- ID:
- ivo://CDS.VizieR/J/ApJS/245/10
- Title:
- A catalog of galaxies in direction of Perseus
- Short Name:
- J/ApJS/245/10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 5437 morphologically classified sources in the direction of the Perseus galaxy cluster core, among them 496 early-type low-mass galaxy candidates. The catalog is primarily based on V-band imaging data acquired with the William Herschel Telescope, which we used to conduct automated source detection and derive photometry. We additionally reduced archival Subaru multiband imaging data in order to measure aperture colors and perform a morphological classification, benefiting from 0.5" seeing conditions in the r-band data. Based on morphological and color properties, we extracted a sample of early-type low-mass galaxy candidates with absolute V-band magnitudes in the range of -10 to -20mag. In the color-magnitude diagram, the galaxies are located where the red sequence for early-type cluster galaxies is expected, and they lie on the literature relation between absolute magnitude and Sersic index. We classified the early-type dwarf candidates into nucleated and nonnucleated galaxies. For the faint candidates, we found a trend of increasing nucleation fraction toward brighter luminosity or higher surface brightness, similar to what is observed in other nearby galaxy clusters. We morphologically classified the remaining sources as likely background elliptical galaxies, late-type galaxies, edge-on disk galaxies, and likely merging systems and discussed the expected contamination fraction through non-early-type cluster galaxies in the magnitude-size surface brightness parameter space. Our catalog reaches its 50% completeness limit at an absolute V-band luminosity of -12mag and a V-band surface brightness of 26mag/arcsec^2^. This makes it the largest and deepest catalog with coherent coverage compared to previous imaging studies of the Perseus cluster.
« Previous |
1 - 10 of 75
|
Next »
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/212/21
- Title:
- A deep Chandra ACIS survey of M83
- Short Name:
- J/ApJS/212/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained a series of deep X-ray images of the nearby galaxy M83 using Chandra, with a total exposure of 729ks. Combining the new data with earlier archival observations totaling 61ks, we find 378 point sources within the D_25_ contour of the galaxy. We find 80 more sources, mostly background active galactic nuclei (AGNs), outside of the D_25_contour. Of the X-ray sources, 47 have been detected in a new radio survey of M83 obtained using the Australia Telescope Compact Array. Of the X-ray sources, at least 87 seem likely to be supernova remnants (SNRs), based on a combination of their properties in X-rays and at other wavelengths. We attempt to classify the point source population of M83 through a combination of spectral and temporal analysis. As part of this effort, we carry out an initial spectral analysis of the 29 brightest X-ray sources. The soft X-ray sources in the disk, many of which are SNRs, are associated with the spiral arms, while the harder X-ray sources, mostly X-ray binaries (XRBs), do not appear to be. After eliminating AGNs, foreground stars, and identified SNRs from the sample, we construct the cumulative luminosity function (CLF) of XRBs brighter than 8x10^35^erg/s. Despite M83's relatively high star formation rate, the CLF indicates that most of the XRBs in the disk are low mass XRBs.
- ID:
- ivo://CDS.VizieR/J/ApJ/827/46
- Title:
- A deep Chandra ACIS survey of M51
- Short Name:
- J/ApJ/827/46
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained a deep X-ray image of the nearby galaxy M51 using Chandra. Here we present the catalog of X-ray sources detected in these observations and provide an overview of the properties of the point-source population. We find 298 sources within the D_25_ radii of NGC 5194/5, of which 20% are variable, a dozen are classical transients, and another half dozen are transient-like sources. The typical number of active ultraluminous X-ray sources in any given observation is ~5, and only two of those sources persist in an ultraluminous state over the 12yr of observations. Given reasonable assumptions about the supernova remnant population, the luminosity function is well described by a power law with an index between 1.55 and 1.7, only slightly shallower than that found for populations dominated by high-mass X-ray binaries (HMXBs), which suggests that the binary population in NGC 5194 is also dominated by HMXBs. The luminosity function of NGC 5195 is more consistent with a low-mass X-ray binary dominated population.
- ID:
- ivo://CDS.VizieR/J/ApJ/728/38
- Title:
- AEGIS: demographics of X-ray and optical AGN
- Short Name:
- J/ApJ/728/38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We develop a new diagnostic method to classify galaxies into active galactic nucleus (AGN) hosts, star-forming galaxies, and absorption-dominated galaxies by combining the [OIII]/H{beta} ratio with rest-frame U-B color. This can be used to robustly select AGNs in galaxy samples at intermediate redshifts (z<1). We compare the result of this optical AGN selection with X-ray selection using a sample of 3150 galaxies with 0.3<z<0.8 and I_AB_<22, selected from the DEEP2 Galaxy Redshift Survey and the All-wavelength Extended Groth Strip International Survey. Among the 146 X-ray sources in this sample, 58% are classified optically as emission-line AGNs, the rest as star-forming galaxies or absorption-dominated galaxies. The latter are also known as "X-ray bright, optically normal galaxies" (XBONGs).
- ID:
- ivo://CDS.VizieR/J/ApJ/700/103
- Title:
- Ages of star clusters in M33
- Short Name:
- J/ApJ/700/103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a result of age estimation for star clusters in M33. We obtain color-magnitude diagrams (CMDs) of resolved stars in 242 star clusters from the Hubble Space Telescope/Wide Field Planetary Camera 2 images. We estimate ages of 100 star clusters among these, by fitting the Padova theoretical isochrones to the observational CMDs. Age distribution of the star clusters shows a dominant peak at log(t)~7.8. Majority of star clusters are younger than log(t)=9.0, while 10 star clusters are older than log(t)~9.0. There is only one cluster younger than log(t)=7 in this study, which is in contrast with the results based on the integrated photometry of star clusters in the previous studies. Radial distribution of the cluster ages shows that young- to intermediate-age clusters are found from the center to the outer region, while old clusters are distributed farther from the M33 center. We briefly discuss the implication of the results with regard to the formation of the M33 cluster system.
- ID:
- ivo://CDS.VizieR/J/AJ/135/588
- Title:
- Arecibo legacy fast ALFA survey V.
- Short Name:
- J/AJ/135/588
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a second catalog of HI sources detected in the Arecibo Legacy Fast ALFA Survey. We report 488 detections over 135deg^2^, within the region of the sky having 22<RA<03 and +26<DE<+28. We present here the detections that have either (a) S/N>6.5, where the reliability of the catalog is better than 95% or (b) 5.0<S/N<6.5 and a previously measured redshift that corroborates our detection. Of the 488 objects presented here, 49 are high-velocity clouds or clumps thereof with negative heliocentric recession velocities. These clouds are mostly very compact and isolated, while some of them are associated with large features such as Wright's Cloud or the northern extension of the Magellanic Stream. The remaining 439 candidate detections are identified as extragalactic objects and have all been matched with optical counterparts. Five of the six galaxies detected with M_HI_<10^7.5^ solMass are satellites of either the NGC672/IC1727 nearby galaxy pair or their neighboring dwarf irregular galaxy NGC784. The data of this catalog release include a slice through the Pisces-Perseus foreground void, a large nearby underdensity of galaxies. We report no detections within the void, where our catalog is complete for systems with HI masses of 10^8^M_{sun}_.
- ID:
- ivo://CDS.VizieR/J/A+A/590/A31
- Title:
- ASTRODEEP Frontier Fields Catalogues
- Short Name:
- J/A+A/590/A31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multiwavelength photometric catalogues (HST, Spitzer and Hawk-I K band) for the first two of the Frontier Fields, Abell2744 and MACSJ0416 (plus their parallel fields). To detect faint sources even in the central regions of the clusters, we develop a robust and repeatable procedure that uses the public codes Galapagos and Galfit to model and remove most of the light contribution from both the brightest cluster members as well as the ICL. We perform the detection on the HST H160 processed image to obtain a pure H-selected sample. We also add a sample of sources which are undetected in the H160 image but appear on a stacked infrared image. Photometry in the other HST bands is obtained using SExtractor, performed again on residual images after the Galfit procedure for foreground light removal. Photometry on the Hawk-I and IRAC bands has been obtained using our PSF-matching deconfusion code T-PHOT. A similar procedure, but without the need for the foreground light removal, is adopted for the Parallel fields. The procedure allows for the detection and the photometric measurements of ~2500 sources per field. We deliver and release complete photometric H-detected catalogues, with the addition of a complementary sample of infrared-detected sources. All objects have multiwavelength coverage including B to H HST bands, plus K band from Hawk-I, and 3.6 - 4.5 {\mu}m from Spitzer. Full and detailed treatment of photometric errors is included. We perform basic sanity checks on the reliability of our results. The multiwavelength catalogues are publicly available and are ready to be used for scientific purposes. Our procedures allows for the detection of outshined objects near the bright galaxies, which, coupled with the magnification effect of the clusters, can reveal extremely faint high redshift sources. Full analysis on photometric redshifts is presented in a companion Paper II. We present the first public release of photometric redshifts, galaxy rest-frame properties and associated magnification values in the cluster and parallel pointings of the first two Frontier Fields, Abell-2744 and MACS-J0416. We exploit a multi-wavelength catalogue ranging from HST to ground-based K and Spitzer IRAC which is specifically designed to enable detection and measurement of accurate fluxes in crowded cluster regions. The multi-band information is used to derive photometric redshifts and physical properties of sources detected either in the H-band image alone or from a stack of four WFC3 bands. To minimize systematics median photometric redshifts are assembled from six different approaches to photo-z estimates. Their reliability is assessed through a comparison with available spectroscopic samples. State of the art lensing models are used to derive magnification values on an object-by-object basis by taking into account sources positions and redshifts. We show that photometric redshifts reach a remarkable ~3-5% accuracy. After accounting for magnification the H band number counts are found in agreement at bright magnitudes with number counts from the CANDELS fields, while extending the presently available samples to galaxies intrinsically as faint as H160~32-33 thanks to strong gravitational lensing. The Frontier Fields allow to probe the galaxy stellar mass distribution at 0.5-1.5dex lower masses, depending on magnification, with respect to extragalactic wide fields, including sources at Mstar~10^7-10^8^M_{sun}_ at z>5. Similarly, they allow the detection of objects with intrinsic SFRs>1dex lower than in the CANDELS fields reaching 0.1-1M_{sun}_/yr at z~6-10.
- ID:
- ivo://CDS.VizieR/J/PAZh/44/383
- Title:
- Byurakan-IRAS galaxies (BIG) with SDSS spectra
- Short Name:
- J/PAZh/44/383
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The sample of Byurakan-IRAS galaxies (BIG) has been created based on optical identifications of IRAS Point Source Catalog (PSC) at high galactic latitudes. As a result, 1178 galaxies have been identified. 172 of them have been observed spectroscopically with Byurakan Astrophysical Observatory (BAO, Armenia) 2.6m, Special Astrophysical Observatory (SAO, Russia) 6m and Observatoire de Haute Provence (OHP, France) 1.93m telescopes. Later on, spectra were obtained for more 83 BIG objects in Sloan Digital Sky Survey (SDSS). We have extracted and studied these spectra, classified them and measured spectral features. Diagnostic diagrams have been built to distinguish starbursts (SB), LINERs and Seyfert galaxies. Cross-correlations were made for these objects with multiwavelength (MW) catalogues and their physical properties were studied. Among these 83 objects, 55 HII, 8 Seyfert galaxies, 2 LINERs, 4 other AGN, 6 composite spectrum objects, and 8 other emission-line galaxies have been revealed. Three of these objects are Ultra-Luminous InfraRed Galaxies (ULIRG).
- ID:
- ivo://CDS.VizieR/J/ApJ/823/95
- Title:
- CANDELS GOODS-S sources Chandra counterparts
- Short Name:
- J/ApJ/823/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Improving the capabilities of detecting faint X-ray sources is fundamental to increase the statistics on faint high-z AGN and star-forming galaxies. We performed a simultaneous Maximum Likelihood PSF fit in the [0.5-2]keV and [2-7]keV energy bands of the 4Ms Chandra Deep Field South (CDFS) data at the position of the 34930 CANDELS H-band selected galaxies. For each detected source we provide X-ray photometry and optical counterpart validation. We validated this technique by means of a raytracing simulation. We detected a total of 698 X-ray point-sources with a likelihood L>4.98 (i.e.> 2.7{sigma}). We show that the prior knowledge of a deep sample of Optical-NIR galaxies leads to a significant increase of the detection of faint (i.e. ~10^-17^cgs in the [0.5-2]keV band) sources with respect to "blind" X-ray detections. By including previous catalogs, this work increases the total number of X-ray sources detected in the 4Ms CDFS, CANDELS area to 793, which represents the largest sample of extremely faint X-ray sources assembled to date. Our results suggest that a large fraction of the optical counterparts of our X-ray sources determined by likelihood ratio actually coincides with the priors used for the source detection. Most of th e new detected sources are likely star-forming galaxies or faint absorbed AGN. We identified a few sources sources with putative photometric redshift z>4. Despite the low number statistics, this sample significantly increases the number of X-ray selected candidate high-z AGN.
- ID:
- ivo://CDS.VizieR/J/ApJS/179/19
- Title:
- CDFS survey: 2 Ms source catalogs
- Short Name:
- J/ApJS/179/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present point-source catalogs for the ~2Ms exposure of the Chandra Deep Field-South (CDF-S) this is one of the two most sensitive X-ray surveys ever performed. The survey covers an area of ~436arcmin^2^ and reaches on-axis sensitivity limits of ~1.9x10^-17^ and ~1.3x10^-16^ergs/cm^2^/s for the 0.5-2.0 and 2-8keV bands, respectively. Four hundred and sixty-two X-ray point sources are detected in at least one of three X-ray bands that were searched; 135 of these sources are new compared to the previous ~1Ms CDF-S detections. Source positions are determined using centroid and matched-filter techniques; the median positional uncertainty is ~0.36". The X-ray-to-optical flux ratios of the newly detected sources indicate a variety of source types; ~55% of them appear to be active galactic nuclei, while ~45% appear to be starburst and normal galaxies. In addition to the main Chandra catalog, we provide a supplementary catalog of 86 X-ray sources in the ~2Ms CDF-S footprint that was created by merging the ~250ks Extended Chandra Deep Field-South with the CDF-S this approach provides additional sensitivity in the outer portions of the CDF-S. A second supplementary catalog that contains 30 X-ray sources was constructed by matching lower significance X-ray sources to bright optical counterparts (R<23.8) the majority of these sources appear to be starburst and normal galaxies. The total number of sources in the main and supplementary catalogs is 578. Optical R-band counterparts and basic optical and infrared photometry are provided for the X-ray sources in the main and supplementary catalogs. We also include existing spectroscopic redshifts for 224 of the X-ray sources.