- ID:
- ivo://CDS.VizieR/J/ApJS/208/24
- Title:
- Spitzer MIR AGN survey. I.
- Short Name:
- J/ApJS/208/24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a program of optical and near-infrared spectroscopic follow-up of candidate active galactic nuclei (AGNs) selected in the mid-infrared. This survey selects both normal and obscured AGNs closely matched in luminosity across a wide range, from Seyfert galaxies with bolometric luminosities L _bol_~10^10^L_{sun}_ to highly luminous quasars (L_bol_~10^14^L_{sun}_), all with redshifts ranging from 0 to 4.3. Samples of candidate AGNs were selected with mid-infrared color cuts at several different 24{mu}m flux density limits to ensure a range of luminosities at a given redshift. The survey consists of 786 candidate AGNs and quasars, of which 672 have spectroscopic redshifts and classifications. Of these, 137 (20%) are type 1 AGNs with blue continua, 294 (44%) are type 2 objects with extinctions A_V_>~5 toward their AGNs, 96 (14%) are AGNs with lower extinctions (A_V_~1), and 145 (22%) have redshifts, but no clear signs of AGN activity in their spectra. Of the survey objects 50% have L_bol_>10^12^L_{sun}_, in the quasar regime. We present composite spectra for type 2 quasars and objects with no signs of AGN activity in their spectra. We also discuss the mid-infrared - emission-line luminosity correlation and present the results of cross correlations with serendipitous X-ray and radio sources.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/653/675
- Title:
- Spitzer 24{mu}m photometry of A dwarfs
- Short Name:
- J/ApJ/653/675
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report 24 and/or 70um measurements of ~160 A-type main-sequence stars using the Multiband Imaging Photometer for Spitzer (MIPS).
- ID:
- ivo://CDS.VizieR/J/ApJ/620/1010
- Title:
- Spitzer 24{mu}m photometry of A dwarfs
- Short Name:
- J/ApJ/620/1010
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report new Spitzer 24{mu}m photometry of 76 main-sequence A-type stars. We combine these results with previously reported Spitzer 24{mu}m data and 24 and 25{mu}m photometry from the Infrared Space Observatory and the Infrared Astronomy Satellite. The result is a sample of 266 stars with mass close to 2.5M_Sun_ all detected to at least the ~7{sigma} level relative to their photospheric emission.
- ID:
- ivo://CDS.VizieR/J/AJ/144/135
- Title:
- Spitzer 24{mu}m photometry of Hipparcos F stars
- Short Name:
- J/AJ/144/135
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted a study of debris disks around F stars in order to explore correlations between rotation, stellar winds, and circumstellar disks. We obtained new 24{mu}m photometry from the Multiband Imaging Photometer for Spitzer (MIPS) camera for a sample of 188 relatively nearby F dwarfs with various rotation rates and optical colors, and combined it with archival MIPS data for 66 more F stars, as well as Wide-field Infrared Survey Explorer data for the entire sample, plus 9 more F stars. Based on the objects' K_s_-[24] and [3.4]-[22] colors, we identify 22 stars in our sample as having 22 and/or 24{mu}m excesses above our detection limit, 13 of which are new discoveries. Our overall disk detection rate is 22/263, or 8%, consistent with previous determinations of disk fractions in the solar neighborhood. While fast-rotating stars are expected to have strong winds capable of efficiently removing dust, we find no correlation between rotational velocity and infrared excess. Similarly, we find no significant difference in excess detection rate between late-type F stars, which have convective surfaces, and early-type F stars, which have fully radiative envelopes. However, the essentially unknown range of ages in this sample may be washing out any effects relating rotation, winds, and disks.
- ID:
- ivo://CDS.VizieR/J/AJ/141/1
- Title:
- Spitzer observations of GOODS fields
- Short Name:
- J/AJ/141/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Spitzer 16um imaging of the Great Observatories Origins Deep Survey (GOODS) fields. We survey 150 arcmin^2^ in each of the two GOODS fields (North and South), to an average 3{sigma} depth of 40 and 65uJy, respectively. We detect ~1300 sources in both fields combined. We validate the photometry using the 3-24um spectral energy distribution of stars in the fields compared to Spitzer spectroscopic templates. Comparison with ISOCAM and AKARI observations in the same fields shows reasonable agreement, though the uncertainties are large. We provide a catalog of photometry, with sources cross-correlated with available Spitzer, Chandra, and Hubble Space Telescope data. Galaxy number counts show good agreement with previous results from ISOCAM and AKARI with improved uncertainties.
- ID:
- ivo://CDS.VizieR/J/ApJ/713/330
- Title:
- Spitzer observations of major-merger galaxies
- Short Name:
- J/ApJ/713/330
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Spitzer observations for a sample of close major-merger galaxy pairs (KPAIR sample) selected from cross-matches between the 2MASS Extended Source Catalog and Sloan Digital Sky Survey Data Release 3. The goals are to study the star formation activity in these galaxies and to set a local bench mark for the cosmic evolution of close major mergers. The Spitzer KPAIR sample (27 pairs, 54 galaxies) includes all spectroscopically confirmed spiral-spiral (S+S) and spiral-elliptical (S+E) pairs in a parent sample that is complete for primaries brighter than K=12.5 mag, projected separations of 5h^-1^kpc<=s<=20h^-1^kpc, and mass ratios <=2.5. The Spitzer data, consisting of images in seven bands (3.6, 4.5, 5.8, 8, 24, 70, 160um), show very diversified IR emission properties.
- ID:
- ivo://CDS.VizieR/J/AJ/133/2072
- Title:
- Spitzer observations of NGC 2362
- Short Name:
- J/AJ/133/2072
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a mid-infrared imaging survey of the ~5Myr old cluster NGC 2362 carried out with the Infrared Array Camera (IRAC) on board the Spitzer Space Telescope. The archival mid-infrared data were merged with extant Halpha emission data, optical and near-infrared photometry, and moderate-resolution optical spectroscopy to identify the remnant disk-bearing population of the cluster and to estimate the fraction of stars that still retain primordial circumstellar disks. The principal sample of 232 suspected cluster members with masses ranging from ~10 to 0.3M_{sun}_ (B2-M5 spectral types) was drawn from known Halpha emission stars, X-ray-detected stars from a single 100ks archival Chandra observation, and established lithium-rich stars. A second sample of 153 stars over a similar mass range whose membership status was based on optical photometry alone was also examined.
- ID:
- ivo://CDS.VizieR/J/ApJ/674/336
- Title:
- Spitzer observations of NGC 1333
- Short Name:
- J/ApJ/674/336
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive analysis of structure in the young, embedded cluster, NGC 1333 using members identified with Spitzer and 2MASS photometry based on their IR-excess emission. A total of 137 members are identified in this way, composed of 39 protostars and 98 more evolved pre-main-sequence stars with disks. Of the latter class, four are transition/debris disk candidates.
- ID:
- ivo://CDS.VizieR/J/ApJ/698/1
- Title:
- Spitzer observations of NGC 2362
- Short Name:
- J/ApJ/698/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Expanding upon the Infrared Array Camera (IRAC) survey from Dahm & Hillenbrand (2007, Cat. J/AJ/133/2072), we describe Spitzer IRAC and Multiband Imaging Photometer for Spitzer observations of the populous, 5Myr old open cluster NGC 2362. We analyze the mid-IR colors of cluster members and compared their spectral energy distributions (SEDs) to star+circumstellar disk models to constrain the disk morphologies and evolutionary states. Combining our data with other Spitzer surveys, we investigate the evolution of debris disks around high/intermediate-mass stars and investigate timescales for giant planet formation.
- ID:
- ivo://CDS.VizieR/J/AJ/141/11
- Title:
- Spitzer observations of planet-host stars
- Short Name:
- J/AJ/141/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Since giant planets scatter planetesimals within a few tidal radii of their orbits, the locations of existing planetesimal belts indicate regions where giant planet formation failed in bygone protostellar disks. Infrared observations of circumstellar dust produced by colliding planetesimals are therefore powerful probes of the formation histories of known planets. Here we present new Spitzer infrared spectrograph (IRS) spectrophotometry of 111 solar-type stars, including 105 planet hosts. Our observations reveal 11 debris disks, including two previously undetected debris disks orbiting HD 108874 and HD 130322. Combining the 32um spectrophotometry with previously published MIPS photometry, we find that the majority of debris disks around solar-type stars have temperatures in the range 60<~T_dust_<~100K. Assuming a dust temperature T_dust_=70K, which is representative of the nine debris disks detected by both IRS and MIPS, debris rings surrounding Sun-like stars orbit between 15 and 240AU depending on the mean particle size. Our observations imply that the planets detected by radial-velocity searches formed within 240AU of their parent stars. If any of the debris disks studied here have mostly large, blackbody emitting grains, their companion giant planets must have formed in a narrow region between the ice line and 15AU.