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- ID:
- ivo://CDS.VizieR/J/A+A/385/816
- Title:
- LSB galaxies rotation curves
- Short Name:
- J/A+A/385/816
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- File rawcurve contains the raw rotation curves of the low surface brightness galaxies. These data are not corrected for inclination. File procurve contains the processed rotation curves that can be directly used for mass modelling.
- ID:
- ivo://CDS.VizieR/J/MNRAS/507/300
- Title:
- Massive Compact Galaxies in MaNGA
- Short Name:
- J/MNRAS/507/300
- Date:
- 03 Dec 2021 00:51:01
- Publisher:
- CDS
- Description:
- We characterized the kinematics, morphology, and stellar population (SP) properties of a sample of massive compact quiescent galaxies (MCGs, 10<~logM*/M_{sun}_<~11 and re~1-3kpc) in the MaNGA Survey, with the goal of constraining their formation, assembly history, and assessing their relation with non-compact quiescent galaxies. We compared their properties with those of a control sample of median-sized quiescent galaxies (re~4-8kpc) with similar effective velocity dispersions. MCGs have elevated rotational support, as evidenced by a strong anticorrelation between the Gauss-Hermite moment h3 and V/{sigma}. In contrast, 30 per cent of control sample galaxies (CSGs) are slow rotators, and fast-rotating CSGs generally show a weak h3-V/{sigma} anticorrelation. MCGs and CSGs have similar ages, but MCGs are more metal-rich and {alpha}-enhanced. Both MCGs and CSGs have shallow negative metallicity gradients and flat [{alpha}/Fe] gradients. On average, MCGs and CSGs have flat age gradients, but CSGs have a significantly larger dispersion of gradient values. The kinematics and SP properties of MCGs suggest that they experienced highly dissipative gas-rich events, such as mergers, followed by an intense, short, and centrally concentrated burst of star formation, between 4 and 10Gyr ago (z~0.4-2), and had a quiet accretion history since then. This sequence of events might be analogous to, although less extreme than, the compaction events that formed compact quiescent galaxies at z~2. The small sizes of MCGs, and the high efficiency and short duration of their last star formation episode suggest that they are descendants of compact post-starburst galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/649/A7
- Title:
- MC structure and properties
- Short Name:
- J/A+A/649/A7
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- This work is part of the Gaia Data Processing and Analysis Consortium papers published with the Gaia Early Data Release 3 (EDR3). It is one of the demonstration papers aiming to highlight the improvements and quality of the newly published data by applying them to a scientific case. We use the Gaia EDR3 data to study the structure and kinematics of the Magellanic Clouds. The large distance to the Clouds is a challenge for the Gaia astrometry. The Clouds lie at the very limits of the usability of the Gaia data, which makes the Clouds an excellent case study for evaluating the quality and properties of the Gaia data. The basis of our work are two samples selected to provide a representation as clean as possible of the stars of the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC). The selection used criteria based on position, parallax, and proper motions to remove foreground contamination from the Milky Way, and allowed the separation of the stars of both Clouds. From these two samples we defined a series of subsamples based on cuts in the colour-magnitude diagram; these subsamples were used to select stars in a common evolutionary phase and can also be used as approximate proxies of a selection by age. We compared the Gaia Data Release 2 (DR2) and Gaia EDR3 performances in the study of the Magellanic Clouds and show the clear improvements in precision and accuracy in the new release. We also show that the systematics still present in the data make the determination of the 3D geometry of the LMC a difficult endeavour; this is at the very limit of the usefulness of the Gaia EDR3 astrometry, but it may become feasible with the use of additional external data. We derive radial and tangential velocity maps and global profiles for the LMC for the several subsamples we defined. To our knowledge, this is the first time that the two planar components of the ordered and random motions are derived for multiple stellar evolutionary phases in a galactic disc outside the Milky Way, showing the differences between younger and older phases. We also analyse the spatial structure and motions in the central region, the bar, and the disc, providing new insights into features and kinematics. Finally, we show that the Gaia EDR3 data allows clearly resolving the Magellanic Bridge, and we trace the density and velocity flow of the stars from the SMC towards the LMC not only globally, but also separately for young and evolved populations. This allows us to confirm an evolved population in the Bridge that is slightly shift from the younger population. Additionally, we were able to study the outskirts of both Magellanic Clouds, in which we detected some well-known features and indications of new ones.
- ID:
- ivo://CDS.VizieR/J/ApJ/885/87
- Title:
- Milky Way mass model and rotation curve
- Short Name:
- J/ApJ/885/87
- Date:
- 15 Mar 2022 08:00:47
- Publisher:
- CDS
- Description:
- We discuss a model for the Milky Way obtained by fitting the observed terminal velocities with the radial acceleration relation. The resulting stellar surface density profile departs from a smooth exponential disk, having bumps and wiggles that correspond to massive spiral arms. These features are used to estimate the term for the logarithmic density gradient in the Jeans equation, which turn out to have exactly the right location and amplitude to reconcile the apparent discrepancy between the stellar rotation curve and that of the interstellar gas. This model also predicts a gradually declining rotation curve outside the solar circle with slope -1.7km/s/kpc, as subsequently observed.
- ID:
- ivo://CDS.VizieR/J/A+A/416/507
- Title:
- Minor-axis velocity gradients in disk galaxies
- Short Name:
- J/A+A/416/507
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the ionized-gas kinematics and photometry of a sample of 4 spiral galaxies which are characterized by a zero-velocity plateau along the major axis and a velocity gradient along the minor axis, respectively. By combining these new kinematical data with those available in the literature for the ionized-gas component of the S0s and spirals listed in the Revised Shapley-Ames Catalog of Bright Galaxies we realized that about 50% of unbarred galaxies show a remarkable gas velocity gradient along the optical minor axis. This fraction rises to about 60% if we include unbarred galaxies with an irregular velocity profile along the minor axis. This phenomenon is observed all along the Hubble sequence of disk galaxies, and it is particularly frequent in early-type spirals. Since minor-axis velocity gradients are unexpected if the gas is moving onto circular orbits in a disk coplanar to the stellar one, we conclude that non-circular and off-plane gas motions are not rare in the inner regions of disk galaxies.
- ID:
- ivo://CDS.VizieR/J/MNRAS/466/2006
- Title:
- Phoenix dwarf galaxy RV and [Fe/H] catalog
- Short Name:
- J/MNRAS/466/2006
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Transition type dwarf galaxies are thought to be systems undergoing the process of transformation from a star-forming into a passively evolving dwarf, which makes them particularly suitable to study evolutionary processes driving the existence of different dwarf morphological types. Here we present results from a spectroscopic survey of ~200 individual red giant branch stars in the Phoenix dwarf, the closest transition type with a comparable luminosity to 'classical' dwarf galaxies. We measure a systemic heliocentric velocity Vhelio=-21.2+/-1.0km/s. Our survey reveals the clear presence of prolate rotation that is aligned with the peculiar spatial distribution of the youngest stars in Phoenix. We speculate that both features might have arisen from the same event, possibly an accretion of a smaller system. The evolved stellar population of Phoenix is relatively metal-poor (<[Fe/H]>=-1.49+/-0.04dex) and shows a large metallicity spread (sigma_[Fe/H]_=0.51+/-0.04dex), with a pronounced metallicity gradient of -0.13+/-0.01dex/arcmin similar to luminous, passive dwarf galaxies. We also report a discovery of an extremely metal-poor star candidate in Phoenix and discuss the importance of correcting for spatial sampling when interpreting the chemical properties of galaxies with metallicity gradients. This study presents a major leap forward in our knowledge of the internal kinematics of the Phoenix transition type dwarf galaxy and the first wide area spectroscopic survey of its metallicity properties.
- ID:
- ivo://CDS.VizieR/J/AJ/154/41
- Title:
- Rotational velocities of M33
- Short Name:
- J/AJ/154/41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new deep HI survey of the galaxy Messier 33 is presented, based on observations obtained at the Dominion Radio Astrophysical Observatory. We observe a perturbed outer gas distribution and kinematics in M33, and confirm the disk warping as a significant twist of the major axis of the velocity field, although no strong tilt is measured, in agreement with previous work. Evidence for a new low-brightness HI component with anomalous velocity is reported. It harbors a large velocity scatter, as its kinematics both exceeds and lags the rotation of the disk, and leaks in the forbidden velocity zone of apparent counterrotation. The observations also reveal wide and multiple-peak HI profiles that can be partly explained by crowded orbits in the framework of the warp model. Asymmetric motions are identified in the velocity field as possible signatures of a lopsided potential and the warp. The mass distribution modeling of the hybrid H{alpha}-HI rotation curve favors a cuspy dark matter halo with a concentration in disagreement with the {Lambda}CDM dark halo mass-concentration relationship. The total mass enclosed in 23kpc is 8,10^10^M_{Sun}_, of which 11% are stars and gas. At the virial radius of the cuspy halo, the resulting total mass is 5,10^11^M_{Sun}_, but with a baryonic mass fraction of only 2%. This strongly suggests a more realistic radius encompassing the total mass of M33 that is well smaller than the virial radius of the halo, possibly comparable to the size of the HI disk.
- ID:
- ivo://CDS.VizieR/J/ApJ/785/63
- Title:
- Rotation curve of the Milky Way
- Short Name:
- J/ApJ/785/63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The rotation curve (RC) of our Galaxy, the Milky Way, is constructed starting from its very inner regions (few hundred parsecs) out to a large galactocentric distance of ~200 kpc using kinematical data on a variety of tracer objects moving in the gravitational potential of the Galaxy, without assuming any theoretical models of the visible and dark matter (DM) components of the Galaxy. We study the effect on the RC due to the uncertainties in the values of the Galactic constants (GCs) R_0_ and V_0_ (these being the Sun's distance from and circular rotation speed around the Galactic center, respectively) and the velocity anisotropy parameter {beta} of the halo tracer objects used for deriving the RC at large galactocentric distances. The resulting RC in the disk region is found to depend significantly on the choice of the GCs, while the dominant uncertainty in the RC at large distances beyond the stellar disk comes from the uncertainty in the value of {beta}. In general we find that the mean RC steadily declines at distances beyond ~60 kpc, independently of the value of {beta}. Also, at a given radius, the circular speed is lower for larger values of {beta} (i.e., for more radially biased velocity anisotropy). Considering that the largest possible value of {beta} is unity, which corresponds to stellar orbits being purely radial, our results for the case of {beta}=1 give a lower limit to the total mass of the Galaxy within ~200 kpc, M(200 kpc)>~(6.8+/-4.1)x10^11^ M_{sun}_, independently of any model of the DM halo of the Galaxy.
- ID:
- ivo://CDS.VizieR/J/AJ/114/2402
- Title:
- Rotation curves of early-type galaxies
- Short Name:
- J/AJ/114/2402
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Optical long-slit rotation curves have been studied for 304 northern Sb-Sc galaxies from the Courteau-Faber (CF) sample designed for Tully-Fischer (TF) applications; r-band photometry exists also for each galaxy of the sample. The procedure of rotation curve (RC) extraction and construction of optical profiles are analogous to 21cm integrated linewidths. More than 20% of the galaxies were observed twice or more, allowing for a proper determination of systematic errors. Various measures of maximum rotational velocity to be used as input in the TF relation are tested on the basis of their repeatability, minimization of TF scatter, and match with 21cm linewidths. The best measure of TF velocity, V2.2 is given at the location of peak rotational velocity of a pure exponential disk. An alternative measure to V2.2 which makes no assumption about the luminosity profile or shape of the rotation curve is Vhist, the 20% width of the velocity histogram, though the match with 21cm linewidths is not good. The paper shows that optical TF calibrations yield internal scatter comparable to, if not smaller than, the best calibrations based on single-dish 21cm radio linewidths. Tables 6 and 7 contain the values of the parameters fitting the rotation curves of two samples of galaxies: the CF (Courteau-Faber) sample (table6) and the MAT (Mathewson et al., 1992ApJS...81..413M) sample (table7). Two fitting models were used: the ArcTan function (Model 1) where the velocity varies as v(r) = v(0) + K . arctan(R) (R being (r-r_0_)/r_t_) and a multi-parameter function (Model 2) modelling the rotation curve close to a solid-body close to the rotation center, and close to a flat rotation at large distances (see section 5 of the paper).
