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We investigate the accuracy of the parametric recovery of the line‐of‐sight velocity distribution (LOSVD) of the stars in a galaxy while working in pixel space. Problems appear when the data have a low signal‐to‐noise ratio or the observed LOSVD is not well sampled by the data. We propose a simple solution based on maximum penalized likelihood, and we apply it to the common situation in which the LOSVD is described by a Gauss‐Hermite series. We compare different techniques by extracting the stellar kinematics from observations of the barred lenticular galaxy NGC 3384 obtained with the SAURON integral‐field spectrograph.

The formation and evolution of galaxies is one of the great outstanding problems of astrophysics. Within the broad context of hierachical structure formation, we have only a crude picture of how galaxies like our own came into existence. A detailed physical picture where individual stellar populations can be associated with (tagged to) elements of the protocloud is far beyond our current understanding. Important clues have begun to emerge from both the Galaxy (near-field cosmology) and the high redshift universe (far-field cosmology). Here we focus on the fossil evidence provided by the Galaxy. Detailed studies of the Galaxy lie at the core of understanding the complex processes involved in baryon dissipation. This is a necessary first step toward achieving a successful theory of galaxy formation.

Stellar SiO masers are found in the atmospheres of asymptotic giant branch (AGB) stars with several maser transitions observed around 43 and 86 GHz. At least 28 SiO maser stars have been detected within ∼2 pc projected distance from Sgr A* by the Very Large Array (VLA) and Atacama Millimeter/submillimeter Array (ALMA). A subset of these masers have been studied for several decades and form the basis of the radio reference frame that anchors the reference frame for infrared stars in the Galactic Center (GC). We present new observations of the GC masers from VLA and ALMA. These new data combined with extant maser astrometry provide 3D positions, velocities, and acceleration limits. The proper motions and Doppler velocities are measured with unprecedented precision for these masers. We further demonstrate how these measurements may be used to trace the stellar and dark matter mass distributions within a few pc of Sgr A*.

The Pulkovo Compilation of Radial Velocities (PCRV) has been made to study the stellar kinematics in the local spiral arm. The PCRV contains weighted mean absolute radial velocities for 35 495 Hipparcos stars of various spectral types and luminosity classes over the entire celestial sphere mainly within 500 pc of the Sun. The median accuracy of the radial velocities obtained is 0.7 km s super(-1). Results from 203 publications were used in the catalogue. Four of them were used to improve the radial velocities of standard stars from the IAU list. The radial velocities of 155 standard stars turned out to be constant within 0.3 km s super(-1). These stars were used to analyze 47 768 mean radial velocities for 37 200 stars from 12 major publications (80% of all the data used). Zero-point discrepancies and systematic dependences on radial velocity, B-V color index, right ascension, and declination were found in radial velocity differences of the form \"publication minus IAU list of standards.\" These discrepancies and dependences were approximated and taken into account when calculating the weighted mean radial velocities. 1128 stars whose independent radial-velocity determinations were available at least in three of these publications and agreed within 3 km s super(-1) were chosen as the work list of secondary standards. Radial-velocity differences of the form \"publication minus list of secondary standards\" were used by analogy to correct the zero points and systematic dependences in the radial velocities from 33 more publications ( 13% of the data used). In addition, the radial velocities from 154 minor publications (7% of the data used) pertaining to well-known instruments were used without any corrections.

▪ Abstract  Until the late 1990s the rich Hyades and the sparse UMa clusters were the only coeval, comoving concentrations of stars known within 60 pc of Earth. Both are hundreds of millions of years old. Then beginning in the late 1990s the TW Hydrae Association, the Tucana/Horologium Association, the β Pictoris Moving Group, and the AB Doradus Moving Group were identified within ∼60 pc of Earth, and the η Chamaeleontis cluster was found at 97 pc. These young groups (ages 8–50 Myr), along with other nearby, young stars, will enable imaging and spectroscopic studies of the origin and early evolution of planetary systems.

Abstract In order to understand the interaction between dark matter and baryonic matter in the galaxy evolution history, it is fundamental to constrain dark matter (DM) distribution in galaxies. However, it is difficult to constrain DM profile in the central region of early type galaxy because of the lack of extended neutral hydrogen gas and the degeneracy between dynamical stellar M/L and DM profile. To resolve this difficulty, we conducted combined analysis of ALMA cold molecular gas kinematics and MUSE stellar kinematics of early type fast rotator galaxy NGC1380. In addition, we used HST image to trace the stellar luminosity distribution. With the help of high resolution of ALMA image and large field of view of MUSE, we derived the central BH mass, stellar bulge, disk and DM profile.

We mapped the stellar population and emission gas properties in the nuclear region of NGC 6868 using datacubes extracted with Gemini Multi-Object Spectrograph (GMOS) in the Integral Field Unit (IFU) mode. To obtain the star-formation history of this galaxy we used the starlight code together with the new generation of MILES simple stellar population models. The stellar population dominating (95% in light fraction) the central region of NGC 6868 is old and metal rich (~10 Gyr, 2.2 Z⊙). We also derived the kinematics and emission line fluxes of ionized gas with the IFSCube package. A rotation disk is clearly detected in the nuclear region of the galaxy and no broad components were detected. Also, there is a region where the emission lines disappear almost completely, probably due to diffuse ionized gas component. Channel maps, diagnostic diagrams and stellar kinematics are still under analysis.

We have used near-infrared and optical Integral Field Spectroscopy along with optical images to study the inner 100 pc of NGC 4111 in a project to investigate the stellar and gas kinematics in the surroundings of Supermassive Black Holes in nearby galaxies. We have compared the inner stellar and gas kinematics with data of the outer regions of the galaxy. We found larger scale hot ionized gas and warm molecular gas within the inner 100 pc that is in counter-rotation relative to the stellar kinematics, a sign of inflowing material that is probably triggering an Active Galactic Nucleus. This is supported by the nuclear X-ray emission which is heating the molecular gas and causing it to emit. The presence of large amounts of dust in a polar ring suggests that this is a fairly recent event probably due to the capture of a dwarf galaxy.

Based on the stellar proper motions of the TGAS (Gaia DR1) catalogue, we have analyzed the velocity field of main-sequence stars and red giants from the TGAS catalogue with heliocentric distances up to 1.5 kpc. We have obtained four variants of kinematic parameters corresponding to different methods of calculating the distances from the parallaxes of stars measured with large relative errors. We have established that within the Ogorodnikov–Milne model changing the variant of distances affects significantly only the solar velocity components relative to the chosen centroid of stars, provided that the solution is obtained in narrow ranges of distances (0.1 kpc). The estimates of all the remaining kinematic parameters change little. This allows the Oort coefficients and related Galactic rotation parameters as well as all the remaining Ogorodnikov–Milne model parameters (except for the solar terms) to be reliably estimated irrespective of the parallax measurement accuracy. The main results obtained from main-sequence stars in the range of distances from 0.1 to 1.5 kpc are: A = 16.29 ± 0.06 km s −1 kpc −1 , B = −11.90 ± 0.05 km s −1 kpc −1 , C = −2.99 ± 0.06 km s −1 kpc −1 , K = −4.04 ± 0.16 km s −1 kpc −1 , and the Galactic rotation period P = 217.41 ± 0.60 Myr. The analogous results obtained from red giants in the range from 0.2 to 1.6 kpc are: the Oort constants A = 13.32 ± 0.09 km s −1 kpc −1 , B = −12.71 ± 0.06 km s −1 kpc −1 , C = −2.04 ± 0.08 km s −1 kpc −1 , K = −2.72 ± 0.19 km s −1 kpc −1 , and the Galactic rotation period P = 236.03 ± 0.98 Myr. The Galactic rotation velocity gradient along the radius vector (the slope of the Galactic rotation curve) is −4.32 ± 0.08 km s −1 kpc −1 for main-sequence stars and −0.61 ± 0.11 km s −1 kpc −1 for red giants. This suggests that the Galactic rotation velocity determined from main-sequence stars decreases with increasing distance from the Galactic center faster than it does for red giants.

Abstract We present our ongoing work of using two independent tracers to estimate the supermassive black hole mass in the nearby early-type galaxy NGC 6958; namely integrated stellar and molecular gas kinematics. We used data from the Atacama Large Millimeter/submillimeter Array (ALMA), and the adaptive-optics assisted Multi-Unit Spectroscopic Explorer (MUSE) and constructed state-of-the-art dynamical models. The different methods provide black hole masses of (2.89±2.05)×10 8 M ⊙ from stellar kinematics and (1.35±0.09)×10 8 M ⊙ from molecular gas kinematics which are consistent within their 3σ uncertainties. Compared to recent M BH - σ e scaling relations, we derive a slightly over-massive black hole. Our results also confirm previous findings that gas-based methods tend to provide lower black hole masses than stellar-based methods. More black hole mass measurements and an extensive analysis of the method-dependent systematics are needed in the future to understand this noticeable discrepancy.