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- ID:
- ivo://CDS.VizieR/J/AJ/162/207
- Title:
- Dark-floored pits in Sputnik Planitia on Pluto
- Short Name:
- J/AJ/162/207
- Date:
- 02 Feb 2022 06:18:01
- Publisher:
- CDS
- Description:
- Sputnik Planitia, Pluto's gigantic, volatile ice glacier, hosts numerous scientific mysteries, including the presence of thousands of elongated pit structures. We examine various attributes of these pit structures in New Horizons data sets, revealing their length, aspect ratio, and orientation properties; we also study their reflectivities, colors, and compositions, and compare these attributes to some other relevant regions on Pluto. We then comment on origin mechanisms of the pits and also the fate of the missing volatiles represented by the pits on Sputnik Planitia. From a sample of 317 pits, we find typical length/width ratios of 2-4, with their major axis preferentially oriented approximately north-south. We also find that the floors of large pits in our sample have similar single-scattering albedos and colors to dark material on crater rims and floors (i.e., possible subsurface windows) in Burney basin. We also find that the base of the three pits in our sample, large enough to study with LEISA IR spectroscopy, display both CH_4_ and N_2_ absorption features, as do the dark regions in crater windows in Burney basin. Evidence for a sublimation erosion origin for the pits is supported over both the explosion/ejecta venting and structural collapse alternatives. Finally, we find that the mass lost by the pits on Sputnik Planitia most likely lies condensed elsewhere, on Pluto's surface, relocated there by volatile transport as opposed to removal by escape to space or photochemical conversion.
- ID:
- ivo://CDS.VizieR/J/MNRAS/417/1210
- Title:
- DA-white dwarfs from SDSS and UKIDSS
- Short Name:
- J/MNRAS/417/1210
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a method which uses colour-colour cuts on the Sloan Digital Sky Survey (SDSS) photometry to select white dwarfs with hydrogen-rich (DA) atmospheres without the recourse to spectroscopy. This method results in a sample of DA white dwarfs that is 95 per cent complete at an efficiency of returning a true DA white dwarf of 62 per cent. The approach was applied to SDSS Data Release 7 for objects with and without SDSS spectroscopy.
- ID:
- ivo://CDS.VizieR/J/ApJ/898/161
- Title:
- 500days of ASASSN-18pg multiwavelength obs.
- Short Name:
- J/ApJ/898/161
- Date:
- 16 Mar 2022 00:55:51
- Publisher:
- CDS
- Description:
- We present nearly 500 days of observations of the tidal disruption event (TDE) ASASSN-18pg, spanning from 54 days before peak light to 441 days after peak light. Our data set includes X-ray, UV, and optical photometry, optical spectroscopy, radio observations, and the first published spectropolarimetric observations of a TDE. ASASSN-18pg was discovered on 2018 July 11 by the All-Sky Automated Survey for Supernovae (ASAS-SN) at a distance of d=78.6Mpc; with a peak UV magnitude of m~14, it is both one of the nearest and brightest TDEs discovered to-date. The photometric data allow us to track both the rise to peak and the long-term evolution of the TDE. ASASSN-18pg peaked at a luminosity of L~2.4x10^44^erg/s, and its late-time evolution is shallower than a flux {propto}t^-5/3^ power-law model, similar to what has been seen in other TDEs. ASASSN-18pg exhibited Balmer lines and spectroscopic features consistent with Bowen fluorescence prior to peak, which remained detectable for roughly 225days after peak. Analysis of the two-component H{alpha} profile indicates that, if they are the result of reprocessing of emission from the accretion disk, the different spectroscopic lines may be coming from regions between ~10 and ~60 lt-days from the black hole. No X-ray emission is detected from the TDE, and there is no evidence of a jet or strong outflow detected in the radio. Our spectropolarimetric observations indicate that the projected emission region is likely not significantly aspherical, with the projected emission region having an axis ratio of >~0.65.
- ID:
- ivo://CDS.VizieR/J/ApJ/882/106
- Title:
- DB white dwarfs with SDSS and Gaia data
- Short Name:
- J/ApJ/882/106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive analysis of DB white dwarfs drawn from the Sloan Digital Sky Survey, based on model fits to ugriz photometry and medium-resolution spectroscopy from the Sloan Digital Sky Survey. We also take advantage of the exquisite trigonometric parallax measurements recently obtained by the Gaia mission. Using the so-called photometric and spectroscopic techniques, we measure the atmospheric and physical parameters of each object in our sample (Teff, logg, H/He, Ca/He, R, M), and compare the values obtained from both techniques in order to assess the precision and accuracy of each method. We then explore in great detail the surface gravity, stellar mass, and hydrogen abundance distributions of DB white dwarfs as a function of effective temperature. We present some clear evidence for a large population of unresolved double-degenerate binaries composed of DB+DB and even DB+DA white dwarfs. In the light of our results, we finally discuss the spectral evolution of DB white dwarfs, in particular the evolution of the DB-to-DA ratio as a function of Teff, and we revisit the question of the origin of hydrogen in DBA white dwarfs.
- ID:
- ivo://CDS.VizieR/J/A+A/546/A79
- Title:
- 400d Cluster Survey Weak Lensing Programme II
- Short Name:
- J/A+A/546/A79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Evolution in the mass function of galaxy clusters sensitively traces both the expansion history of the Universe and cosmological structure formation. Robust cluster mass determinations are a key ingredient for a reliable measurement of this evolution, especially at high redshift. Weak gravitational lensing is a promising tool for, on average, unbiased mass estimates. This weak lensing project aims at measuring reliable weak lensing masses for a complete X-ray selected sample of 36 high redshift (0.35<z<0.9) clusters. The goal of this paper is to demonstrate the robustness of the methodology against commonly encountered problems, including pure instrumental effects, the presence of bright (8-9mag) stars close to the cluster centre, ground based measurements of high-z (z~0.8) clusters, and the presence of massive unrelated structures along the line-sight.
- ID:
- ivo://CDS.VizieR/J/A+A/598/A32
- Title:
- 2D decomposition of CALIFA galaxies
- Short Name:
- J/A+A/598/A32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a two-dimensional multi-component photometric decomposition of 404 galaxies from the Calar Alto Legacy Integral Field Area Data Release 3 (CALIFA-DR3). They represent all possible galaxies with no clear signs of interaction and not strongly inclined in the final CALIFA data release. Galaxies are modelled in the g, r, and i Sloan Digital Sky Survey (SDSS) images including, when appropriate, a nuclear point source, bulge, bar, and an exponential or broken disc component. We use a human-supervised approach to determine the optimal number of structures to be included in the fit. The dataset, including the photometric parameters of the CALIFA sample, is released together with statistical errors and a visual analysis of the quality of each fit. The analysis of the photometric components reveals a clear segregation of the structural composition of galaxies with stellar mass. At high masses (log(M*/M_{sun}_)>11), the galaxy population is dominated by galaxies modelled with a single Sersic or a bulge+disc with a bulge-to-total (B/T) luminosity ratio B/T>0.2. At intermediate masses (9.5<log(M*/M_{sun}_)<11), galaxies described with bulge+disc but B/T<0.2 are preponderant, whereas, at the low mass end (log(M*/M_{\sun}_)<9.5), the prevailing population is constituted by galaxies modelled with either pure discs or nuclear point sources+discs (i.e., no discernible bulge). The analyses of the extended multi-component radial profile result in a volume-corrected distribution of 62%, 28%, and 10% for the so-called Type I (pure exponential), Type II (down-bending), and Type III (up-bending) disc profiles, respectively. These fractions are in discordance with previous findings. We argue that the different methodologies used to detect the breaks are the main cause for these differences.
- ID:
- ivo://CDS.VizieR/II/164
- Title:
- DDO Photoelectric Photometric Catalog
- Short Name:
- II/164
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalogue collects the DDO photometric data published in the astronomical literature until the end of 1988, and contains 8034 DDO measurements, concerning 6139 stars. The DDO 6-filter has the following peak wavelengths and widths: ------------------------ Filter Peak Width [nm] [nm] ------------------------ 35 346.0 38.3 38 381.5 33.0 41 416.6 8.3 42 425.7 7.3 45 451.7 7.6 48 488.6 18.6 51 (*) 513.0 13.4 ------------------------ (*) additional to DDO.
- ID:
- ivo://CDS.VizieR/V/33
- Title:
- DDO Photometry and Radial Velocities at Galactic Poles
- Short Name:
- V/33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalogue includes the DDO photometry and the radial velocities observed for the study of the kinematics and abundance gradients of G and K stars in the Galactic poles regions.
- ID:
- ivo://CDS.VizieR/J/other/SAAOC/15.30
- Title:
- DDO photometry of E-region stars
- Short Name:
- J/other/SAAOC/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper describes the observations and gives the results of a series of observations of bright E-region stars (Cousins A.W.J. and Stoy R.H., 1962RGOB...49....3C) for use as zero point stars for DDO photometry in the southern hemisphere. The list comprises 45 stars, all brighter than V=6.0, and gives the colours in the instrumental system with internal s.e. +/-0.001mag and m_48_ with s.e. +/-0.002mag. The observed m_48_ is indistinguishable from McClure's system and has the same zero point (+/-0.002mag). The individual E-region zero points have been established with s.e. +/-0.001 relative to the instrumental system, but the colour equations (and zero point corrections) to transform the instrumental colours to McClure's system have still to be finalised. For a description of the DDO photometric system, see e.g. <GCPD/12>
