- ID:
- ivo://CDS.VizieR/J/ApJS/206/8
- Title:
- COSMOS/UltraVISTA Ks-selected catalogs v4.1
- Short Name:
- J/ApJS/206/8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog covering 1.62deg^2^ of the COSMOS/UltraVISTA field with point-spread function (PSF) matched photometry in 30 photometric bands. The catalog covers the wavelength range 0.15-24{mu}m including the available GALEX, Subaru, Canada-France-Hawaii Telescope, VISTA, and Spitzer data. Catalog sources have been selected from the DR1 UltraVISTA K_s_ band imaging that reaches a depth of K_s,tot_=23.4 AB (90% completeness). The PSF-matched catalog is generated using position-dependent PSFs ensuring accurate colors across the entire field. Also included is a catalog of photometric redshifts (z_phot_) for all galaxies computed with the EAZY code. Comparison with spectroscopy from the zCOSMOS 10k bright sample shows that up to z~1.5 the z_phot_ are accurate to {Delta}z/(1+z)=0.013, with a catastrophic outlier fraction of only 1.6%. The z_phot_ also show good agreement with the z_phot_ from the NEWFIRM Medium Band Survey out to z~3. A catalog of stellar masses and stellar population parameters for galaxies determined using the FAST spectral energy distribution fitting code is provided for all galaxies. Also included are rest-frame U-V and V-J colors, L_2800_ and L_IR_. The UVJ color-color diagram confirms that the galaxy bi-modality is well-established out to z~2. Star-forming galaxies also obey a star-forming "main sequence" out to z~2.5, and this sequence evolves in a manner consistent with previous measurements. The COSMOS/UltraVISTA K_s_-selected catalog covers a unique parameter space in both depth, area, and multi-wavelength coverage and promises to be a useful tool for studying the growth of the galaxy population out to z~3-4.
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452. COSMOS 70um sources
- ID:
- ivo://CDS.VizieR/J/ApJ/709/572
- Title:
- COSMOS 70um sources
- Short Name:
- J/ApJ/709/572
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a large robust sample of 1503 reliable and unconfused 70um selected sources from the multiwavelength data set of the Cosmic Evolution Survey. Using the Spitzer IRAC and MIPS photometry, we estimate the total infrared (IR) luminosity, LIR (8-1000um), by finding the best-fit template from several different template libraries. The long-wavelength 70 and 160um data allow us to obtain a reliable estimate of LIR, accurate to within 0.2 and 0.05dex, respectively. The 70um data point enables a significant improvement over the luminosity estimates possible with only a 24um detection. The full sample spans a wide range in IR luminosity, LIR~10^8^-10^14^L_{sun}_, with a median luminosity of 10^11.4^L_{sun}_. We identify a total of 687 luminous, 303 ultraluminous, and 31 hyperluminous infrared galaxies (LIRGs, ULIRGs, and HyLIRGs) over the redshift range 0.01<z<3.5 with a median redshift of 0.5. Presented here are the full spectral energy distributions (SEDs) for each of the sources compiled from the extensive multiwavelength data set from the ultraviolet (UV) to the far-infrared. A catalog of the general properties of the sample (including the photometry, redshifts, and LIR) is included with this paper.
- ID:
- ivo://CDS.VizieR/J/MNRAS/459/1170
- Title:
- Coulour-Period relation for Cepheids
- Short Name:
- J/MNRAS/459/1170
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We compare mid-infrared (IR) 3.6 and 4.5{mu}m Warm Spitzer observations for Cepheids in the Milky Way and the Large and Small Magellanic Clouds. Using models, we explore in detail the effect of the CO rotation-vibration band-head at 4.6{mu}m on the mid-IR photometry. We confirm the temperature sensitivity of the CO band-head at 4.6{mu}m and find no evidence for an effect at 3.6{mu}m. We compare the ([3.6]-[4.5]) period-colour relations in the MW, LMC and SMC. The slopes of the period-colour relations for the three galaxies are in good agreement, but there is a trend in zero-point with metallicity, with the lowest metallicity Cepheids having redder mid-IR colours. Finally, we present a colour-[Fe/H] relation based on published spectroscopic metallicities. This empirical relation, calibrated to the metallicity system of Genovali et al., demonstrates that the ([3.6]-[4.5]) colour provides a reliable metallicity indicator for Cepheids, with a precision comparable to current spectroscopic determinations.
- ID:
- ivo://CDS.VizieR/J/ApJS/203/15
- Title:
- Counterparts to 1.4GHz sources in ECDF-S
- Short Name:
- J/ApJS/203/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study a sample of 883 sources detected in a deep Very Large Array survey at 1.4GHz in the Extended Chandra Deep Field South. This paper focuses on the identification of their optical and infrared (IR) counterparts. We use a likelihood-ratio technique that is particularly useful when dealing with deep optical images to minimize the number of spurious associations. We find a reliable counterpart for 95% of our radio sources. Most of the counterparts (74%) are detected at optical wavelengths, but there is a significant fraction (21%) that are only detectable in the IR. Combining newly acquired optical spectra with data from the literature, we are able to assign a redshift to 81% of the identified radio sources (37% spectroscopic). We also investigate the X-ray properties of the radio sources using the Chandra 4Ms and 250ks observations. In particular, we use a stacking technique to derive the average properties of radio objects undetected in the Chandra images. The results of our analysis are collected in a new catalog containing the position of the optical/IR counterpart, the redshift information, and the X-ray fluxes. It is the deepest multi-wavelength catalog of radio sources, which will be used for future study of this galaxy population.
- ID:
- ivo://CDS.VizieR/J/ApJS/237/18
- Title:
- Cr, Co, and Ni abundances for metal-poor red giants
- Short Name:
- J/ApJS/237/18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present measurements of the abundances of chromium, cobalt, and nickel in 4113 red giants, including 2277 stars in globular clusters (GCs), 1820 stars in the Milky Way's dwarf satellite galaxies, and 16 field stars. We measured the abundances from mostly archival Keck/DEIMOS medium-resolution spectroscopy with a resolving power of R~6500 and a wavelength range of approximately 6500-9000{AA}. The abundances were determined by fitting spectral regions that contain absorption lines of the elements under consideration. We used estimates of temperature, surface gravity, and metallicity that we previously determined from the same spectra. We estimated systematic error by examining the dispersion of abundances within mono- metallic GCs. The median uncertainties for [Cr/Fe], [Co/Fe], and [Ni/Fe] are 0.20, 0.20, and 0.13, respectively. Finally, we validated our estimations of uncertainty through duplicate measurements, and we evaluated the accuracy and precision of our measurements through comparison to high-resolution spectroscopic measurements of the same stars.
- ID:
- ivo://CDS.VizieR/J/AJ/125/1298
- Title:
- C star population in outer disk of M31
- Short Name:
- J/AJ/125/1298
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We employ the CFH12K mosaic to identify carbon stars, using the R, I, CN, and TiO photometric technique, in a 2240 arcmin2 area, ranging from 17 to 30kpc of the southwest disk of M31, barely reaching the edge of the observed H I disk. We found 945 C stars with <I_0_>=19.94mag and {sigma}=0.47. The surface density of C stars along the major axis of M31 follows an exponential profile with a scale length of 4.85+/-0.35kpc, in agreement with adopted values for the scale length of the disk population. Our survey partially overlaps with the recently discovered G1 density enhancement by Ferguson et al. We confirm that no AGB star excess is detectable in the surveyed part of the clump. The C/M ratio, along the major axis, is derived over a distance range of 7kpc. The strong C/M gradient seen contrasts with results of previous studies of the C stars in M31.
- ID:
- ivo://CDS.VizieR/J/ApJ/892/112
- Title:
- CTIO/DECam LCs for Galactic bulge variable stars
- Short Name:
- J/ApJ/892/112
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With the advent of the Legacy Survey of Space and Time, time-domain astronomy will be faced with an unprecedented volume and rate of data. Real-time processing of variables and transients detected by such large-scale surveys is critical to identifying the more unusual events and allocating scarce follow-up resources efficiently. We develop an algorithm to identify these novel events within a given population of variable sources. We determine the distributions of magnitude changes (dm) over time intervals (dt) for a given passband f, p_f_^(dm|dt)^, and use these distributions to compute the likelihood of a test source being consistent with the population or being an outlier. We demonstrate our algorithm by applying it to the DECam multiband time-series data of more than 2000 variable stars identified by Saha+ (2019, J/ApJ/874/30) in the Galactic Bulge that are largely dominated by long-period variables and pulsating stars. Our algorithm discovers 18 outlier sources in the sample, including a microlensing event, a dwarf nova, and two chromospherically active RS CVn stars, as well as sources in the blue horizontal branch region of the color-magnitude diagram without any known counterparts. We compare the performance of our algorithm for novelty detection with the multivariate Kernel Density Estimator and Isolation Forest on the simulated PLAsTiCC data set. We find that our algorithm yields comparable results despite its simplicity. Our method provides an efficient way for flagging the most unusual events in a real-time alert-broker system.
- ID:
- ivo://CDS.VizieR/J/AJ/154/85
- Title:
- CTIO/DECam photometry of RR Lyrae stars in M5
- Short Name:
- J/AJ/154/85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We characterize the absolute magnitudes and colors of RR Lyrae stars in the globular cluster M5 in the ugriz filter system of the Dark Energy Camera (DECam). We provide empirical period-luminosity (P-L) relationships in all five bands based on 47 RR Lyrae stars of the type ab and 14 stars of the type c. The P-L relationships were found to be better constrained for the fundamental-mode RR Lyrae stars in the riz passbands, with dispersions of 0.03, 0.02 and 0.02mag, respectively. The dispersion of the color at minimum light was found to be small, supporting the use of this parameter as a means to obtain accurate interstellar extinctions along the line of sight up to the distance of the RR Lyrae star. We found a trend of color at minimum light with a pulsational period that, if taken into account, brings the dispersion in color at minimum light to 0.016 mag for the (r-i), (i-z), and (r-z) colors. These calibrations will be very useful for using RR Lyrae stars from DECam observations as both standard candles for distance determinations and color standards for reddening measurements.
- ID:
- ivo://CDS.VizieR/J/A+A/640/A128
- Title:
- Cygnus OB2 association NIR light curves
- Short Name:
- J/A+A/640/A128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a J, H, and K photometric variability survey of the central 0.78 square degrees of the young OB association Cygnus OB2. We used data observed with the Wide-Field CAMera at the United Kingdom Infrared Telescope in 2007 (spanning 217 days) to investigate the light curves of 5083 low mass candidate members in the association and explore the occurrence and main characteristics of their near-infrared variability. We identified 2529 stars (~50% of the sample) with significant variability with time-scales ranging from days to months. We classified the variable stars into the following three groups according to their light curve morphology: periodic variability (1697 stars), occultation variability (124 stars), and other types of variability (726 stars). We verified that the disk-bearing stars in our sample are significantly more variable in the near-infrared than diskless stars, with a steep increase in the disk-fraction among stars with higher variability amplitude. We investigated the trajectories described by variable stars in the color-space and measured slopes for 335 stars describing linear trajectories. Based on the trajectories in the color-space, we inferred that the sample analyzed is composed of a mix of young stars presenting variability due to hot and cold spots, extinction by circumstellar material, and changes in the disk emission in the near-infrared. We contemplated using the use of near- infrared variability to identify disk-bearing stars and verified that 53.4% of the known disk-bearing stars in our sample could have been identified as such based solely on their variability. We present 18 newly identified disk- bearing stars and 14 eclipsing binary candidates among CygOB2 lower-mass members.
- ID:
- ivo://CDS.VizieR/J/MNRAS/411/1585
- Title:
- CZ Lac multiperiodic Blazhko modulation
- Short Name:
- J/MNRAS/411/1585
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A thorough analysis of the multicolour CCD observations of the RRab-type variable, CZ Lacertae, is presented. The observations were carried out in two consecutive observing seasons in 2004 and 2005 within the framework of the Konkoly Blazhko Survey of bright, northern, short-period RRab variables.
