- ID:
- ivo://CDS.VizieR/J/ApJ/835/208
- Title:
- 2D stellar kinematics of Mrk 1216
- Short Name:
- J/ApJ/835/208
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Mrk 1216 is a nearby, early-type galaxy with a small effective radius of 2.8kpc and a large stellar velocity dispersion of 308km/s for its K-band luminosity of 1.4x10^11^L_{sun}_. Using integral field spectroscopy assisted by adaptive optics from Gemini North, we measure spatially resolved stellar kinematics within ~450pc of the galaxy nucleus. The galaxy exhibits regular rotation with velocities of +/-180km/s and a sharply peaked velocity dispersion profile that reaches 425km/s at the center. We fit axisymmetric, orbit-based dynamical models to the combination of these high angular resolution kinematics, large-scale kinematics extending to roughly three effective radii, and Hubble Space Telescope imaging, resulting in a constraint of the mass of the central black hole in Mrk 1216. After exploring several possible sources of systematics that commonly affect stellar-dynamical black hole mass measurements, we find a black hole mass of M_BH_=(4.9+/-1.7)x10^9^M_{sun}_ and an H-band stellar mass-to-light ratio of {Upsilon}_H_=1.3+/-0.4{Upsilon}_{sun}_ (1{sigma} uncertainties). Mrk 1216 is consistent with the local black hole mass-stellar velocity dispersion relation, but is a factor of ~5-10 larger than expectations from the black hole mass-bulge luminosity and black hole mass-bulge mass correlations when conservatively using the galaxy's total luminosity or stellar mass. This behavior is quite similar to the extensively studied compact galaxy NGC 1277. Resembling the z~2 quiescent galaxies, Mrk 1216 may be a passively evolved descendant, and perhaps reflects a previous era when galaxies contained over-massive black holes relative to their bulge luminosities/masses, and the growth of host galaxies had yet to catch up.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/370/1223
- Title:
- Dynamical properties of 15 nearby galaxy groups
- Short Name:
- J/MNRAS/370/1223
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Here, we present an investigation of the properties of 15 nearby galaxy groups and their constituent galaxies. The groups are selected from the Group Evolution Multiwavelength Study (GEMS) and all have X-ray as well as wide-field neutral hydrogen (HI) observations. Group membership is determined using a friends-of-friends algorithm on the positions and velocities from the 6-degree Field Galaxy Survey and NASA/IPAC Extragalactic Database. For each group we derive their physical properties using this membership, including: velocity dispersions (sigma_v_), virial masses (M_V_), total K-band luminosities [L_K_(Tot)] and early-type fractions (f_early_) and present these data for the individual groups.
- ID:
- ivo://CDS.VizieR/J/A+AS/139/483
- Title:
- Early-type gal. kinematics in compact groups
- Short Name:
- J/A+AS/139/483
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present measurements of stellar kinematics for seven early-type galaxies in HCG 67, HCG 74, and HCG 79. These data are aimed at studying the relation between the environment and the dynamics, structure and stellar content of early-type galaxies. In the present three groups, the kinematic features we observed cannot be associated unambiguously to physical interactions. Visible morphological peculiarities do not appear correlated with kinematical perturbations.
- ID:
- ivo://CDS.VizieR/J/A+A/342/671
- Title:
- Early-type spiral galaxies kinematics
- Short Name:
- J/A+A/342/671
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the stellar and ionized-gas velocity curves and velocity-dispersion profiles along the major axis for six early-type spiral galaxies. Two of these galaxies, namely NGC 2179 and NGC 2775, are particularly suited for the study of dark matter halos. Using their luminosity profiles and modeling their stellar and gaseous kinematics, we derive the mass contributions of the luminous and the dark matter to the total potential. In NGC 2179 we find that the data (measured out to about the optical radius R_opt_) unambiguously require the presence of a massive dark halo. For the brighter and bigger object NGC 2775, we can rule out a significant halo contribution at radii R<~0.6R_opt_. Although preliminary, these results agree with the familiar mass distribution trend known for late-type spirals of comparable mass.
- ID:
- ivo://CDS.VizieR/J/MNRAS/321/277
- Title:
- EFAR Catalog. VII.
- Short Name:
- J/MNRAS/321/277
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present peculiar velocities for 85 clusters of galaxies in two large volumes at distances between 6000 and 15000km/s in the directions of Hercules-Corona Borealis and Perseus-Pisces-Cetus (the EFAR sample). These velocities are based on Fundamental Plane (FP) distance estimates for early-type galaxies in each cluster. We fit the FP using a maximum likelihood algorithm which accounts for both selection effects and measurement errors, and yields FP parameters with smaller bias and variance than other fitting procedures. We obtain a best-fitting FP with coefficients consistent with the best existing determinations. We measure the bulk motions of the sample volumes using the 50 clusters with the best-determined peculiar velocities.
- ID:
- ivo://CDS.VizieR/J/ApJ/805/65
- Title:
- FLAMES observations of NGC 5128's globular clusters
- Short Name:
- J/ApJ/805/65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the dynamical properties of 125 compact stellar systems (CSSs) in the nearby giant elliptical galaxy NGC 5128, using high-resolution spectra (R~26000) obtained with Very Large Telescope/FLAMES. Our results provide evidence for a new type of star cluster, based on the CSS dynamical mass scaling relations. All radial velocity (v_r_) and line-of-sight velocity dispersion ({sigma}_los_) measurements are performed with the penalized pixel fitting (ppxf) technique, which provided {sigma}_ppxf_ estimates for 115 targets. The {sigma}_ppxf_ estimates are corrected to the 2D projected half-light radii, {sigma}_1/2_, as well as the cluster cores, {sigma}_0_, accounting for observational/aperture effects and are combined with structural parameters, from high spatial resolution imaging, in order to derive total dynamical masses (M_dyn_) for 112 members of NGC5128's star cluster system. In total, 89 CSSs have dynamical masses measured for the first time along with the corresponding dynamical mass-to-light ratios ({sigma}_1/2_). We find two distinct sequences in the {gamma}^dyn^_V_-M_dyn_ plane, which are well approximated by power laws of the forms {gamma}^dyn^_V_{propto}M_dyn_^0.33+/-0.04^ and {gamma}^dyn^_V_{propto}M_dyn_^0.79+/-0.04^. The shallower sequence corresponds to the very bright tail of the globular cluster luminosity function (GCLF), while the steeper relation appears to be populated by a distinct group of objects that require significant dark gravitating components such as central massive black holes and/or exotically concentrated dark matter distributions. This result would suggest that the formation and evolution of these CSSs are markedly different from the "classical" globular clusters in NGC 5128 and the Local Group, despite the fact that these clusters have luminosities similar to the GCLF turnover magnitude. We include a thorough discussion of myriad factors potentially influencing our measurements.
- ID:
- ivo://CDS.VizieR/J/ApJS/246/2
- Title:
- Galaxy cluster cat. from SDSS-DR13 (GalWCat19)
- Short Name:
- J/ApJS/246/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Utilizing the SDSS-DR13 spectroscopic data set, we create a new publicly available catalog of 1800 galaxy clusters (GalWeight cluster catalog, GalWCat19) and a corresponding catalog of 34,471 identified member galaxies. The clusters are identified from overdensities in redshift phase space. The GalWeight technique introduced by Abdullah+ (2018ApJ...861...22A) is then applied to identify cluster members. The completeness of the cluster catalog (GalWCat19) and the procedure followed to determine cluster mass are tested on the Bolshoi N-body simulations. The 1800 GalWCat19 clusters range in redshift between 0.01 and 0.2 and have masses in the range of (0.4-14)x10^14^h^-1^M_{sun}_. The cluster catalog provides a large number of cluster parameters, including sky position, redshift, membership, velocity dispersion, and mass at overdensities {Delta}=500, 200, 100, and 5.5. The 34471 member galaxies are identified within the radius at which the density is 200 times the critical density of the universe. The galaxy catalog provides the coordinates of each galaxy and the ID of the cluster that the galaxy belongs to. The cluster velocity dispersion scales with mass as log({sigma}_200_)=log(946+/-52km/s)+ (0.349+/-0.142)log[h(z)M_200_/10^1 5^M_{sun}], with a scatter of {delta}log{sigma}=0.06+/-0.04.
- ID:
- ivo://CDS.VizieR/J/ApJ/843/16
- Title:
- Galaxy groups within 3500km/s
- Short Name:
- J/ApJ/843/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A study of the group properties of galaxies in our immediate neighborhood provides a singular opportunity to observationally constrain the halo mass function, a fundamental characterization of galaxy formation. Detailed studies of individual groups have provided the coefficients of scaling relations between a proxy for the virial radius, velocity dispersion, and mass that usefully allow groups to be defined over the range 10^10^-10^15^M_{sun}_. At a second hierarchical level, associations are defined as regions around collapsed halos extending to the zero-velocity surface at the decoupling from cosmic expansion. The most remarkable result of the study emerges from the construction of the halo mass function from the sample. At ~10^12^M_{sun}_, there is a jog from the expectation Sheth-Tormen function, such that halo counts drop by a factor ~3 in all lower mass bins.
- ID:
- ivo://CDS.VizieR/J/A+A/374/394
- Title:
- Gas and stars kinematics in disc galaxies
- Short Name:
- J/A+A/374/394
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Ionized gas and stellar kinematical parameters have been measured along the major axis of 20 nearby disc galaxies. We discuss the properties of each sample galaxy, distinguishing between those characterized by regular or peculiar kinematics. In early-type disc galaxies, ionized gas tends to rotate faster than stars and to have a lower velocity dispersion (V_g_>V_*_ and {sigma}_g_<{sigma}_*_), whereas in late-type spirals, gas and stars show almost the same rotation velocities and velocity dispersions (V_g_=~V_*_ and {sigma}_g_=~{sigma}_*_). Incorporating the early-type disc galaxies studied by Bertola et al. (1995ApJ...448L..13B), Fisher (1997, Cat. <J/AJ/113/950>) and Corsini et al. (1999, Cat. <J/A+A/342/671>), we have compiled a sample of some 40 galaxies for which the major-axis radial profiles of both the stellar and gaseous components have been measured. The value of {sigma}_*_ measured at R_e_/4 turns out to be strongly correlated with the galaxy morphological type, while {sigma}_g_ is not and sometimes takes values above the range expected from thermal motions or small-scale turbulence.
- ID:
- ivo://CDS.VizieR/J/A+A/440/107
- Title:
- Gas velocity curve along five spiral galaxies
- Short Name:
- J/A+A/440/107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the minor-axis kinematics of ionized gas and stars for a sample of 5 spiral galaxies, which are characterized by either a zero or a shallow gas velocity gradient along their major axis. The asymmetric velocity profiles observed along the minor axis of NGC 4064 and NGC 4189 can be explained as due to the presence of a bar. This is also the case of NGC 4178 where the innermost portion of the gaseous disk is nearly face on. In NGC 4424 and NGC 4941, we measured non-zero gas velocities only in the central regions along the minor axis and gas velocities drop to zero at larger radii. This kinematic feature is suggestive of the presence of an orthogonally-rotating gaseous component which is confined in the innermost regions (i.e. an inner polar disk) to be confirmed with integral-field spectroscopy.
