- ID:
- ivo://CDS.VizieR/J/AJ/126/197
- Title:
- The Carina projects. I. Bright variables stars
- Short Name:
- J/AJ/126/197
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new BV time series data of the Carina dwarf spheroidal galaxy (dSph). Current data cover an area of ~0.3deg^2^ around the center of the galaxy and allow us to identify 92 variables. Among them 75 are RR Lyrae stars, 15 are bona fide anomalous Cepheids, one might be a Galactic field RR Lyrae star, and one is located along the Carina red giant branch. Expanding upon the seminal photographic investigation by Saha, Monet, & Seitzer (1986AJ.....92..302S) we supply, for the first time, accurate estimates of their pulsation parameters (periods, amplitudes, mean magnitudes, and colors) on the basis of CCD photometry. Approximately 50% of both RR Lyrae stars and anomalous Cepheids are new identifications. Among the RR Lyrae sample, six objects are new candidate double-mode (RRd) variables. On the basis of their pulsation properties we estimate that two variables (V158, V182) are about 50% more massive than typical RR Lyrae stars, while the bulk of the anomalous Cepheids are roughly a factor of 2 more massive than fundamental-mode (RRab) RR Lyrae stars.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/830/126
- Title:
- The Carina project. X. Radial velocities
- Short Name:
- J/ApJ/830/126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new radial velocity (RV) measurements of old (horizontal branch) and intermediate-age (red clump) stellar tracers in the Carina dwarf spheroidal. They are based on more than 2200 low-resolution spectra collected with VIMOS at Very Large Telescope (VLT). The targets are faint (20<~V<~21.5mag), but the accuracy at the faintest limit is <=9km/s. These data were complemented with RV measurements either based on spectra collected with FORS2 and FLAMES/GIRAFFE at VLT or available in the literature. We ended up with a sample of 2748 stars and among them, 1389 are candidate Carina stars. We found that the intermediate-age stellar component shows a well-defined rotational pattern around the minor axis. The western and the eastern side of the galaxy differ by +5 and -4km/s when compared with the main RV peak. The old stellar component is characterized by a larger RV dispersion and does not show evidence of the RV pattern. We compared the observed RV distribution with N-body simulations for a former disky dwarf galaxy orbiting a giant Milky Way-like galaxy. We rotated the simulated galaxy by 60{deg} with respect to the major axis, we kept the observer on the orbital plane of the dwarf and extracted a sample of stars similar to the observed one. Observed and predicted V_rot_/{sigma} ratios across the central regions are in remarkable agreement. This evidence indicates that Carina was a disky dwarf galaxy that experienced several strong tidal interactions with the Milky Way. Owing to these interactions, Carina transformed from a disky to a prolate spheroid and the rotational velocity transformed into random motions.
- ID:
- ivo://CDS.VizieR/J/ApJS/197/21
- Title:
- The Carnegie-Irvine Galaxy Survey (CGS). I.
- Short Name:
- J/ApJS/197/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Carnegie-Irvine Galaxy Survey (CGS) is a long-term program to investigate the photometric and spectroscopic properties of a statistically complete sample of 605 bright (B_T_<12.9mag), southern ({delta}<0{deg}) galaxies using the facilities at Las Campanas Observatory. This paper, the first in a series, outlines the scientific motivation of CGS, defines the sample, and describes the technical aspects of the optical broadband (BVRI) imaging component of the survey, including details of the observing program, data reduction procedures, and calibration strategy. The overall quality of the images is quite high, in terms of resolution (median seeing ~1"), field of view (8.9'x8.9'), and depth (median limiting surface brightness ~27.5, 26.9, 26.4, and 25.3mag/arcsec^2^ in the B, V, R, and I bands, respectively). We prepare a digital image atlas showing several different renditions of the data, including three-color composites, star-cleaned images, stacked images to enhance faint features, structure maps to highlight small-scale features, and color index maps suitable for studying the spatial variation of stellar content and dust. In anticipation of upcoming science analyses, we tabulate an extensive set of global properties for the galaxy sample. These include optical isophotal and photometric parameters derived from CGS itself, as well as published information on multiwavelength (ultraviolet, U-band, near-infrared, far-infrared) photometry, internal kinematics (central stellar velocity dispersions, disk rotational velocities), environment (distance to nearest neighbor, tidal parameter, group, or cluster membership), and HI content.
- ID:
- ivo://CDS.VizieR/J/ApJS/243/24
- Title:
- The CASBaH galaxy redshift survey
- Short Name:
- J/ApJS/243/24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the survey for galaxies in the fields surrounding nine sightlines to far-UV bright, z~1 quasars that define the COS Absorption Survey of Baryon Harbors (CASBaH) program. The photometry and spectroscopy that comprise the data set come from a mixture of public surveys (SDSS, DECaLS) and our dedicated efforts on private facilities (Keck, MMT, LBT). We report the redshifts and stellar masses for 5902 galaxies within ~10 comoving-Mpc of the sightlines with a median of \bar{z}=0.28 and \bar{M}_*_~10^10.1^M_{sun}_. This data set, publicly available as the CASBaH specDB, forms the basis of several recent and ongoing CASBaH analyses. Here, we perform a clustering analysis of the galaxy sample with itself (auto-correlation) and against the set of O VI absorption systems (cross-correlation) discovered in the CASBaH quasar spectra with column densities N(O^+5^)>=10^13.5^/cm^2^. For each, we describe the measured clustering signal with a power-law correlation function {xi}(r)=(r/r_0_)^-{gamma}^ and find that (r_0_,{gamma})=(5.48+/-0.07h_100_^-1^Mpc,1.33+/-0.04) for the auto-correlation and (6.00_-0.77_^+1.09^h_100_^-1^Mpc,1.25+/-0.18) for galaxy-OVI cross-correlation. We further estimate a bias factor of b_gg_=1.3+/-0.1 from the galaxy-galaxy auto-correlation, indicating the galaxies are hosted by halos with mass M_halo_~10^12.1+/-0.05^M_{sun}_. Finally, we estimate an OVI-galaxy bias factor b_OVI_=1.0+/-0.1 from the cross-correlation which is consistent with OVI absorbers being hosted by dark matter halos with typical mass M_halo_~10^11^M_{sun}_. Future works with upcoming data sets (e.g., CGM2) will improve upon these results and will assess whether any of the detected OVI arises in the intergalactic medium.
- ID:
- ivo://CDS.VizieR/J/A+A/597/A18
- Title:
- The central black hole in NGC 4414
- Short Name:
- J/A+A/597/A18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present our mass estimate of the central black hole in the isolated spiral galaxy NGC 4414. Using natural guide star adaptive optics assisted observations with the Gemini Near-Infrared Integral Field Spectrometer (NIFS) and the natural seeing Gemini Multi-Object Spectrographs-North (GMOS), we derived two-dimensional stellar kinematic maps of NGC 4414 covering the central 1.5-arcsec and 10-arcsec, respectively, at a NIFS spatial resolution of 0.13-arcsec. The kinematic maps reveal a regular rotation pattern and a central velocity dispersion dip down to around 105km/s. We constructed dynamical methods using two different methods: Jeans anisotropic dynamical modeling and axisymmetric Schwarzschild modeling. Both modeling methods give consistent results, but we cannot constrain the lower mass limit and only measure an upper limit for the black hole mass of M_bh_=1.56x10^6^M_{sun}_ (at 3{sigma{ level) which is at least 1{sigma} below the recent Mbh-sigma_e relations. Further tests with dark matter, mass-to-light ratio variation and different light models confirm that our results are not dominated by uncertainties. The derived upper limit mass is not only below the Mbh-sigma_e relation, but is also five times lower than the lower limit black hole mass anticipated from the resolution limit of the sphere of influence. This proves that via high quality integral field data we are now able to push black hole measurements down to at least five times less than the resolution limit.
876. The CfA2S catalog
- ID:
- ivo://CDS.VizieR/J/ApJS/121/287
- Title:
- The CfA2S catalog
- Short Name:
- J/ApJS/121/287
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present redshifts for a sample of 4391 galaxies with magnitude m_B(0)_<=15.5 covering 20h<=RA<=4h in right ascension and -2.5{deg}<=DE<=90{deg} in declination. This sample is complete for all galaxies in the merge of the Zwicky et al. and Nilson catalogs in the south Galactic cap. Redshifts for 2964 of these were measured as part of the second CfA Redshift Survey. The data reveal large voids in the foreground and background of the Perseus-Pisces Supercluster. The largest of these voids lies at a mean velocity ~8000km/s, has diameter ~5000km/s, and is enclosed by a complex of dense structures. The large structure known as the Perseus-Pisces Supercluster forms the near side of this complex. On the far side of this large void, at a mean velocity ~12000km/s, there is another coherent dense wall. The structures in this survey support the view that galaxies generally lie on surfaces surrounding or nearly surrounding low-density regions or voids.
- ID:
- ivo://CDS.VizieR/J/ApJS/201/30
- Title:
- The Chandra COSMOS survey. III.
- Short Name:
- J/ApJS/201/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Chandra COSMOS Survey (C-COSMOS) is a large, 1.8Ms, Chandra program that has imaged the central 0.9deg^2^ of the COSMOS field down to limiting depths of 1.9x10^-16^erg/cm^2^/s in the soft (0.5-2keV) band, 7.3x10^-16^erg/cm^2^/s in the hard (2-10keV) band, and 5.7x10^-16^erg/cm^2^/s in the full (0.5-10keV) band. In this paper we report the i, K, and 3.6um identifications of the 1761 X-ray point sources. We use the likelihood ratio technique to derive the association of optical/infrared counterparts for 97% of the X-ray sources. For most of the remaining 3%, the presence of multiple counterparts or the faintness of the possible counterpart prevented a unique association. For only 10 X-ray sources we were not able to associate a counterpart, mostly due to the presence of a very bright field source close by. Only two sources are truly empty fields. The full catalog, including spectroscopic and photometric redshifts and classification described here in detail, is available online.
878. The CNOC2 survey. I.
- ID:
- ivo://CDS.VizieR/J/ApJS/129/475
- Title:
- The CNOC2 survey. I.
- Short Name:
- J/ApJS/129/475
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Canadian Network for Observational Cosmology Field Galaxy Redshift Survey (CNOC2) obtained spectroscopic redshifts for about 6200 galaxies to a nominal limit of R=21.5. The survey area of about 1.5 square degrees was spread over four patches on the sky. This catalog presents photometry and redshifts for all galaxies in the CNOC2 0223+00 Patch (area of 1409 square arcminutes). A future paper will provide catalogs for the other three patches.
- ID:
- ivo://CDS.VizieR/J/ApJS/224/24
- Title:
- The COSMOS2015 catalog
- Short Name:
- J/ApJS/224/24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the COSMOS2015 catalog, which contains precise photometric redshifts and stellar masses for more than half a million objects over the 2deg^2^ COSMOS field. Including new YJHKs images from the UltraVISTA-DR2 survey, Y-band images from Subaru/Hyper-Suprime-Cam, and infrared data from the Spitzer Large Area Survey with the Hyper-Suprime-Cam (SPLASH) Spitzer legacy program, this near-infrared-selected catalog is highly optimized for the study of galaxy evolution and environments in the early universe. To maximize catalog completeness for bluer objects and at higher redshifts, objects have been detected on a {chi}^2^ sum of the YJHKs and z^++^ images. The catalog contains ~6x10^5^ objects in the 1.5deg^2^ UltraVISTA-DR2 region and ~1.5x10^5^ objects are detected in the "ultra-deep stripes" (0.62deg^2^) at Ks<=24.7 (3{sigma}, 3", AB (AB) magnitude). Through a comparison with the zCOSMOS-bright spectroscopic redshifts, we measure a photometric redshift precision of {sigma}_{Delta}z/(1+zs)_=0.007 and a catastrophic failure fraction of {eta}=0.5%. At 3<z<6 , using the unique database of spectroscopic redshifts in COSMOS, we find {sigma}_{Delta}z/(1+zs)_=0.021 and {eta}=13.2% . The deepest regions reach a 90% completeness limit of 10^10^M_{sun}_ to z=4. Detailed comparisons of the color distributions, number counts, and clustering show excellent agreement with the literature in the same mass ranges. COSMOS2015 represents a unique, publicly available, valuable resource with which to investigate the evolution of galaxies within their environment back to the earliest stages of the history of the universe.
- ID:
- ivo://CDS.VizieR/J/ApJ/877/81
- Title:
- The C3R2 survey: DR2 new spectroscopic redshifts
- Short Name:
- J/ApJ/877/81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Complete Calibration of the Color-Redshift Relation (C3R2) survey is a multi-institution, multi-instrument survey that aims to map the empirical relation of galaxy color to redshift to i~24.5 (AB), thereby providing a firm foundation for weak lensing cosmology with the Stage IV dark energy missions Euclid and WFIRST. Here we present 3171 new spectroscopic redshifts obtained in the 2016B and 2017A semesters with a combination of DEIMOS, LRIS, and MOSFIRE on the Keck telescopes. The observations come from all of the Keck partners: Caltech, NASA, the University of Hawaii, and the University of California. Combined with the 1283 redshifts published in DR1, the C3R2 survey has now obtained and published 4454 high-quality galaxy redshifts. We discuss updates to the survey design and provide a catalog of photometric and spectroscopic data. Initial tests of the calibration method performance are given, indicating that the sample, once completed and combined with extensive data collected by other spectroscopic surveys, should allow us to meet the cosmology requirements for Euclid, and make significant headway toward solving the problem for WFIRST. We use the full spectroscopic sample to demonstrate that galaxy brightness is weakly correlated with redshift once a galaxy is localized in the Euclid or WFIRST color space, with potentially important implications for the spectroscopy needed to calibrate redshifts for faint WFIRST and LSST sources.