- ID:
- ivo://CDS.VizieR/J/ApJ/671/470
- Title:
- MIPS survey of YSOs in Vela Molecular Ridge-D
- Short Name:
- J/ApJ/671/470
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new, unbiased Spitzer MIPS imaging survey (~1.8deg^2^) of the young stellar content of the Vela Molecular Ridge-D (VMR-D) is presented. The survey is complete down to 5 and 250mJy at 24 and 70{mu}m, respectively. A total of 849 sources are detected at 24{mu}m, and 52 of them also have a 70{mu}m counterpart. The VMR-D region is one that we have already partially mapped in dust and gas millimeter emission, and we discuss the correlation between the Spitzer compact sources and the millimeter contours. About half of the 24{mu}m sources are located inside the region delimited by the ^12^CO(1-0) contours, corresponding to only one-third of the full area mapped with MIPS. Therefore, the 24{mu}m source density increases by about 100% moving from outside to inside the CO contours. For the 70{mu}m sources, the corresponding density increase is a factor of 4. About 400 sources of these have a 2MASS counterpart, and we have used this to construct a Ks versus Ks-[24] diagram and to identify the protostellar population inside the cloud.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/459/1403
- Title:
- M31 IRAC 3.6/4.5um extended survey
- Short Name:
- J/MNRAS/459/1403
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results from an extended survey of the Andromeda galaxy (M31) using 41.1h of observations by Spitzer-IRAC at 3.6 and 4.5{mu}m. This survey extends previous observations to the outer disc and halo, covering total lengths of 44 and 66 along the minor and major axes, respectively. We have produced surface brightness profiles by combining the integrated light from background-corrected maps with stellar counts from a new catalogue of point sources. Using auxiliary catalogues, we have carried out a statistical analysis in colour-magnitude space to discriminate M31 objects from foreground Milky Way stars and background galaxies. The catalogue includes 426 529 sources, of which 66 per cent have been assigned probability values to identify M31 objects with magnitude depths of [3.6]=19.0+/-0.2, [4.5]=18.7+/-0.2. We discuss applications of our data for constraining the stellar mass and characterizing point sources in the outer radii.
- ID:
- ivo://CDS.VizieR/J/ApJS/247/44
- Title:
- Mira-like variables from the KELT survey
- Short Name:
- J/ApJS/247/44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sample of 4132 Mira-like variables (red variables with long periods and high amplitudes) in the Kilodegree Extremely Little Telescope (KELT) survey. Of these, 376 are new Mira-like detections. We used Two Micron All Sky Survey (2MASS) colors to identify candidate asymptotic giant branch stars. We searched for photometric variability among the candidate asymptotic giant branch stars and identified stars that show periodic variability. We selected variables with high amplitudes and strong periodic behavior using a Random Forest classifier. Of the sample of 4132 Mira-like variables, we estimate that 70% are Miras and 30% are semiregular (SR) variables. We also adopt the method of using (W_RP_-W_Ks_) versus (J-Ks) colors in distinguishing between O-rich and C-rich Miras and find it to be an improvement over 2MASS colors.
- ID:
- ivo://CDS.VizieR/J/ApJ/886/33
- Title:
- MIR reverberation mapping analysis of 87 z<0.5 PG AGNs
- Short Name:
- J/ApJ/886/33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The continued operation of the Wide-field Infrared Survey Explorer (WISE), combined with several ground-based optical transient surveys (e.g., CRTS, ASAS-SN, and PTF), offers an unprecedented opportunity to explore the dust structures in luminous active galactic nuclei (AGNs). We use these data for a mid-IR dust reverberation mapping (RM) study of 87 archetypal Palomar-Green quasars at z<~0.5. To cope with various contaminations of the photometry data and the sparse time sampling of the light curves, procedures to combine these data sets and retrieve the dust RM signals have been developed. We find that ~70% of the sample (with a completeness correction up to 95%) has convincing mid-IR time lags in the WISE W1 (~3.4{mu}m) and W2 (~4.5{mu}m) bands, and they are proportional to the square root of the AGN luminosity. Combined with previous K-band (~2.2{mu}m) RM results in the literature, the inferred dust emission size ratios are R_K_:R_W1_:R_W2_=0.6:1:1.2. Under simple assumptions, we put preliminary constraints on the projected dust surface density at these bands and reveal the possibly different torus structures among hot-dust-deficient, warm-dust-deficient, and normal quasars from the reverberation signals. With multi-epoch Spitzer data and later WISE photometry, we also explore AGN IR variability at 10-24{mu}m over a 5yr timescale. Except for blazars and flat-spectrum radio sources, the majority of AGNs have typical variation amplitudes at 24{mu}m of no more than 10% of that in the W1 band, indicating that the dust reverberation signals damp out quickly at longer wavelengths. In particular, steep-spectrum radio quasars also lack strong 24{mu}m variability, consistent with the unification picture of radio-loud AGNs.
- ID:
- ivo://CDS.VizieR/J/ApJ/806/231
- Title:
- MISFITS survey: HCO+ obs. of Spitzer YSOs
- Short Name:
- J/ApJ/806/231
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an HCO^+^ J=3->2 survey of Class 0+I and Flat SED young stellar objects (YSOs) found in the Gould Belt clouds by surveys with Spitzer. Our goal is to provide a uniform Stage 0+I source indicator for these embedded protostar candidates. We made single point HCO^+^ J=3->2 measurements toward the source positions at the CSO and APEX of 546 YSOs (89% of the Class 0+I + Flat SED sample). Using the criteria from van Kempen et al. (2009, J/A+A/498/167), we classify sources as Stage 0+I or bona fide protostars and find that 84% of detected sources meet the criteria. We recommend a timescale for the evolution of Stage 0+I (embedded protostars) of 0.54Myr. We find significant correlations of HCO^+^ integrated intensity with {alpha} and T_bol_ but not with L_bol_. The detection fraction increases smoothly as a function of {alpha} and L_bol_, while decreasing smoothly with T_bol_. Using the Stage 0+I sources tightens the relation between protostars and high extinction regions of the cloud; 89% of Stage I sources lie in regions with A_V_>8mag. Class 0+I and Flat SED YSOs that are not detected in HCO^+^ have, on average, a factor of ~2 higher T_bol_ and a factor of ~5 lower L_bol_than YSOs with HCO^+^ detections. We find less YSO contamination, defined as the number of undetected YSOs divided by the total number surveyed, for sources with T_bol_<~600K and L_bol_>~1L_{sun}_. The contamination percentage is >90% at A_V_<4mag and decreases as A_V_ increases.
- ID:
- ivo://CDS.VizieR/J/MNRAS/459/140
- Title:
- M81, LMC and 3C 273/Coma 17-60keV obs.
- Short Name:
- J/MNRAS/459/140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of a deep survey of three extragalactic fields, M81 (exposure of 9.7Ms), Large Magellanic Cloud (6.8 Ms) and 3C 273/Coma (9.3Ms), in the hard X-ray (17-60keV) energy band with the IBIS telescope onboard the INTEGRAL observatory, based on 12 years of observations (2003-2015). The combined survey reaches a 4{sigma} peak sensitivity of 0.18mCrab (2.6x10^-12^erg/s/cm^2^) and sensitivity better than 0.25 and 0.87mCrab over 10 per cent and 90 per cent of its full area of 4900 deg^2^, respectively. We have detected in total 147 sources at S/N>4{sigma}, including 37 sources observed in hard X-rays for the first time. The survey is dominated by extragalactic sources, mostly active galactic nuclei (AGN). The sample of identified sources contains 98 AGN (including 64 Seyfert galaxies, seven low-ionization nuclear emission-line region galaxies, three X-ray bright optically normal galaxies, 16 blazars and eight AGN of unclear optical class), two galaxy clusters (Coma and Abell 3266), 17 objects located in the Large and Small Magellanic Clouds (13 high- and two low-mass X-ray binaries and two X-ray pulsars), three Galactic cataclysmic variables, one ultraluminous X-ray source (M82 X-1) and one blended source (SWIFT J1105.7+5854). The nature of 25 sources remains unknown, so that the survey's identification is currently complete at 83 per cent. We have constructed AGN number-flux relations (log N-log S) and calculated AGN number densities in the local Universe for the entire survey and for each of the three extragalactic fields.
- ID:
- ivo://CDS.VizieR/J/AJ/132/231
- Title:
- MMT hectospec redshift survey of 24um sources
- Short Name:
- J/AJ/132/231
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectroscopic survey using the MMT Hectospec fiber spectrograph of 24um sources selected with the Spitzer Space Telescope in the Spitzer First Look Survey. We report 1296 new redshifts for 24um sources, including 599 with f_nu_(24um)>=1mJy. Combined with 291 additional redshifts for sources from the Sloan Digital Sky Survey (SDSS), our observing program was highly efficient and is ~90% complete for i<=21mag and f_nu_(24um)>=1mJy and 35% complete for i<=20.5mag and 0.3mJy<=f_nu_(24um)<1.0mJy. Our Hectospec survey includes 1078 and 168 objects spectroscopically classified as galaxies and QSOs, respectively. Combining the Hectospec and SDSS samples, we find 24 mselected galaxies to zgal<=0.98 and QSOs to zQSO<=3.6, with mean redshifts of <zgal>=0.27 and <zQSO>=1.1. As part of this publication, we include the redshift catalogs and the reduced spectra; these are also available through the NASA/IPAC Infrared Science Archive.
- ID:
- ivo://CDS.VizieR/J/ApJ/751/55
- Title:
- MMT hypervelocity star survey. II.
- Short Name:
- J/ApJ/751/55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of five new unbound hypervelocity stars (HVSs) in the outer Milky Way halo. Using a conservative estimate of Galactic escape velocity, our targeted spectroscopic survey has now identified 16 unbound HVSs as well as a comparable number of HVSs ejected on bound trajectories. A Galactic center origin for the HVSs is supported by their unbound velocities, the observed number of unbound stars, their stellar nature, their ejection time distribution, and their Galactic latitude and longitude distribution. Other proposed origins for the unbound HVSs, such as runaway ejections from the disk or dwarf galaxy tidal debris, cannot be reconciled with the observations. An intriguing result is the spatial anisotropy of HVSs on the sky, which possibly reflects an anisotropic potential in the central 10-100pc region of the Galaxy. Further progress requires measurement of the spatial distribution of HVSs over the southern sky. Our survey also identifies seven B supergiants associated with known star-forming galaxies; the absence of B supergiants elsewhere in the survey implies there are no new star-forming galaxies in our survey footprint to a depth of 1-2Mpc.
- ID:
- ivo://CDS.VizieR/J/PASJ/63/S379
- Title:
- MOIRCS Deep Survey deep and wide catalogs
- Short Name:
- J/PASJ/63/S379
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep J-, H-, and Ks-band imaging data of the MOIRCS Deep Survey (MODS), which was carried out with the Multi-Object Infrared Camera and Spectrograph (MOIRCS) mounted on the Subaru Telescope in the GOODS-North region. The data reach 5{sigma} total limiting magnitudes for point sources of J=23.9, H=22.8, and Ks=22.8 (Vega magnitude) over 103 arcmin^2^ (wide field). In 28 arcmin^2^ of the survey area, which is an ultra-deep field of the MODS (deep field), the data reach 5{sigma} depths of J=24.8, H=23.4, and Ks=23.8. The spatial resolutions of the combined images are FWHM~0.6" and ~0.5" for the wide and deep fields in all bands, respectively. Combining the MODS data with the multi-wavelength public data taken with the HST, Spitzer, and other ground-based telescopes in the GOODS field, we constructed a multi-wavelength photometric catalog of Ks-selected sources.
1100. MOIRCS Deep Survey. VII.
- ID:
- ivo://CDS.VizieR/J/PASJ/63/S363
- Title:
- MOIRCS Deep Survey. VII.
- Short Name:
- J/PASJ/63/S363
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigated rest-frame near-infrared (NIR) morphologies of a sample of 139 galaxies with Ms>=1x10^109M_{sun}_ at z=0.8-1.2 in the GOODS-North field using our deep NIR imaging data (MOIRCS Deep Survey, MODS). We focused on Luminous Infrared Galaxies (LIRGs), which dominate a high star formation rate (SFR) density at z~1, in a sample identified by cross-correlating with the Spitzer/MIPS 24mum source catalog. We performed two-dimensional light profile fittings of z~1 galaxies in the Ks-band (rest-frame J-band) with a single-component Sersic model.
