- ID:
- ivo://CDS.VizieR/J/A+AS/129/87
- Title:
- ROSAT RASS II observations of IRAS galaxies
- Short Name:
- J/A+AS/129/87
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 120000 X-ray sources detected in the RASS II processing of the ROSAT All-Sky Survey are correlated with the 14315 IRAS galaxies selected from the IRAS Point Source Catalogue: 372 IRAS galaxies show X-ray emission within a distance of 100 arcsec from the infrared position. By inspecting the structure of the X-ray emission in overlays on optical images we quantify the likelihood that the X-rays originate from the IRAS galaxy. For 197 objects the soft X-ray emission is very likely associated with the IRAS galaxy. Their soft X-ray properties are determined and compared with their far-infrared emission.
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- ID:
- ivo://CDS.VizieR/J/ApJ/897/122
- Title:
- Rotational velocities for PHANGS sample of galaxies
- Short Name:
- J/ApJ/897/122
- Date:
- 11 Mar 2022
- Publisher:
- CDS
- Description:
- We present kinematic orientations and high-resolution (150pc) rotation curves for 67 main-sequence star-forming galaxies surveyed in CO (2-1) emission by PHANGS-ALMA. Our measurements are based on the application of a new fitting method tailored to CO velocity fields. Our approach identifies an optimal global orientation as a way to reduce the impact of nonaxisymmetric (bar and spiral) features and the uneven spatial sampling characteristic of CO emission in the inner regions of nearby galaxies. The method performs especially well when applied to the large number of independent lines of sight contained in the PHANGS CO velocity fields mapped at 1" resolution. The high-resolution rotation curves fitted to these data are sensitive probes of mass distribution in the inner regions of these galaxies. We use the inner slope as well as the amplitude of our fitted rotation curves to demonstrate that CO is a reliable global dynamical mass tracer. From the consistency between photometric orientations from the literature and kinematic orientations determined with our method, we infer that the shapes of stellar disks in the mass range of log(M*(M{odot}))=9.0-10.9 probed by our sample are very close to circular and have uniform thickness.
- 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/PAZh/27/250
- Title:
- Rotation curves for 135 edge-on galaxies
- Short Name:
- J/PAZh/27/250
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The table contains parameters for 135 edge-on galaxies. The observations were carried out with the 6-m Special Astrophysical Observatory telescope.
- 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).
- ID:
- ivo://CDS.VizieR/J/AJ/111/696
- Title:
- Rotation curves of Seyfert galaxies with companions
- Short Name:
- J/AJ/111/696
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents imaging and optical spectroscopy of paired Seyfert galaxies and their companions. The aim is to seek common properties of Seyfert galaxies in interacting systems, which might provide evidence of AGN triggering in a way independent of the usual two-sample statistics which have proven ambiguous on this issue. Three kinds of comparison have been made -- the kinds of interactions involving Seyfert galaxies, the relative luminosities of the Seyferts and their companions, and the level of kinematic disturbance as measured from rotation curves. (1) Dynamics and tidal features have been used to determine (or at least limit) the sense of orbital motion (direct/ retrograde/polar with respect to the Seyfert galaxy's disk) for many of these pairs. There is no obviously preferred kind of interaction -- direct, polar, and retrograde encounters are all well represented, despite the gross differences in dynamical response of a disk to these various kinds of encounter. To the extent that triggering of Seyfert nuclei occurs due to tidal encounters, the existence of a perturbation seems more important than its exact duration or detailed effects on the disk. However, the ratio of merging to paired Seyferts is higher than for disk galaxies in general, consistent with more effective triggering of AGN in this specific phase; the implied time scale for enhanced occurrence during mergers is the same as the timescape for merger remnants to appear as such, a few disk-edge crossing times (typically several times 10^8yr). (2) Seyfert nuclei occur preferentially in the brighter members of galaxy pairs, by a median of 0.93mag after making the maximal correction for contaminating nonstellar light in the nuclei. Only about 1/3 of this effect can be accounted for by the known tendency of Seyfert nuclei to occur in more luminous galaxies. Enhancement of AGN by interactions is evidently more effective for more luminous galaxies (though this will also be the case if both star formation and AGN occurrence are enhanced in the same galaxies). (3) The rotation curves of the paired Seyferts show systematically small regions of rising or solid-body rotation compared to the disk radius, as a group comparable to Sa but very different from Sb or Sc galaxies (even for Seyfert galaxies with Hubble type later than Sa). There is weak evidence that this difference is also present with respect to more isolated Seyfert galaxies. Despite the obvious utility of a dynamically disturbed disk for transport of angular momentum and "feeding the monster," Seyfert galaxies in pairs actually have smaller kinematic disturbances (measured by the maximum departure from a symmetric rotation curve, normalized to the full rotation amplitude) than found in a complete sample of non-Seyfert spirals in pairs.
- ID:
- ivo://CDS.VizieR/J/ApJS/145/213
- Title:
- Rotation measures of compact sources in CGPS
- Short Name:
- J/ApJS/145/213
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Canadian Galactic Plane Survey is providing new rotation measures (RMs) for compact extragalactic sources in the Galactic plane at a solid-angle density of roughly 1 source per square degree. To date, we have derived reliable RM values for 380 sources along lines of sight through the disk of the Galaxy in the first and second quadrants. The purpose is to provide a data set useful for studies of the magneto-ionic component of the Galactic interstellar medium (ISM). We present the method used to obtain the measurements and the resulting RMs.
- ID:
- ivo://CDS.VizieR/J/MNRAS/442/3329
- Title:
- Rotation measures of 2642 quasars
- Short Name:
- J/MNRAS/442/3329
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained the rotation measures (RMs) of 2642 quasars by using cross-identification of the most updated quasar catalogue and the RM catalogue. After discounting the foreground Galactic Faraday rotation of the Milky Way, we obtain the residual rotation measure (RRM) of these quasars. We have carefully discarded the effects from measurement and systematical uncertainties of RRMs as well as large RRMs from RM outliers, and we have obtained marginal evidence for the redshift evolution of the real dispersion of RRMs which steadily increases to 10rad/m^2^ about z~1 and is saturated at higher redshifts. Ionized clouds in the form of galaxy halos, galaxy clusters or cosmological filaments with different RM dispersion widths could produce the observed RRM evolutions. However, current data sets cannot constrain the contributions from galaxy halos and cosmic webs. Future measurements of RMs for a large sample of quasars with high precision are necessary to disentangle these different contributions.
- ID:
- ivo://CDS.VizieR/J/ApJ/898/102
- Title:
- Rotation velocity & dynamical mass of gal. from HI sp.
- Short Name:
- J/ApJ/898/102
- Date:
- 21 Mar 2022 08:49:45
- Publisher:
- CDS
- Description:
- The integrated 21cm HI emission profile of a galaxy encodes valuable information on the kinematics, spatial distribution, and dynamical state of its cold interstellar medium. The line width, in particular, reflects the rotation velocity of the galaxy, which, in combination with a size scale, can be used to constrain the dynamical mass of the system. We introduce a new method based on the concept of the curve of growth to derive a set of robust parameters to characterize the line width, asymmetry, and concentration of the integrated HI spectra. We use mock spectra to evaluate the performance of our method, to estimate realistic systematic uncertainties for the proposed parameters, and to correct the line widths for the effects of instrumental resolution and turbulence broadening. Using a large sample of nearby galaxies with available spatially resolved kinematics, we demonstrate that the newly defined line widths can predict the rotational velocities of galaxies to within an accuracy of <~30km/s. We use the calibrated line widths, in conjunction with the empirical relation between the size and mass of HI disks, to formulate a prescription for estimating the dynamical mass within the HI-emitting region of gas-rich galaxies. Our formalism yields dynamical masses accurate to ~0.3dex based solely on quantities that can be derived efficiently and robustly from current and future extragalactic HI surveys. We further extend the dynamical mass calibration to the scale of the dark matter halo.
