- ID:
- ivo://CDS.VizieR/J/other/Ap/54.147
- Title:
- Study of 230 IRAS-FSC galaxies
- Short Name:
- J/other/Ap/54.14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From the cross-correlation of the IRAS FSC catalog with the radio FIRST catalog, 230 infrared galaxies were selected having optical classifications and redshifts from SDSS and NED. To understand the nature of these objects we have compared them with a sample of bright ULIRGs with fluxes f>1Jy at 60-micron and with 14 optically faint IRAS FSC galaxies, showing that IRAS galaxies are not always strong infrared sources. We also have calibrated Star Formation Rates based on luminosities of the PAH feature at 7.7-micron and 1.4GHz radio flux densities, which confirmed the consistency between these two SFRs. We have estimated the extinction for our 230 objects using SFRs calibrated from the PAH feature compared to ultraviolet flux, which shows that only 1% of the ultraviolet continuum typically escapes extinction by dust within a starburst. As our 230 galaxies have no spectra available from Spitzer Space Telescope (SST) archive, to estimate the infrared flux at 7.7 (for SB galaxies) or 8.0 (for AGN and composite) micron, we have used the median ratios of the IRAS fluxes at 25-micron to fluxes at 7.7 or 8.0-micron estimated for each 41.0<logL(IR)<41.9, 42.0<logL(IR)<42.9, 43.0<logL(IR)<43.9, 44.0<logL(IR)<44.9, and 45.0<logL(IR)<45.9 luminosity bins, using objects having spectra from SST archive.
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Search Results
- ID:
- ivo://CDS.VizieR/J/other/ChA+A/34.367
- Title:
- Study of PGC-54-like galaxies
- Short Name:
- J/other/ChA+A/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With the improved Peng's method, we have made the image processing and spiral arm fitting of the newly released spiral galactic images of Sloan Digital Sky Survey (SDSS), and obtained the equivalent thicknesses of galactic disks, as well as the tangential angles of spiral arms of 73 spiral galaxies. These physical quantities are very important for future studies on the properties of spiral galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/818/73
- Title:
- Study of protostars in the Perseus molecular cloud
- Short Name:
- J/ApJ/818/73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multiplicity study of all known protostars (94) in the Perseus molecular cloud from a Karl G. Jansky Very Large Array survey at Ka-band (8 mm and 1 cm) and C-band (4 and 6.6 cm). The observed sample has a bolometric luminosity range between 0.1 L_{sun}_ and ~33 L_{sun}_, with a median of 0.7 L_{sun}_. This multiplicity study is based on the Ka-band data, having a best resolution of ~0.065" (15 au) and separations out to ~43" (10000 au) can be probed. The overall multiplicity fraction (MF) is found to be 0.40+/-0.06 and the companion star fraction (CSF) is 0.71+/-0.06. The MF and CSF of the Class 0 protostars are 0.57+/-0.09 and 1.2+/-0.2, and the MF and CSF of Class I protostars are both 0.23+/-0.08. The distribution of companion separations appears bi-modal, with a peak at ~75 au and another peak at ~3000 au. Turbulent fragmentation is likely the dominant mechanism on >1000 au scales and disk fragmentation is likely to be the dominant mechanism on <200 au scales. Toward three Class 0 sources we find companions separated by <30 au. These systems have the smallest separations of currently known Class 0 protostellar binary systems. Moreover, these close systems are embedded within larger (50-400 au) structures and may be candidates for ongoing disk fragmentation.
18234. Study of star V9 in 47 Tuc
- ID:
- ivo://CDS.VizieR/J/A+A/291/121
- Title:
- Study of star V9 in 47 Tuc
- Short Name:
- J/A+A/291/121
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an infrared K-band light curve and a radial velocity curve for the RR Lyrae star V9 in the metal rich globular cluster 47 Tucanae ([Fe/H]=-0.71). Combining these new data with the optical photometry presented in Carney et al. (1993PASP..105..294C), we perform a Baade-Wesselink analysis and derive a distance modulus of 47 Tuc of 13.23mag+/-0.17 and absolute mean magnitudes of <M_V_>=0.32mag and <M_K_>=-0.57mag for V9. We also present a well populated visual-infrared color-magnitude diagram of the cluster, reaching from the upper red giant branch to the subgiant branch.
- ID:
- ivo://CDS.VizieR/J/MNRAS/454/1086
- Title:
- Study of the COSC Korean astronomical catalogue
- Short Name:
- J/MNRAS/454/1086
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The study of old star catalogues provides important astrometric data. Most of the researches based on the old star catalogues were manuscript published in Europe and from Arabic/Islam. However, the old star catalogues published in East Asia did not get attention. Therefore, among the East Asian star catalogues we focus on a particular catalogue recorded in a Korean almanac. Its catalogue contains 277 stars that are positioned in a region within 10{deg} of the ecliptic plane. The stars in the catalogue were identified using the modern Hipparcos catalogue (Cat. I/239). We identified 274 among 277 stars, which is a rate of 98.9 percent. The catalogue records the epoch of the stars' positions as AD 1396.0. However, by using all of the identified stars we found that the initial epoch of the catalogue is AD 1363.1+/-3.2. In conclusion, the star catalogue was compiled and edited from various older star catalogues. We assume a correlation with the Almagest by Ptolemaios. This study presents newly analysed results from the historically important astronomical data discovered in East Asia. Therefore, this star catalogue will become important data for comparison with the star catalogues published in Europe and from Arabic/Islam.
- ID:
- ivo://CDS.VizieR/J/AJ/157/111
- Title:
- Study of three early-type contact twin binaries
- Short Name:
- J/AJ/157/111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Three eclipsing binaries, CT Tau, GU Mon, and V701 Sco, are early-type contact binaries with infrared excess from circumbinary matter. We present the multi-color photometry for CT Tau and GU Mon, whose spectral types of B1V are identified by the low-precision spectra. Combining these new light curves (LCs) with previously reported LCs and radial velocity curves, we perform a synthesized analysis to estimate/update the stellar absolute parameters of the three systems. Their mass ratios are close to unity (i.e., q~1), which indicates that the binary system comprising of twin components may be undergoing a slow Case A mass transfer. From the period analysis, the light-time orbit in the (O-C) curve may result from the third condense companion around the binary system although no evidence could be provided by the third light l_3_. From the spectral energy distribution for three binaries, the excess infrared (IR) emissions are above the photospheric emissions, which can be seen at the 22.1 {mu}m for CT Tau and GU Mon, and 11.6 {mu}m, 14.5 {mu}m, and 22.1 {mu}m for V701 Sco, respectively. This kind of infrared excess for the early-type star may be attributed to the circumbinary matter by stellar wind.
18237. Study of Two HgMn Stars
- ID:
- ivo://CDS.VizieR/J/AZh/71/588
- Title:
- Study of Two HgMn Stars
- Short Name:
- J/AZh/71/588
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Three spectra of HD182308 (HR 7361) and four spectra of HD178065 (HR 7245) were obtained from 1989 to 1990 with the Main Stellar Spectrograph of the 6-m telescope at the Special Astrophysical Observatory and with the Coude spectrograph of the 2-m telescope of the Rozhen Observatory of the Bulgarian Academy of Sciences. Spectra were obtained in the range of 3700-4900A with inverse dispersion of 9 A/mm. Spectral resolution was close to 0.25A. Elemental abundances of two HgMn stars, HD 178065 and HD 182308, were found. Objects: --------------------------------------- RA (2000) DE Designation(s) --------------------------------------- 19 19 46.03 +64 23 26.7 HD 182308 19 07 08.95 +00 38 29.3 HD 178065 ---------------------------------------
18238. S-type AGB stars in SMC
- ID:
- ivo://CDS.VizieR/J/ApJ/810/116
- Title:
- S-type AGB stars in SMC
- Short Name:
- J/ApJ/810/116
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have identified a new class of Asymptotic Giant Branch (AGB) stars in the Small and Large Magellanic Clouds (SMC/LMC) using optical to infrared photometry, light curves, and optical spectroscopy. The strong dust production and long-period pulsations of these stars indicate that they are at the very end of their AGB evolution. Period-mass-radius relations for the fundamental-mode pulsators give median current stellar masses of 1.14M_{sun}_ in the LMC and 0.94M_{sun}_ in the SMC (with dispersions of 0.21 and 0.18M_{sun}_, respectively), and models suggest initial masses of <1.5M_{sun}_ and <1.25 M_{sun}_, respectively. This new class of stars includes both O-rich and C-rich chemistries, placing the limit where dredge-up allows carbon star production below these masses. A high fraction of the brightest among them should show S star characteristics indicative of atmospheric C/O~1, and many will form O-rich dust prior to their C-rich phase. These stars can be separated from their less-evolved counterparts by their characteristically red J-[8] colors.
- ID:
- ivo://CDS.VizieR/J/MNRAS/439/1648
- Title:
- Subarcsecond mid-infrared atlas of local AGN
- Short Name:
- J/MNRAS/439/1648
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first subarcsecond-resolution mid-infrared (MIR) atlas of local active galactic nuclei (AGN). Our atlas contains 253 AGN with a median redshift of z=0.016, and includes all publicly available MIR imaging performed to date with ground-based 8-m class telescopes, a total of 895 independent measurements. Of these, more than 60% are published here for the first time. We detect extended nuclear emission in at least 21% of the objects, while another 19% appear clearly point-like, and the remaining objects cannot be constrained. Where present, elongated nuclear emission aligns with the ionization cones in Seyferts. Subarcsecond resolution allows us to isolate the AGN emission on scales of a few tens of parsecs and to obtain nuclear photometry in multiple filters for the objects. Median spectral energy distributions (SEDs) for the different optical AGN types are constructed and individual MIR 12 and 18um continuum luminosities are computed. These range over more than six orders of magnitude. In comparison to the arcsecond-scale MIR emission as probed by Spitzer, the continuum emission is much lower on subarcsecond scales in many cases. The silicate feature strength is similar on both scales and generally appears in emission (absorption) in type I (II) AGN. However, the polycyclic aromatic hydrocarbon emission appears weaker or absent on subarcsecond scales. The differences of the MIR SEDs on both scales are particularly large for AGN/starburst composites and close-by (and weak) AGN. The nucleus dominates over the total emission of the galaxy only at luminosities >~10^44^erg/s. The AGN MIR atlas is well suited not only for detailed investigation of individual sources but also for statistical studies of AGN unification.
18240. Subaru H images of UM673
- ID:
- ivo://CDS.VizieR/J/A+A/566/A36
- Title:
- Subaru H images of UM673
- Short Name:
- J/A+A/566/A36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We performed a detailed photometric analysis of the lensed system UM673 (Q0142-100) and an analysis of the tentative lens models. High-resolution adaptive optics images of UM673 taken with the Subaru telescope in the H band were examined. We also analysed the J, H and K-band observational data of UM673 obtained with the 1.3m telescope at the CTIO observatory. We present photometry of quasar components A and B of UM673, the lens, and the nearby bright galaxy using H-band observational data obtained with the Subaru telescope. Based on the CTIO observations of UM673, we also present J- and H-band photometry and estimates of the J, H and K-band flux ratios between the two UM673 components in recent epochs. The near-infrared fluxes of the A and B components of UM673 and their published optical fluxes are analysed to measure extinction properties of the lensing galaxy. We estimate the extinction-corrected flux ratio between components A and B to be about 2.14 mag. We discuss lens models for the UM673 system constrained with the positions of the UM673 components, their flux ratio, and the previously measured time delay.