- ID:
- ivo://CDS.VizieR/J/ApJ/449/527
- Title:
- Galaxies in the zone of avoidance
- Short Name:
- J/ApJ/449/527
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have selected a sample of 876 galaxy candidates from the IRAS Point Source Catalog in the region of 2h<RA<10h and 0deg<DE<36deg, which crosses the Galactic anticenter part of the Zone of Avoidance (ZOA) and includes most of the highly obscured Orion-Taurus complex region. We have identified galaxies among the candidate sources by attempting to detect the 21cm H I line of those sources which were not known to be galaxies at the beginning of the survey. In this manner, we constructed a galaxy sample which is largely free from Galactic reddening. Of the 272 observed candidates, 89 were detected in the H I line up to a heliocentric velocity of v_h_~16,000km/s. The resulting galaxy sample of 717 galaxies is fairly complete (within about 10%) and uniform (within about 4%) in the part of the survey area 10deg away from the Galactic plane and for velocities up to at least 9000km/s. This provides, for the first time, a largely unbiased view on the large-scale structures in much of the survey area. Our main results are the following: (1) Several large voids are identified. In particular, a void between RA~3h and 4h, up to v_h_~6000km/s, separates the Pisces-Perseus supercluster at RA<3h from structures at RA>4h; and a "nearby void" occupies most of our survey area and reaches out to a redshift of nearly 3000km/s. (2) We found no nearby galaxy concentration that could significantly contribute to the "Local Velocity Anomaly" (LVA), but a general excess of galaxies around v_h_~5000km/s in the survey area. (3) The contrast between the "Great Wall" at v_h_~8500km/s and the void in front of it appears to gradually diffuse out after it enters the Zone of Avoidance from the northern Galactic hemisphere. (4) Our data combined with other galaxy surveys in or near the Galactic anticenter part of the ZOA suggest that the main ridge of the Pisces-Perseus supercluster does also not extend to Abell 569, a cluster in the northern Galactic hemisphere, and that the simple gravitational model consisting of the Local Void of Tully & Fisher, our nearby void, and Puppis and Fornax-Eridanus clusters would predict a LVA whose direction is probably too far away from that derived from observations.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/107/521
- Title:
- Galaxies redshifts, 210<l<360, |b|<15
- Short Name:
- J/ApJS/107/521
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out a redshift survey of an IRAS flux-limited (f_60_>0.6) galaxy sample behind the southern Milky Way, 210{deg}<l<360{deg} at |b|<15{deg}. The survey includes redshifts for 951 galaxies, ~500 of which are new. Of these 951 galaxies, 462 are in the zone 5{deg}<b<15{deg} and 353 are in the zone -15{deg}<b<-5{deg}. Though the innermost region of the Milky Way (|b|=5{deg}) remains opaque except in the longitude near 240, the detected galaxies show a high degree of completeness (~70%) in the zones 5{deg}<b<15{deg} and -15{deg}<b<-5{deg}. The cone diagrams exhibiting the detailed distribution of IRAS galaxies in the region 210{deg}<l<360{deg}, |b|<15{deg} shows two clusters in the Puppis region (l=240{deg}, b=-7{deg}, v=2400km/s; l=245{deg}, b=-5{deg}, v=7500km/s), the A3627 cluster (l=325{deg}, b=-7{deg}; v=4500km/s), the S4 cluster (l=280{deg}, b=7{deg}; v=5500km/s), and a possible void at l=245{deg}, v=3000km/s. The region 270{deg}<l<350{deg} is dominated by overdensity of galaxies representing the extension of the Hydra-Centaurus complex in the positive latitudes and the Pavo-Indus complex in the negative latitudes. A velocity histogram of galaxies in the GA region 290{deg}<l<350{deg}, |b|<15{deg}. reveals a substantial overdensity of galaxies in the velocity range 2400-5000km/s. The centroid of this overdensity is located at 4000km/s. The broad increased density of galaxies seen in our data corresponds with the distant concentration seen at 4500km/s in the supergalactic plane survey that covers the same longitude range like ours in l, but a larger range in latitude b (-30{deg} to -10{deg} and +10{deg} to +45{deg}). This lends support to the idea that the overdensity extends all the way from the Centaurus-Hydra complex (l=302{deg}, b=+22{deg}) in the north to the major concentration of the Pavo-Indus supercluster (l=332{deg}, b=-24{deg}) in the south, through the Milky Way. We conclude that the peak of the overdensity responsible for the peculiar velocity field in the local region is possibly situated in the Milky Way itself.
- ID:
- ivo://CDS.VizieR/J/A+A/507/713
- Title:
- Galaxies with strong PAH emission
- Short Name:
- J/A+A/507/713
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the fourth in a series of papers based on the ISOCAM Parallel Survey at 6.7um. While the first three papers have been devoted to active galactic nuclei (AGN), here we report on emission-line galaxies without AGN signatures in their optical spectra. Polycyclic aromatic hydrocarbon (PAH) emission has been found in both starbursts and modestly starforming galaxies, but the relation between starforming activity and PAH luminosity is still a matter of debate. The different correlation degrees could be caused by the variety of optical and far-infrared sample selection criteria. In order to obtain a census of the typical properties of PAH emitting galaxies, we here study moderately distant galaxies which have been selected by their PAH emission.
- ID:
- ivo://CDS.VizieR/J/A+A/551/A8
- Title:
- Galaxy clusters in XMM field within CFHT-LS D4
- Short Name:
- J/A+A/551/A8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The XMM-Newton Distant Cluster Project (XDCP) aims at the identification of a well defined sample of X-ray selected clusters of galaxies at redshifts z>0.8. As part of this project, we analyse the deep XMM-Newton exposure covering one of the CFHTLS deep fields to quantify the cluster content. We validate the optical follow-up strategy as well as the X-ray selection function. We search for extended X-ray sources in archival XMM-Newton EPIC observations. Multi-band optical imaging is performed to select high redshift cluster candidates among the extended X-ray sources. Here we present a catalogue of the extended sources in one the deepest LBQS ~250ks XMM-Newton fields targeting LBQS J2212-1759 covering ~0.2 square degrees. The cluster identification is based, among others, on deep imaging with the ESO VLT and from the CFHT legacy survey. The confirmation of cluster candidates is done by VLT/FORS2 multi-object spectroscopy. Photometric redshifts from the CFHTLS D4 are utilized to confirm the effectiveness of the X-ray cluster selection method. The survey sensitivity is computed with extensive Monte-Carlo simulations. At a flux limit of S(0.5-2.0keV)~2.5e-15erg/s/cm2 we achieve a completeness level higher than 50% in an area of ~0.13 square degrees. We detect six galaxy clusters above this limit with optical counterparts, of which 5 are new spectroscopic discoveries. Two newly discovered X-ray luminous galaxy clusters are at z>1.0, another two at z=0.41 and one at z=0.34. For the most distant X-ray selected cluster in this field at z=1.45 we find additional (active) member galaxies from both X-ray and spectroscopic data. Additionally, we find evidence of large scale structures at moderate redshifts of z=0.41 and z=0.34. The quest for distant clusters in archival XMM-Newton data has led to the detection of six clusters in a single field, making XMM-Newton an outstanding tool for cluster surveys. Three of these clusters are at z>1, which emphasises the valuable contribution of small, yet deep surveys to cosmology. Beta-models are appropriate descriptions for the cluster surface brightness to perform cluster detection simulations in order to compute the X-ray selection function. The constructed log N-log S tends to favour a scenario where no evolution in the cluster X-ray luminosity function (XLF) takes place.
- ID:
- ivo://CDS.VizieR/J/ApJ/782/64
- Title:
- Galaxy structural parameters from 3.6um images
- Short Name:
- J/ApJ/782/64
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have performed two-dimensional multicomponent decomposition of 144 local barred spiral galaxies using 3.6{mu}m images from the Spitzer Survey of Stellar Structure in Galaxies. Our model fit includes up to four components (bulge, disk, bar, and a point source) and, most importantly, takes into account disk breaks. We find that ignoring the disk break and using a single disk scale length in the model fit for Type II (down-bending) disk galaxies can lead to differences of 40% in the disk scale length, 10% in bulge-to-total luminosity ratio (B/T), and 25% in bar-to-total luminosity ratios. We find that for galaxies with B/T>=0.1, the break radius to bar radius, r_br_/R_bar_, varies between 1 and 3, but as a function of B/T the ratio remains roughly constant. This suggests that in bulge-dominated galaxies the disk break is likely related to the outer Lindblad resonance of the bar and thus moves outward as the bar grows. For galaxies with small bulges, B/T<0.1, r_br_/R_bar_ spans a wide range from 1 to 6. This suggests that the mechanism that produces the break in these galaxies may be different from that in galaxies with more massive bulges. Consistent with previous studies, we conclude that disk breaks in galaxies with small bulges may originate from bar resonances that may be also coupled with the spiral arms, or be related to star formation thresholds.
- ID:
- ivo://CDS.VizieR/J/ApJS/234/18
- Title:
- GALEX/S4G surface brightness profiles. I.
- Short Name:
- J/ApJS/234/18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new spatially resolved surface photometry in the far-ultraviolet (FUV) and near-ultraviolet (NUV) from images obtained by the Galaxy Evolution Explorer (GALEX) and IRAC1 (3.6{mu}m) photometry from the Spitzer Survey of Stellar Structure in Galaxies (S^4^G). We analyze the radial surface brightness profiles {mu}FUV, {mu}NUV, and {mu}[3.6], as well as the radial profiles of (FUV-NUV), (NUV-[3.6]), and (FUV-[3.6]) colors in 1931 nearby galaxies (z<0.01). The analysis of the 3.6 {mu}m surface brightness profiles also allows us to separate the bulge and disk components in a quasi-automatic way and to compare their light and color distribution with those predicted by the chemo-spectrophotometric models for the evolution of galaxy disks of Boissier & Prantzos (2000MNRAS.312..398B). The exponential disk component is best isolated by setting an inner radial cutoff and an upper surface brightness limit in stellar mass surface density. The best-fitting models to the measured scale length and central surface brightness values yield distributions of spin and circular velocity within a factor of two of those obtained via direct kinematic measurements. We find that at a surface brightness fainter than {mu}[3.6]=20.89mag arcsec^-2^, or below 3x10^8^M_{sun}_/kpc^2^ in stellar mass surface density, the average specific star formation rate (sSFR) for star-forming and quiescent galaxies remains relatively flat with radius. However, a large fraction of GALEX Green Valley galaxies show a radial decrease in sSFR. This behavior suggests that an outside-in damping mechanism, possibly related to environmental effects, could be testimony of an early evolution of galaxies from the blue sequence of star-forming galaxies toward the red sequence of quiescent galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/894/88
- Title:
- {gamma}-ray emission of star-forming galaxies
- Short Name:
- J/ApJ/894/88
- Date:
- 19 Jan 2022 13:04:51
- Publisher:
- CDS
- Description:
- A majority of the {gamma}-ray emission from star-forming galaxies is generated by the interaction of high-energy cosmic rays with the interstellar gas and radiation fields. Star-forming galaxies are expected to contribute to both the extragalactic {gamma}-ray background and the IceCube astrophysical neutrino flux. Using roughly 10yr of {gamma}-ray data taken by the Fermi Large Area Telescope, in this study we constrain the {gamma}-ray properties of star-forming galaxies. We report the detection of 11 bona fide {gamma}-ray-emitting galaxies and 2 candidates. Moreover, we show that the cumulative {gamma}-ray emission of below-threshold galaxies is also significantly detected at ~5{sigma} confidence. The {gamma}-ray luminosity of resolved and unresolved galaxies is found to correlate with the total (8-1000{mu}m) infrared luminosity as previously determined. Above 1GeV, the spectral energy distribution of resolved and unresolved galaxies is found to be compatible with a power law with a photon index of ~2.2-2.3. Finally, we find that star-forming galaxies account for roughly 5% and 3% of the extragalactic {gamma}-ray background and the IceCube neutrino flux, respectively.
- ID:
- ivo://CDS.VizieR/J/A+A/654/A150
- Title:
- Gas and young stars in CMa OB1 assoc.
- Short Name:
- J/A+A/654/A150
- Date:
- 21 Mar 2022 09:18:01
- Publisher:
- CDS
- Description:
- The relationship between young stellar clusters and their respective parental molecular clouds remains an open issue. Recent inquiries consider the similarities between substructures of clouds and clusters and whether they are a coincidence or, rather, an indication of a physical relationship. To address these issues, we studied the CMa OB1/R1 region, which shows evidence of a complex star formation history. We obtained molecular cloud mapping with the IRAM-30 metre telescope to reveal the physical conditions of an unexplored side of the CMa region with the aim of comparing the morphology of the clouds to the distribution of young stellar objects (YSOs). We also studied the cloud kinematics in pursuit of gradients and jet signatures that could trace different star formation scenarios. The YSOs were selected on the basis of astrometric data from Gaia EDR3 that characterize the moving groups. The distance of 1099_-24_^+25^pc was obtained for the sample, based on the mean error-weighted parallax. Optical and near-infrared photometry was used to verify the evolutionary status and circumstellar characteristics of the YSOs. Among the selected candidates, we found 40 members associated with the cloud: 1 Class I, 11 Class II, and 28 Class III objects. Comparing the spatial distribution of the stellar population with the cores revealed by the ^13^CO map, we verified that peaks of emission coincide with the position of YSOs, confirming the association of these objects to their dense natal gas. Our observations support the large-scale scenario of the CMa shell-like structure formation as a relic of successive supernova events.
- ID:
- ivo://CDS.VizieR/J/A+A/422/941
- Title:
- Gas content in 1038 interacting galaxies
- Short Name:
- J/A+A/422/941
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A study of the gas content in 1038 interacting galaxies, essentially selected from Arp (<VII/74>), Arp and Madore (<VII/170>), Vorontsov-Velyaminov (<VII/236>) catalogues and some of the published literature, is presented here. The data on the interstellar medium have been extracted from a number of sources in the literature and compared with a sample of 1916 normal galaxies. The mean values for each of the different ISM tracers (FIR, 21cm, CO lines, X-ray) have been estimated by means of survival analysis techniques, in order to take into account the presence of upper limits.
- ID:
- ivo://CDS.VizieR/J/ApJS/73/359
- Title:
- 1.49 GHz atlas of the IRAS bright galaxies
- Short Name:
- J/ApJS/73/359
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains 1.49 GHz VLA observations of sources from the IRAS Bright Galaxy Sample. The original IRAS Bright Galaxy Sample (Soifer et al., 1987ApJ...320..238S) comprises 324 extragalactic objects with 60 micron flux densities above 5.4 Jy. It is the infrared analog of the radio 3CR or optical Shapley-Ames samples. Recalibration of the IRAS flux densities led to a revised Bright Galaxy Sample (Soifer et al., 1989AJ.....98..766S) containing 313 sources stronger than 5.24 Jy at 60 microns. Only one source from these samples was not detected (NGC1377) at 1.49 GHz. For most sources, multiple observations were conducted with different synthesized beam areas. Thus, for a given galaxy there may be several rows in the table reporting data at different angular resolution or reporting different radio components of the object. A low-resolution observation was used to yield an accurate total flux density and a high-resolution observation was used to resolve the brightest components clearly. These observations were originally presented in Condon, et al., (1990ApJS...73..359C).
