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2311. Searching transiting planets around halo stars. I.
ID:
ivo://CDS.VizieR/J/AJ/162/125
Title:
Searching transiting planets around halo stars. I.
Short Name:
J/AJ/162/125
Date:
21 Mar 2022 00:52:16
Publisher:
CDS
Description:
By measuring the elemental abundances of a star, we can gain insight into the composition of its initial gas cloud-the formation site of the star and its planets. Planet formation requires metals, the availability of which is determined by the elemental abundance. In the case where metals are extremely deficient, planet formation can be stifled. To investigate such a scenario requires a large sample of metal-poor stars and a search for planets therein. This paper focuses on the selection and validation of a halo star sample. We select ~17000 metal-poor halo stars based on their Galactic kinematics, and confirm their low metallicities ([Fe/H]<-0.5), using spectroscopy from the literature. Furthermore, we perform high-resolution spectroscopic observations using LBT/PEPSI and conduct detailed metallicity ([Fe/H]) analyses on a sample of 13 previously-known halo stars that also have hot kinematics. We can use the halo star sample presented here to measure the frequency of planets and to test planet formation in extremely metal-poor environments. The result of the planet search and its implications will be presented and discussed in a companion paper by Boley et al.
2312. SED for 7 stellar calibrators
ID:
ivo://CDS.VizieR/J/A+A/533/A107
Title:
SED for 7 stellar calibrators
Short Name:
J/A+A/533/A107
Date:
21 Oct 2021
Publisher:
CDS
Description:
Among late-type red giants, an interesting change occurs in the structure of the outer atmospheric layers as one moves to later spectral types in the Hertzsprung-Russell diagram: a chromosphere is always present, but the coronal emission diminishes and a cool massive wind steps in. Where most studies have focussed on short-wavelength observations, this article explores the influence of the chromosphere and the wind on long-wavelength photometric measurements. The goal of this study is to assess wether a set of standard near-infrared calibration sources are fiducial calibrators in the far-infrared, beyond 50um. The observational spectral energy distributions were compared with the theoretical model predictions for a sample of nine K- and M-giants. The discrepancies found are explained using basic models for flux emission originating in a chromosphere or an ionised wind.
2313. SED of Spitzer quasars (QUEST)
ID:
ivo://CDS.VizieR/J/ApJ/666/806
Title:
SED of Spitzer quasars (QUEST)
Short Name:
J/ApJ/666/806
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is the second paper studying the QSOs in the Spitzer QUEST sample. Previously we presented new PAH measurements and argued that most of the observed far-infrared (FIR) radiation is due to star-forming activity. Here we present spectral energy distributions (SEDs) by supplementing our data with optical, NIR, and FIR observations. We define two subgroups, of "weak FIR" and "strong FIR" QSOs, and a third group of FIR nondetections. Assuming a starburst origin for the FIR, we obtain "intrinsic" active galactic nucleus (AGN) SEDs by subtracting a starburst template from the mean SEDs. The resulting SEDs are remarkably similar for all groups.
2314. SEDs of ELAIS-S1 mid-IR sources
ID:
ivo://CDS.VizieR/J/ApJ/684/136
Title:
SEDs of ELAIS-S1 mid-IR sources
Short Name:
J/ApJ/684/136
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the broadband SEDs of the largest available highly complete (72%) spectroscopic sample of MIR-selected galaxies and AGNs at intermediate redshift. The sample contains 203 extragalactic sources from the 15um ELAIS-SWIRE survey, all with measured spectroscopic redshift. Most of these sources have full multiwavelength coverage from the FUV (GALEX) to the FIR (Spitzer) and lie in the redshift range 0.1<z<1.3. This large sample allows us for the first time to characterize the spectral properties of sources responsible for the strong evolution observed in the MIR. Based on SED-fitting, we have classified the MIR sources, identifying AGN signatures in about 50% of them. This fraction is significantly higher than that derived from optical spectroscopy (~29%) and is due in particular to the identification of AGN activity in objects spectroscopically classified as galaxies (the spectroscopic classification may be somewhat unreliable because of host galaxy dilution in the optical). It is likely that in most of our objects, the AGN is either obscured or low luminosity, and thus dominates the energetic output only in the MIR, showing up just in the range where the host galaxy SED has a minimum. The fraction of AGNs strongly depends on flux density, with that derived through the SED-fitting about 20% at S_15um_~0.5-1mJy and gradually increasing to 100% at S_15um_>10mJy, while that obtained from optical spectroscopy is never >30%, even at higher flux densities.
2315. SEGUE stellar parameter pipeline. V.
ID:
ivo://CDS.VizieR/J/AJ/141/90
Title:
SEGUE stellar parameter pipeline. V.
Short Name:
J/AJ/141/90
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a method for the determination of [{alpha}/Fe] ratios from low-resolution (R=2000) SDSS/SEGUE stellar spectra. By means of a star-by-star comparison with degraded spectra from the ELODIE spectral library and with a set of moderately high-resolution (R=15000) and medium-resolution (R=6000) spectra of SDSS/SEGUE stars, we demonstrate that we are able to measure [{alpha}/Fe] from SDSS/SEGUE spectra (with S/N>20/1) to a precision of better than 0.1dex, for stars with atmospheric parameters in the range Teff=[4500,7000]K, logg=[1.5,5.0], and [Fe/H]=[-1.4,+0.3], over the range [{alpha}/Fe]=[-0.1,+0.6]. For stars with [Fe/H]<-1.4, our method requires spectra with slightly higher signal-to-noise to achieve this precision (S/N>25/1).
2316. Seismic global parameters of 372 KIC
ID:
ivo://CDS.VizieR/J/A+A/618/A109
Title:
Seismic global parameters of 372 KIC
Short Name:
J/A+A/618/A109
Date:
21 Oct 2021
Publisher:
CDS
Description:
Oscillation modes with a mixed character, as observed in evolved low-mass stars, are highly sensitive to the physical properties of the innermost regions. Measuring their properties is therefore extremely important to probe the core, but requires some care, due to the complexity of the mixed-mode pattern. The aim of this work is to provide a consistent description of the mixed-mode pattern of low-mass stars, based on the asymptotic expansion. We also study the variation of the gravity offset epsilon_g_ with stellar evolution. We revisit previous works about mixed modes in red giants and empirically test how period spacings, rotational splittings, mixed-mode widths, and heights can be estimated in a consistent view, based on the properties of the mode inertia ratios. From the asymptotic fit of the mixed-mode pattern of a large set of red giants at various evolutionary stages, we derive unbiased and precise asymptotic parameters. As the asymptotic expansion of gravity modes is verified with a precision close to the frequency resolution for stars on the red giant branch (10^-4^ in relative values), we can derive accurate values of the asymptotic parameters. We decipher the complex pattern in a rapidly rotating star, and explain how asymmetrical splittings can be inferred. We also revisit the stellar inclinations in two open clusters, NGC 6819 and NGC 6791: our results show that the stellar inclinations in these clusters do not have privileged orientation in the sky. The variation of the asymptotic gravity offset with stellar evolution is investigated in detail. We also derive generic properties that explain under which conditions mixed modes can be observed.
2317. Seismic global parameters of 6111 KIC
ID:
ivo://CDS.VizieR/J/A+A/588/A87
Title:
Seismic global parameters of 6111 KIC
Short Name:
J/A+A/588/A87
Date:
21 Oct 2021
Publisher:
CDS
Description:
The space missions CoRoT and Kepler have provided photometric data of unprecedented quality for asteroseismology. A very rich oscillation pattern has been discovered for red giants, including mixed modes that are used to decipher the red giants' interiors. They carry information on the radiative core of red giant stars and bring strong constraints on stellar evolution. Since more than 15000 red giant light curves have been observed by Kepler, we have developed a simple and efficient method for automatically characterizing the mixed-mode pattern and measuring the asymptotic period spacing. With the asymptotic expansion of the mixed modes, we have revealed the regularity of the gravity-mode pattern. The stretched periods were used to study the evenly space periods with a Fourier analysis and to measure the gravity period spacing, even when rotation severely complicates the oscillation spectra.
2318. Seyfert galaxies in the mid-IR
ID:
ivo://CDS.VizieR/J/ApJ/705/14
Title:
Seyfert galaxies in the mid-IR
Short Name:
J/ApJ/705/14
Date:
21 Oct 2021
Publisher:
CDS
Description:
An analysis of archival mid-infrared (mid-IR) spectra of Seyfert galaxies from the Spitzer Space Telescope observations is presented. We characterize the nature of the mid-IR active nuclear continuum by subtracting a template starburst spectrum from the Seyfert spectra. The long wavelength part of the spectrum contains a strong contribution from the starburst-heated cool dust; this is used to effectively separate starburst-dominated Seyferts from those dominated by the active nuclear continuum. Within the latter category, the strength of the active nuclear continuum drops rapidly beyond ~20um. On average, type 2 Seyferts have weaker short-wavelength active nuclear continua as compared to type 1 Seyferts. Type 2 Seyferts can be divided into two types, those with strong polycyclic aromatic hydrocarbon (PAH) bands and those without.
2319. SFI++ II. A new I-band Tully-Fisher catalog
ID:
ivo://CDS.VizieR/J/ApJS/172/599
Title:
SFI++ II. A new I-band Tully-Fisher catalog
Short Name:
J/ApJS/172/599
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the SFI++ data set, a homogeneously derived catalog of photometric and rotational properties and the Tully-Fisher distances and peculiar velocities derived from them. We make use of digital optical images, optical long-slit spectra, and global HI line profiles to extract parameters of relevance to disk scaling relations, incorporating several previously published data sets as well as a new photometric sample of some 2000 objects. According to the completeness of available redshift samples over the sky area, we exploit both a modified percolation algorithm and the Voronoi-Delaunay method to assign individual galaxies to groups as well as clusters, thereby reducing scatter introduced by local orbital motions. We also provide corrections to the peculiar velocities for both homogeneous and inhomogeneous Malmquist bias, making use of the 2MASS Redshift Survey density field to approximate large-scale structure. The final SFI++ peculiar velocity catalog contains 4861 field and cluster galaxies.
2320. SFR & AGN in most luminous local universe LINERs
ID:
ivo://CDS.VizieR/J/MNRAS/462/2878
Title:
SFR & AGN in most luminous local universe LINERs
Short Name:
J/MNRAS/462/2878
Date:
21 Oct 2021
Publisher:
CDS
Description:
This work presents the properties of 42 objects in the group of the most luminous, highest star formation rate (SFR) low-ionization nuclear emission-line regions (LINERs) at z=0.04-0.11. We obtained long-slit spectroscopy of the nuclear regions for all sources, and FIR data (Herschel and IRAS) for 13 of them. We measured emission-line intensities, extinction, stellar populations, stellar masses, ages, active galactic nuclei (AGN) luminosities, and SFRs. We find considerable differences from other low-redshift LINERs, in terms of extinction, and general similarity to star-forming galaxies. We confirm the existence of such luminous LINERs in the local universe, after being previously detected at z~0.3 by Tommasin et al. The median stellar mass of these LINERs corresponds to 6-7x10^10^M_{sun}_ which was found in previous work to correspond to the peak of relative growth rate of stellar populations and therefore for the highest SFRs. Other LINERs although showing similar AGN luminosities have lower SFR. We find that most of these sources have LAGN~LSF suggesting co-evolution of black hole and stellar mass. In general, the fraction of local LINERs on the main sequence of star-forming galaxies is related to their AGN luminosity.

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