- ID:
- ivo://CDS.VizieR/J/ApJS/227/3
- Title:
- Full spectroscopic data release of the SPT-GMOS
- Short Name:
- J/ApJS/227/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of SPT-GMOS, a spectroscopic survey with the Gemini Multi-Object Spectrograph (GMOS) on Gemini South. The targets of SPT-GMOS are galaxy clusters identified in the SPT-SZ survey, a millimeter-wave survey of 2500deg^2^ of the southern sky using the South Pole Telescope (SPT). Multi-object spectroscopic observations of 62 SPT-selected galaxy clusters were performed between 2011 January and 2015 December, yielding spectra with radial velocity measurements for 2595 sources. We identify 2243 of these sources as galaxies, and 352 as stars. Of the galaxies, we identify 1579 as members of SPT-SZ galaxy clusters. The primary goal of these observations was to obtain spectra of cluster member galaxies to estimate cluster redshifts and velocity dispersions. We describe the full spectroscopic data set and resulting data products, including galaxy redshifts, cluster redshifts, and velocity dispersions, and measurements of several well-known spectral indices for each galaxy: the equivalent width, W, of [OII]{lambda}{lambda}3727, 3729 and H-{delta}, and the 4000{AA} break strength, D4000. We use the spectral indices to classify galaxies by spectral type (i.e., passive, post-starburst, star-forming), and we match the spectra against photometric catalogs to characterize spectroscopically observed cluster members as a function of brightness (relative to m*). Finally, we report several new measurements of redshifts for ten bright, strongly lensed background galaxies in the cores of eight galaxy clusters. Combining the SPT-GMOS data set with previous spectroscopic follow-up of SPT-SZ galaxy clusters results in spectroscopic measurements for >100 clusters, or ~20% of the full SPT-SZ sample.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/309/749
- Title:
- Fundamental plane of early type galaxies
- Short Name:
- J/A+A/309/749
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyse the residuals to the fundamental plane (FP) of elliptical galaxies as a function of stellar-population indicators; these are based on the line-strength parameter Mg2 and on UBVRI broad-band colors, and are partly derived from new observations. The effect of the stellar populations accounts for approximately half the observed variation of the mass-to-light ratio responsible for the FP tilt. The residual tilt can be explained by the contribution of two additional effects: the dependence of the rotational support, and possibly that of the spatial structure, on the luminosity. We conclude to a constancy of the dynamical-to-stellar mass ratio. This probably extends to globular clusters as well, but the dominant factor would be here the luminosity dependence of the structure rather than that of the stellar population. This result also implies a constancy of the fraction of dark matter over all the scalelength covered by stellar systems. Our compilation of internal stellar kinematics of galaxies is appended.
- ID:
- ivo://CDS.VizieR/J/ApJ/689/913
- Title:
- Fundamental planes of early-type galaxies
- Short Name:
- J/ApJ/689/913
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derive the fundamental plane (FP) relation for a sample of 1430 early-type galaxies (ETGs) in the optical (r band) and the near-infrared (K band), by combining SDSS-DR5 and UKIDSS (UKIRT Infrared Deep Sky Survey, 2007MNRAS.379.1599L), second release data. With such a large, homogeneous data set, we are able to assess the dependence of the FP on the wave band. Our analysis indicates that the FP of luminous early-type galaxies is essentially wave band-independent, with its coefficients increasing at most by 8% from the optical to the NIR. This finding fits well into a consistent picture in which the tilt of the FP is not driven by stellar populations but results from other effects, such as nonhomology. In this framework, the optical and NIR FPs require more massive galaxies to be slightly more metal-rich than less massive ones, and to have highly synchronized ages, with an age variation per decade in mass smaller than a few percent.
- ID:
- ivo://CDS.VizieR/J/ApJ/859/2
- Title:
- Fundamental stellar & halo data for local galaxies
- Short Name:
- J/ApJ/859/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We build templates of rotation curves as a function of the I-band luminosity via the mass modeling (by the sum of a thin exponential disk and a cored halo profile) of suitably normalized, stacked data from wide samples of local spiral galaxies. We then exploit such templates to determine fundamental stellar and halo properties for a sample of about 550 local disk-dominated galaxies with high-quality measurements of the optical radius R_opt_ and of the corresponding rotation velocity V_opt_. Specifically, we determine the stellar M_*_ and halo M_H_ masses, the halo size R_H_ and velocity scale V_H_, and the specific angular momenta of the stellar j_*_ and dark matter j_H_ components. We derive global scaling relationships involving such stellar and halo properties both for the individual galaxies in our sample and for their mean within bins; the latter are found to be in pleasing agreement with previous determinations by independent methods (e.g., abundance matching techniques, weak-lensing observations, and individual rotation curve modeling). Remarkably, the size of our sample and the robustness of our statistical approach allow us to attain an unprecedented level of precision over an extended range of mass and velocity scales, with 1{sigma} dispersion around the mean relationships of less than 0.1dex. We thus set new standard local relationships that must be reproduced by detailed physical models, which offer a basis for improving the subgrid recipes in numerical simulations, that provide a benchmark to gauge independent observations and check for systematics, and that constitute a basic step toward the future exploitation of the spiral galaxy population as a cosmological probe.
- ID:
- ivo://CDS.VizieR/J/ApJ/863/89
- Title:
- Gaia DR2 PMs of stars in ultra-faint MW satellites
- Short Name:
- J/ApJ/863/89
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The second data release from the Gaia mission (DR2) provides a comprehensive and unprecedented picture of the motions of astronomical sources in the plane of the sky, extending from the solar neighborhood to the outer reaches of the Milky Way. I present proper-motion measurements based on Gaia DR2 for 17 ultra-faint dwarf galaxies within 100kpc of the Milky Way. I compile the spectroscopically confirmed member stars in each dwarf bright enough for Gaia astrometry from the literature, producing member samples ranging from two stars in Triangulum II to 68 stars in Bootes I. From the spectroscopic member catalogs, I estimate the proper motion of each system. I find good agreement with the proper motions derived by the Gaia collaboration for Bootes I and Leo I. The tangential velocities for 14 of the 17 dwarfs are determined to better than 50km/s, more than doubling the sample of such measurements for Milky Way satellite galaxies. The orbital pericenters are well constrained, with a mean value of 38kpc. Only one satellite, Tucana III, is on an orbit passing within 15kpc of the Galactic center, suggesting that the remaining ultra-faint dwarfs are unlikely to have experienced severe tidal stripping. As a group, the ultra-faint dwarfs are on high-velocity, eccentric, retrograde trajectories, with nearly all of them having space motions exceeding 370km/s. A large majority of the objects are currently close to the pericenters of their orbits. In a low-mass (M_vir_=0.9x10^12^M_{sun}_) Milky Way potential, eight out of the 17 galaxies lack well-defined apocenters and appear likely to be on their first infall, indicating that the Milky Way mass may be larger than previously estimated or that many of the ultra-faint dwarfs are associated with the Magellanic Clouds. The median eccentricity of the ultra-faint dwarf orbits is 0.79, similar to the values seen in numerical simulations but distinct from the rounder orbits of the more luminous dwarf spheroidals.
- ID:
- ivo://CDS.VizieR/J/ApJ/899/140
- Title:
- 632 Gaia Ultracompact Dwarf galaxy candidates
- Short Name:
- J/ApJ/899/140
- Date:
- 14 Mar 2022 00:54:57
- Publisher:
- CDS
- Description:
- Tidally stripped galaxy nuclei and luminous globular clusters (GCs) are important tracers of the halos and assembly histories of nearby galaxies, but are difficult to reliably identify with typical ground-based imaging data. In this paper we present a new method to find these massive star clusters using Gaia DR2, focusing on the massive elliptical galaxy Centaurus A (Cen A). We show that stripped nuclei and GCs are partially resolved by Gaia at the distance of Cen A, showing characteristic astrometric and photometric signatures. We use this selection method to produce a list of 632 new candidate luminous clusters in the halo of Cen A out to a projected radius of 150kpc. Adding in broadband photometry and visual examination improves the accuracy of our classification. In a spectroscopic pilot program we have confirmed five new luminous clusters, which includes the 7th and 10th most luminous GC in Cen A. Three of the newly discovered GCs are further away from Cen A than all previously known GCs. Several of these are compelling candidates for stripped nuclei. We show that our novel Gaia selection method retains at least partial utility out to distances of ~25Mpc and hence is a powerful tool for finding and studying star clusters in the sparse outskirts of galaxies in the local universe.
- ID:
- ivo://CDS.VizieR/J/A+AS/141/123
- Title:
- Galaxies behind Southern Milky Way
- Short Name:
- J/A+AS/141/123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A deep optical galaxy search in the southern Milky Way - aimed at reducing the width of the Zone of Avoidance - revealed 3279 galaxy candidates on the IIIaJ film copies of the ESO/SRC survey above the diameter limit of D greater than approximately 0.2 arcmin. Only 112 (3.4%) were previously catalogued. The surveyed region (266<l<296 and -10<b<+8) lies in the extension of the Hydra and Antlia clusters. Optical properties of the unveiled galaxies such as positions, diameters, magnitudes, morphological types are given in Table 1. Cross-identifications with the IRAS PSC (Cat. <II/125>) are given in Table 2.
- ID:
- ivo://CDS.VizieR/J/A+A/380/441
- Title:
- Galaxies behind Southern Milky Way. II.
- Short Name:
- J/A+A/380/441
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this second paper of the catalogue series of galaxies behind the southern Milky Way, we report on the deep optical galaxy search in the Crux region (289{deg}<~l<~318{deg} and -10{deg}<~b<~10{deg}) and the Great Attractor region (316{deg}<~l<~338{deg} and -10{deg}<~b<~10{deg}). The galaxy catalogues are presented, a brief description of the galaxy search given, as well as a discussion on the distribution and characteristics of the uncovered galaxies. A total of 8183 galaxies with major diameters D>~0.2 arcmin were identified in this ~850 square degree area: 3759 galaxies in the Crux region and 4423 galaxies in the Great Attractor region. Of the 8183 galaxies, 229 (2.8%) were catalogued before in the optical (3 in radio) and 251 galaxies have a reliable (159), or likely (92) cross-identification in the IRAS Point Source Catalogue (3.1%). A number of prominent overdensities and filaments of galaxies are identified. They are not correlated with the Galactic foreground extinction and hence indicative of extragalactic large-scale structures. Redshifts obtained at the South African Astronomical Observatory (SAAO) for 518 of the newly catalogued galaxies in the Crux and Great Attractor regions (Fairall et al., 1998, Cat. <J/A+AS/127/463>; Woudt et al., 1999, Cat. <J/A+A/352/39>) confirm distinct voids and clusters in the area here surveyed. With this optical galaxy search, we have reduced the width of the optical `Zone of Avoidance' for galaxies with extinction-corrected diameters larger than 1.3' from extinction levels A_B>~1.0mag to A_B>~3.0mag: the remaining optical Zone of Avoidance is now limited by |b|<~3{deg} (see Fig. 16).
- ID:
- ivo://CDS.VizieR/J/MNRAS/446/3943
- Title:
- galaxies 2D phot. decompositions in SDSS-DR7
- Short Name:
- J/MNRAS/446/3943
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of 2D, point spread function-corrected de Vacouleurs, Sersic, de Vacouleurs+Exponential, and Sersic+Exponential fits of ~7x10^5^ spectroscopically selected galaxies drawn from the Sloan Digital Sky Survey (SDSS) Data Release 7. Fits are performed for the SDSS r band utilizing the fitting routine galfit and analysis pipeline pymorph. We compare these fits to prior catalogues. Fits are analysed using a physically motivated flagging system. The flags suggest that more than 90 percent of two-component fits can be used for analysis. We show that the fits follow the expected behaviour for early and late galaxy types. The catalogues provide a robust set of structural and photometric parameters for future galaxy studies. We show that some biases remain in the measurements, e.g. the presence of bars significantly affect the bulge measurements although the bulge ellipticity may be used to separate barred and non-barred galaxies, and about 15 percent of bulges of two-component fits are also affected by resolution. The catalogues are available in electronic format. We also provide an interface for generating postage stamp images of the 2D model and residual as well as the 1D profile. These images can be generated for a user-uploaded list of galaxies on demand.
- ID:
- ivo://CDS.VizieR/J/other/AstBu/69.247
- Title:
- Galaxies in Lynx-Cancer void
- Short Name:
- J/other/AstBu/69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work we present the results of photometrical study of 85 objects from the updated sample of galaxies residing in the nearby Lynx-Cancer void. The images in filters u,g,r,i from the Sloan Digital Sky Survey database are used for photometry. The following model-independent parameters are obtained: integrated magnitudes and colours, effective radii and the respective surface brightnesses, optical and Holmberg radii. On results of the radial surface brightness profile analysis, their central values and scalelengths of model discs are derived. The colours of the outer parts of void galaxies are examined and compared to those of the model evolutionary tracks of the PEGASE2 package. This allowed to obtain estimates of the time since the epoch of star formation T_SF_. Among the latter group, the low-luminosity objects with M_B_>-13.2 dominate. The derived integrated absolute magnitudes and colours are used for galaxy stellar mass estimates. All available data on integrated galaxy HI fluxes are used to derive their parameter M(HI)/L_B_ and to estimate their gas mass-fraction. The small ~10% subgroup of the most gas-rich galaxies, with M(HI)/L_B_>2.5, shows gas mass-fractions reaching (94-99)%. Many of these objects also show atypically blue colours of their outer parts. To check possible statistical differences of void galaxy properties and galaxy samples formed with more general criteria, we compared the void sample galaxy parameters with those of 195 galaxies from the Equatorial Survey (ES), formed as a part of the blind HI survey HIPASS. In the common luminosity range (-18.5<M_g_<-13.5) the compared samples show similarity. The lowest luminosity void galaxies differ from the main ES sample. However, there are also ~7% faint so called 'inchoate' galaxies among ES sample with the elevated parameter M(HI)/L_B_, majority of which are situated far from massive neighbours and are probably the analogs of void galaxies.