- ID:
- ivo://CDS.VizieR/J/ApJ/724/1336
- Title:
- An extragalactic ^12^CO J=3-2 survey
- Short Name:
- J/ApJ/724/1336
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of a ^12^COJ=3-2 survey of 125 nearby galaxies obtained with the 10m Heinrich Hertz Telescope, with the aim to characterize the properties of warm and dense molecular gas in a large variety of environments. With an angular resolution of 22", ^12^CO3-2 emission was detected in 114 targets. Based on 61 galaxies observed with equal beam sizes the ^12^CO3-2/1-0 integrated line intensity ratio R_31_ is found to vary from 0.2 to 1.9, with an average value of 0.81. No correlations are found for R_31_ to Hubble-type and far-infrared luminosity. Possible indications for a correlation with inclination angle and the 60um/100um color temperature of the dust are not significant. Higher R_31_ ratios than in "normal" galaxies, hinting at enhanced molecular excitation, may be found in galaxies hosting active galactic nuclei. Even higher average values are determined for galaxies with bars or starbursts, the latter being identified by the ratio of infrared luminosity versus isophotal area, log [(L_FIR_/L_{sun}_)/(D^2^_25_/kpc^2^)]>7.25. (U)LIRGs are found to have the highest averaged R_31_ value. This may be a consequence of particularly vigorous star formation activity, triggered by galaxy interaction and merger events.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AZh/88/22
- Title:
- Angles rotation/magnetic moment in pulsars
- Short Name:
- J/AZh/88/22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Data on the pulse structure and variations of the linear polarization angle at frequencies near 1GHz have been used to estimate the angles {beta} between the rotational axis and magnetic moment of the neutron stars associated with 80 pulsars.
- ID:
- ivo://CDS.VizieR/J/A+A/611/A74
- Title:
- Angular differential imaging of MCW 758
- Short Name:
- J/A+A/611/A74
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Transition disks offer the extraordinary opportunity to look for newly born planets and investigate the early stages of planet formation. In this context we observed the Herbig A5 star MWC 758 with the L'-band vector vortex coronagraph installed in the near infrared camera and spectrograph NIRC2 at the Keck II telescope, with the aim of unveiling the nature of the spiral structure by constraining the presence of planetary companions in the system. Our high-contrast imaging observations show a bright ({Delta}L'=7.0+/-0.3mag) point-like emission, south of MWC 758 at a deprojected separation of ~20au (r=0.111"+/-0.004") from the central star. We also recover the two spiral arms (south-east and north-west), already imaged by previous studies in polarized light, and discover a third one to the south-west of the star. No additional companions were detected in the system down to 5 Jupiter masses beyond 0.6" from the star. We propose that the bright L' band emission could be caused by the presence of an embedded and accreting protoplanet, although the possibility of it being an asymmetric disk feature cannot be excluded. The spiral structure is probably not related to the protoplanet candidate, unless on an inclined and eccentric orbit, and it could be due to one (or more) yet undetected planetary companions at the edge of or outside the spiral pattern. Future observations and additional simulations will be needed to shed light on the true nature of the point-like source and its link with the spiral arms.
- ID:
- ivo://CDS.VizieR/J/A+A/405/627
- Title:
- Angular dimensions of 312 planetary nebulae
- Short Name:
- J/A+A/405/627
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of direct measurements done on H{alpha} (or H{alpha}+[NII]) images of 312 planetary nebulae. For each planetary nebulae deconvolved FWHM and resolution size from Gaussian fit and from second-moment method and direct measurement at 10% level are presented.
- ID:
- ivo://CDS.VizieR/J/MNRAS/373/435
- Title:
- Angular momentum evolution of Algol binaries
- Short Name:
- J/MNRAS/373/435
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have compiled the well-determined absolute parameters of Algol-type binaries. The lists contain the parameters of 74 detached and 61 semi-detached close binaries. The double-lined eclipsing binaries provide not only the most accurate determinations of stellar mass, radius and temperatures but also distance-independent luminosity for each of their individual components. The distributions of the primary and secondary masses of detached binaries (DBs) are similar, whilst the secondary masses of the semidetached binaries (SDBs) are mostly smaller than 2M_{sun}_ with a peak in the M2-bin (0.21-1.0). The components of the DBs are almost all located in the main-sequence band. On the contrary, the secondary components of the SDBs have larger radii and luminosity with respect to the same mass and the same effective temperature of main-sequence counterparts. They occupy a region of the Hertzsprung-Russell diagram between terminal-age main sequence and giants.
- ID:
- ivo://CDS.VizieR/J/A+A/651/L15
- Title:
- Angular-momentum plane for disc galaxies
- Short Name:
- J/A+A/651/L15
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The relations between the specific angular momenta (j) and masses (M) of galaxies are often used as a benchmark in analytic models and hydrodynamical simulations as they are considered to be amongst the most fundamental scaling relations. Using accurate measurements of the stellar (j*), gas (jgas), and baryonic (jbar) specific angular momenta for a large sample of disc galaxies, we report the discovery of tight correlations between j, M, and the cold gas fraction of the interstellar medium (fgas). At fixed fgas, galaxies follow parallel power laws in 2D (j, M) spaces, with gas-rich galaxies having a larger j* and jbar (but a lower jgas) than gas-poor ones. The slopes of the relations have a value around 0.7. These new relations are amongst the tightest known scaling laws for galaxies. In particular, the baryonic relation (jbar-Mbar-fgas), arguably the most fundamental of the three, is followed not only by typical discs but also by galaxies with extreme properties, such as size and gas content, and by galaxies previously claimed to be outliers of the standard 2D j-M relations. The stellar relation (j*-M*-fgas) may be connected to the known j*-M* bulge fraction relation; however, we argue that the jbar-Mbar-fgas relation can originate from the radial variation in the star formation efficiency in galaxies, although it is not explained by current disc instability models.
- ID:
- ivo://CDS.VizieR/J/MNRAS/452/4274
- Title:
- Angular sizes of AGN cores at 2-43GHz
- Short Name:
- J/MNRAS/452/4274
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have measured the angular sizes of radio cores of active galactic nuclei (AGN) and analyzed their sky distributions and frequency dependencies to study synchrotron opacity in AGN jets and the strength of angular broadening in the interstellar medium. We have used archival very long baseline interferometry (VLBI) data of more than 3000 compact extragalactic radio sources observed at frequencies, {nu}, from 2 to 43GHz to measure the observed angular size of VLBI cores. We have found a significant increase in the angular sizes of the extragalactic sources seen through the Galactic plane (|b|<10{deg}) at 2, 5 and 8GHz, about 1/3 of which show significant scattering. These sources are mainly detected in directions to the Galactic bar, the Cygnus region, and a region with galactic longitudes 220{deg}<l<260{deg} (the Fitzgerald window). The strength of interstellar scattering of the AGNs is found to correlate with the Galactic H{alpha} intensity, free-electron density, and Galactic rotation measure. The dependence of scattering strengths on source redshift is insignificant, suggesting that the dominant scattering screens are located in our Galaxy. The observed angular size of Sgr-A* is found to be the largest among thousands of AGN observed over the sky; we discuss possible reasons of this strange result. Excluding extragalactic radio sources with significant scattering, we find that angular size of opaque cores in AGN scales typically as {nu}^-1^ confirming predictions of a conical synchrotron jet model with equipartition.
- ID:
- ivo://CDS.VizieR/J/MNRAS/390/1133
- Title:
- Anisotropic distribution of satellite galaxies
- Short Name:
- J/MNRAS/390/1133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We identify satellites of isolated galaxies in the Sloan Digital Sky Survey and examine their angular distribution. Using mock catalogues generated from cosmological N-body simulations, we demonstrate that the selection criteria used to select isolated galaxies and their satellites in large galaxy redshift surveys must be very strict in order to correctly identify systems in which the primary galaxy dominates its environment. We demonstrate that the criteria used in many previous studies instead select predominantly group members. We refine a set of selection criteria for which the group contamination is estimated to be less than 7 per cent and present a catalogue of the resulting sample.
999. AN Lyn light maxima
- ID:
- ivo://CDS.VizieR/J/A+A/328/235
- Title:
- AN Lyn light maxima
- Short Name:
- J/A+A/328/235
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New uvby data collected of AN Lyn together with the reanalysis of old data establish that this star is a multiperiodic pulsator. Three independent frequencies ({nu}_1_=10.1756, {nu}_2_=18.1309 and {nu}_3_=9.5598c/d) and some interactions between them are found to be present in the light curve. Changes in amplitude with a large time scale are confirmed for the main frequency. Moreover, changes in amplitude are also present for the secondary frequencies, especially for {nu}_3_. After subtraction of the secondary frequencies from the light curves, the classical O-C method has been used to analyse the behaviour of the main period. A comparison is made between AN Lyn and the other two known {delta} Sct stars with atypical light curves, i.e., V1719 Cyg and V798 Cyg. New uvby data have been also collected for V1719 Cyg and the O-C method has been used to analyse the behaviour of the main period. It is found that the main pulsation of this star can be well described by means of a linear ephemeris with a period of P=0.26729700d over the last eighteen years. Finally, analysis of the different data sets available in the literature do not reveal significative changes in the amplitude of the main frequency of V1719 Cyg.
- ID:
- ivo://CDS.VizieR/J/A+A/458/453
- Title:
- Annex to 7th Cat. of Galactic WR Stars
- Short Name:
- J/A+A/458/453
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper gathers, from the literature and private communication, 72 new Galactic Population I Wolf-Rayet stars and 17 candidate WCLd stars, recognized and/or discovered after the publication of The VIIth Catalogue of Galactic Wolf-Rayet Stars (Cat. III/215). This brings the total number of known Galactic Wolf-Rayet stars to 298, of which 24 (8%) are in open cluster Westerlund 1, and 60 (20%) are in open clusters near the Galactic Center.
