- ID:
- ivo://CDS.VizieR/J/MNRAS/395/1695
- Title:
- Spitzer mid-IR spectroscopy of LIRGs
- Short Name:
- J/MNRAS/395/1695
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results on low-resolution mid-infrared (MIR) spectra of 70 IR-luminous galaxies obtained with the infrared spectrograph (IRS) onboard Spitzer. We selected sources from the European Large Area Infrared Survey with S_15_>0.8mJy and photometric or spectroscopic z>1. About half of the samples are quasi-stellar objects (QSOs) in the optical, while the remaining sources are galaxies, comprising both obscured active galactic nuclei (AGN) and starbursts. Redshifts were obtained from optical spectroscopy, photometric redshifts and the IRS spectra. The later turn out to be reliable for obscured and/or star-forming sources, thus becoming an ideal complement to optical spectroscopy for redshift estimation.
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Search Results
- 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/679/720
- Title:
- Spitzer observations of the Hyades
- Short Name:
- J/ApJ/679/720
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the Spitzer Space Telescope to search for infrared excess at 24, 70, and 160um due to debris disks around a sample of 45 FGK-type members of the Hyades. We supplement our observations with archival 24 and 70um Spitzer data of an additional 22 FGK-type and 11 A-type Hyades members in order to provide robust statistics on the incidence of debris disks at 625Myr of age, an era corresponding to the late heavy bombardment in the solar system. We find that none of the 67 FGK-type stars in our sample show evidence for a debris disk, while 2 out of the 11 A-type stars do. This difference in debris disk detection rate is likely to be due to a sensitivity bias in favor of early-type stars. The fractional disk luminosity, L_dust_/L_*_, of the disks around the two A-type stars is ~4x10^-5^, a level that is below the sensitivity of our observations toward the FGK-type stars. However, our sensitivity limits for FGK-type stars are able to exclude, at the 2{sigma} level, frequencies higher than 12% and 5% of disks with L_dust_/L_*_>1x10^-4^ and L_dust_/L_*_>5x10^-4^, respectively. We also use our sensitivity limits and debris disk models to constrain the maximum mass of dust, as a function of distance from the stars, that could remain undetected around our targets.
- 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.
- ID:
- ivo://CDS.VizieR/J/A+A/631/A167
- Title:
- SPT-S J041839-4751.8 APEX spectra
- Short Name:
- J/A+A/631/A167
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of six far-infrared fine structure lines in the z=4.225 lensed dusty star-forming galaxy SPT 0418-47 (SPT-S J041839-4751.8) to probe the physical conditions of its inter stellar medium (ISM). In particular, we report Atacama Pathfinder EXperiment (APEX) detections of the [OI] 145um and [OIII] 88um lines and Atacama Compact Array (ACA) detections of the [NII] 122 and 205um lines. The [OI] 145um/[CII] 158um line ratio is ~5x higher compared to the average of local galaxies. We interpret this as evidence that the ISM is dominated by photo-dissociation regions with high gas densities. The line ratios, and in particular those of [OIII] 88um and [NII] 122um imply that the ISM in SPT 0418-47 is already chemically enriched to nearly solar metallicity. While the strong gravitational amplification was required to detect these lines with APEX, larger samples can be observed with the Atacama Large Millimeter/submillimeter Array (ALMA), and should allow observers to determine if the dense, solar metallicity ISM is common among these highly star-forming galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/779/61
- Title:
- SPT-SZ survey point sources at 95, 150 & 220GHz
- Short Name:
- J/ApJ/779/61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a point-source catalog from 771deg^2^ of the South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) survey at 95, 150, and 220GHz. We detect 1545 sources above 4.5{sigma} significance in at least one band. Based on their relative brightness between survey bands, we classify the sources into two populations, one dominated by synchrotron emission from active galactic nuclei, and one dominated by thermal emission from dust-enshrouded star-forming galaxies. We find 1238 synchrotron and 307 dusty sources. We cross-match all sources against external catalogs and find 189 unidentified synchrotron sources and 189 unidentified dusty sources. The dusty sources without counterparts are good candidates for high-redshift, strongly lensed submillimeter galaxies. We derive number counts for each population from 1Jy down to roughly 11, 4, and 11mJy at 95, 150, and 220GHz. We compare these counts with galaxy population models and find that none of the models we consider for either population provide a good fit to the measured counts in all three bands. The disparities imply that these measurements will be an important input to the next generation of millimeter-wave extragalactic source population models.
- ID:
- ivo://CDS.VizieR/J/ApJ/683/822
- Title:
- Star formation in Ophiuchus and Perseus II.
- Short Name:
- J/ApJ/683/822
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a census of the population of deeply embedded young stellar objects (YSOs) in the Ophiuchus molecular cloud complex based on a combination of Spitzer Space Telescope mid-infrared data from the "Cores to Disks" (c2d) legacy team and JCMT/SCUBA submillimeter maps from the COMPLETE team. We have applied a method developed for identifying embedded protostars in Perseus to these data sets and in this way construct a relatively unbiased sample of 27 candidate embedded protostars with envelopes more massive than our sensitivity limit (about 0.1M_{sun}_).
- ID:
- ivo://CDS.VizieR/J/A+A/521/A61
- Title:
- Stars associated to Eagle Nebula (M16=NGC6611)
- Short Name:
- J/A+A/521/A61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Massive star-forming regions are characterized by intense ionizing fluxes, strong stellar winds and, occasionally, supernovae explosions, all of which have important effects on the surrounding media, on the star-formation process and on the evolution of young stars and their circumstellar disks. We present a multiband study of the massive young cluster NGC 6611 and its parental cloud (the Eagle Nebula) with the aim of studying how OB stars affect the early stellar evolution and the formation of other stars. We search for evidence of triggering of star formation by the massive stars inside NGC 6611 on a large spatial scale (~10 parsec) and ongoing disk photoevaporation in NGC 6611 and how its efficiency depends on the mass of the central stars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/421/3027
- Title:
- Statisical study of galaxy dust emissions
- Short Name:
- J/MNRAS/421/3027
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the Herschel-ATLAS survey to conduct the first large-scale statistical study of the submillimetre properties of optically selected galaxies. Using ~80000 r-band selected galaxies from 126deg^2^ of the GAMA survey, we stack into submillimetre imaging at 250, 350 and 500um to gain unprecedented statistics on the dust emission from galaxies at z<0.35. We find that low-redshift galaxies account for 5 per cent of the cosmic 250-um background (4 per cent at 350um; 3 per cent at 500um), of which approximately 60 per cent comes from 'blue' and 20 per cent from 'red' galaxies (rest-frame g-r).
- ID:
- ivo://CDS.VizieR/J/A+A/654/A135
- Title:
- 12 strong galactic bars CO spectra
- Short Name:
- J/A+A/654/A135
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- While some galactic bars show recent massive star formation (SF) along them, some others present a lack of it. Whether bars with low level of SF are a consequence of low star formation efficiency, low gas inflow rate, or dynamical effects, remains a matter of debate. In order to study the physical conditions that enable or prevent SF, we perform a multi-wavelength analysis of 12 strongly barred galaxies with total stellar masses log10(M*/M_{sun}_){in}[10.2,11], chosen to host different degrees of SF along the bar major axis without any prior condition on gas content. We observe the CO(1-0) and CO(2-1) emission within bars with the IRAM-30m telescope (beam sizes of 1.7-3.9kpc and 0.9-2.0kpc, respectively; 7-8 pointings per galaxy on average). We estimate molecular gas masses (Mmol) from the CO(1-0) and CO(2-1) emissions. SF rates (SFR) are calculated from GALEX near-ultraviolet (UV) and WISE 12um images within the beam-pointings, covering the full bar extent (SFRs are also derived from far-UV and 22um). Results. We detect molecular gas along the bars of all probed galaxies. Molecular gas and SFR surface densities span the ranges log10({Sigma}_mol_/[M_{sun}_/pc^2^]){in}[0.4,2.4] and log10({Sigma}_SFR_/[M_{sun}_/pc/kpc^2^]){in}[-3.25,-0.75], respectively. The star formation efficiency (SFE=SFR/Mmol) in bars varies between galaxies by up to an order of magnitude (SFE{in}[0.1,1.8]Gyr^-1^). On average, SFEs are roughly constant along bars. SFEs are not significantly different from the mean value in spiral galaxies reported in the literature (~0.43Gyr^-1^), regardless of whether we estimate Mmol from CO(1-0) or CO(2-1). Interestingly, the higher the total stellar mass of the host galaxy, the lower the SFE within their bars. In particular, the two galaxies in our sample with lowest SFE and {Sigma}_SFR_ (NGC 4548 and NGC 5850, SFE<=0.25Gyr^-1^, {Sigma}_SFR_<=10^-2.25^M_{sun}_/yr/kpc^2^, M*<=10^10.7^M_{sun}_) are also the ones hosting massive bulges and signs of past interactions with nearby companions. We present a statistical analysis of the SFE in bars for a sample of 12 galaxies. The SFE in strong bars is not systematically inhibited (either in the central, mid- or end-parts of the bar). Both environmental and internal quenching are likely responsible for the lowest SFEs reported in this work.
