- ID:
- ivo://CDS.VizieR/J/A+A/596/A86
- Title:
- Lynx-Cancer void sample galaxies HI data
- Short Name:
- J/A+A/596/A86
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Void population consists mainly of late-type and low surface brightness (LSB) dwarf galaxies, whose atomic hydrogen is the main component of their baryonic matter. Therefore observations of void galaxy HI are mandatory to understand both their evolution and dynamics. Our aim was to obtain integrated HI parameters for a fainter part of the nearby Lynx-Cancer void galaxy sample (total of 45 objects) with the Nancay Radio Telescope (NRT) and to conduct the comparative analysis of the whole 103 void galaxies with known HI data with a sample of similar galaxies residing in denser environments of the Local Volume. For HI observations we used the NRT with its sensitive antenna/receiver system FORT and standard processing. The comparison of the void and "control" samples on the parameter M(HI)/L_B_ is conducted with the non-parametric method "The 2x2 Contingency Table test". We obtained new HI data for about 40% of the Lynx-Cancer galaxy sample. Along with data from the literature, we use for further analysis data for 103 void objects. The proxy of the evolutional parameter M(HI)/L_B_ of the void sample is compared with that of 82 galaxies of morphological types 8-10 residing in the Local Volume groups and aggregates. At the confidence level of P=0.988, we conclude that for the same luminosity, these void galaxies are systematically gas-richer, in average by ~39%. This result is consistent with the authors' earlier conclusion on the smaller gas metallicities and evidences for the slower low-mass galaxy evolution in voids.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/other/PASAu/6.471
- Title:
- Magellanic Clouds bridge region HI profiles
- Short Name:
- J/other/PASAu/6.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Two hundred and seventeen HI profiles at positions approximately 1degree apart in the bridge region between the Small and Large Magellanic Clouds have been observed with a 15' arc beam. Diagrams of all the profiles, lists of column densities and average radial velocities are given, together with details of the extensive Gaussian analysis needed to account for the components. It is shown that the bridge region is most complex. (a) Two radial velocity (1) groups, +214 and +238km/s, represent the actual HI bridge between the two galaxies. (b) Three other components, at mean radial velocities of +155, +177 and +195km/s are seen to be integral parts of the SMC, stretching east to RA~04h. (c) A further three components in groups at mean radial Velocities +253, +272 and +293km/s appear to be extensions of HI from the main body of the LMC. Nine sets of five closely spaced observations in the lower Magellanic Stream and in the bridge region at high sensitivity supply further information about the region.
- ID:
- ivo://CDS.VizieR/J/A+A/333/L35
- Title:
- Magellanic Clouds Cepheids Fourier decomposition
- Short Name:
- J/A+A/333/L35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The radial velocity and light curves of 24 Cepheids in the Magellanic Clouds, with period in the range 30-134d, were Fourier decomposed with the aim of detecting resonance effects between pulsation modes. The Tables contain the list of stars, the details of the analysis and the Fourier parameters.
- ID:
- ivo://CDS.VizieR/J/MNRAS/471/4571
- Title:
- Magellanic Inter-Cloud Project. III
- Short Name:
- J/MNRAS/471/4571
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Magellanic Bridge (MB) is a gaseous stream that links the Large (LMC) and Small (SMC) Magellanic Clouds. Current simulations suggest that the MB forms from a recent interaction between the Clouds. In this scenario, the MB should also have an associated stellar bridge formed by stars tidally stripped from the SMC by the LMC. There are several observational evidences for these stripped stars, from the presence of intermediate age populations in the MB and carbon stars, to the recent observation of an over-density of RR Lyrae stars offset from the MB. However, spectroscopic confirmation of stripped stars in the MB remains lacking. In this paper, we use medium resolution spectra to derive the radial velocities and metallicities of stars in two fields along the MB. We show from both their chemistry and kinematics that the bulk of these stars must have been tidally stripped from the SMC. This is the first spectroscopic evidence for a dwarf galaxy being
- ID:
- ivo://CDS.VizieR/J/ApJ/883/11
- Title:
- Magellan/IMACS spectra of Crater II & Hercules
- Short Name:
- J/ApJ/883/11
- Date:
- 21 Jan 2022 09:25:05
- Publisher:
- CDS
- Description:
- We investigate the possibility that the dwarf galaxies Crater II and Hercules have previously been tidally stripped by the Milky Way. We present Magellan/IMACS spectra of candidate member stars in both objects. We identify 37 members of Crater II, 25 of which have velocity measurements in the literature, and we classify three stars within that subset as possible binaries. We find that including or removing these binary candidates does not change the derived velocity dispersion of Crater II. Excluding the binary candidates, we measure a velocity dispersion of {sigma}_Vlos_=2.7_-0.4_^+0.5^km/s, corresponding to M/L=47_-13_^+17^M_{sun}_/L_{sun}_. We measure a mean metallicity of [Fe/H]=-1.95_-0.05_^+0.06^, with a dispersion of {sigma}_[Fe/H]_=0.18_-0.08_^+0.06^. Our velocity dispersion and metallicity measurements agree with previous measurements for Crater II, and confirm that the galaxy resides in a kinematically cold dark-matter halo. We also search for spectroscopic members stripped from Hercules in the possible extratidal stellar overdensities surrounding the dwarf. For both galaxies, we calculate proper motions using Gaia DR2 astrometry, and use their full 6D phase space information to evaluate the probability that their orbits approach sufficiently close to the Milky Way to experience tidal stripping. Given the available kinematic data, we find a probability of ~40% that Hercules has suffered tidal stripping. The proper motion of Crater II makes it almost certain to be stripped.
- ID:
- ivo://CDS.VizieR/J/ApJ/857/145
- Title:
- MagLiteS Carina II and Carina III spectroscopy
- Short Name:
- J/ApJ/857/145
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Magellan/IMACS, Anglo-Australian Telescope/AAOmega+2dF, and Very Large Telescope/GIRAFFE+FLAMES spectroscopy of the Carina II (CarII) and Carina III (CarIII) dwarf galaxy candidates, recently discovered in the Magellanic Satellites Survey (MagLiteS). We identify 18 member stars in Car II, including two binaries with variable radial velocities and two RR Lyrae stars. The other 14 members have a mean heliocentric velocity v_hel_=477.2+/-1.2km/s and a velocity dispersion of {sigma}_v_=3.4_-0.8_^+1.2^km/s. Assuming Car II is in dynamical equilibrium, we derive a total mass within the half-light radius of 1.0_-0.4_^+0.8^x10^6^M_{sun}_, indicating a mass-to-light ratio of 369_-161_^+309^M_{sun}_/L_{sun}_. From equivalent width measurements of the calcium triplet lines of nine red giant branch (RGB) stars, we derive a mean metallicity of [Fe/H]=-2.44+/-0.09 with dispersion {sigma}_[Fe/H]_=0.22_-0.07_^+0.10^. Considering both the kinematic and chemical properties, we conclude that CarII is a dark-matter-dominated dwarf galaxy. For CarIII, we identify four member stars, from which we calculate a systemic velocity of v_hel_=284.6_-3.1_^+3.4^km/s. The brightest RGB member of CarIII has a metallicity of [Fe/H]=-1.97+/-0.12. Due to the small size of the Car III spectroscopic sample, we cannot conclusively determine its nature. Although these two systems have the smallest known physical separation ({Delta}d~10kpc) among Local Group satellites, the large difference in their systemic velocities, ~200km/s, indicates that they are unlikely to be a bound pair. One or both systems are likely associated with the Large Magellanic Cloud (LMC), and may remain LMC satellites today. No statistically significant excess of {gamma}-ray emission is found at the locations of Car II and Car III in eight years of Fermi-LAT data.
- ID:
- ivo://CDS.VizieR/J/A+A/511/A54
- Title:
- Magnetic cycles and radial-velocity for 8 stars
- Short Name:
- J/A+A/511/A54
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ever increasing level of precision achieved by present and future radial velocity instruments is opening the way to the discovery of very low mass, long period planets (e.g. solar-system analogs). These systems will be detectable as low amplitude signals in radial-velocity (RV). However, an important obstacle to their detection may be the existence of stellar magnetic cycles with similar timescales. Here we present the results of a long term program to measure simultaneously radial-velocities and stellar activity indicators (CaII, H{alpha}, HeI) for a sample of stars with known activity cycles. Our results suggest that all these stellar activity indexes can be used to trace the stellar magnetic cycle in solar-type stars. Further to this, we find clear indications that different parameters of the HARPS cross-correlation function (BIS, FWHM, and Contrast) are also sensitive to activity level variations. Finally, we show that though in a few cases slight correlations or anti-correlations between radial-velocity and the activity level of the star exist, their origin is still not clear. We can however conclude that for our targets (early-K dwarfs) we do not find evidence for radial-velocity variations induced by variations of the stellar magnetic cycle with amplitudes significantly above 1m/s.
- ID:
- ivo://CDS.VizieR/J/AJ/154/140
- Title:
- MALT90 kinematic distances to molecular clumps
- Short Name:
- J/AJ/154/140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using molecular-line data from the Millimetre Astronomy Legacy Team 90 GHz Survey (MALT90), we have estimated kinematic distances to 1905 molecular clumps identified in the ATLASGAL 870 {mu}m continuum survey over the longitude range 295{deg}<l<350{deg}. The clump velocities were determined using a flux-weighted average of the velocities obtained from Gaussian fits to the HCO^+^, HNC, and N_2_H^+^ (1-0) transitions. The near/far kinematic distance ambiguity was addressed by searching for the presence or absence of absorption or self-absorption features in 21 cm atomic hydrogen spectra from the Southern Galactic Plane Survey. Our algorithm provides an estimation of the reliability of the ambiguity resolution. The Galactic distribution of the clumps indicates positions where the clumps are bunched together, and these locations probably trace the locations of spiral arms. Several clumps fall at the predicted location of the far side of the Scutum-Centaurus arm. Moreover, a number of clumps with positive radial velocities are unambiguously located on the far side of the Milky Way at galactocentric radii beyond the solar circle. The measurement of these kinematic distances, in combination with continuum or molecular-line data, now enables the determination of fundamental parameters such as mass, size, and luminosity for each clump.
- ID:
- ivo://CDS.VizieR/J/AJ/141/131
- Title:
- Mapping the asymmetric thick disk. III.
- Short Name:
- J/AJ/141/131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the first two papers of this series, Larsen et al. (1996ApJ...468L..99L) describe our faint CCD survey in the inner Galaxy and map the overdensity of thick disk stars in Quadrant 1 (Q1) to 5kpc or more along the line of sight. The regions showing the strongest excess are above the density contours of the bar in the Galactic disk. In this third paper on the asymmetric thick disk, we report on radial velocities and derived metallicity parameters for over 4000 stars in Q1, above and below the plane, and in Quadrant 4 (Q4) above the plane.
- ID:
- ivo://CDS.VizieR/VII/198
- Title:
- Mark III Catalog of Galaxy Peculiar Velocities
- Short Name:
- VII/198
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Tully-Fisher and Dn-sigma distances, radial velocities, and associated catalog and observational data for the spiral, irregular, and elliptical galaxies that comprise the Mark 3 catalog are given in 5 different kinds of tables for seven separate data sets. Users interested only in the resulting distances need use only the files listed in sections 3 (Grouped spiral distance files), 4 (Elliptical galaxy distance files), and 5 (Comparison of galaxy distances).
