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2981. Upper Scorpius spectroscopy and photometry
ID:
ivo://CDS.VizieR/J/AJ/160/44
Title:
Upper Scorpius spectroscopy and photometry
Short Name:
J/AJ/160/44
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have refined the census of stars and brown dwarfs in the Upper Sco association (~10Myr, ~145pc) by (1) updating the selection of candidate members from our previous survey to include the high-precision astrometry from the second data release of Gaia, (2) obtaining spectra of a few hundred candidate members to measure their spectral types and verify their youth, and (3) assessing the membership (largely with Gaia astrometry) of 2020 stars toward Upper Sco that show evidence of youth in this work and previous studies. We arrive at a catalog of 1761 objects that are adopted as members of Upper Sco. The distribution of spectral types among the adopted members is similar to those in other nearby star-forming regions, indicating a similar initial mass function. In previous studies, we have compiled mid-infrared photometry from the Wide-field Infrared Survey Explorer and the Spitzer Space Telescope for members of Upper Sco and used those data to identify the stars that show evidence of circumstellar disks; we present the same analysis for our new catalog of members. As in earlier work, we find that the fraction of members with disks increases with lower stellar masses, ranging from <~10% for >1M{sun} to ~22% for 0.01-0.3M{sun}. Finally, we have estimated the relative ages of Upper Sco and other young associations using their sequences of low-mass stars in M_G_RP__ versus G_BP_-G_RP_. This comparison indicates that Upper Sco is a factor of two younger than the {beta}Pic association (21-24Myr) according to both nonmagnetic and magnetic evolutionary models.
2982. U Sco outburst and pre-outburst optical spectrum
ID:
ivo://CDS.VizieR/J/A+A/559/A121
Title:
U Sco outburst and pre-outburst optical spectrum
Short Name:
J/A+A/559/A121
Date:
21 Oct 2021
Publisher:
CDS
Description:
Optical spectroscopic observations of the recurrent nova U Scorpii during its outburst in 2010 were obtained during 0.83-162.5 days after outburst maximum. Three spectra were obtained during pre-outburst quiescence. This paper discusses these observations along with optical polarimetric and radio continuum (610MHz, 1280MHz ; GMRT) data obtained during the 2010 outburst.
2983. UV and optical line variations in {epsilon} Persei
ID:
ivo://CDS.VizieR/J/ApJ/525/420
Title:
UV and optical line variations in {epsilon} Persei
Short Name:
J/ApJ/525/420
Date:
21 Oct 2021
Publisher:
CDS
Description:
The rapid variable star, {epsilon} Per (B0.5 IV-III), displays the largest amplitude profile fluctuations known among the growing number of massive, spectrum-variable stars. Here we present an analysis of a continuous 5 day run of IUE UV spectroscopy, and we show for the first time that the systematic, blue-to-red moving patterns observed in high-quality optical spectra are also present in the UV photospheric lines. We present cross-correlation functions of the individual spectra with that of a narrow-lined standard that produce a high signal-to-noise ratio representation of the blue-to-red moving bump patterns found in individual lines. We then use time series analysis methods to determine the periodic components of the profile variations (after reregistering the spectra to correct for binary motion). There are at least six periods present (ranging from 8.46 to 2.27 hr), and most of these signals are also found in optical line variations observed in 1986 (although the relative amplitudes have changed significantly). Furthermore, analysis of a shorter time series of IUE spectra from 1984 shows that similar periods were present then. We also present H{alpha} and He I 6678 profiles obtained with the Georgia State University Multi-Telescope Telescope, which were made simultaneously with IUE, and we show that the profile variations are essentially identical in the UV and optical ranges.
2984. UVBI magnitudes and redshifts in HDF-South
ID:
ivo://CDS.VizieR/J/AJ/126/1208
Title:
UVBI magnitudes and redshifts in HDF-South
Short Name:
J/AJ/126/1208
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalog of 97 (*) spectroscopic redshifts of z<1 galaxies in the Hubble Deep Field South (HDF-S) and its flanking fields (FFs). In the HDF-S proper we observed approximately half the galaxies brighter than I_814_(AB)=24 and obtained redshifts for 76% of them. Targets in our HDF-S sample were preselected to be at z<1 based on photometric redshifts, while in the FFs a simple magnitude cut was used. The photometric redshift preselection in the HDF-S resulted in a spectroscopic success rate that is significantly higher than in the FFs, where no preselection was applied. The rms precision of our redshift measurements, determined from repeat observations, is {delta}z=0.0003. We present the photometry and redshifts for the 97 objects for which we secured spectroscopic redshifts and describe the basic properties of this sample. The photometry was derived from the HST observations; the spectroscopy was obtained at the VLT using the FORS2 spectrograph on the Kueyen (UT2) and Yepun (UT4) 8.2m telescopes. (*) Actually, 103 redshifts in table1.
2985. UVB/NIR spectroscopy GRB hosts
ID:
ivo://CDS.VizieR/J/A+A/653/A83
Title:
UVB/NIR spectroscopy GRB hosts
Short Name:
J/A+A/653/A83
Date:
22 Feb 2022
Publisher:
CDS
Description:
We present the updated census and statistics of Lyman-alpha emitting long gamma-ray bursts host galaxies (LAE-LGRBs). We investigate the properties of a sub-sample of four LAE-LGRBs (GRBs: 011211, 021004, 060926, 070110). The combined observations of their afterglow and host galaxy allow us to test the shell model commonly used to fit Lyman-alpha emission line spectra.
2986. UV Bright Star Spectrophotometric Catalog
ID:
ivo://CDS.VizieR/III/39A
Title:
UV Bright Star Spectrophotometric Catalog
Short Name:
III/39A
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalogue contains observations carried out by the S2/68 Ultraviolet Sky Survey Telescope (UVSST) aboard the ESRO Satellite TD-1, which measured the absolute ultraviolet flux distribution between 2740A (274nm) and 1350A (135nm). The data presented in this catalogue were obtained during the first observation period, which lasted from 19 March 1972 to 31 October 1972, and contains the brightest objects, for which the signal is good enough to give valuable spectrophotometric information. The Faint Star Catalogue, which contains the photometric data of the stars up to the limit of detectability of the instrument, is known as the "Catalogue of Ultraviolet Fluxes", by Thompson et al. (catalog <II/59>) The S2/68 experiment has been described by Boksenberg et al. (=1973MNRAS.163..291B) and the absolute calibration by Humphries et al. (=1976A&A....49..389H).
2987. UVES sky atlas
ID:
ivo://CDS.VizieR/J/A+A/407/1157
Title:
UVES sky atlas
Short Name:
J/A+A/407/1157
Date:
21 Oct 2021
Publisher:
CDS
Description:
These tables list positions, widths and peak fluxes for the sky emission lines. The listings follow the subdivision in settings which is followed throughout the text and listed in Table 3.
2988. UVES spectra of Feige 46 and LSIV -14 116
ID:
ivo://CDS.VizieR/J/A+A/643/A22
Title:
UVES spectra of Feige 46 and LSIV -14 116
Short Name:
J/A+A/643/A22
Date:
21 Oct 2021
Publisher:
CDS
Description:
Hot subdwarf stars of spectral types O and B represent a poorly understood phase in the evolution of low-mass stars, in particular of close compact binaries. A variety of phenomena are observed, which make them important tools for several astronomical disciplines. For instance, the richness of oscillations of many subdwarfs are important for asteroseismology. Furthermore, hot subdwarfs are among the most chemically peculiar stars known. Two intermediate He-rich hot subdwarf stars, LSIV -14 116 and Feige 46, are particularly interesting, because they show extreme enrichments of heavy elements such as Ge, Sr, Y, and Zr, strikingly similar in both stars. In addition, both stars show light oscillations at periods incompatible with standard pulsation theory and form the class of V366 Aqr variables. We investigate whether the similar chemical compositions extend to more complete abundance patterns in both stars and validate the pulsations in Feige 46 using its recent TESS light curve. High-resolution optical and near-ultraviolet spectroscopy are combined with non-local-thermodynamical-equilibrium model atmospheres and synthetic spectra calculated with Tlusty and Synspec to determine detailed metal abundance patterns in both stars consistently. Many previously unidentified lines are identified for the first time with transitions originating from GaIII, GeIII-IV, SeIII, KrIII, SrII-III, YIII, ZrIII-IV, and SnIV, most of which have not been observed so far in any star. The abundance patterns of 19 metals in both stars are almost identical, light metals being only slightly more abundant in Feige 46 while Zr, Sn, and Pb are slightly less enhanced compared to LSIV -14 116. Both abundance patterns are distinctively different from those of normal He-poor hot subdwarfs of similar temperature. The extreme enrichment in heavy metals of more than 4 dex compared to the Sun is likely the result of strong atmospheric diffusion processes that operate similarly in both stars while their similar patterns of C, N, O, and Ne abundances might provide clues to their as yet unclear evolutionary history. Finally, we find that the periods of the pulsation modes in Feige 46 are stable to better than dP/dt~=10^-8^s/s. This is is not compatible with dP/dt predicted for pulsations driven by the epsilon-mechanism and excited by helium-shell flashes in a star which is evolving, for example, onto the extended horizontal branch.
2989. UVES Spectrum of APM BR J0307-4945
ID:
ivo://CDS.VizieR/J/A+A/370/426
Title:
UVES Spectrum of APM BR J0307-4945
Short Name:
J/A+A/370/426
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the first high-resolution (6.2 to 7.7km/s FWHM) spectra of the APM BR J0307-4945 quasar at z_em_=4.73 obtained with UVES on the 8.2m VLT Kueyen telescope. We focus our analysis on a damped Lyman-{alpha} system at z_abs_=4.466, the most distant DLA system known to the present date, observed when the age of the universe was only 1.3Gyr. The following table lists the wavelengths and equivalent widths for all absorption-line features (except the telluric lines) redwards of the quasar Ly-{alpha} emission detected at 4{sigma} in equivalent width. The transition names and approximate redshifts are specified for the features we successfully identified. About 80% of the absorption lines redwards of the quasar Ly-{alpha} emission have been identified, corresponding to 13 metal-line systems.
2990. UV FeII template from LBQS 2113-4538
ID:
ivo://CDS.VizieR/J/A+A/562/A34
Title:
UV FeII template from LBQS 2113-4538
Short Name:
J/A+A/562/A34
Date:
21 Oct 2021
Publisher:
CDS
Description:
MgII line is of extreme importance for intermediate quasars since it allows to measure the black hole mass in these sources and to use them as probes of the distribution of dark energy in the Universe, as a complementary tool to SN Ia. Reliable use of MgII requires good understanding of all systematic effects involved in the measurement of the line properties, including the contamination by FeII UV emission.

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