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22051. The star formation history of the LMC
ID:
ivo://CDS.VizieR/J/AJ/138/1243
Title:
The star formation history of the LMC
Short Name:
J/AJ/138/1243
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the first ever global, spatially resolved reconstruction of the star formation history (SFH) of the Large Magellanic Cloud (LMC), based on the application of our StarFISH analysis software to the multiband photometry of 20 million of its stars from the Magellanic Clouds Photometric Survey (MCPS). The general outlines of our results are consistent with previously published results: following an initial burst of star formation, there was a quiescent epoch from approximately 12 to 5Gyr ago. Star formation then resumed and has proceeded until the current time at an average rate of roughly 0.2M_{sun}_/yr, with temporal variations at the factor of 2 level.
22052. The stars
ID:
ivo://edu.gavo.org/eurovo/aida_stars
Title:
The stars
Date:
27 Dec 2024 08:31:13
Publisher:
The GAVO DC team
Description:
Stars have different colors and luminosities. Following this tutorial we will learn what star luminosity and color are, and which information about stellar evolution we can obtain from them.
22053. The 90000 stars Supplement to the PPM Catalogue
ID:
ivo://CDS.VizieR/I/208
Title:
The 90000 stars Supplement to the PPM Catalogue
Short Name:
I/208
Date:
21 Oct 2021
Publisher:
CDS
Description:
Since its appearance in 1966, the SAO Catalogue (SAO, 1966) has been the primary source for stellar positions and proper motions. Typical values for the rms errors are 1 arcsec in the positions at epoch 1990, and 1.5 arcsec/century in the proper motions. The corresponding figures for the AGK3 (Heckmann et al., 1975) on the northern hemisphere are 0.45 arcsec and 0.9 arcsec/century. Common to both catalogues is the fact that proper motions area derived from two observational epochs only. Both catalogues are nominally on the B1950/FK4 coordinate system. The PPM Star Catalogue (Roeser and Bastian, 1991, Bastian et al., 1993; for a short description see Roeser and Bastian, 1993) effectively replaced these catalogues by providing more precise astrometric data for more stars on the J2000/FK5 coordinate system. Compared to the SAO Catalogue the improvement in precision is about a factor of 3 on the northern and a factor of 6 to 10 on the southern hemisphere. In addition, the number of stars is increased by about 50 percent. Typical values for the rms errors on the northern hemisphere are 0.27 arcsec in the positions at epoch 1990, and 0.42 arcsec/century in the proper motions. On the southern hemisphere PPM is much better, the corresponding figures being 0.11 arcsec and 0.30 arcsec/century. The improvement over the SAO Catalogue was made possible by the advent of new big catalogues of position measurements and by the inclusion of the century-old Astrographic Catalogue (AC) into the derivation of proper motions (for a description of AC see Eichhorn, 1974). But even PPM does not fully exploit the treasure of photographic position measurements available in the astronomical literature of the last 100 years. The Astrographic Catalogue contains roughly four million stars that are not included in PPM. For most of them no precise modern-epoch position measurements exist. Thus it is not yet possible to derive proper motions with PPM quality for all AC stars. But among the 4 million there is a subset of some 100,000 CPC-2 stars that are not included in PPM. These stars constitute the 90,000 Stars Supplement to PPM. See file "desc.txt" for complete explanations provided by the authors.
22054. The stellar content of Trumpler 37
ID:
ivo://CDS.VizieR/J/AN/334/673
Title:
The stellar content of Trumpler 37
Short Name:
J/AN/334/673
Date:
21 Oct 2021
Publisher:
CDS
Description:
With an apparent cluster diameter of 1.5deg and an age of ~4Myr, Trumpler 37 is an ideal target for photometric monitoring of young stars as well as for the search of planetary transits, eclipsing binaries and other sources of variability. The YETI consortium has monitored Trumpler 37 throughout 2010 and 2011 to obtain a comprehensive view of variable phenomena in this region. In this first paper we present the cluster properties and membership determination as derived from an extensive investigation of the literature. We also compared the coordinate list to some YETI images. For 1872 stars we found literature data. Among them 774 have high probability of being member and 125 a medium probability. Based on infrared data we re-calculate a cluster extinction of 0.9-1.2mag. We can confirm the age and distance to be 3-5Myr and ~870pc. Stellar masses are determined from theoretical models and the mass function is fitted with a power-law index of {alpha}=1.90 (0.1-0.4M_{sun}_) and {alpha}=1.12 (1-10M_{sun}_).
22055. The stellar membership of the Taurus SFR
ID:
ivo://CDS.VizieR/J/AJ/156/271
Title:
The stellar membership of the Taurus SFR
Short Name:
J/AJ/156/271
Date:
21 Oct 2021
Publisher:
CDS
Description:
The high-precision astrometry from the second data release of the Gaia mission (Cat. I/345) has made it possible to greatly improve the census of members of nearby clusters and associations. I have applied the Gaia data to the Taurus star-forming region, refining the sample of known members and identifying candidates for undiscovered members. The resulting samples of members and candidates provide the best constraints to date on the distribution of ages and the initial mass function (IMF) in Taurus. Several studies over the last 30 years have proposed the existence of a population of older stars (>~10 Myr) that is associated with the Taurus clouds. The data from Gaia demonstrate that such a population does not exist. Meanwhile, previous IMF estimates for small fields surrounding the Taurus aggregates have exhibited a surplus of K7-M0 stars (0.7-0.8 M_{sun}_) relative to star-forming clusters such as IC 348 and the Orion Nebula Cluster. However, that difference disappears when the new census of the entire region is considered, which should be complete for spectral types earlier than M6-M7 at A_J_<1. Thus, there is little variation in the stellar IMF across the 3-4 orders of magnitude in stellar density that are present in nearby star-forming regions. Finally, I note that the proper motions of two previously known members, KPNO 15 and 2MASS J04355209+2255039, indicate that they may have been ejected from the same location within the L1536 cloud ~7200 years ago.
22056. The Stromlo-APM Redshift Survey IV
ID:
ivo://CDS.VizieR/J/ApJS/107/201
Title:
The Stromlo-APM Redshift Survey IV
Short Name:
J/ApJS/107/201
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Stromlo-APM Redshift Survey consists of 1797 galaxies with b(J)<17.15 selected randomly at a rate of 1 in 20 from Automated Plate Measurement (APM) scans. The survey covers a solid angle of 1.3sr (4300 square degrees) in the south galactic cap. Redshifts have been measured for 1790 (99.6%) of the galaxies. The median galaxy recession velocity is 15,300 km/s and so the volume probed is approximately V=1.38 million Mpc^3/h^3.
22057. The 1st year of the Swift SMC Survey (S-CUBED)
ID:
ivo://CDS.VizieR/J/ApJ/868/47
Title:
The 1st year of the Swift SMC Survey (S-CUBED)
Short Name:
J/ApJ/868/47
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Swift Small Magellanic Cloud (SMC) Survey, S-CUBED, is a high-cadence shallow X-ray survey of the SMC. The survey consists of 142 tiled pointings covering the optical extent of the SMC, which is performed weekly by NASA's Neil Gehrels Swift Observatory, with an exposure per tile of 60s. The survey is focused on discovery and monitoring of X-ray outbursts from the large known and unknown population of Be/X-ray binaries (BeXRBs) in the SMC. Given the very low background of Swift's X-ray telescope, even with a short exposure per tile, S-CUBED is typically sensitive to outbursts in the SMC at >1%-2% Eddington luminosity for a typical 1.4M_{sun}_ neutron star compact object. This sensitivity, combined with the high cadence and the fact that the survey can be performed all year round, makes it a powerful discovery tool for outbursting accreting X-ray pulsars in the SMC. In this paper we describe results from the first year of observations of S-CUBED, which includes the 1SCUBEDX catalog of 265 X-ray sources, 160 of which are not identified with any previously cataloged X-ray source. We report on bulk properties of sources in the 1SCUBEDX catalog. Finally, we focus on results of S-CUBED observations of several interesting sources, which includes discovery of three Type II outbursts from BeXRBs and the detection of Type I outbursts and orbital periods in six BeXRB systems.
22058. The submillimeter spectrum of glycolaldehyde
ID:
ivo://CDS.VizieR/J/ApJ/723/845
Title:
The submillimeter spectrum of glycolaldehyde
Short Name:
J/ApJ/723/845
Date:
21 Oct 2021
Publisher:
CDS
Description:
Glycolaldehyde (HOCH_2_CHO) is a sugar-related interstellar prebiotic molecule that has been detected in two star-forming regions, Sgr B2(N) and G31.41+0.31. Glycolaldehyde is suspected to form from photodissociation-driven ice chemistry, and therefore can be used to trace complex organic chemistry in interstellar environments. The relative abundance of glycolaldehyde to its structural isomers, methyl formate (HCOOCH_3_) and acetic acid (CH_3_COOH), can be used to constrain astrochemical models. Given its central role in the complex chemistry of the interstellar medium, glycolaldehyde has been suggested as a prime molecular target for upcoming high-frequency molecular line searches using new far-infrared observatories. In particular, glycolaldehyde is a target for the Herschel Space Observatory HEXOS Key Program, which is conducting spectral line surveys of the Sgr B2(N) and Orion KL star-forming regions across the entire HIFI band. Laboratory investigation of glycolaldehyde in the HIFI frequency range is required before its lines can be identified in these spectra. We have therefore acquired the laboratory spectrum of glycolaldehyde in selected frequency ranges across the submillimeter range. We present here the laboratory spectral analysis of the ground vibrational state of glycolaldehyde up to 1.2THz.
22059. The SUGAR model. Training dataset
ID:
ivo://CDS.VizieR/J/A+A/636/A46
Title:
The SUGAR model. Training dataset
Short Name:
J/A+A/636/A46
Date:
21 Oct 2021
Publisher:
CDS
Description:
This analysis develops a new SNe Ia spectral energy distribution (SED) model, called the SUpernova Generator And Reconstructor (SUGAR), which improves the spectral description of SNe Ia, and consequently could improve the distance measurements. This model was constructed from SNe Ia spectral properties and spectrophotometric data from the Nearby Supernova Factory collaboration. In a first step, a principal component analysis-like method was used on spectral features measured at maximum light, which allowed us to extract the intrinsic properties of SNe Ia. Next, the intrinsic properties were used to extract the average extinction curve. Third, an interpolation using Gaussian processes facilitated using data taken at different epochs during the lifetime of an SN Ia and then projecting the data on a fixed time grid. Finally, the three steps were combined to build the SED model as a function of time and wavelength. This is the SUGAR model. The proper way to cite the data can be found at https://snfactory.lbl.gov/snf/data/index.html
22060. The Super-CLASS GMRT catalogue - SCG
ID:
ivo://CDS.VizieR/J/MNRAS/462/917
Title:
The Super-CLASS GMRT catalogue - SCG
Short Name:
J/MNRAS/462/917
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of 325MHz Giant Metrewave Radio Telescope observations of a supercluster field, known to contain five Abell clusters at redshift z~0.2. We achieve a nominal sensitivity of 34uJy/beam towards the phase centre. We compile a catalogue of 3257 sources with flux densities in the range 183uJy-1.5Jy within the entire ~6.5deg^2^ field of view. Subsequently, we use available survey data at other frequencies to derive the spectral index distribution for a sub-sample of these sources, recovering two distinct populations - a dominant population which exhibit spectral index trends typical of steep-spectrum synchrotron emission, and a smaller population of sources with typically flat or rising spectra. We identify a number of sources with ultrasteep spectra or rising spectra for further analysis, finding two candidate high-redshift radio galaxies and three gigahertz-peaked-spectrum radio sources. Finally, we derive the Euclidean-normalized differential source counts using the catalogue compiled in this work, for sources with flux densities in excess of 223uJy. Our differential source counts are consistent with both previous observations at this frequency and models of the low-frequency source population. These represent the deepest source counts yet derived at 325MHz. Our source counts exhibit the well-known flattening at mJy flux densities, consistent with an emerging population of star-forming galaxies; we also find marginal evidence of a downturn at flux densities below 308uJy, a feature so far only seen at 1.4GHz.

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