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- ID:
- ivo://CDS.VizieR/J/A+A/572/A40
- Title:
- Outflow of H_2_ gas from NGC3256
- Short Name:
- J/A+A/572/A40
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The nuclei of merging galaxies are often deeply buried in dense layers of gas and dust. In these regions, gas outflows driven by starburst and active galactic nuclear activity are believed to play a crucial role in the evolution of these galaxies. However, to fully understand this process it is essential to resolve the morphology and kinematics of such outflows. Using near-infrared integral-field spectroscopy obtained with SINFONI on the Very Large Telescope, we detect a kpc-scale structure of high-velocity molecular hydrogen (H_2_) gas associated with the deeply buried secondary nucleus of the infrared-luminous merger-galaxy NGC 3256. We show that this structure is most likely the hot component of a molecular outflow, which was recently also detected in the cold molecular gas through CO emission.
- ID:
- ivo://CDS.VizieR/J/ApJ/703/L99
- Title:
- Outlandish orbit of HAT-P-7b
- Short Name:
- J/ApJ/703/L99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We show that the exoplanet HAT-P-7b has an extremely tilted orbit, with a true angle of at least 86{deg} with respect to its parent star's equatorial plane, and a strong possibility of retrograde motion. We also report evidence for an additional planet or companion star. The evidence for the unparalleled orbit and the third body is based on precise observations of the star's apparent radial velocity (RV). The anomalous RV due to rotation (the Rossiter-McLaughlin effect) was found to be a blueshift during the first half of the transit and a redshift during the second half, an inversion of the usual pattern, implying that the angle between the sky-projected orbital and stellar angular momentum vectors is 182.5{deg}+/-9.4{deg}. The third body is implicated by excess RV variation of the host star over 2yr. Some possible explanations for the tilted orbit of HAT-P-7b are a close encounter with another planet, the Kozai effect, and resonant capture by an inward-migrating outer planet.
- ID:
- ivo://CDS.VizieR/J/ApJS/146/1
- Title:
- O VI absorption in FUSE survey
- Short Name:
- J/ApJS/146/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Far Ultraviolet Spectroscopic Explorer (FUSE) observations of the O VI {lambda}{lambda}1031.926, 1037.617 absorption lines associated with gas in and near the Milky Way, as detected in the spectra of a sample of 100 extragalactic targets and two distant halo stars. We combine data from several FUSE Science Team programs with guest observer data that were public before 2002 May 1. The sight lines cover most of the sky above Galactic latitude |b|>25{deg}, at lower latitude the ultraviolet extinction is usually too large for extragalactic observations.
- ID:
- ivo://CDS.VizieR/J/ApJS/146/125
- Title:
- O VI in the galactic halo
- Short Name:
- J/ApJS/146/125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Far-Ultraviolet Spectroscopic Explorer (FUSE) spectra of 100 extragalactic objects and two distant halo stars are analyzed to obtain measures of O VI {lambda}{lambda}1031.93, 1037.62 absorption along paths through the Milky Way thick disk/halo.
- ID:
- ivo://CDS.VizieR/J/ApJ/764/78
- Title:
- Oxygen abundances in nearby FGK stars
- Short Name:
- J/ApJ/764/78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Atmospheric parameters and oxygen abundances of 825 nearby FGK stars are derived using high-quality spectra and a non-local thermodynamic equilibrium analysis of the 777nm OI triplet lines. We assign a kinematic probability for the stars to be thin-disk (P_1_), thick-disk (P_2_), and halo (P_3_) members. We confirm previous findings of enhanced [O/Fe] in thick-disk (P_2_>0.5) relative to thin-disk (P_1_>0.5) stars with [Fe/H]<~-0.2, as well as a "knee" that connects the mean [O/Fe]-[Fe/H] trend of thick-disk stars with that of thin-disk members at [Fe/H]>~-0.2. Nevertheless, we find that the kinematic membership criterion fails at separating perfectly the stars in the [O/Fe]-[Fe/H] plane, even when a very restrictive kinematic separation is employed. Stars with "intermediate" kinematics (P_1_<0.7, P_2_<0.7) do not all populate the region of the [O/Fe]-[Fe/H] plane intermediate between the mean thin-disk and thick-disk trends, but their distribution is not necessarily bimodal. Halo stars (P_3_>0.5) show a large star-to-star scatter in [O/Fe]-[Fe/H], but most of it is due to stars with Galactocentric rotational velocity V<-200km/s; halo stars with V>-200km/s follow an [O/Fe]-[Fe/H] relation with almost no star-to-star scatter. Early mergers with satellite galaxies explain most of our observations, but the significant fraction of disk stars with "ambiguous" kinematics and abundances suggests that scattering by molecular clouds and radial migration have both played an important role in determining the kinematic and chemical properties of solar neighborhood stars.
- ID:
- ivo://CDS.VizieR/J/A+A/465/271
- Title:
- Oxygen abundances in nearby stars
- Short Name:
- J/A+A/465/271
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The abundances of iron and oxygen are homogeneously determined in a sample of 523 nearby (d<150pc) FGK disk and halo stars with metallicities in the range -1.5<[Fe/H]<0.5. Iron abundances were obtained from an LTE analysis of a large set of FeI and FeII lines with reliable atomic data. Oxygen abundances were inferred from a restricted non-LTE analysis of the 777nm OI triplet. We adopted the infrared flux method temperature scale and surface gravities based on Hipparcos trigonometric parallaxes.
- ID:
- ivo://CDS.VizieR/J/other/ApSS/347.365
- Title:
- Paired galaxies and their supernovae
- Short Name:
- J/other/ApSS/347
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the influence of close neighbor galaxies on the properties of supernovae (SNe) and their host galaxies using 56 SNe located in pairs of galaxies with different levels of star formation (SF) and nuclear activity. The statistical study of SN hosts shows that there is no significant difference between morphologies of hosts in our sample and the larger general sample of SN hosts in the Sloan Digital Sky Survey (SDSS) Data Release 8 (DR8). The mean distance of type II SNe from nuclei of hosts is greater by about a factor of 2 than that of type Ibc SNe. The distributions and mean distances of SNe are consistent with previous results compiled with the larger sample. For the first time it is shown that SNe Ibc are located in pairs with significantly smaller difference of radial velocities between components than pairs containing SNe Ia and II. We consider this as a result of higher star formation rate (SFR) of these closer systems of galaxies. SN types are not correlated with the luminosity ratio of host and neighbor galaxies in pairs. The orientation of SNe with respect to the preferred direction toward neighbor galaxy is found to be isotropic and independent of kinematical properties of the galaxy pair.
- ID:
- ivo://CDS.VizieR/J/AJ/123/3356
- Title:
- Palomar/MSU nearby star spectroscopic survey. III.
- Short Name:
- J/AJ/123/3356
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-resolution echelle spectroscopy of 676 nearby M dwarfs. Our measurements include radial velocities, equivalent widths of important chromospheric emission lines, and rotational velocities for rapidly rotating stars. We identify several distinct groups by their H{alpha} properties and investigate variations in chromospheric activity among early (M0-M2.5) and mid (M3-M6) dwarfs. Using a volume-limited sample together with a relationship between age and chromospheric activity, we show that the rate of star formation in the immediate solar neighborhood has been relatively constant over the last 4Gyr. In particular, our results are inconsistent with recent large bursts of star formation. We use the correlation between H{alpha} activity and age as a function of color to set constraints on the properties of L and T dwarf secondary components in binary systems. We also identify a number of interesting stars, including rapid rotators, radial velocity variables, and spectroscopic binaries.
- ID:
- ivo://CDS.VizieR/J/A+A/419/533
- Title:
- Pal 13 UBV, proper motions and radial velocities
- Short Name:
- J/A+A/419/533
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recently, combining radial velocities from Keck/HIRES echelle spectra with published proper motion membership probabilities, Cote et al. (2002ApJ...574..783C) observed a sample of 21 stars, probable members of Palomar 13, a globular cluster in the Galactic halo. Their projected velocity dispersion sigma_p_=2.2+/-0.4km/s gives a mass-to-light ratio M/L_V_=40^+24^_-17_, about one order of magnitude larger than the usual estimate for globular clusters. We present here radial velocities measured from three different CCD frames of commissioning observations obtained with the new ESO/VLT instrument FLAMES (Fibre Large Array Multi Element Spectrograph). From these data, now publicly available, we measure the homogeneous radial velocities of eight probable members of this globular cluster. A new projected velocity dispersion sigma_p_=0.6-0.9+/-0.3km/s implies Palomar 13 mass-to-light ratio M/L_V_=3-7, similar to the usual value for globular clusters. We discuss briefly the two most obvious reasons for the previous unusual mass-to-light ratio finding: binaries, now clearly detected, and more homogeneous data from the multi-fibre FLAMES spectrograph.
