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2891. TheoSSA TMAP Web Interface
ID:
ivo://org.gavo.dc/theossa/q/web
Title:
TheoSSA TMAP Web Interface
Short Name:
tmap_web
Date:
27 Dec 2024 08:31:03
Publisher:
The GAVO DC team
Description:
TheoSSA provides spectral energy distributions based on model atmosphere calculations. Currently, we serve results obtained using the Tübingen NLTE Model Atmosphere Package (TMAP) for hot compact stars.
2892. The Panchromatic High-Resolution Spectroscopic Survey of Local Group Star Clusters PCSLG
ID:
ivo://org.gavo.dc/pcslg/q/ssa
Title:
The Panchromatic High-Resolution Spectroscopic Survey of Local Group Star Clusters PCSLG
Short Name:
PCSLG SSAP
Date:
27 Dec 2024 08:31:12
Publisher:
The GAVO DC team
Description:
This dataset contains spectroscopic observations of 29 globular clusters in the Magellanic Clouds and the Milky Way performed with VLT/X-shooter over eight full nights.
2893. The PHLEK survey: oxygen & helium abundances
ID:
ivo://CDS.VizieR/J/ApJ/896/77
Title:
The PHLEK survey: oxygen & helium abundances
Short Name:
J/ApJ/896/77
Date:
11 Mar 2022
Publisher:
CDS
Description:
We present Keck NIRSPEC and Keck NIRES spectroscopy of sixteen metal-poor galaxies that have pre-existing optical observations. The near-infrared (NIR) spectroscopy specifically targets the HeI{lambda}10830{AA} emission line, due to its sensitivity to the physical conditions of the gas in HII regions. We use these NIR observations, combined with optical spectroscopy, to determine the helium abundance of sixteen galaxies across a metallicity range 12+log_10_(O/H)=7.13-8.00. This data set is combined with two other samples where metallicity and helium abundance measurements can be secured: star-forming galaxies selected from the Sloan Digital Sky Survey spectroscopic database, and existing low-metallicity systems in the literature. We calculate a linear fit to these measurements, accounting for intrinsic scatter, and report a new determination of the primordial helium number abundance, y_P_=0.0805_-0.0017_^+0.0017^, which corresponds to a primordial helium mass fraction Y_P_=0.2436_-0.0040_^+0.0039^. Using our determination of the primordial helium abundance in combination with the latest primordial deuterium measurement, (D/H)_P_x10^5^=2.527+/-0.030, we place a bound on the baryon density {Omega}_b_h^2^=0.0215_-0.0005_^+0.0005^ and the effective number of neutrino species N_eff_=2.85_-0.25_^+0.28^. These values are in 1.3{sigma} agreement with those deduced from the Planck satellite observations of the temperature fluctuations imprinted on the cosmic microwave background.
2894. The red spectrum of HD 101065
ID:
ivo://CDS.VizieR/J/A+A/339/165
Title:
The red spectrum of HD 101065
Short Name:
J/A+A/339/165
Date:
21 Oct 2021
Publisher:
CDS
Description:
Wavelength list for Przybylski's star (a rapidly rotation Ap star) including a measurement of the line depths.
2895. Thermal emission spectrum of WASP-189b
ID:
ivo://CDS.VizieR/J/A+A/640/L5
Title:
Thermal emission spectrum of WASP-189b
Short Name:
J/A+A/640/L5
Date:
21 Oct 2021
Publisher:
CDS
Description:
Temperature inversion layers are predicted to be present in ultra-hot giant planet atmospheres. Although such inversion layers have recently been observed in several ultra-hot Jupiters, the chemical species responsible for creating the inversion remain unidentified. Here, we present observations of the thermal emission spectrum of an ultra-hot Jupiter, WASP-189b, at high spectral resolution using the HARPS-N spectrograph. Using the cross-correlation technique, we detect a strong FeI signal. The detected FeI spectral lines are found in emission, which is direct evidence of a temperature inversion in the planetary atmosphere. We further performed a retrieval on the observed spectrum using a forward model with an MCMC approach. When assuming a solar metallicity, the best-fit result returns a temperature of 4320 K at the top of the inversion, which is significantly hotter than the planetary equilibrium temperature (2641 K). The temperature at the bottom of the inversion is determined as 2200 K. Such a strong temperature inversion is probably created by the absorption of atomic species like FeI.
2896. Thermonuclear X-ray bursts. II. Eddington limit
ID:
ivo://CDS.VizieR/J/ApJ/747/77
Title:
Thermonuclear X-ray bursts. II. Eddington limit
Short Name:
J/ApJ/747/77
Date:
21 Oct 2021
Publisher:
CDS
Description:
Time-resolved X-ray spectroscopy of thermonuclear bursts observed from low-mass X-ray binaries offer a unique tool to measure neutron-star masses and radii. In this paper, we continue our systematic analysis of all the X-ray bursts observed with Rossi X-ray Timing Explorer from X-ray binaries. We determine the events that show clear evidence for photospheric radius expansion and measure the Eddington limits for these accreting neutron stars using the bolometric fluxes attained at the touchdown moments of each X-ray burst. We employ a Bayesian technique to investigate the degree to which the Eddington limit for each source remains constant between bursts. We find that for sources with a large number of radius expansion bursts, systematic uncertainties are at a 5%-10% level. Moreover, in six sources with only pairs of Eddington-limited bursts, the distribution of fluxes is consistent with a ~10% fractional dispersion. This indicates that the spectroscopic measurements of neutron-star masses and radii using thermonuclear X-ray bursts can reach the level of accuracy required to distinguish between different neutron-star equations of state, provided that uncertainties related to the overall flux calibration of X-ray detectors are of comparable magnitude.
2897. The RMS survey: ^13^CO observations of YSOs
ID:
ivo://CDS.VizieR/J/A+A/487/253
Title:
The RMS survey: ^13^CO observations of YSOs
Short Name:
J/A+A/487/253
Date:
21 Oct 2021
Publisher:
CDS
Description:
MSX names, positions, observational rms values and molecular line parameters obtained from Gaussian fits to all detected components made towards the RMS sample of massive young stellar object candidates located in the southern Galactic plane.
2898. The RMS survey: water masers of YSOs
ID:
ivo://CDS.VizieR/J/A+A/507/795
Title:
The RMS survey: water masers of YSOs
Short Name:
J/A+A/507/795
Date:
21 Oct 2021
Publisher:
CDS
Description:
The red MSX source (RMS) survey has identified a large sample of candidate massive young stellar objects (MYSOs) and ultra compact (UC) HII regions from a sample of ~2000 MSX and 2MASS colour selected sources. To search for H_2_O masers towards a large sample of young high mass stars and to investigate the statistical correlation of H_2_O masers with the earliest stages of massive star formation. We have used the Mopra Radio telescope to make position-switched observations towards ~500 UCHII regions and MYSOs candidates identified from the RMS survey and located between 190{deg}<l<30{deg}. These observations have a 4{sigma} sensitivity of ~1Jy and a velocity resolution of ~0.4km/s.
2899. The role of the host star's metallicity
ID:
ivo://CDS.VizieR/J/A+A/624/A94
Title:
The role of the host star's metallicity
Short Name:
J/A+A/624/A94
Date:
21 Oct 2021
Publisher:
CDS
Description:
Most of our current understanding of the planet formation mechanism is based on the planet metallicity correlation derived mostly from solar-type stars harbouring gas-giant planets. To achieve a more extensive grasp on the substellar formation process, we aim to analyse in terms of their metallicity a diverse sample of stars (in terms of mass and spectral type) covering the whole range of possible outcomes of the planet formation process (from planetesimals to brown dwarfs and low-mass binaries). Our methodology is based on the use of high-precision stellar parameters derived by our own group in previous works from high-resolution spectra by using the iron ionisation and equilibrium conditions. All values were derived in an homogeneous way, except for the M dwarfs where a methodology based on the use of pseudo equivalent widths of spectral features was used. Our results show that as the mass of the substellar companion increases the metallicity of the host star tends to lower values. The same trend is maintained when analysing stars with low-mass stellar companions and a tendency towards a wide range of host star's metallicity is found for systems with low-mass planets. We also confirm that more massive planets tend to orbit around more massive stars. The core-accretion formation mechanism for planet formation achieves its maximum efficiency for planets with masses in the range 0.2 and 2M_{Jup}_. Substellar objects with higher masses have higher probabilities of being formed as stars. Low-mass planets and planetesimals might be formed by core-accretion even around low-metallicity stars.
2900. The rotational spectrum of acrylamide
ID:
ivo://CDS.VizieR/J/A+A/659/A111
Title:
The rotational spectrum of acrylamide
Short Name:
J/A+A/659/A111
Date:
15 Mar 2022 06:07:15
Publisher:
CDS
Description:
Numerous complex organic molecules have been detected in the universe and among them are amides, which are considered as prime models for species containing a peptide linkage. In its backbone, acrylamide (CH_2_CHC(O)NH_2_) bears not only the peptide bond, but also the vinyl functional group that is a common structural feature in many interstellar compounds. This makes acrylamide an interesting candidate for searches in the interstellar medium. In addition, a tentative detection of the related molecule propionamide (C_2_H_5_C(O)NH_2_) has been recently claimed toward Sgr B2(N). The aim of this work is to extend the knowledge of the laboratory rotational spectrum of acrylamide to higher frequencies, which would make it possible to conduct a rigorous search for interstellar signatures of this amide using millimeter wave astronomy. We measured and analyzed the rotational spectrum of acrylamide between 75 and 480GHz. We searched for emission of acrylamide in the imaging spectral line survey ReMoCA performed with the Atacama Large Millimeter/submillimeter Array toward Sgr B2(N). We also searched for propionamide in the same source. The astronomical spectra were analyzed under the assumption of local thermodynamic equilibrium. We report accurate laboratory measurements and analyses of thousands of rotational transitions in the ground state and two excited vibrational states of the most stable syn form of acrylamide. In addition, we report an extensive set of rotational transitions for the less stable skew conformer. Tunneling through a low energy barrier between two symmetrically equivalent configurations has been revealed for this higher-energy species. Neither acrylamide nor propionamide were detected toward the two main hot molecular cores of Sgr B2(N). We did not detect propionamide either toward a position located to the east of the main hot core, thereby undermining the recent claim of its interstellar detection toward this position. We find that acrylamide and propionamide are at least 26 and 14 times less abundant, respectively, than acetamide toward the main hot core Sgr B2(N1S), and at least 6 and 3 times less abundant, respectively, than acetamide toward the secondary hot core Sgr B2(N2). A comparison with results of astrochemical kinetics model for related species suggests that acrylamide may be a few hundred times less abundant than acetamide, corresponding to a value that is at least an order of magnitude lower than the observational upper limits. Propionamide may be as little as only a factor of two less abundant than the upper limit derived toward Sgr B2(N1S). Lastly, the spectroscopic data presented in this work will aid future searches of acrylamide in space.

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