- ID:
- ivo://CDS.VizieR/VI/49
- Title:
- Constellation Boundary Data
- Short Name:
- VI/49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A computer readable catalog of constellation boundary data is presented in a form suitable for the construction of star charts and atlases. Two data files are available, one for equator and equinox 1875 and the other for equator and equinox 2000. In addition to the data files a documentation file is available that includes a table listing the abbreviations used for the constellations as well as a more detailed discussion of the preparation of the catalog. The present catalog of constellation boundary data is complementary to that of Roman (1987). Roman's catalog should be used to determine in which constellation an object lies in. The present catalog is more suited to the construction of star charts and atlases. Both catalogs were based on Delporte (1930).
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- ID:
- ivo://CDS.VizieR/J/A+A/608/A46
- Title:
- Constraining cosmic scatter
- Short Name:
- J/A+A/608/A46
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the stellar parameters, abundances, associated errors and the linelist of a set of 23 metal-poor and very metal-poor halo stars. Stellar parameters and chemical abundances were derived in a line-by-line differential analysis from equivalent widths of UVES/VLT spectra. The differential analysis provided us unprecedented small data scatter and errors. Our sample, along with data from different authors in different metallicity ranges, allowed us to do an extensive comparison of the chemical abundances with the predictions of a Galaxy chemical evolution model.
- ID:
- ivo://CDS.VizieR/J/ApJ/834/49
- Title:
- Constraining the epoch of reionization
- Short Name:
- J/ApJ/834/49
- Date:
- 09 Feb 2022 14:54:48
- Publisher:
- CDS
- Description:
- We combine observational data on a dozen independent cosmic properties at high-z with the information on reionization drawn from the spectra of distant luminous sources and the cosmic microwave background (CMB) to constrain the interconnected evolution of galaxies and the intergalactic medium since the dark ages. The only acceptable solutions are concentrated in two narrow sets. In one of them reionization proceeds in two phases: a first one driven by Population III stars, completed at z~10, and after a short recombination period a second one driven by normal galaxies, completed at z~6. In the other set both kinds of sources work in parallel until full reionization at z~6. The best solution with double reionization gives excellent fits to all the observed cosmic histories, but the CMB optical depth is 3{sigma} larger than the recent estimate from the Planck data. Alternatively, the best solution with single reionization gives less good fits to the observed star formation rate density and cold gas mass density histories, but the CMB optical depth is consistent with that estimate. We make several predictions, testable with future observations, that should discriminate between the two reionization scenarios. As a byproduct our models provide a natural explanation to some characteristic features of the cosmic properties at high-z, as well as to the origin of globular clusters.
- ID:
- ivo://CDS.VizieR/J/A+A/624/A116
- Title:
- Constraints on the progenitor of SN 1987A
- Short Name:
- J/A+A/624/A116
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With the same method as used previously, we investigate neutrino-driven explosions of a larger sample of blue supergiant models. The blue supergiants were evolved as single-star progenitors. The larger sample includes three new presupernova stars. The results are compared with light-curve observations of the peculiar type IIP SN 1987A. The explosions were modeled in 3D with the neutrino-hydrodynamics code PROMETHEUS-HOTB, and light-curve calculations were performed in spherical symmetry with the radiation-hydrodynamics code CRAB, starting at a stage of nearly homologous expansion. Our results confirm the basic findings of the previous work: 3D neutrino-driven explosions with SN 1987A-like energies synthesize an amount of Ni-56 that is consistent with the radioactive tail of the light curve. Moreover, the models mix hydrogen inward to minimum velocities below 400km/s as required by spectral observations and a 3D analysis of molecular hydrogen in SN 1987A. Hydrodynamic simulations with the new progenitor models, which possess smaller radii than the older ones, show much better agreement between calculated and observed light curves in the initial luminosity peak and during the first 20 days. A set of explosions with similar energies demonstrated that a high growth factor of Rayleigh-Taylor instabilities at the (C+O)/He composition interface combined with a weak interaction of fast Rayleigh-Taylor plumes, where the reverse shock occurs below the He/H interface, provides a sufficient condition for efficient outward mixing of Ni-56 into the hydrogen envelope. This condition is realized to the required extent only in one of the older stellar models, which yielded a maximum velocity of around 3000km/s for the bulk of ejected Ni-56, but failed to reproduce the helium-core mass of 6M_{sun}_ inferred from the absolute luminosity of the presupernova star. We conclude that none of the single-star progenitor models proposed for SN 1987A to date satisfies all constraints set by observations.
- ID:
- ivo://CDS.VizieR/J/MNRAS/465/4678
- Title:
- 9380 contact binaries from CRTS VSC
- Short Name:
- J/MNRAS/465/4678
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We construct a sample of 9380 contact binaries (W UMa systems) by using the Catalina Real-Time Transient Survey Variables Sources Catalogue. By measuring brightness change rates, light-curve statistics, and temperatures for this sample, we improve the understanding of contact binary light-curve characteristics, and luminosity variability on decadal time-scales. We show that binaries with convective outer envelopes have a different distribution of light-curve amplitudes and magnitude differences between eclipse minima than binaries with radiative outer envelopes. We find that more than 2000 binaries exhibit a linear change in mean brightness over the 8-yr timespan of observations with at least 3{sigma} significance. We note that 25.9 per cent of binaries with convective outer envelopes exhibit a significant change in brightness, while only 10.5 per cent of radiative binaries exhibit a significant change in brightness. In 205 binaries (2.2 per cent), we find that a sinusoid model better describes the luminosity trend within the 8-yr observation timespan. For these binaries, we report the amplitudes and periods (as estimated using observed half-periods) of this sinusoidal brightness variation and discuss possible mechanisms driving the variation.
- ID:
- ivo://CDS.VizieR/J/AcA/51/259
- Title:
- Contact binaries in OGLE-I database
- Short Name:
- J/AcA/51/259
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The present catalog contains the most numerous, observationally homogeneous sample of contact binaries. It is derived from the OGLE experiment (Optical Gravitational Lensing Experiment), in the direction of the Galactic Bulge and the Galactic bar. The observations were made with the 1-m Swope telescope at Las Campanas Observatory in Chile, over the period 1992 to 1995. The present catalog includes the 1575 newly discovered contact binaries fainter than I=18mag as well as the 1165 brighter contact binaries previously published. It also includes a list of 506 objects with nearly sinusoidal light curves, to ease the comparison and/or distinction between contact binaries with the sinusoidal light curves and pulsating stars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/507/4914
- Title:
- Contact-binary (68346) 2001 KZ66 light curves
- Short Name:
- J/MNRAS/507/4914
- Date:
- 19 Jan 2022 09:12:40
- Publisher:
- CDS
- Description:
- The YORP effect is a small thermal-radiation torque experienced by small asteroids, and is considered to be crucial in their physical and dynamical evolution. It is important to understand this effect by providing measurements of YORP for a range of asteroid types to facilitate the development of a theoretical framework. We are conducting a long-term observational study on a selection of near-Earth asteroids to support this. We focus here on (68346) 2001 KZ66, for which we obtained both optical and radar observations spanning a decade. This allowed us to perform a comprehensive analysis of the asteroid's rotational evolution. Furthermore, radar observations from the Arecibo Observatory enabled us to generate a detailed shape model. We determined that (68346) is a retrograde rotator with its pole near the southern ecliptic pole, within a 15-degree radius of longitude 170 degrees and latitude -85-degrees. By combining our radar-derived shape model with the optical light curves we developed a refined solution to fit all available data, which required a YORP strength of (8.43+/-0.69)x10^-8^rad/day/day. (68346) has a distinct bifurcated shape comprising a large ellipsoidal component joined by a sharp neckline to a smaller non-ellipsoidal component. This object likely formed from either the gentle merging of a binary system, or from the deformation of a rubble pile due to YORP spin-up. The shape exists in a stable configuration close to its minimum in topographic variation, where regolith is unlikely to migrate from areas of higher potential.
- ID:
- ivo://CDS.VizieR/J/ApJ/849/20
- Title:
- Contents of RESOLVE & ECO galaxy groups
- Short Name:
- J/ApJ/849/20
- Date:
- 18 Nov 2021 00:26:09
- Publisher:
- CDS
- Description:
- We examine the z=0 group-integrated stellar and cold baryonic (stars + cold atomic gas) mass functions (group SMF and CBMF) and the baryonic collapse efficiency (group cold baryonic to dark matter halo mass ratio) using the RESOLVE and ECO survey galaxy group catalogs and a GALFORM semi-analytic model (SAM) mock catalog. The group SMF and CBMF fall off more steeply at high masses and rise with a shallower low-mass slope than the theoretical halo mass function (HMF). The transition occurs at the group-integrated cold baryonic mass M_bary_^cold^~10^11^M_{sun}_. The SAM, however, has significantly fewer groups at the transition mass ~10^11^M_{sun}_ and a steeper low-mass slope than the data, suggesting that feedback is too weak in low-mass halos and conversely too strong near the transition mass. Using literature prescriptions to include hot halo gas and potential unobservable galaxy gas produces a group BMF with a slope similar to the HMF even below the transition mass. Its normalization is lower by a factor of ~2, in agreement with estimates of warm-hot gas making up the remaining difference. We compute baryonic collapse efficiency with the halo mass calculated two ways, via halo abundance matching (HAM) and via dynamics (extended all the way to three-galaxy groups using stacking). Using HAM, we find that baryonic collapse efficiencies reach a flat maximum for groups across the halo mass range of M_halo_~10^11.4-12^M_{sun}_, which we label "nascent groups". Using dynamics, however, we find greater scatter in baryonic collapse efficiencies, likely indicating variation in group hot-to-cold baryon ratios. Similarly, we see higher scatter in baryonic collapse efficiencies in the SAM when using its true groups and their group halo masses as opposed to friends-of-friends groups and HAM masses.
- ID:
- ivo://CDS.VizieR/J/A+A/614/A48
- Title:
- Continuous rise of bulges out of galactic disks
- Short Name:
- J/A+A/614/A48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A key subject in extragalactic astronomy concerns the chronology and driving mechanisms of bulge formation in late-type galaxies (LTGs). The standard scenario distinguishes between classical bulges and pseudo-bulges (CBs and PBs, respectively), the first thought to form monolithically prior to disks and the second gradually out of disks. These two bulge formation routes obviously yield antipodal predictions on the bulge age and bulge-to-disk age contrast, both expected to be high (low) in CBs (PBs). Our main goal is to explore whether bulges in present-day LTGs segregate into two evolutionary distinct classes, as expected from the standard scenario. Other questions motivating this study center on evolutionary relations between LTG bulges and their hosting disks, and the occurrence of accretion-powered nuclear activity as a function of bulge stellar mass M* and stellar surface density {Sigma}*. In this study we have combined three techniques - surface photometry, spectral modeling of integral field spectroscopy data and suppression of stellar populations younger than an adjustable age cutoff with the code REMOVE YOUNG (RY) - toward a systematic analysis of the physical and evolutionary properties (e.g., M* , {Sigma}* and mass-weighted stellar age <t*>_M_ and metallicity <Z*>_M_, respectively) of a representative sample of 135 nearby (<=130Mpc) LTGs from the CALIFA survey that cover a range between 10^8.9^M_{sun}_ and 10^11.5^M_{sun}_ in total stellar mass M_*,T_. In particular, the analysis here revolves around <{delta}{mu}9G>, a new distance- and formally extinction-independent measure of the contribution by stellar populations of age >=9Gyr to the mean r-band surface brightness of the bulge. We argue that <{delta}{mu}9Gx > offers a handy semi-empirical tracer of the physical and evolutionary properties of LTG bulges and a promising means for their characterization.
- ID:
- ivo://CDS.VizieR/J/A+A/564/A128
- Title:
- Continuum and CO maps of 3C 293
- Short Name:
- J/A+A/564/A128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Powerful radio galaxies show evidence of ongoing active galactic nuclei (AGN) feedback, mainly in the form of fast, massive outflows. But it is not clear how these outflows affect the star formation of their hosts. We investigate the different manifestations of AGN feedback in the evolved, powerful radio source 3C 293 and their impact on the molecular gas of its host galaxy, which harbors young star-forming regions and fast outflows of H i and ionized gas. We study the distribution and kinematics of the molecular gas of 3C 293 using high spatial resolution observations of the ^12^CO(1-0) and ^12^CO(2-1) lines, and the 3mm and 1 continuum taken with the IRAM Plateau de Bure interferometer. We mapped the molecular gas of 3C 293 and compared it with the dust and star-formation images of the host. We searched for signatures of outflow motions in the CO kinematics, and re-examined the evidence of outflowing gas in the HI spectra. We also derived the star formation rate (SFR) and star formation efficiency (SFE) of the host with all available SFR tracers from the literature, and compared them with the SFE of young and evolved radio galaxies and normal star-forming galaxies. The ^12^CO(1-0) emission line shows that the molecular gas in 3C 293 is distributed along a massive (M(H_2_)~2.2x10^10^M_{sun}_) ~24" (21kpc) diameter warped disk, that rotates around the AGN. Our data show that the dust and the star formation are clearly associated with the CO disk. The ^12^CO(2-1) emission is located in the inner 7kpc (diameter) region around the AGN, coincident with the inner part of the ^12^CO(1-0) disk. Both the ^12^CO(1-0) and ^12^CO(2-1) spectra reveal the presence of an absorber against the central regions of 3C 293 that is associated with the disk. We do not detect any fast (500km/s) outflow motions in the cold molecular gas. The host of 3C 293 shows an SFE consistent with the Kennicutt-Schmidt law of normal galaxies and young radio galaxies, and it is 10-50 times higher than the SFE estimated with the 7.7um PAH emission of evolved radio galaxies. Our results suggest that the apparently low SFE of evolved radio galaxies may be caused by an underestimation of the SFR and/or an overestimation of the molecular gas densities in these sources. The molecular gas of 3C 293, while not incompatible with a mild AGN-triggered flow, does not reach the high velocities (500km/s) observed in the HI spectrum. We find no signatures of AGN feedback in the molecular gas of 3C 293.