- ID:
- ivo://CDS.VizieR/J/A+A/459/391
- Title:
- Dynamics of NGC 4636 globular cluster system
- Short Name:
- J/A+A/459/391
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first dynamical study of the globular cluster system of NGC 4636. It is the southernmost giant elliptical galaxy of the Virgo cluster and is claimed to be extremely dark matter dominated, according to X-ray observations. Globular clusters are used as dynamical tracers to investigate, by stellar dynamical means, the dark matter content of this galaxy. Several hundred medium resolution spectra were acquired at the VLT with FORS 2/MXU. We obtained velocities for 174 globular clusters in the radial range 0.90'<R<15.5', or 0.5-9R_e_ in units of effective radius. Assuming a distance of 15Mpc, the clusters are found at projected galactocentric distances in the range 4 to 70kpc, the overwhelming majority within 30kpc. The measured line-of-sight velocity dispersions are compared to Jeans-models.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/416/36
- Title:
- Dynamics of the Galaxy Cluster Abell 2634
- Short Name:
- J/ApJ/416/36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Velocities are presented for 254 galaxies in the rich Abell cluster 2634. Positions are given for 274 additional galaxies for which further investigation is desirable.
- ID:
- ivo://CDS.VizieR/J/A+A/618/A186
- Title:
- Dynamic spectra of 10 pulsars
- Short Name:
- J/A+A/618/A186
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Pulsars scintillate. Dynamic spectra show brightness variation of pulsars in the time and frequency domain. Secondary spectra demonstrate the distribution of fluctuation power in the dynamic spectra. Dynamic spectra strongly depend on observational frequencies, but were often observed at frequencies lower than 1.5GHz. Scintillation observations at higher frequencies help to constrain the turbulence feature of the interstellar medium over a wide frequency range and can detect the scintillations of more distant pulsars. Ten pulsars were observed at 2250MHz (S-band) with the Jiamusi 66m telescope to study their scintillations. Their dynamic spectra were first obtained, from which the decorrelation bandwidths and time scales of diffractive scintillation were then derived by autocorrelation. Secondary spectra were calculated by forming the Fourier power spectra of the dynamic spectra. Most of the newly obtained dynamic spectra are at the highest frequency or have the longest time span of any published data for these pulsars. For PSRs B0540+23, B2324+60 and B2351+61, these were the first dynamic spectra ever reported. The frequency-dependence of scintillation parameters indicates that the intervening medium can rarely be ideally turbulent with a Kolmogorov spectrum. The thin screen model worked well at S-band for the scintillation of PSR B1933+16. Parabolic arcs were detected in the secondary spectra of three pulsars, PSRs B0355+54, B0540+23 and B2154+40, all of which were asymmetrically distributed. The inverted arclets of PSR B0355+54 were seen to evolve along the main parabola within a continuous observing session of 12 hours, from which the angular velocity of the pulsar was estimated that was consistent with the measurement by very long baseline interferometry (VLBI).
- ID:
- ivo://CDS.VizieR/J/AZh/82/231
- Title:
- Dynamic stability of selected multiple stars
- Short Name:
- J/AZh/82/231
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The abundances of chemical elements in the atmospheres of seven classical barium stars are derived.
- ID:
- ivo://CDS.VizieR/J/MNRAS/437/1070
- Title:
- DYNAMO. H{alpha} luminous galaxies sample
- Short Name:
- J/MNRAS/437/1070
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- DYNAMO is a multiwavelength, spatially resolved survey of local (z~0.1) star-forming galaxies designed to study evolution through comparison with samples at z=~2. Half of the sample has integrated H{alpha luminosities of >10^42^erg/s, the typical lower limit for resolved spectroscopy at z=~2. The sample covers a range in stellar mass (10^9^-10^11^M_{sun_) and star formation rate (0.2-100M_{sun}_/yr). In this first paper of a series, we present integral-field spectroscopy of H{alpha emission for the sample of 67 galaxies. We infer gas fractions in our sample as high as =~0.8, higher than typical for local galaxies. Gas fraction correlates with stellar mass in galaxies with star formation rates below 10M_{sun}_/yr, as found by COLDGASS, but galaxies with higher star formation rates have higher than expected gas fractions. There is only a weak correlation, if any, between gas fraction and gas velocity dispersion. Galaxies in the sample visually classified as disc-like are offset from the local stellar mass Tully-Fisher relation to higher circular velocities, but this offset vanishes when both gas and stars are included in the baryonic Tully-Fisher relation. The mean gas velocity dispersion of the sample is =~50km/s, and V/{sigma} ranges from 2 to 10 for most of the discs, similar to 'turbulent' galaxies at high redshift. Half of our sample show disc-like rotation, while ~20 percent show no signs of rotation. The division between rotating and non-rotating is approximately equal for the sub-samples with either star formation rates >10M_{sun}_/yr, or specific star formation rates typical of the star formation 'main sequence' at z=~2. Across our whole sample, we find good correlation between the dominance of `turbulence' in galaxy discs (as expressed by V/{sigma}) and gas fraction as has been predicted for marginally stable Toomre discs. Comparing our sample with many others at low- and high-redshift reveals a correlation between gas velocity dispersion and star formation rate. These findings suggest the DYNAMO discs are excellent candidates for local galaxies similar to turbulent z=~2 disc galaxies.
- ID:
- ivo://padc.obspm.planeto/dynastvo/q/epn_core
- Title:
- DynastVO ephemeris service
- Short Name:
- DynAstVO
- Date:
- 01 Aug 2024 02:02:56
- Publisher:
- Paris Astronomical Data Centre
- Description:
- This database displays calculated orbital parameters for small bodies
- ID:
- ivo://CDS.VizieR/J/AJ/139/2639
- Title:
- DY Peg times of light maximum
- Short Name:
- J/AJ/139/2639
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We measure two new times of light maximum of the SX Phoenicis star DY Pegasi in 2008 December and collect 410 pe/CCD times of light maximum that had been published. These data could be modeled with a nonlinear fit including a continuously decreasing period change (dP/dt=-9.04x10^-12^days/day) and a periodic change with a period of 42.2 yr. If this periodic change is caused by the light traveling time effect of an orbital motion of DY Pegasi in a binary system, the deduced mass of the companion could be 0.028M_{sun}_ and it is probably a brown dwarf.
5218. DZ stars in SDSS DR4
- ID:
- ivo://CDS.VizieR/J/ApJ/663/1291
- Title:
- DZ stars in SDSS DR4
- Short Name:
- J/ApJ/663/1291
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed analysis of a large spectroscopic and photometric sample of DZ white dwarfs based on our latest model atmosphere calculations. We revise the atmospheric parameters of the trigonometric parallax sample of Bergeron, Leggett, & Ruiz (2001, Cat. <J/ApJS/133/413>, 12 stars) and analyze 147 new DZ white dwarfs discovered in the SDSS. The inclusion of metals and hydrogen in our model atmosphere calculations leads to different atmospheric parameters than those derived from pure helium models.
- ID:
- ivo://CDS.VizieR/J/MNRAS/390/383
- Title:
- E+A and companion galaxies
- Short Name:
- J/MNRAS/390/383
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Based on our intensive spectroscopic campaign with the GoldCam spectrograph on the Kitt Peak National Observatory (KPNO) 2.1-m telescope, we have constructed the first catalogue of E+A galaxies with spectroscopic companion galaxies, and investigated a probability that an E+A galaxy has close companion galaxies. We selected 660 E+A galaxies with 4.0{AA}<H{delta} EW at a redshift of <0.167 from the Data Release 5 of the Sloan Digital Sky Survey (SDSS). We selected their companion candidates from the SDSS imaging data, and classified them into true companions, fore/background galaxies and companion candidates using the SDSS and our KPNO spectra. We observed 26 companion candidates of E+A galaxies at the KPNO to measure their redshifts. Their spectra showed that 17 targets are true companion galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/297/61
- Title:
- E+A galaxies in Cl0939+472
- Short Name:
- J/A+A/297/61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of a study of E+A galaxies in the cluster Cl0939+472 (z=0.41). We have used a series of narrow-band filters (FWHM~=90-200A) covering the range from 3800 to 9200A, and broad band B, R, I filters to obtain low resolution spectra for all galaxies brighter than R=22.5mag in a 5'x5' cluster field. Two of the narrow-band filters have been chosen to measure the 4000A-break index, and 3 filters were centered on the H_{beta}_, H_{gamma}_ and H_{delta}_ lines which are indicators of recent star formation.