- 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.
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Search Results
- 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).
- ID:
- ivo://CDS.VizieR/J/A+AS/143/269
- Title:
- 6.7GHz methanol maser emission survey
- Short Name:
- J/A+AS/143/269
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the first results of a search for 6.7GHz methanol masers in the direction of 1399 IRAS objects north of declination -20{deg} with the flux densities greater than 100 Jy at 60 {mu}m and the flux density ratio F_60_/F_25_>1. Observations were made with the sensitivity of 1.7 Jy and the velocity resolution of 0.04km/s using the 32-m Torun radio telescope. Maser emission was found in 182 sources, including 70 new detections. 32 new sources were identified with objects of radio emission associated with star-forming regions. Comparison of the present data set with other observations suggests that about 65% of methanol masers exhibit moderate or strong variations on time-scales of about 4 and 8 years.
- ID:
- ivo://CDS.VizieR/J/ApJS/196/9
- Title:
- 95GHz methanol maser survey toward GLIMPSE EGOs
- Short Name:
- J/ApJS/196/9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of a systematic survey for 95GHz class I methanol masers toward a new sample of 192 massive young stellar object candidates associated with ongoing outflows (known as extended green objects or EGOs) identified from the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) survey. The observations were made with the Australia Telescope National Facility (ATNF) Mopra 22m radio telescope and resulted in the detection of 105 new 95GHz class I methanol masers. For 92 of the sources our observations provide the first identification of a class I maser transition associated with these objects (i.e., they are new class I methanol maser sources). Our survey proves that there is indeed a high detection rate (55%) of class I methanol masers toward EGOs. Comparison of the GLIMPSE point sources associated with EGOs with and without class I methanol maser detections shows that they have similar mid-IR colors, with the majority meeting the color selection criteria -0.6<[5.8]-[8.0]<1.4 and 0.5<[3.6]-[4.5]<4.0. Investigations of the Infrared Array Camera and Multiband Imaging Photometer for Spitzer 24um colors and the associated millimeter dust clump properties (mass and density) of the EGOs for the sub-samples based on the class of methanol masers they are associated with suggest that the stellar mass range associated with class I methanol masers extends to lower masses than for class II methanol masers, or alternatively class I methanol masers may be associated with more than one evolutionary phase during the formation of a high-mass star.
- ID:
- ivo://CDS.VizieR/J/ApJ/731/L41
- Title:
- 1.4GHz observations of bright early-type galaxies
- Short Name:
- J/ApJ/731/L41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have measured the radio continuum emission of 396 early-type galaxies brighter than K=9, using 1.4GHz imagery from the NRAO Very Large Array Sky Survey, Green Bank 300ft Telescope, and 64m Parkes Radio Telescope. For M_K_<-24 early-type galaxies, the distribution of radio powers at fixed absolute magnitude spans four orders of magnitude and the median radio power is proportional to K-band luminosity to the power 2.78+/-0.16. The measured flux densities of M_K_<-25.5 early-type galaxies are greater than zero in all cases. It is thus highly likely that the most massive galaxies always host an active galactic nucleus or have recently undergone star formation.