- ID:
- ivo://CDS.VizieR/I/346
- Title:
- FON Astrographic Catalogue Southern Part (FONAC-S)
- Short Name:
- I/346
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog of positions and B-magnitudes of stars and galaxies of the southern sky (from -20{deg} to +2{deg}) was created as a part of the FON (Russian abbreviation Photographic Sky Survey) project at the Ulugh Beg Astronomical Institute (UBAI) of the Uzbekistan Academy of Sciences. The data accumulated in the Photographic Archive of the UBAI were used. The total number of processed plates is 1963. Astronegatives were digitized with Epson Expression 10000XL scanners in the 1200 dpi scanning mode. The majority of plates have a size of 30x30cm. The catalog contains the data on 13 413 268 stars and galaxies with B<=17.5m at the epoch of 1984.97. The coordinates of stars and galaxies were obtained in the Tycho-2 reference system, and B-magnitudes were determined in the system of photoelectric standards. The mean internal errors of the catalog are {sigma}_RA,DE_=0.23" and {sigma}_B_=0.15mag for all objects or {sigma}_RA,DE_=0.085" and {sigma}_B_=0.054mag for the objects in the B=7-14mag range. The convergence between the catalog and Tycho-2 is characterized by the following values: 0.042" and 0.16m. The mean-square difference in coordinates from the catalog and from UCAC-4 is {sigma}_RA,DE_=0.26" (9 892 697 objects, or 73.75% of stars and galaxies, were identified).
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Search Results
- ID:
- ivo://CDS.VizieR/I/342
- Title:
- FON Astrographic Catalogue, Version 3.0
- Short Name:
- I/342
- Date:
- 05 Nov 2021
- Publisher:
- CDS
- Description:
- The catalog of equatorial coordinates {alpha} and {delta} and B-magnitudes of stars of the northern sky (from -4{deg} to +90{deg}) was created as a part of the FON project at the Main Astronomical Observatory of the National Academy of Sciences of Ukraine. The data accumulated in the Joint Digital Archive of the Ukrainian Virtual Observatory were used. The total number of processed plates is 2260. Astronegatives were digitized with Microtek ScanMaker 9800XL TMA and Epson Expression 10000XL scanners in the 1200 dpi scanning mode. The majority of plates have a size of 30x30cm (13000x13000-pixels). The catalog contains the data on 19451751 stars and galaxies with B<=16.5m at the epoch of 1988.1. The coordinates of stars and galaxies were obtained in the Tycho-2 reference system, and B-magnitudes were determined in the system of photoelectric standards. The mean internal errors of the catalog are {simag}_RA,DE_=0.23" and {sigma}_B_=0.14mag for all objects or {simag}_RA,DE_=0.10" and {sigma}_B_=0.07mag for stars in the B=7-14mag range. The convergence between the catalog and Tycho-2 is characterized by the following values: 0.06" and 0.15m. The mean-square difference in coordinates from the catalog and from UCAC-4 is {simag}_RA,DE_= 0.30" (18 742 932 objects, or 96.36% of stars and galaxies, were cross-identified).
- ID:
- ivo://CDS.VizieR/J/A+A/376/1106
- Title:
- Forbidden transitions in Co(16+)
- Short Name:
- J/A+A/376/1106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Theoretical line strengths and transition probabilities for electric quadrupole (E2) transitions between levels belonging to several important configurations of Co16+ are reported. The calculations have been carried out with the Relativistic Quantum Defect Orbital (RQDO) method. A general good accord between the present results and some earlier theoretical data is found. Some of the E2 transition probabilities are reported for the first time. The correct systematic behaviour of the RQDO line strengths along the spectral series is reproduced by the present results in the absence of configuration mixing. This semiempirical method appears to adequately describe E2 transitions in this medium-Z atomic system.
- ID:
- ivo://CDS.VizieR/J/A+A/555/A12
- Title:
- Foreground Galactic stars properties
- Short Name:
- J/A+A/555/A12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the chemical and kinematic properties of roughly a thousand FLAMES-GIRAFFE LR8 spectra of faint magnitude foreground Galactic stars observed serendipitously during extra-galactic surveys in four lines-of-sight: three in the southern Galactic hemisphere (surveys of the Carina, Fornax and Sculptor dwarf spheroidal galaxies) and one in the northern Galactic hemisphere (a survey of the Sextans dwarf spheroidal galaxy). The foreground stars span distances up to ~3kpc from the Galactic plane and Galactocentric radii up to 11kpc. The stellar atmospheric parameters (effective temperature, surface gravity, metallicity) are obtained by an automated parameterisation pipeline and the distances of the stars are then derived by a projection of the atmospheric parameters on a set of theoretical isochrones using a Bayesian approach. The metallicity gradients are estimated for each line-of-sight and compared with predictions from the Besancon model of the Galaxy, in order to test the chemical structure of the thick disc. Finally, we use the radial velocities in each line-of-sight to derive a proxy for either the azimuthal or the vertical component of the orbital velocity of the stars. Only three lines-of-sight have a sufficient number of foreground stars for a robust analysis. Towards Sextans in the Northern Galactic hemisphere and Sculptor in the South, we measure a consistent decrease in mean metallicity with height from the Galactic plane, suggesting a chemically symmetric thick disc. This decrease can either be due to an intrinsic thick disc metallicity gradient, or simply due to a change in the thin disc/thick disc population ratio and no intrinsic metallicity gradients for the thick disc. We favour the latter explanation. In contrast, we find evidence of an unpredicted metal-poor population in the direction of Carina. This population was earlier detected by Wyse et al. (2006ApJ...639L..13W), but our more detailed analysis provides robust estimates of its location (|Z|<1kpc), metallicity (-2<[M/H]<-1dex) and azimuthal orbital velocity (V_phi_~120km/s).
- ID:
- ivo://CDS.VizieR/J/ApJ/901/134
- Title:
- Foreground galaxies toward FRB 190608 from SDSS
- Short Name:
- J/ApJ/901/134
- Date:
- 21 Feb 2022 09:50:38
- Publisher:
- CDS
- Description:
- Fast radio burst (FRB) 190608 was detected by the Australian Square Kilometre Array Pathfinder (ASKAP) and localized to a spiral galaxy at z_host_=0.11778 in the Sloan Digital Sky Survey (SDSS) footprint. The burst has a large dispersion measure (DM_FRB_=339.8pc/cm^3^) compared to the expected cosmic average at its redshift. It also has a large rotation measure (RM_FRB_=353rad/m^2^) and scattering timescale ({tau}=3.3ms at 1.28GHz). Chittidi+ (2021ApJ...922..173C) perform a detailed analysis of the ultraviolet and optical emission of the host galaxy and estimate the host DM contribution to be 110+/-37pc/cm^3^. This work complements theirs and reports the analysis of the optical data of galaxies in the foreground of FRB 190608 in order to explore their contributions to the FRB signal. Together, the two studies delineate an observationally driven, end-to-end study of matter distribution along an FRB sightline, the first study of its kind. Combining our Keck Cosmic Web Imager (KCWI) observations and public SDSS data, we estimate the expected cosmic dispersion measure DM_cosmic along the sightline to FRB 190608. We first estimate the contribution of hot, ionized gas in intervening virialized halos (DM_halos_~7-28pc/cm^3^). Then, using the Monte Carlo Physarum Machine methodology, we produce a 3D map of ionized gas in cosmic web filaments and compute the DM contribution from matter outside halos (DM_IGM_~91-126pc/cm^3^). This implies that a greater fraction of ionized gas along this sightline is extant outside virialized halos. We also investigate whether the intervening halos can account for the large FRB rotation measure and pulse width and conclude that it is implausible. Both the pulse broadening and the large Faraday rotation likely arise from the progenitor environment or the host galaxy.
- ID:
- ivo://CDS.VizieR/J/ApJ/717/L133
- Title:
- Formaldehyde maser flares in IRAS 18566+0408
- Short Name:
- J/ApJ/717/L133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report results of an extensive observational campaign of the 6cm formaldehyde maser in the young massive stellar object IRAS 18566+0408 (G37.55+0.20) conducted from 2002 to 2009. Using the Arecibo Telescope, the Very Large Array, and the Green Bank Telescope, we discovered quasi-periodic formaldehyde flares (P~237 days). Based on Arecibo observations, we also discovered correlated variability between formaldehyde (H_2_CO) and methanol (CH_3_OH) masers. The H_2_CO and CH_3_OH masers are not spatially coincident, as demonstrated by different line velocities and high angular resolution MERLIN observations. The flares could be caused by variations in the infrared radiation field, possibly modulated by periodic accretion onto a young binary system.
- ID:
- ivo://CDS.VizieR/J/MNRAS/449/2438
- Title:
- Formamide detection with ASAI-IRAM
- Short Name:
- J/MNRAS/449/2438
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Formamide (NH_2_CHO) has been proposed as a pre-biotic precursor with a key role in the emergence of life on Earth. While this molecule has been observed in space, most of its detections correspond to high-mass star-forming regions. Motivated by this lack of investigation in the low-mass regime, we searched for formamide, as well as isocyanic acid (HNCO), in 10 low- and intermediate-mass pre-stellar and protostellar objects. The present work is part of the IRAM Large Programme ASAI (Astrochemical Surveys At IRAM), which makes use of unbiased broad-band spectral surveys at millimetre wavelengths. We detected HNCO in all the sources and NH_2_CHO in five of them. We derived their abundances and analysed them together with those reported in the literature for high-mass sources. For those sources with formamide detection, we found a tight and almost linear correlation between HNCO and NH_2_CHO abundances, with their ratio being roughly constant - between 3 and 10 - across 6 orders of magnitude in luminosity. This suggests the two species are chemically related. The sources without formamide detection, which are also the coldest and devoid of hot corinos, fall well off the correlation, displaying a much larger amount of HNCO relative to NH_2_CHO. Our results suggest that, while HNCO can be formed in the gas-phase during the cold stages of star formation, NH_2_CHO forms most efficiently on the mantles of dust grains at these temperatures, where it remains frozen until the temperature rises enough to sublimate the icy grain mantles. We propose hydrogenation of HNCO as a likely formation route leading to NH_2_CHO.
- ID:
- ivo://CDS.VizieR/J/MNRAS/427/2047
- Title:
- Formation of cD Galaxies and their Clusters
- Short Name:
- J/MNRAS/427/2047
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In order to study the mechanism of formation of cD galaxies we search for possible dependencies between the K-band luminosity of cDs and the parameters of their host clusters which we select to have a dominant cD galaxy, corresponding to a cluster morphology of Bautz-Morgan (BM) type I. As a comparison sample we use cD galaxies in clusters where they are not dominant, which we define here as non-BM I (NBMI) type clusters. We find that for 71 BM I clusters the absolute K-band luminosity of cDs depends on the cluster richness, but less strongly on the cluster velocity dispersion. Meanwhile, for 35 NBMI clusters the correlation between cD luminosity and cluster richness is weaker, and is absent between cD luminosity and velocity dispersion. In addition, we find that the luminosity of the cD galaxy hosted in BM I clusters tends to increase with the cD's peculiar velocity with respect to the cluster mean velocity. In contrast, for NBMI clusters the cD luminosity decreases with increasing peculiar velocity. Also, the X-ray luminosity of BM I clusters depends on the cluster velocity dispersion, while in NBMI clusters such a correlation is absent. These findings favour the cannibalism scenario for the formation of cD galaxies. We suggest that cDs in clusters of BM I type were formed and evolved preferentially in one and the same cluster. In contrast, cDs in NBMI type clusters were either originally formed in clusters that later merged with groups or clusters to form the current cluster, or are now in the process of merging.
- ID:
- ivo://CDS.VizieR/J/A+A/604/A129
- Title:
- Formation of MW halo and its dwarf satellites
- Short Name:
- J/A+A/604/A129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a homogeneous set of accurate atmospheric parameters for a complete sample of very and extremely metal-poor stars in the dwarf spheroidal galaxies (dSphs) Sculptor, Ursa Minor, Sextans, Fornax, Bootes I, Ursa Major II, and Leo IV. We also deliver a Milky Way (MW) comparison sample of giant stars covering the -4<[Fe/H]<-1.7 metallicity range. We show that, in the [Fe/H]=>-3.7 regime, the non-local thermodynamic equilibrium (NLTE) calculations with non-spectroscopic effective temperature (Teff) and surface gravity (log g) based on the photometric methods and known distance provide consistent abundances of the FeI and FeII lines. This justifies the FeI/FeII ionisation equilibrium method to determine log g for the MW halo giants with unknown distance. The atmospheric parameters of the dSphs and MW stars were checked with independent methods. In the [Fe/H]>-3.5 regime, the TiI/TiII ionisation equilibrium is fulfilled in the NLTE calculations. In the logg-Teff plane, all the stars sit on the giant branch of the evolutionary tracks corresponding to [Fe/H]=-2 to -4, in line with their metallicities. For some of the most metal-poor stars of our sample, we hardly achieve consistent NLTE abundances from the two ionisation stages for both iron and titanium. We suggest that this is a consequence of the uncertainty in the Teff-colour relation at those metallicities. The results of these work provide the base for a detailed abundance analysis presented in a companion paper.
- ID:
- ivo://CDS.VizieR/J/MNRAS/446/3478
- Title:
- Fornax A MWA 154MHz image
- Short Name:
- J/MNRAS/446/3478
- Date:
- 07 Feb 2022 14:41:00
- Publisher:
- CDS
- Description:
- We present new low-frequency observations of the nearby radio galaxy Fornax A at 154MHz with the Murchison Widefield Array, microwave flux-density measurements obtained from WMAP and Planck data, and {gamma}-ray flux densities obtained from Fermi data. We also compile a comprehensive list of previously published images and flux-density measurements at radio, microwave and X-ray energies. A detailed analysis of the spectrum of Fornax A between 154 and 1510MHz reveals that both radio lobes have a similar spatially averaged spectral index, and that there exists a steep-spectrum bridge of diffuse emission between the lobes. Taking the spectral index of both lobes to be the same, we model the spectral energy distribution of Fornax A across an energy range spanning 18 orders of magnitude, to investigate the origin of the X-ray and {gamma}-ray emission. A standard leptonic model for the production of both the X-rays and {gamma}-rays by inverse-Compton scattering does not fit the multiwavelength observations. Our results best support a scenario where the X-rays are produced by inverse-Compton scattering and the {gamma}-rays are produced primarily by hadronic processes confined to the filamentary structures of the Fornax A lobes.