- ID:
- ivo://CDS.VizieR/II/371
- Title:
- The Dark Energy Survey (DES): Data Release 2
- Short Name:
- II/371
- Date:
- 31 Jan 2022
- Publisher:
- CDS
- Description:
- We present the second public data release of the Dark Energy Survey, DES DR2, based on optical/near-infrared imaging by the Dark Energy Camera mounted on the 4m Blanco telescope at Cerro Tololo Inter-American Observatory in Chile. DES DR2 consists of reduced single-epoch and coadded images, a source catalog derived from coadded images, and associated data products assembled from 6yr of DES science operations. This release includes data from the DES wide-area survey covering ~5000deg^2^ of the southern Galactic cap in five broad photometric bands, grizY. DES DR2 has a median delivered point-spread function FWHM of g=1.11", r=0.95", i=0.88", z=0.83", and Y=0.90", photometric uniformity with a standard deviation of <3mmag with respect to Gaia DR2 G band, a photometric accuracy of ~11mmag, and a median internal astrometric precision of ~27mas. The median coadded catalog depth for a 1farcs95 diameter aperture at signal-to-noise ratio =10 is g=24.7, r=24.4, i=23.8, z=23.1, and Y=21.7mag. DES DR2 includes ~691 million distinct astronomical objects detected in 10169 coadded image tiles of size 0.534deg^2^ produced from 76217 single-epoch images. After a basic quality selection, benchmark galaxy and stellar samples contain 543 million and 145 million objects, respectively.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/352/297
- Title:
- The dust content of planetary nebulae
- Short Name:
- J/A+A/352/297
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This table contains the dust temperatures and dust-to-gas mass ratios derived for a sample of planetary nebulae and the observational data used for these determinations
- ID:
- ivo://CDS.VizieR/J/PAZh/38/15
- Title:
- Total-to-selective extinction ratio within 700pc
- Short Name:
- J/PAZh/38/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Multicolor photometry from the Tycho-2 and 2MASS catalogues for 11990 OB (2008AstL...34....7G; 2012AstL...38..694G) and 30671 K-type red giant branch stars (2011AstL...37..707G) is used to detect systematic large-scale variations of the interstellar extinction law within the nearest kiloparsec. The characteristic of the extinction law, the total-to-selective extinction ratio Rv, which also characterizes the size and other properties of interstellar dust grains, has been calculated for various regions of space by the extinction law extrapolation method. The results for the two classes of stars agree: the standard deviation of the "red giants minus OB" Rv differences within 500pc of the Sun is 0.2. The detected Rv variations between 2.2 and 4.4 not only manifest themselves in individual clouds but also span the entire space near the Sun, following Galactic structures. In the Local Bubble within about 100 pc of the Sun, Rv has a minimum. In the inner part of the Gould Belt and at high Galactic latitudes, at a distance of about 150 pc from the Sun, Rv reaches a maximum and then decreases to its minimum in the outer part of the Belt and other directions at a distance of about 500 pc from the Sun, returning to its mean values far from the Sun. The detected maximum of Rv at high Galactic latitudes is important when allowance is made for the interstellar extinction toward extragalactic objects. In addition, a monotonic increase in Rv by 0.3 per kpc toward the Galactic center has been found near the Galactic equator. It is consistent with the result obtained by Zasowski et al. (2009ApJ...707..510Z) for much of the Galaxy. Ignoring the Rv variations and traditionally using a single value for the entire space must lead to systematic errors in the calculated distances reaching 10%.
- ID:
- ivo://CDS.VizieR/J/ApJ/799/215
- Title:
- 26 type II-Plateau supernovae parameters
- Short Name:
- J/ApJ/799/215
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new self-consistent and versatile method that derives photospheric radius and temperature variations of Type II-Plateau supernovae based on their expansion velocities and photometric measurements. We apply the method to a sample of 26 well-observed, nearby supernovae with published light curves and velocities. We simultaneously fit ~230 velocity and ~6800mag measurements distributed over 21 photometric passbands spanning wavelengths from 0.19 to 2.2{mu}m. The light-curve differences among the Type II-Plateau supernovae are well modeled by assuming different rates of photospheric radius expansion, which we explain as different density profiles of the ejecta, and we argue that steeper density profiles result in flatter plateaus, if everything else remains unchanged. The steep luminosity decline of Type II-Linear supernovae is due to fast evolution of the photospheric temperature, which we verify with a successful fit of SN 1980K. Eliminating the need for theoretical supernova atmosphere models, we obtain self-consistent relative distances, reddenings, and nickel masses fully accounting for all internal model uncertainties and covariances. We use our global fit to estimate the time evolution of any missing band tailored specifically for each supernova, and we construct spectral energy distributions and bolometric light curves. We produce bolometric corrections for all filter combinations in our sample. We compare our model to the theoretical dilution factors and find good agreement for the B and V filters. Our results differ from the theory when the I, J, H, or K bands are included. We investigate the reddening law toward our supernovae and find reasonable agreement with standard R~3.1 reddening law in UBVRI bands. Results for other bands are inconclusive. We make our fitting code publicly available.
- ID:
- ivo://CDS.VizieR/J/ApJ/541/841
- Title:
- UBV photometry and ages of Trapezium systems
- Short Name:
- J/ApJ/541/841
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We sought to determine the maximum age of Trapezium systems by studying possible trapezium systems that were selected independently of their occurrence in H II regions. We started with the unpublished catalog by Allen, Tapia & Parrao (1977RMxAA...3..119A) of all the known visual systems having three or more stars in which the maximum separation is less than 3.0 times the minimum separation. Their catalog has 968 such systems whose most frequent primary type is F, which does not describe young systems. With a CCD on the Kitt Peak 0.9m telescope we obtained UBV frames for 265 systems accessible with our equipment on Kitt Peak. The frames were used to obtain UBV photometry for about 1500 stars with an accuracy of 0.04mag between V=7 and 14mag. Also these frames were used to obtain astrometry with an accuracy of +/-0.015{deg} in position angle and +/-0.01" in separation. For the brightest star in each system we obtained a spectral type to determine the distance and reddening to the system.
- ID:
- ivo://CDS.VizieR/J/AJ/121/891
- Title:
- UBV photometry of LMC OB associations
- Short Name:
- J/AJ/121/891
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using ultraviolet photometry from the Ultraviolet Imaging Telescope (UIT) combined with photometry and spectroscopy from three ground-based optical data sets we have analyzed the stellar content of OB associations and field areas in and around the regions N79, N81, N83, and N94 in the Large Magellanic Cloud. In particular, we compare data for the OB association Lucke-Hodge 2 (LH 2) to determine how strongly the initial mass function (IMF) may depend on different photometric reductions and calibrations.
- ID:
- ivo://CDS.VizieR/II/20A
- Title:
- UBV Photometry of O and B Stars in Vela
- Short Name:
- II/20A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photoelectric UBV values, derived from observations made at the Boyden and ESO observatories, are presented for 358 early-type stars in the Vela section of the southern Milky Way. Remarks, accurate positions and notes have been added in July 2016 at CDS (Francois Ochsenbein)
- ID:
- ivo://CDS.VizieR/J/AJ/151/33
- Title:
- UBVRIz light curves of 51 Type II supernovae
- Short Name:
- J/AJ/151/33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a compilation of UBVRIz light curves of 51 type II supernovae discovered during the course of four different surveys during 1986-2003: the Cerro Tololo Supernova Survey, the Calan/Tololo Supernova Program (C&T), the Supernova Optical and Infrared Survey (SOIRS), and the Carnegie Type II Supernova Survey (CATS). The photometry is based on template-subtracted images to eliminate any potential host galaxy light contamination, and calibrated from foreground stars. This work presents these photometric data, studies the color evolution using different bands, and explores the relation between the magnitude at maximum brightness and the brightness decline parameter (s) from maximum light through the end of the recombination phase. This parameter is found to be shallower for redder bands and appears to have the best correlation in the B band. In addition, it also correlates with the plateau duration, being shorter (longer) for larger (smaller) s values.
- ID:
- ivo://CDS.VizieR/J/ApJ/778/127
- Title:
- UKIDSS+FIRST+SDSS red QSOs candidates
- Short Name:
- J/ApJ/778/127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a pilot survey to find dust-reddened quasars by matching the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) radio catalog to the UKIDSS near-infrared survey and using optical data from Sloan Digital Sky Survey to select objects with very red colors. The deep K-band limit provided by UKIDSS allows for finding more heavily reddened quasars at higher redshifts as compared with previous work using FIRST and Two Micron All Sky Survey (2MASS). We selected 87 candidates with K<=17.0 from the UKIDSS Large Area Survey (LAS) First Data Release (DR1), which covers 190deg^2^. These candidates reach up to ~1.5mag below the 2MASS limit and obey the color criteria developed to identify dust-reddened quasars. We have obtained 61 spectroscopic observations in the optical and/or near-infrared, as well as classifications in the literature, and have identified 14 reddened quasars with E(B-V)>0.1, including 3 at z>2. We study the infrared properties of the sample using photometry from the Wide-Field Infrared Survey Explorer and find that infrared colors improve the efficiency of red quasar selection, removing many contaminants in an infrared-to-optical color-selected sample alone. The highest-redshift quasars (z>~2) are only moderately reddened, with E(B-V)~0.2-0.3. We find that the surface density of red quasars rises sharply with faintness, comprising up to 17% of blue quasars at the same apparent K-band flux limit. We estimate that to reach more heavily reddened quasars (i.e., E(B-V)>~0.5) at z>2 and a depth of K=17, we would need to survey at least ~2.5 times more area.
- ID:
- ivo://CDS.VizieR/J/ApJ/869/56
- Title:
- Updated calibration of the CSP-I SNe Ia sample
- Short Name:
- J/ApJ/869/56
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of the final data release of the Carnegie Supernova Project I (CSP-I; Krisciunas+ 2017, J/AJ/154/211), focusing on the absolute calibration of the luminosity-decline rate relation for Type Ia supernovae (SNe Ia) using new intrinsic color relations with respect to the color-stretch parameter, s_BV_, enabling improved dust extinction corrections. We investigate to what degree the so-called fast-declining SNe Ia can be used to determine accurate extragalactic distances. We estimate the intrinsic scatter in the luminosity-decline rate relation and find it ranges from +/-0.13mag to +/-0.18mag with no obvious dependence on wavelength. Using the Cepheid variable star data from the SH0ES project (Riess+ 2016, J/ApJ/826/56), the SN Ia distance scale is calibrated and the Hubble constant is estimated using our optical and near-infrared sample, and these results are compared to those determined exclusively from a near-infrared subsample. The systematic effect of the supernova's host galaxy mass is investigated as a function of wavelength and is found to decrease toward redder wavelengths, suggesting this effect may be due to dust properties of the host. Using estimates of the dust extinction derived from optical and near-infrared wavelengths and applying these to the H band, we derive a Hubble constant H0=73.2+/-2.3km/s/Mpc, whereas using a simple B-V color correction applied to the B band yields H0=72.7+/-2.1km/s/Mpc. Photometry of two calibrating SNe Ia from the CSP-II sample, SN 2012ht and SN 2015F, is presented and used to improve the calibration of the SN Ia distance ladder.
