- ID:
- ivo://CDS.VizieR/J/other/Ap/41.356
- Title:
- FBS 10th list of red stars
- Short Name:
- J/other/Ap/41.35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A 10th list of late-type M and C stars found on plates of the First Byurakan Spectral Sky Survey in the -11{deg}<{delta}<-7{deg} belt within area of about 1070{deg}^2^ is given. The list contains data on 169 red stars, 117 of which were found for the first time: 8 are new C stars, 3 are C-star candidates, 104 are M stars, 1 is either an M or an S star, and 1 object on the survey plate cannot be classified; of the 117 objects, 47 are unidentified IRAS sources. A statistical analysis of the objects that are and are not identified with IRAS sources shows that the identified stars are, with a high probability, brighter and have relatively more massive envelopes. Two stars were found to have fairly large brightness variability (with an amplitude of at least 6.0mag). Gas-dust shells are assumed to exist around nine of the IRAS sources. The equatorial coordinates, spectral types, and stellar magnitudes, determined on Palomar E maps, are given for the selected objects.
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- ID:
- ivo://CDS.VizieR/J/A+A/418/445
- Title:
- FCOS Ultra Compact Dwarf galaxies radial vel.
- Short Name:
- J/A+A/418/445
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The relation between the Ultra Compact Dwarf galaxies (hereafter UCDs) recently discovered in the Fornax cluster (Drinkwater et al., 2003Natur.423..519D; Mieske et al., 2002, Cat. <J/A+A/383/823>) and the brightest globular clusters associated with the central galaxy NGC 1399 has been investigated in the spectroscopic Fornax Compact Object Survey FCOS. FCOS was carried out with the 2.5m du Pont telescope at Las Campanas, in the three nights of 2002/12/04 to 2002/12/06. Mieske et al. (2002, Cat. <J/A+A/383/823>) deals with the first part FCOS-1, this paper deals with the larger FCOS-2. The spectral resolution of FCOS was approx. 4{AA}. In the FCOS, 280 unresolved objects with 0<(V-I)<1.5mag in the magnitude space covering UCDs and bright globular clusters (18<V<21mag) were observed spectroscopically, among them 185 in FCOS-2. In the entire FCOS-sample there are five already known UCDs and 54 new Fornax members, 12 from FCOS-1 and 42 from FCOS-2.
- ID:
- ivo://CDS.VizieR/J/ApJ/551/852
- Title:
- FCRAO CO survey of the outer Galaxy
- Short Name:
- J/ApJ/551/852
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A summary of global properties and an evaluation of the equilibrium state of molecular regions in the outer Galaxy are presented from the decomposition of the Five College Radio Astronomy Observatory (FCRAO, see 1998ApJS..115..241H) Outer Galaxy Survey and targeted ^12^CO and ^13^CO observations (at 115GHz) of four giant molecular cloud complexes. The ensemble of identified objects includes both small, isolated clouds and clumps within larger cloud complexes.
- ID:
- ivo://CDS.VizieR/J/A+A/527/A134
- Title:
- Fe abundances for 28 XMM galaxy clusters
- Short Name:
- J/A+A/527/A134
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The abundances of Fe in the intracluster medium of nearby (z<0.08) clusters were measured up to 0.3~0.5r_180_. We analyzed 28 clusters of galaxies observed with XMM-Newton. We derived Fe abundances from the flux ratios of Fe lines to the continuum within an energy range of 3.5-6keV to minimize and evaluate systematic uncertainties.
- ID:
- ivo://CDS.VizieR/J/A+A/522/A26
- Title:
- Fe Abundances in metal-poor stars
- Short Name:
- J/A+A/522/A26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The determination of Lithium abundance A(Li) is extremely sensitive to the adopted temperature scale, so that a Teff bias might mimic a trend in A(Li). We present here VLT-UVES Li abundances for 28 halo dwarf stars between [Fe/H]=-2.5 and -3.5, 10 of which have [Fe/H]<-3. Four different Teff scales have been used: Direct Infrared Flux Method (IRFM) has been used on the basis of 2MASS infrared photometry; H{alpha} wings have been fitted against two synthetic grids computed by means of 1D LTE atmosphere models, and a grid of H{alpha} profiles computed by means of 3D hydrodynamical atmosphere models. As a result, we confirm previous claims that A(Li) does not exhibit a plateau below [Fe/H]=-3. A strong positive correlation with [Fe/H] appears, not influenced by the choice of the Teff estimator. From a linear fit, we obtain a strong slope of about 0.30 dex in A(Li) per dex in [Fe/H], significant to 2-3, and consistent within 1 among all the four Teff estimators. A significant slope is also detected in the A(Li)-Teff plane, driven mainly by the coolest stars in the sample (Teff<6250), which appear Li-poor. However, removing such stars does not alter significantly the behavior in the A(Li)-[Fe/H] plane. When the full sample is considered, the scatter in A(Li) increases by a factor of 2 towards lower metallicities, while the plateau appears very thin above [Fe/H]=-2.8. At this metallicity, the plateau lies at A(Li)3D,NLTE=2.199+/-0.086.
- ID:
- ivo://CDS.VizieR/J/PASP/121/117
- Title:
- Fe and Ti abundances of 12 low-metallicity M stars
- Short Name:
- J/PASP/121/117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have calculated Fe and Ti abundances in 12 low-metallicity main sequence M stars using high-resolution spectra. These subdwarf and extreme-subdwarf stars allow us to extend our calibration of a method to determine cool-dwarf-star metallicities using molecular band strength indices from low-resolution spectra. Our calibration can now be used to determine metallicity to within +/-0.3dex for stars with [Fe/H] between -1.5 and +0.05 and temperatures between 3500 and 4000K. We also report a method to estimate temperatures for M dwarfs using equivalent width measurements of the infrared CaII triplet and the KI line at 7699{AA}. Our metallicity measurements show that the recently proposed classification system for low-mass stars (dwarfs, subdwarfs, extreme subdwarfs, and ultrasubdwarfs) does represent a metallicity sequence, with the ultrasubdwarfs the most metal-poor stars.
- ID:
- ivo://CDS.VizieR/J/A+A/655/A68
- Title:
- FEDReD III: Unraveling the 3D structure of Vela
- Short Name:
- J/A+A/655/A68
- Date:
- 10 Mar 2022 07:24:47
- Publisher:
- CDS
- Description:
- The Vela complex is a region of the sky that gathers several stellar and interstellar structures in a few hundred square degrees. Gaia data now allows us to obtain a 3D view of the Vela interstellar structures through the dust extinction. We used the FEDReD (Field Extinction-Distance Relation Deconvolver) algorithm on near-infrared 2MASS data, cross-matched with the Gaia DR2 catalogue, to obtain a 3D cube of extinction density. We applied the FellWalker algorithm on this cube to locate clumps and dense structures. We analysed 18 million stars on 450 deg 2 to obtain the extinction density of the Vela complex from 0.5 to 8kpc at l in [250, 280] and b in [-10, 5].This cube reveals the complete morphology of known structures and relations between them. In particular, we show that the Vela Molecular Ridge is more likely composed by three substructures instead of four, as suggested by the 2D densities. These substructures form the shell of a large cavity. This cavity is visually aligned with the Vela supernova remnant but located at a larger distance. We provide a catalogue of location, distance, size and total dust content of ISM clumps that we extracted.
- ID:
- ivo://CDS.VizieR/J/A+A/659/A77
- Title:
- FEEDBACK from the NGC7538 HII region
- Short Name:
- J/A+A/659/A77
- Date:
- 14 Mar 2022 07:43:25
- Publisher:
- CDS
- Description:
- The interaction of expanding HII regions with their environmental cloud is one of the central questions driving the SOFIA legacy program FEEDBACK. We want to understand the interaction of the prototypical NGC7538 HII region with the neighboring molecular cloud hosting several active star-forming regions. Using the Stratospheric Observatory for Infrared Astronomy (SOFIA), we mapped an area of ~210'^2^ (~125pc^2^) around NGC7538 in the velocity-resolved ionized carbon fine-structure line [CII] at 1.9THz (158um). Complementary observed atomic carbon [CI] at 492GHz and high-J CO(8-7) data, as well as the archival near- and far-infrared, cm continuum, CO(3-2), and HI data are folded into the analysis. The ionized carbon [CII] data reveal rich morphological and kinematic structures. While the overall morphology follows the general ionized gas that is also visible in the radio continuum emission, the channel maps show multiple bubble-like structures with sizes on the order of ~80-100'' (~1.0-1.28pc). While at least one of them may be an individual feedback bubble driven by the main exciting sources of the NGC7538 HII region (the O3 and O9 stars IRS6 and IRS5), the other bubble-like morphologies may also be due to the intrinsically porous structure of the HII region. An analysis of the expansion velocities around 10km/s indicates that thermal expansion is not sufficient but that wind-driving from the central O-stars is required. The region exhibits a general velocity gradient across, but we also identify several individual velocity components. The most blue-shifted [CII] component has barely any molecular or atomic counterparts. At the interface to the molecular cloud, we find a typical photon-dominated region (PDR) with a bar-shape. Ionized C+, atomic C0 and molecular carbon CO show a layered structure in this PDR. The carbon in the PDR is dominated by its ionized C+ form with atomic C0 and molecular CO masses of ~0.45+/-0.1M_{sun}_ and ~1.2+/-0.1M_{sun}_, respectively, compared to the ionized carbon C+ in the range of 3.6-9.7M_{sun}_. This bar-shaped PDR exhibits a velocity-gradient across, indicating motions along the line of sight toward the observer. Even if it is shown to be dominated by two nearby exciting sources (IRS6 and IRS5), the NGC7538 HII region exhibits a diverse set of substructures that interact with each other as well as with the adjacent cloud. Compared to other recent [CII] observations of HII regions (e.g., Orion Veil, RCW120, RCW49), the bubble-shape morphologies revealed in [CII] emission that are indicative of expanding shells are recurring structures of PDRs.
- ID:
- ivo://CDS.VizieR/J/A+A/656/A45
- Title:
- Feeding and feedback in Fornax A
- Short Name:
- J/A+A/656/A45
- Date:
- 14 Mar 2022 07:47:57
- Publisher:
- CDS
- Description:
- We present a multi-wavelength study of the gaseous medium surrounding the nearby active galactic nucleus (AGN), Fornax A. Using MeerKAT, ALMA, and MUSE observations, we reveal a complex distribution of the atomic (HI), molecular (CO 1-0), and ionised gas in its centre and along the radio jets. By studying the multi-scale kinematics of the multi-phase gas, we reveal the presence of concurrent AGN feeding and feedback phenomena. Several clouds and an extended 3kpc filament - perpendicular to the radio jets and the inner disc (r<4.5kpc) - show highly-turbulent kinematics, which likely induces non-linear condensation and subsequent chaotic cold accretion (CCA) onto the AGN. In the wake of the radio jets and in an external (r>4.5kpc) ring, we identify an entrained massive (~10^7^M_{sun}_) multi-phase outflow (v_OUT_~2000km/s^). The rapid flickering of the nuclear activity of Fornax A (~3Myr) and the gas experiencing turbulent condensation raining onto the AGN provide quantitative evidence that a recurrent, tight feeding and feedback cycle may be self-regulating the activity of FORN, in agreement with CCA simulations. To date, this is one of the most in-depth probes of such a mechanism, paving the way to apply these precise diagnostics to a larger sample of nearby AGN hosts and their multi-phase Interstellar Medium.
- ID:
- ivo://CDS.VizieR/J/A+A/404/661
- Title:
- Fe5270, Fe5335, Mgb and Mg_2_ synthetic indices
- Short Name:
- J/A+A/404/661
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have computed a grid of synthetic spectra in the wavelength range {lambda}{lambda}4600-5600{AA} using revised model atmospheres, for a range of atmospheric parameters and values of [alpha-elements/Fe]=0.0 and +0.4. The Lick indices Fe5270, Fe5335, Mgb and Mg_2_ are measured on the grid spectra, for FWHM=2 to 8.3{AA}. Relations between the indices Fe5270, Fe5335 and Mg_2_ and stellar parameters effective temperature T_eff_, logg, [Fe/H] and [alpha/Fe], valid in the range 4000K>=T_eff_>=7000K, are presented. These fitting functions are given for FWHM=3.5 and 8.3{AA}. The indices were also measured for a list of 97 reference stars with well-known stellar parameters observed at ESO and OHP, and these are compared to the computed indices. Finally, a comparison of the indices measured on the observed spectra and those derived from the fitting functions based on synthetic spectra is presented.