- 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/MNRAS/453/1965
- Title:
- Star-forming compact groups
- Short Name:
- J/MNRAS/453/1965
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a local sample (z<0.15) of 280 star-forming compact groups (SFCGs) of galaxies identified in the ultraviolet Galaxy Evolution EXplorer (GALEX) All-sky Imaging Survey (AIS). So far, just one prototypical example of SFCG, the Blue Infalling Group, has been studied in detail in the Local Universe. The sample of SFCGs is mainly the result of applying a Friends-of-Friends group finder in the space of celestial coordinates with a maximum linking-length of 1.5 arcmin and choosing groups with a minimum number of four members of bright UV-emitting 17<FUV<20.5 sources (mostly galaxies) from the GALEX/AIS catalogue. The result from the search are 280 galaxy groups composed by 226, 39, 11 and 4 groups of four, five, six and seven bright ultraviolet (UV) members, respectively. Only 59 of these 280 newly identified SFCGs have a previous catalogued group counterpart. Group redshifts are available for at least one member in 75 per cent of the SFCGs, and over 40 per cent of the SFCGs have redshifts measured for two or more galaxies. 26 of the SFCGs appear to be located in the infalling regions of clusters with known redshift. The SFCG sample presents a combination of properties different from the group samples studied up to now, such as low-velocity dispersions (sigma_l-o-s_~120km/s), small crossing-times (H_0_t_c_~0.05) and high star formation content (95 per cent of star-forming galaxies). This points to the SFCGs being in an evolutionary stage distinct from those groups selected in the optical and near-infrared ranges. Once redshifts are obtained to discard interlopers, SFCGs will constitute a unique sample of SFCGs.
- ID:
- ivo://CDS.VizieR/J/MNRAS/401/1521
- Title:
- Stellar masses of Lyman break galaxies at z~3
- Short Name:
- J/MNRAS/401/1521
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of a large survey of the mid-infrared (mid-IR) properties of 248 Lyman Break Galaxies (LBGs) with confirmed spectroscopic redshift using deep Spitzer/Infrared Array Camera (IRAC) observations in six cosmological fields. By combining the new mid-IR photometry with optical and near-infrared observations, we model the spectral energy distributions (SEDs) employing a revised version of the Bruzual and Charlot synthesis population code that incorporates a new treatment of the thermal-pulsating asymptotic giant branch phase (CB07). Our primary aim is to investigate the impact of the AGB phase in the stellar masses of the LBGs, and compare our new results with previous stellar mass estimates. We investigate the stellar mass of the LBG population as a whole and assess the benefits of adding longer wavelengths to estimates of stellar masses for high-redshift galaxies.
- ID:
- ivo://CDS.VizieR/J/MNRAS/460/2862
- Title:
- Stellar mass of brightest cluster galaxies
- Short Name:
- J/MNRAS/460/2862
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using a sample of 98 galaxy clusters recently imaged in the near-infrared with the European Southern Observatory (ESO) New Technology Telescope, WIYN telescope and William Herschel Telescope, supplemented with 33 clusters from the ESO archive, we measure how the stellar mass of the most massive galaxies in the universe, namely brightest cluster galaxies (BCGs), increases with time. Most of the BCGs in this new sample lie in the redshift range 0.2<z<0.6, which has been noted in recent works to mark an epoch over which the growth in the stellar mass of BCGs stalls. From this sample of 132 clusters, we create a subsample of 102 systems that includes only those clusters that have estimates of the cluster mass. We combine the BCGs in this subsample with BCGs from the literature, and find that the growth in stellar mass of BCGs from 10 billion years ago to the present epoch is broadly consistent with recent semi-analytic and semi-empirical models. As in other recent studies, tentative evidence indicates that the stellar mass growth rate of BCGs may be slowing in the past 3.5 billion years. Further work in collecting larger samples, and in better comparing observations with theory using mock images, is required if a more detailed comparison between the models and the data is to be made.
- ID:
- ivo://CDS.VizieR/J/MNRAS/313/469
- Title:
- Streaming motions of galaxy clusters. I.
- Short Name:
- J/MNRAS/313/469
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The present paper is the first in a series presenting results of the "Streaming Motions of Abell Cluster" (SMAC) project. We present new spectroscopic data for 532 early-type galaxies, predominantly Abell cluster members with cz<12000km/s. We tabulate 919 individual measurements, from six observing runs, for recession velocity, cz, central velocity dispersion, {sigma}, and magnesium line-strength indices, Mg_2_ and Mgb. The median estimated error, per measurement, in {sigma} is 5 per cent. The Mg_2_ line-strength data have median errors of 0.009mag. The observed scatter between repeat measurements is largely accounted for by photon-counting errors. These data will be employed in forthcoming papers, where they will form part of a merged and standardized catalogue of Fundamental Plane data for use in cluster distance estimates and peculiar velocity analyses.
- ID:
- ivo://CDS.VizieR/J/MNRAS/369/1131
- Title:
- Structures in the GA region
- Short Name:
- J/MNRAS/369/1131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To further our understanding of the Great Attractor (GA), we have undertaken a redshift survey using the 2dF on the AAT. Clusters and filaments in the GA region were targeted with 25 separate pointings resulting in approximately 2600 new redshifts. Targets included poorly studied X-ray clusters from the CIZA catalogue as well as the Cen-Crux and PKS 1343-601 clusters, both of which lie close to the classic GA centre. For nine clusters in the region, we report velocity distributions as well as virial and projected mass estimates. The virial mass of CIZA J1324.75736, now identified as a separate structure from the Cen-Crux cluster, is found to be ~3x10^14^M_{sun}_ in good agreement with the X-ray inferred mass. In the PKS 1343-601 field, five redshifts are measured of which four are new. An analysis of redshifts from this survey, in combination with those from the literature, reveals the dominant structure in the GA region to be a large filament, which appears to extend from Abell S0639 (l=281{deg}, b=+11{deg}) to (l~5{deg}, b~-50{deg}), encompassing the Cen-Crux, CIZA J1324.75736, Norma and Pavo II clusters. Behind the Norma Cluster at cz~15000km/s, the masses of four rich clusters are calculated. These clusters (Triangulum-Australis, Ara, CIZA J1514.64558 and CIZA J1410.44246) may contribute to a continued large- scale flow beyond the GA. The results of these observations will be incorporated into a subsequent analysis of the GA flow.
- ID:
- ivo://CDS.VizieR/J/MNRAS/421/3060
- Title:
- Subaru/XMM Deep Field radio imaging. III.
- Short Name:
- J/MNRAS/421/3060
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectroscopic and 11-band photometric redshifts for galaxies in the 100-uJy Subaru/XMM-Newton Deep Field radio source sample. We find good agreement between our redshift distribution and that predicted by the Square Kilometre Array (SKA) Simulated Skies project. We find no correlation between K-band magnitude and radio flux, but show that sources with 1.4-GHz flux densities below ~1mJy are fainter in the near-infrared than brighter radio sources at the same redshift, and we discuss the implications of this result for spectroscopically incomplete samples where the K-z relation has been used to estimate redshifts. We use the infrared-radio correlation to separate our sample into radio-loud and radio-quiet objects and show that only radio-loud hosts have spectral energy distributions consistent with predominantly old stellar populations, although the fraction of objects displaying such properties is a decreasing function of radio luminosity.
- ID:
- ivo://CDS.VizieR/J/MNRAS/384/1611
- Title:
- Submm observations in gravitational lenses
- Short Name:
- J/MNRAS/384/1611
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted a submillimetre mapping survey of faint, gravitationally lensed sources, where we have targeted 12 galaxy clusters and additionally the New Technology Telescope (NTT) Deep Field. The total area surveyed is 71.5arcmin^2^ in the image plane; correcting for gravitational lensing, the total area surveyed is 40arcmin^2^ in the source plane for a typical source redshift z>>2.5. In the deepest maps, an image plane depth of 1{sigma} rms ~0.8mJy is reached. This survey is the largest survey to date to reach such depths. In total 59 sources were detected, including three multiply imaged sources. The gravitational lensing makes it possible to detect sources with flux density below the blank field confusion limit. The lensing-corrected fluxes range from 0.11 to 19mJy. After correcting for multiplicity, there are 10 sources with fluxes <2mJy of which seven have submJy fluxes, doubling the number of such sources known. Number counts are determined below the confusion limit. At 1mJy, the integrated number count is ~10^4^deg^-2^, and at 0.5mJy it is ~2x10^4^deg^-2^. Based on the number counts, at a source plan flux limit of 0.1mJy, essentially all of the 850-m background emission has been resolved. The dominant contribution (>50 per cent) to the integrated background arises from sources with fluxes S850 between 0.4 and 2.5mJy, while the bright sources S850>6mJy contribute only 10 per cent.
359. SuperCLASS. I.
- ID:
- ivo://CDS.VizieR/J/MNRAS/495/1706
- Title:
- SuperCLASS. I.
- Short Name:
- J/MNRAS/495/1706
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The SuperCLuster Assisted Shear Survey (SuperCLASS) is a legacy programme using the e-MERLIN interferometric array. The aim is to observe the sky at L-band (1.4GHz) to a r.m.s. of 7uJy/beam over an area of 1 square degrees centred on the Abell 981 supercluster. The main scientific objectives of the project are: (i) to detect the effects of weak lensing in the radio in preparation for similar measurements that will be made by the Square Kilometre Array (SKA); (ii) an extinction free census of star formation and AGN activity at z up to 1. In this paper we give an overview of the project including the science goals and multi-wavelength coverage before presenting the first data release. We have analysed around 400 hours of e-MERLIN data which has allowed us to create a DR1 mosaic covering an area ~0.26 square degrees to the full depth. These observations have been supplemented with complementary radio observations from the Karl G. Jansky Very Large Array (VLA) and optical/near infra-red observations taken with the Subaru, Canada-France-Hawaii and Spitzer Telescopes. The main data product is a catalogue of 887 sources detected by the VLA, of which 395 are detected by e-MERLIN and 197 of these are resolved. We have investigated the size, flux and spectral index properties of these sources and find them to be compatible with previous studies. Preliminary photometric redshifts, and an assessment of galaxy shapes measured in the radio data, combined with a radio-optical cross-correlation technique to probe cosmic shear in a supercluster environment, are presented in companion papers.
- ID:
- ivo://CDS.VizieR/J/other/ChJAA/8.385
- Title:
- Superluminal motion in AGN
- Short Name:
- J/other/ChJAA/8.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have collected an up-to-date sample of 123 superluminal sources (84 quasars, 27 BL Lac objects and 12 galaxies) and calculated the apparent velocities ({beta}_app_) for 224 components in the sources with the {Lambda}-CDM model. We checked the relationships between their proper motions, redshifts, {beta}_app_ and 5GHz flux densities. Our analysis shows that the radio emission is strongly boosted by the Doppler effect. The superluminal motion and the relativistic beaming boosting effect are, to some extent, the same in active galactic nuclei.
