/ApJ/710/1627
- Title:
- Mid-IR photometry of cold brown dwarfs
- Short Name:
- J/ApJ/710/1627
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new Spitzer Infrared Array Camera (IRAC) photometry of 12 very late-type T dwarfs: nine have [3.6], [4.5], [5.8], and [8.0] photometry and three have [3.6] and [4.5] photometry only. Combining this with previously published photometry, we investigate trends with type and color that are useful for both the planning and interpretation of infrared surveys designed to discover the coldest T or Y dwarfs. The online appendix provides a collation of MKO-system YJHKL'M' and IRAC photometry for a sample of M, L, and T dwarfs. There are 12 dwarfs currently known with H-[4.5]>3.0, and 500K<~T_eff_<~800K, which we examine in detail. The ages of the dwarfs in the sample range from very young (0.1-1.0Gyr) to relatively old (3-12Gyr). The mass range is possibly as low as 5 Jupiter masses to up to 70 Jupiter masses, i.e., near the hydrogen burning limit. The metallicities also span a large range, from [m/H]=-0.3 to [m/H]=+0.3.
- ID:
- ivo://CDS.VizieR/J/A+A/570/A110
- Title:
- Mid-IR properties of OH maser galaxies
- Short Name:
- J/A+A/570/A110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We compiled all 119 OH maser galaxies (110 out of them are megamasers, i.e., L_OH_>10L_{sun}_) published so far and cross-identified these OH masers with the Wide-Field Infrared Survey Explorer (WISE) catalog, to investigate the middle infrared (MIR) properties of OH maser galaxies. The WISE magnitude data at the 3.4, 4.6, 12 and 22{mu}m (W1 to W4) are collected for the OH maser sample and one control sample, which are non-detection sources. The color-color diagrams show that both OH megamaser (OHM) and non-OHM (ultra)luminous infrared galaxies ((U)LIRGs) are far away from the single blackbody model line and many of them can follow the path described by the power-law model. The active galaxy nuclei (AGN) fraction is about ~40% for both OHM and non-OHM (U)LIRGs, according to the AGN criteria W1-W2>=0.8. Among the Arecibo survey sample, OHM sources tend to have a lower luminosity at short MIR wavelengths (e.g., 3.4{mu}m and 4.6{mu}m) than that of non-OHM sources, which should come from the low OHM fraction among the survey sample with large 3.4{mu}m and 4.6{mu}m luminosity. The OHM fraction tends to increase with cooler MIR colors (larger F_22{mu}m_/F_3.4{mu}m_). These may be good for sample selection when searching OH megamasers, such as excluding extreme luminous sources at short MIR wavelengths, choosing sources with cooler MIR colors. In the case of the power-law model, we derived the spectral indices for our samples. For the Arecibo survey sample, OHM (U)LIRGs tend to have larger spectral index {alpha}_22-12_ than non-OHM sources, which agrees with previous results. One significant correlation exists between the WISE infrared luminosity at 22{mu}m and the color [W1]-[W4] for the Arecibo OHM hosts. These clues should provide suitable constraints on the sample selection for OH megamaser surveys by future advanced telescopes (e.g., FAST). In addition, the correlation of maser luminosity and the MIR luminosity of maser hosts tends to be non-significant, which may indirectly support the pumping of OHM emission that is dominated by the far infrared radiation, instead of the MIR radiation.
1374. Mid-IR sources in EGS
- ID:
- ivo://CDS.VizieR/J/ApJS/177/431
- Title:
- Mid-IR sources in EGS
- Short Name:
- J/ApJS/177/431
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Extended Groth Strip (EGS) is one of the premier fields for extragalactic deep surveys. Deep observations of the EGS with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope cover an area of 0.38deg^2^ to a 50% completeness limit of 1.5uJy at 3.6um. The catalog comprises 57434 objects detected at 3.6um, with 84%, 28%, and 24% also detected at 4.5, 5.8, and 8.0um, respectively. Number counts are consistent with results from other Spitzer surveys. Color distributions show that the EGS IRAC sources comprise a mixture of populations: low-redshift star-forming galaxies, quiescent galaxies dominated by stellar emission at a range of redshifts, and high-redshift galaxies and AGNs.
- ID:
- ivo://CDS.VizieR/J/ApJ/771/88
- Title:
- Mid-IR Tully-Fisher relation with WISE & 2MTF
- Short Name:
- J/ApJ/771/88
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a mid-infrared Tully-Fisher (TF) relation using photometry from the 3.4{mu}m W1 band of the Wide-field Infrared Survey Explorer (WISE) satellite. The WISE TF relation is formed from 568 galaxies taken from the all-sky 2MASS Tully-Fisher (2MTF) galaxy catalog, spanning a range of environments including field, group, and cluster galaxies. This constitutes the largest mid-infrared TF relation constructed to date. After applying a number of corrections to galaxy magnitudes and line widths, we measure a master TF relation given by M_corr_=-22.24-10.05[log(W_corr_)-2.5], with an average dispersion of {sigma}_WISE_=0.686mag. There is some tension between WISE TF and a preliminary 3.6{mu}m relation, which has a shallower slope and almost no intrinsic dispersion. However, our results agree well with a more recent relation constructed from a large sample of cluster galaxies. We additionally compare WISE TF to the near-infrared 2MTF template relations, finding a good agreement between the TF parameters and total dispersions of WISE TF and the 2MTF K-band template. This fact, coupled with typical galaxy colors of (K-W1)~0, suggests that these two bands are tracing similar stellar populations, including the older, centrally-located stars in the galactic bulge which can (for galaxies with a prominent bulge) dominate the light profile.
- ID:
- ivo://CDS.VizieR/J/ApJ/716/530
- Title:
- Mid-IR variability from the SDWFS
- Short Name:
- J/ApJ/716/530
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the multi-epoch, mid-infrared Spitzer Deep Wide-Field Survey (SDWFS; Ashby et al. 2009, Cat. J/ApJ/701/428) to investigate the variability of objects in 8.1deg^2^ of the NOAO Deep Wide Field Survey Bootes field (NDWFS; Jannuzi & Dey 1999ASPC..191..111J). We perform a Difference Image Analysis of the four available epochs between 2004 and 2008, focusing on the deeper 3.6 and 4.5um bands. Out of 474, 179 analyzed sources, 1.1% meet our standard variability selection criteria that the two light curves are strongly correlated (r>0.8) and that their joint variance ({sigma}_12_) exceeds that for all sources with the same magnitude by 2{sigma}. We then examine the mid-IR colors of the variable sources and match them with X-ray sources from the XBootes survey (Murray et al. 2005ApJS..161....1M), radio catalogs (FIRST (Becker et al., Cat. VIII/71) and WSRT (de Vries et al. 2002, Cat. J/AJ/123/1784)), 24um selected active galactic nucleus (AGN) candidates (see Houck et al. 2005ApJ...622L.105H), and spectroscopically identified AGNs from the AGN and Galaxy Evolution Survey (AGES; C. S. Kochanek et al. 2010, in prep). Based on their mid-IR colors, most of the variable sources are AGNs (76%), with smaller contributions from stars (11%), galaxies (6%), and unclassified objects, although most of the stellar, galaxy, and unclassified sources are false positives. For our standard selection criteria, 11%-12% of the mid-IR counterparts to X-ray sources, 24um AGN candidates, and spectroscopically identified AGNs show variability.
- ID:
- ivo://CDS.VizieR/J/other/Sci/365.478
- Title:
- Milky Way classical Cepheids sample
- Short Name:
- J/other/Sci/365.
- Date:
- 02 Nov 2021 11:28:21
- Publisher:
- CDS
- Description:
- The Milky Way is a barred spiral galaxy, with physical properties inferred from various tracers informed by the extrapolation of structures seen in other galaxies. However, the distances of these tracers are measured indirectly and are model-dependent. We constructed a map of the Milky Way in three dimensions, based on the positions and distances of thousands of classical Cepheid variable stars. This map shows the structure of our Galaxy's young stellar population and allows us to constrain the warped shape of the Milky Way's disk. A simple model of star formation in the spiral arms reproduces the observed distribution of Cepheids.
- ID:
- ivo://CDS.VizieR/J/A+A/585/A101
- Title:
- Milky Way global survey of star clusters. V.
- Short Name:
- J/A+A/585/A101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We determined the integrated magnitudes of 3208 star clusters in the 2MASS near-infrared (JHKs) passbands.
- ID:
- ivo://CDS.VizieR/J/ApJ/788/77
- Title:
- Milky Way L/T/M-dwarfs identified in BoRG survey
- Short Name:
- J/ApJ/788/77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a tally of Milky Way late-type dwarf stars in 68 Wide Field Camera 3 (WFC3) pure-parallel fields (227 arcmin^2^) from the Brightest of Reionizing Galaxies survey for high-redshift galaxies. Using spectroscopically identified M-dwarfs in two public surveys, the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey and the Early Release Science mosaics, we identify a morphological selection criterion using the half-light radius (r_50_), a near-infrared J-H, G-J color region where M-dwarfs are found, and a V-J relation with M-dwarf subtype. We apply this morphological selection of stellar objects, color-color selection of M-dwarfs, and optical-near-infrared color subtyping to compile a catalog of 274 M-dwarfs belonging to the disk of the Milky Way with a limiting magnitude of m_F125W_<24(AB). Based on the M-dwarf statistics, we conclude that (1) the previously identified north-south discrepancy in M-dwarf numbers persists in our sample; there are more M-dwarfs in the northern fields on average than in southern ones, (2) the Milky Way's single disk scale-height for M-dwarfs is 0.3-4 kpc, depending on subtype, (3) the scale-height depends on M-dwarf subtype with early types (M0-4) high scale-height (z_0_=3-4 kpc) and later types M5 and above in the thin disk (z_0_=0.3-0.5 kpc), (4) a second component is visible in the vertical distribution, with a different, much higher scale-height in the southern fields compared to the northern ones. We report the M-dwarf component of the Sagittarius stream in one of our fields with 11 confirmed M-dwarfs, seven of which are at the stream's distance. In addition to the M-dwarf catalog, we report the discovery of 1 T-dwarfs and 30 L-dwarfs from their near-infrared colors. The dwarf scale-height and the relative low incidence in our fields of L- and T-dwarfs in these fields makes it unlikely that these stars will be interlopers in great numbers in color-selected samples of high-redshift galaxies. The relative ubiquity of M-dwarfs however will make them ideal tracers of Galactic halo substructure with EUCLID and reference stars for James Webb Space Telescope observations.
- ID:
- ivo://CDS.VizieR/J/A+A/649/A83
- Title:
- Milky Way nuclear disk KMOS survey
- Short Name:
- J/A+A/649/A83
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- In the central few degrees of the bulge of the Milky Way there is a flattened structure of gas, dust, and stars, known as the central molecular zone, that is similar to nuclear disks in other galaxies. As a result of extreme foreground extinction, we possess only sparse information about the (mostly old) stellar population of the nuclear disk. In this work we present our KMOS spectroscopic survey of the stars in the nuclear disk reaching the old populations. To obtain an unbiased data set, we sampled stars in the full extinction range along each line of sight. We also observed reference fields in neighboring regions of the Galactic bulge. We describe the design and execution of the survey and present first results. We obtain spectra and five spectral indices of 3113 stars with a median S/N of 67 and measure radial velocities for 3051 stars. Of those, 2735 sources have sufficient S/N to estimate temperatures and metallicities from indices. We derive metallicities using the CO 2-0 and Na I K-band spectral features, where we derive our own empirical calibration using metallicities obtained with higher-resolution observations.We use 183 giant stars for calibration spanning in metallicity from -2.5 to 0.6dex and covering temperatures of up to 5500K. The derived index based metallicities deviate from the calibration values with a scatter of 0.32dex. The internal uncertainty of our metallicities is likely smaller. We use these metallicity measurements, together with the CO index, to derive effective temperatures using literature relations. We publish the catalog in this paper. Our data set complements Galactic surveys such as Gaia and APOGEE for the inner 200pc radius of the Milky Way, which is not readily accessible by those surveys owing to extinction. We will use the derived properties in future papers for further analysis of the nuclear disk.
