- ID:
- ivo://CDS.VizieR/J/ApJ/703/1778
- Title:
- Spitzer sources in SWIRE/XMM/ELAIS-S1 field
- Short Name:
- J/ApJ/703/1778
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of optical spectroscopic identifications of sources detected by Spitzer at 3.6 or 24um down to ~10 and ~280uJy, respectively, in the SWIRE/XMM-Newton/ELAIS-S1 field and classified via line width analysis and diagnostic diagrams. A total of 1376 sources down to R~24.2mag have been identified (1362 detected at 3.6um, 419 at 24um, and 405 at both) by low-resolution optical spectroscopy carried out with FORS2, VIMOS, and EFOSC2 at the Very Large Telescope and 3.6m ESO telescope. The spectroscopic campaigns have been carried out over the central 0.6deg^2^ area of ELAIS-S1 which, in particular, has also been observed by XMM-Newton and Chandra. We find the first direct optical spectroscopic evidence that the fraction of active galactic nuclei (AGNs; mostly AGN2) increases with increasing F(24um)/F(R) ratio, reaching values of 70(+/-20)% in the range 316<F(24um)/F(R)<1000. We present an Infrared Array Camera-Multiband Imaging Photometer color-color diagram able to separate AGN1 from obscured AGN2 candidates. After having corrected for the spectroscopic incompleteness of our sample, the result is that the AGN fraction at F(24um)~0.8mJy is ~22(+/-7)% and decreases slowly to ~19(+/-5)% down to F(24um)~0.3mJy.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/671/323
- Title:
- Spitzer Spectra of a 10mJy galaxy sample
- Short Name:
- J/ApJ/671/323
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A complete flux-limited sample of 50 galaxies is presented having f{nu}(24um)>10mJy, chosen from a survey with MIPS on Spitzer of 8.2deg^2^ in the NOAO Deep Wide-Field Survey (NDWFS) region in Bootes. Spectra obtained with the low-resolution modules of IRS on Spitzer are described for 36 galaxies in this sample; 25 show strong PAH emission features characteristic of starbursts, and 11 show silicate absorption or emission, emission lines, or featureless spectra characteristic of AGNs. Infrared or optical spectral classifications are available for 48 of the entire sample of 50; 33 galaxies are classified as starbursts and 15 as AGNs.
- ID:
- ivo://CDS.VizieR/J/ApJ/697/1993
- Title:
- Spitzer study of AGB stars. III.
- Short Name:
- J/ApJ/697/1993
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the third and final part of a census of asymptotic giant branch (AGB) stars in Local Group dwarf irregular (dIrr) galaxies. Papers I (Jackson et al. 2007ApJ...656..818J) and II (Jackson et al. 2007ApJ...667..891J) presented the results for WLM and IC 1613. Included here are Phoenix, LGS 3, DDO 210, Leo A, Pegasus dIrr, and Sextans A. Spitzer photometry at 3.6, 4.5, 5.8, and 8um are presented, along with a more thorough treatment of background galaxy contamination than was presented in Papers I and II. We find that at least a small population of completely optically obscured AGB stars exists in each galaxy, regardless of the galaxy's metallicity, but that higher metallicity galaxies tend to harbor more stars with slight infrared excesses.
- ID:
- ivo://CDS.VizieR/J/PASP/122/1397
- Title:
- Spitzer Survey of Stellar Structure in Galaxies
- Short Name:
- J/PASP/122/1397
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Spitzer Survey of Stellar Structure in Galaxies (S^4^G) is an Exploration Science Legacy Program approved for the Spitzer post-cryogenic mission. It is a volume-, magnitude-, and size-limited (d<40Mpc, |b|>30{deg}, m_Bcorr_<15.5, and D_25_>1') survey of 2331 galaxies using the Infrared Array Camera (IRAC) at 3.6 and 4.5um. Each galaxy is observed for 240s and mapped to >=1.5D_25_. The final mosaicked images have a typical 1sigma rms noise level of 0.0072 and 0.0093MJy/sr at 3.6 and 4.5um, respectively. Our azimuthally averaged surface brightness profile typically traces isophotes at {mu}_3.6um_(AB)(1sigma)~27mag/arcsec^2^, equivalent to a stellar mass surface density of ~1M_{sun}_/pc^2^. thus provides an unprecedented data set for the study of the distribution of mass and stellar structures in the local universe. This large, unbiased, and extremely deep sample of all Hubble types from dwarfs to spirals to ellipticals will allow for detailed structural studies, not only as a function of stellar mass, but also as a function of the local environment. This article introduces the survey and describes the sample selection, the significance of the 3.6 and 4.5um bands for this study, and the data collection and survey strategies.
- ID:
- ivo://CDS.VizieR/J/ApJ/699/1610
- Title:
- Spitzer survey of submillimeter galaxies
- Short Name:
- J/ApJ/699/1610
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Spitzer-IRAC and MIPS mid-IR observations of a sample of 76 radio-detected submillimeter-selected galaxies (SMGs) with spectroscopic redshifts, the largest such sample published to date. From our data, we find that IRAC colors of SMGs are much more uniform as compared with rest-frame UV and optical colors, and z>1.5 SMGs tend to be redder in their mid-IR colors than both field galaxies and lower-z SMGs. However, the IRAC colors of the SMGs overlap those of field galaxies sufficiently that color-magnitude and color-color selection criteria suggested in the literature to identify SMG counterparts produce ambiguous counterparts within an 8" radius in 20%-35% of cases. We use a rest-frame J-H versus H-K color-color diagram and a S24/S8.0 versus S8.0/S4.5 color-color diagram to determine that 13%-19% of our sample are likely to contain active galactic nuclei which dominate their mid-IR emission.
- ID:
- ivo://CDS.VizieR/J/ApJS/237/39
- Title:
- Spitzer survey of UltraVISTA deep Stripes (SMUVS)
- Short Name:
- J/ApJS/237/39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper describes new deep 3.6 and 4.5{mu}m imaging of three UltraVISTA near-infrared survey stripes within the COSMOS field. The observations were carried out with Spitzer's Infrared Array Camera (IRAC) for the Spitzer Matching Survey of the UltraVISTA Deep Stripes (SMUVS). In this work we present our data reduction techniques, and document the resulting mosaics, coverage maps, and catalogs in both IRAC passbands for the three easternmost UltraVISTA survey stripes, covering a combined area of about 0.66deg^2^, of which 0.45deg^2^ have at least 20hr of integration time. SMUVS reaches point-source sensitivities of about 25.0 AB mag (0.13{mu}Jy) at both 3.6 and 4.5{mu}m, with a significance of 4{sigma}, accounting for both survey sensitivity and source confusion. To this limit the SMUVS catalogs contain a total of ~350,000 sources, each of which is detected significantly in at least one IRAC band. Because of its uniform and high sensitivity, relatively large area coverage, and the wide array of ancillary data available in COSMOS, the SMUVS survey will be useful for a large number of cosmological investigations.
- ID:
- ivo://CDS.VizieR/J/ApJ/752/45
- Title:
- SPLASH: Stellar spectroscopy of M31 satellites
- Short Name:
- J/ApJ/752/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a resolved star spectroscopic survey of 15 dwarf spheroidal (dSph) satellites of the Andromeda galaxy (M31). We filter foreground contamination from Milky Way (MW) stars, noting that MW substructure is evident in this contaminant sample. We also filter M31 halo field giant stars and identify the remainder as probable dSph members. We then use these members to determine the kinematical properties of the dSphs. For the first time, we confirm that And XVIII, XXI, and XXII show kinematics consistent with bound, dark-matter-dominated galaxies. From the velocity dispersions for the full sample of dSphs we determine masses, which we combine with the size and luminosity of the galaxies to produce mass-size-luminosity scaling relations. With these scalings we determine that the M31 dSphs are fully consistent with the MW dSphs, suggesting that the well-studied MW satellite population provides a fair sample for broader conclusions. We also estimate dark matter halo masses of the satellites and find that there is no sign that the luminosity of these galaxies depends on their dark halo mass, a result consistent with what is seen for MW dwarfs. Two of the M31 dSphs (And XV, XVI) have estimated maximum circular velocities smaller than 12 km/s (to 1{sigma}), which likely places them within the lowest-mass dark matter halos known to host stars (along with Bootes I of the MW). Finally, we use the systemic velocities of the M31 satellites to estimate the mass of the M31 halo, obtaining a virial mass consistent with previous results.
- ID:
- ivo://CDS.VizieR/J/ApJS/235/36
- Title:
- SPLASH-SXDF multi-wavelength photometric catalog
- Short Name:
- J/ApJS/235/36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multi-wavelength catalog in the Subaru/XMM-Newton Deep Field (SXDF) as part of the Spitzer Large Area Survey with Hyper-Suprime-Cam (SPLASH). We include the newly acquired optical data from the Hyper-Suprime-Cam Subaru Strategic Program, accompanied by IRAC coverage from the SPLASH survey. All available optical and near-infrared data is homogenized and resampled on a common astrometric reference frame. Source detection is done using a multi-wavelength detection image including the u-band to recover the bluest objects. We measure multi-wavelength photometry and compute photometric redshifts as well as physical properties for ~1.17 million objects over ~4.2deg^2^, with ~800000 objects in the 2.4deg^2^ HSC-Ultra-Deep coverage. Using the available spectroscopic redshifts from various surveys over the range of 0<z<6, we verify the performance of the photometric redshifts and we find a normalized median absolute deviation of 0.023 and outlier fraction of 3.2%. The SPLASH-SXDF catalog is a valuable, publicly available resource, perfectly suited for studying galaxies in the early universe and tracing their evolution through cosmic time.
- ID:
- ivo://CDS.VizieR/J/ApJS/224/38
- Title:
- SPOGS. I. SDSS Shocked POststarburst Galaxy cand.
- Short Name:
- J/ApJS/224/38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- There are many mechanisms by which galaxies can transform from blue, star-forming spirals, to red, quiescent early-type galaxies, but our current census of them does not form a complete picture. Recent observations of nearby case studies have identified a population of galaxies that quench "quietly". Traditional poststarburst searches seem to catch galaxies only after they have quenched and transformed, and thus miss any objects with additional ionization mechanisms exciting the remaining gas. The Shocked POststarburst Galaxy Survey (SPOGS) aims to identify transforming galaxies, in which the nebular lines are excited via shocks instead of through star formation processes. Utilizing the Oh-Sarzi-Schawinski-Yi (OSSY, 2011ApJS..195...13O) measurements on the Sloan Digital Sky Survey Data Release 7 catalog, we applied Balmer absorption and shock boundary criteria to identify 1067 SPOG candidates (SPOGs*) within z=0.2. SPOGs* represent 0.2% of the OSSY sample galaxies that exceed the continuum signal-to-noise cut (and 0.7% of the emission line galaxy sample). SPOGs* colors suggest that they are in an earlier phase of transition than OSSY galaxies that meet an "E+A" selection. SPOGs* have a 13% 1.4GHz detection rate from the Faint Images of the Radio Sky at Twenty Centimeters Survey, higher than most other subsamples, and comparable only to low-ionization nuclear emission line region hosts, suggestive of the presence of active galactic nuclei (AGNs). SPOGs* also have stronger Na i D absorption than predicted from the stellar population, suggestive of cool gas being driven out in galactic winds. It appears that SPOGs* represent an earlier phase in galaxy transformation than traditionally selected poststarburst galaxies, and that a large proportion of SPOGs* also have properties consistent with disruption of their interstellar media, a key component to galaxy transformation. It is likely that many of the known pathways to transformation undergo a SPOG phase. Studying this sample of SPOGs* further, including their morphologies, AGN properties, and environments, has the potential for us to build a more complete picture of the initial conditions that can lead to a galaxy evolving.
- ID:
- ivo://CDS.VizieR/J/A+A/628/A23
- Title:
- SPT0346-52 CO and H2O ALMA images
- Short Name:
- J/A+A/628/A23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present and study spatially resolved imaging obtained with the Atacama Large Millimeter/submillimeter Array (ALMA) of multiple ^12^CO(J=6-5, 8-7 and 9-8) and two H_2_O(2_02_-1_11_ and 2_11_-2_02_) emission lines and cold dust continuum toward the gravitationally lensed dusty star forming galaxy SPT0346-52 at z=5.656. Using a visibility-domain source-plane reconstruction we probe the structure and dynamics of the different components of the interstellar medium (ISM) in this galaxy down to scales of 1kpc in the source plane. Measurements of the intrinsic sizes of the different CO emission lines indicate that the higher J transitions trace more compact regions in the galaxy. Similarly, we find smaller dust continuum intrinsic sizes with decreasing wavelength, based on observations at rest-frame 130, 300 and 450um. The source shows significant velocity structure, and clear asymmetry where an elongated structure is observed in the source plane with significant variations in their reconstructed sizes. This could be attributed to a compact merger or turbulent disk rotation. The differences in velocity structure through the different line tracers, however, hint at the former scenario in agreement with previous [CII] line imaging results. Measurements of the CO line ratios and magnifications yield significant variations as a function of velocity, suggesting that modeling of the ISM using integrated values could be misinterpreted. Modeling of the ISM in SPT0346-52 based on delensed fluxes indicate a highly dense and warm medium, qualitatively similar to that observed in high redshift quasar hosts.
