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1651. Minerva-Australis radial velocity of AU Mic
ID:
ivo://CDS.VizieR/J/AJ/162/137
Title:
Minerva-Australis radial velocity of AU Mic
Short Name:
J/AJ/162/137
Date:
14 Mar 2022 08:18:00
Publisher:
CDS
Description:
We report measurements of the sky-projected spin-orbit angle for AU Mic b, a Neptune-size planet orbiting a very young (~20Myr) nearby pre-main-sequence M-dwarf star, which also hosts a bright, edge-on, debris disk. The planet was recently discovered from preliminary analysis of radial-velocity observations and confirmed to be transiting its host star from photometric data from the NASA's TESS mission. We obtained radial-velocity measurements of AU Mic over the course of two partially observable transits and one full transit of planet b from high-resolution spectroscopic observations made with the MINERVA-Australis telescope array. Only a marginal detection of the Rossiter-McLaughlin effect signal was obtained from the radial velocities, in part due to AU Mic being an extremely active star and the lack of full transit coverage plus sufficient out-of-transit baseline. As such, a precise determination of the obliquity for AU Mic b is not possible in this study and we find a sky-projected spin-orbit angle of {lambda}=47_-54_^+26^deg . This result is consistent with both the planet's orbit being aligned or highly misaligned with the spin axis of its host star. Our measurement independently agrees with, but is far less precise than observations carried out on other instruments around the same time that measure a low-obliquity orbit for the planet. AU Mic is the youngest exoplanetary system for which the projected spin-orbit angle has been measured, making it a key data point in the study of the formation and migration of exoplanets-particularly given that the system is also host to a bright debris disk.
1652. M31 integrated light abundances
ID:
ivo://CDS.VizieR/J/ApJ/704/385
Title:
M31 integrated light abundances
Short Name:
J/ApJ/704/385
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the first detailed chemical abundances for five globular clusters (GCs) in M31 from high-resolution (R~25000) spectroscopy of their integrated light (IL). These GCs are the first in a larger set of clusters observed as part of an ongoing project to study the formation history of M31 and its GC population. The data presented here were obtained with the HIRES echelle spectrograph on the Keck I telescope and are analyzed using a new IL spectra analysis method that we have developed. In these clusters, we measure abundances for Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Y, and Ba, ages >=10Gyr, and a range in [Fe/H] of -0.9 to -2.2. As is typical of Milky Way GCs, we find these M31 GCs to be enhanced in the {alpha}-elements Ca, Si, and Ti relative to Fe.
1653. Mira stars discovered in LAMOST DR4
ID:
ivo://CDS.VizieR/J/ApJS/232/16
Title:
Mira stars discovered in LAMOST DR4
Short Name:
J/ApJS/232/16
Date:
21 Oct 2021
Publisher:
CDS
Description:
Based on an extensive spectral study of a photometrically confirmed sample of Mira variables, we find a relationship between the relative Balmer emission-line strengths and spectral temperatures of O-rich Mira stars. The F_H{delta}_/F_H{gamma}_ flux ratio increases from less than unity to five as stars cool down from M0 to M10, which is likely driven by increasing TiO absorption above the deepest shock-emitting regions. We also discuss the relationship between the equivalent widths of the Balmer emission lines and the photometric luminosity phase of our Mira sample stars. Using our 291 Mira spectra as templates for reference, 191 Mira candidates are newly identified from the LAMOST DR4 catalog. We summarize the criteria adopted to select Mira candidates based on emission-line indices and molecular absorption bands. This enlarged spectral sample of Mira variables has the potential to contribute significantly to our knowledge of the optical properties of Mira stars and will facilitate further studies of these late-type, long-period variables.
1654. MIR extinction toward Cyg OB2-12 ISM
ID:
ivo://CDS.VizieR/J/ApJ/895/38
Title:
MIR extinction toward Cyg OB2-12 ISM
Short Name:
J/ApJ/895/38
Date:
11 Mar 2022
Publisher:
CDS
Description:
The sight line toward the luminous blue hypergiant CygOB2-12 is widely used to study interstellar dust on account of its large extinction (AV~10mag) and the fact that this extinction appears to be dominated by dust typical of the diffuse interstellar medium. We present a new analysis of archival Infrared Space Observatory Short Wavelength Spectrometer and Spitzer IRS observations of CygOB2-12 using a model of the emission from the star and its stellar wind to determine the total extinction A{lambda} from 2.4 to 37{mu}m. In addition to the prominent 9.7 and 18{mu}m silicate features, we robustly detect absorption features associated with polycyclic aromatic hydrocarbons, including the first identification of the 7.7{mu}m feature in absorption. The 3.3{mu}m aromatic feature is found to be much broader in absorption than is typically seen in emission. The 3.4 and 6.85{mu}m aliphatic hydrocarbon features are observed with relative strengths that are consistent with observations of these features on sight lines toward the Galactic center. We identify and characterize more than 60 spectral lines in this wavelength range, which may be useful in constraining models of the star and its stellar wind. Based on this analysis, we present an extinction curve A_{lambda}_/A_2.2{mu}m_ that extrapolates smoothly to determinations of the mean Galactic extinction curve at shorter wavelengths and to dust opacities inferred from emission at longer wavelengths, providing a new constraint on models of interstellar dust in the mid-infrared.
1655. MIR spectroscopic catalog of 150 galaxies
ID:
ivo://CDS.VizieR/J/ApJ/701/1123
Title:
MIR spectroscopic catalog of 150 galaxies
Short Name:
J/ApJ/701/1123
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalog of mid-infrared (MIR) spectra of 150 infrared (IR) luminous galaxies in the Spitzer extragalactic first look survey obtained with the IR spectrograph on board the Spitzer Space Telescope. The sample is selected to be brighter than ~0.9mJy at 24um and it has a redshift distribution in the range [0.3, 3.5], with a peak at z=1. It primarily comprises ultraluminous IR galaxies (ULIRGs) at z>~1 and luminous IR galaxies at z<1, as estimated from their monochromatic rest-frame 14um luminosities. The number of sources with spectra that are dominated by an active galactic nucleus (AGN) continuum is 49, while 39 sources have strong, star formation related features.
1656. MIR spectroscopy of NGC 7538 IRS 1
ID:
ivo://CDS.VizieR/J/ApJ/696/471
Title:
MIR spectroscopy of NGC 7538 IRS 1
Short Name:
J/ApJ/696/471
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present high-resolution (R=75000-100000) mid-infrared spectra of the high-mass embedded young star IRS 1 in the NGC 7538 star-forming region. Absorption lines from many rotational states of C_2_H_2_, ^13^C^12^CH_2_, CH_3_, CH_4_, NH_3_, HCN, HNCO, and CS are seen. The gas temperature, column density, covering factor, line width, and Doppler shift for each molecule are derived. All molecules were fit with two velocity components between -54 and -63km/s. We find high column densities (~10^16^cm^-2^) for all the observed molecules compared to values previously reported and present new results for CH_3_ and HNCO. Several physical and chemical models are considered. The favored model involves a nearly edge-on disk around a massive star. Radiation from dust in the inner disk passes through the disk atmosphere, where large molecular column densities can produce the observed absorption line spectrum.
1657. MK classifications of spectroscopic binaries
ID:
ivo://CDS.VizieR/J/ApJS/180/117
Title:
MK classifications of spectroscopic binaries
Short Name:
J/ApJS/180/117
Date:
21 Oct 2021
Publisher:
CDS
Description:
New MK spectral classifications are given for 145 spectroscopic binaries (SBs) with A-F primaries because two-dimensional types are lacking for more than one-third of the A-F SBs with known orbital elements in the current catalog. Compared with the classifications by Morgan, Keenan, and their students, the new classifications give types that are 1.1+/-0.2 subclasses later and 0.7+/-0.1 luminosity classes fainter. Also listed are selected published MK types from Brian Skiff's recent compilation (Cat. <B/mk>).
1658. Mkn 848 MaNGA 3-D data cube
ID:
ivo://CDS.VizieR/J/A+A/623/A171
Title:
Mkn 848 MaNGA 3-D data cube
Short Name:
J/A+A/623/A171
Date:
21 Oct 2021
Publisher:
CDS
Description:
The characterisation of galaxy-scale outflows in terms of their multi-phase and multi-scale nature, amount, and effects of flowing material is crucial to place constraints on models of galaxy formation and evolution. This study can proceed only with the detailed investigation of individual targets. We present a spatially resolved spectroscopic optical data analysis of Mkn 848, a complex system consisting of two merging galaxies at z~0.04 that are separated by a projected distance of 7.5kpc. Motivated by the presence of a multi-phase outflow in the north-west system revealed by the SDSS integrated spectrum, we analysed the publicly available MaNGA data, which cover almost the entire merging system, to study the kinematic and physical properties of cool and warm gas in detail. Galaxy-wide outflowing gas in multiple phases is revealed for the first time in the two merging galaxies. We also detect spatially resolved resonant NaID emission associated with the outflows. The derived outflow energetics (mass rate, and kinetic and momentum power) may be consistent with a scenario in which both winds are accelerated by stellar processes and AGN activity, although we favour an AGN origin given the high outflow velocities and the ionisation conditions observed in the outflow regions. Further deeper multi-wavelength observations are required, however, to better constrain the nature of these multi-phase outflows. Outflow energetics in the north-west system are strongly different between the ionised and atomic gas components, the latter of which is associated with mass outflow rate and kinetic and momentum powers that are one or two dex higher; those associated with the south-east galaxy are instead similar. Strong kiloparsec-scale outflows are revealed in an ongoing merger system, suggesting that feedback can potentially impact the host galaxy even in the early merger phases. The characterisation of the neutral and ionised gas phases has proved to be crucial for a comprehensive study of the outflow phenomena.
1659. 3mm and 1mm spectra of IRC +10420
ID:
ivo://CDS.VizieR/J/A+A/592/A51
Title:
3mm and 1mm spectra of IRC +10420
Short Name:
J/A+A/592/A51
Date:
24 Nov 2021 07:04:25
Publisher:
CDS
Description:
Our knowledge of the chemical properties of the circumstellar ejecta of the most massive evolved stars is particularly poor. We aim to study the chemical characteristics of the prototypical yellow hypergiant star, IRC +10420. For this purpose, we obtained full line surveys at 1 and 3mm atmospheric windows. We have identified 106 molecular emission lines from 22 molecular species. Approximately half of the molecules detected are N-bearing species, in particular HCN, HNC, CN, NO, NS, PN, and N_2_H. We used rotational diagrams to derive the density and rotational temperature of the different molecular species detected. We introduced an iterative method that allows us to take moderate line opacities into account.
1660. M17 massive pms stars X-shooter spectra
ID:
ivo://CDS.VizieR/J/A+A/604/A78
Title:
M17 massive pms stars X-shooter spectra
Short Name:
J/A+A/604/A78
Date:
21 Oct 2021
Publisher:
CDS
Description:
The formation process of massive stars is still poorly understood. Massive young stellar objects (mYSOs) are deeply embedded in their parental clouds; these objects are rare, and thus typically distant, and their reddened spectra usually preclude the determination of their photospheric parameters. M17 is one of the best-studied HII regions in the sky, is relatively nearby, and hosts a young stellar population. We have obtained optical to near-infrared spectra of previously identified candidate mYSOs and a few OB stars in this region with X-shooter on the ESO Very Large Telescope. The large wavelength coverage enables a detailed spectroscopic analysis of the photospheres and circumstellar disks of these candidate mYSOs. We confirm the pre-main-sequence (PMS) nature of six of the stars and characterise the O stars. The PMS stars have radii that are consistent with being contracting towards the main sequence and are surrounded by a remnant accretion disk. The observed infrared excess and the double-peaked emission lines provide an opportunity to measure structured velocity profiles in the disks. We compare the observed properties of this unique sample of young massive stars with evolutionary tracks of massive protostars and propose that these mYSOs near the western edge of the HII region are on their way to become main-sequence stars (~6-20M_{sun}_) after having undergone high mass accretion rates (dMacc/dt~10^-4^-10^-3^M_{sun}_/yr) Their spin distribution upon arrival at the zero age main-sequence (ZAMS) is consistent with that observed for young B stars, assuming conservation of angular momentum and homologous contraction.

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