- ID:
- ivo://CDS.VizieR/J/A+AS/130/341
- Title:
- Groups of Galaxies in PPS
- Short Name:
- J/A+AS/130/341
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a large catalog of galaxy loose groups in the Southern Galactic Hemisphere, selected from the Perseus-Pisces redshift Survey (PPS). Particular care is taken in order to obtain group samples as homogeneous as possible to previously published catalogs. Groups are identified with the adaptive Friends-of-Friends (FoF) algorithm of Huchra & Geller (1982ApJ...257..423H), with suitable normalizations V_0_=350km/s and D_0_=0.231h.Mpc. As a necessary ingredient of FoF algorithms, we obtain the galaxy luminosity function (LF) for PPS. Its Schechter parameters ({alpha}=-1.15+/-0.15, M_*_=-19.3+/-0.1) are in good agreement with similar LF estimates from samples previously used to select groups. The LF normalizations {phi}_*_=0.02h^3^/Mpc^3^ appropriate for PPS yields a density threshold {delta}n/n~180 for the adopted D_0_, apparently rather different from the desired {delta}n/n~80 used in previous studies. We then consider several other link normalizations, and briefly discuss their effect on group properties. We suggest to replace the customarily adopted {delta}n/n parametrization with the more direct D_0_ parametrization. All our catalogs contain N_G_~200 groups, significantly more than in most previous studies where group samples were obtained from galaxy data sets of comparable quality to (but smaller extent than) PPS. The group properties are rather sensitive to the adopted D_0_ and V_0_, but vary little with different redshift corrections, redshift cut-off, and galaxy LF. Loose groups in PPS nicely trace the large scale structure (LSS) in the parent galaxy sample. Physical properties of groups in PPS and in other directly comparable samples are in good agreement. There seems to be a complex interplay among LSS features, FoF grouping procedure, and group properties.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/465/3461
- Title:
- Halpha maps of 3 LIRGS
- Short Name:
- J/MNRAS/465/3461
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have observed three luminous infrared galaxy systems (LIRGS) which are pairs of interacting galaxies, with the Galaxy H{alpha} Fabry-Perot system (GH{alpha}FaS) mounted on the 4.2m William Herschel Telescope at the Roque de los Muchachos Observatory, and combined the observations with the Atacama Large Millimeter Array (ALMA) observations of these systems in CO emission to compare the physical properties of the star formation regions and the molecular gas clouds, and specifically the internal kinematics of the star forming regions. We identified 88 star forming regions in the H$\alpha$ emission data-cubes, and 27 molecular cloud complexes in the CO emission data-cubes. The surface densities of the star formation rate and the molecular gas are significantly higher in these systems than in non-interacting galaxies and the Galaxy, and are closer to the surface densities of the star formation rate and the molecular gas of extreme star forming galaxies at higher redshifts. The large values of the velocity dispersion also show the enhanced gas surface density. The HII regions are situated on the {Sigma}_SFR_-{sigma}_v_ envelope, and so are also in virial equilibrium. Since the virial parameter decreases with the surface densities of both the star formation rate and the molecular gas, we claim that the clouds presented here are gravitationally dominated rather than being in equilibrium with the external pressure.
- ID:
- ivo://CDS.VizieR/J/ApJ/819/143
- Title:
- HCO+ and N2D+ dense cores in Perseus
- Short Name:
- J/ApJ/819/143
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of an HCO^+^ (3-2) and N_2_D^+^ (3-2) molecular line survey performed toward 91 dense cores in the Perseus molecular cloud using the James Clerk Maxwell Telescope, to identify the fraction of starless and protostellar cores with systematic radial motions. We quantify the HCO^+^ asymmetry using a dimensionless asymmetry parameter {delta}_v_, and identify 20 cores with significant blue or red line asymmetries in optically thick emission indicative of collapsing or expanding motions, respectively. We separately fit the HCO^+^ profiles with an analytic collapse model and determine contraction (expansion) speeds toward 22 cores. Comparing the {delta}_v_ and collapse model results, we find that {delta}_v_ is a good tracer of core contraction if the optically thin emission is aligned with the model-derived systemic velocity. The contraction speeds range from subsonic (0.03km/s) to supersonic (0.40km/s), where the supersonic contraction speeds may trace global rather than local core contraction. Most cores have contraction speeds significantly less than their free-fall speeds. Only 7 of 28 starless cores have spectra well-fit by the collapse model, which more than doubles (15 of 28) for protostellar cores. Starless cores with masses greater than the Jeans mass (M/M_J_>1) are somewhat more likely to show contraction motions. We find no trend of optically thin non-thermal line width with M/M_J_, suggesting that any undetected contraction motions are small and subsonic. Most starless cores in Perseus are either not in a state of collapse or expansion, or are in a very early stage of collapse.
- ID:
- ivo://CDS.VizieR/J/ApJS/234/21
- Title:
- hCOSMOS: Hectospec survey of galaxies in COSMOS
- Short Name:
- J/ApJS/234/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the hCOSMOS redshift survey of the COSMOS field conducted with the Hectospec spectrograph on the MMT. In the central 1deg^2^, the hCOS20.6 subset of the survey is >90% complete to a limiting magnitude r=20.6. The hCOSMOS survey includes 1701 new redshifts in the COSMOS field. We also use the total of 4362 new and remeasured objects to derive the age-sensitive D_n_4000 index over the entire redshift interval 0.001<~z<~0.6. For 85% of the quiescent galaxies in hCOS20.6, we measure the central line-of-sight velocity dispersion. To explore potential uses of this survey, we combine previously measured galaxy sizes, profiles, and stellar masses with the spectroscopy. The comparison reveals the known relations among structural, kinematic, and stellar population properties. We also compare redshift and D_n_4000 distributions of hCOS20.6 galaxies with SHELS; a complete spectroscopic survey of 4deg^2^ observed to the same depth. The redshift distributions in the two fields are very different, but the D_n_4000 distribution is remarkably similar. The relation between velocity dispersion and stellar mass for massive hCOS20.6 galaxies is consistent with the local relation from the Sloan Digital Sky Survey. Using measured velocity dispersions, we test a photometric proxy calibrated to galaxies in the local universe. The systematic differences between the measured and photometric proxy velocity dispersions are correlated with galaxy dynamical and stellar population properties highlighting the importance of direct spectroscopic measurements.
- ID:
- ivo://CDS.VizieR/J/ApJ/862/172
- Title:
- HeCS-red: Hectospec surveys of redMaPPer clusters
- Short Name:
- J/ApJ/862/172
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use dense redshift surveys to explore the properties of galaxy clusters selected from the redMaPPer catalog. Our new survey, Hectospec Cluster Survey of red-sequence-selected clusters (HeCS-red), includes 10589 new or remeasured redshifts from MMT/Hectospec observations of 27 redMaPPer clusters at redshifts z=0.08-0.25 with large estimated richnesses (richness estimate {lambda}>64). Our spectra confirm that each candidate cluster corresponds to a large overdensity in redshift space. The redMaPPer photometric redshifts have a slight bias toward higher redshifts. We measure the relation between velocity dispersion {sigma}p and {lambda}. The relation shows intrinsic scatter of 24% (and a range of 2x) in velocity dispersion at fixed richness. We extend our analysis to HeCS-red-ext, a sample that includes several clusters selected by X-ray flux or Sunyaev-Zeldovich signal. The heterogeneous sample of 121 clusters in HeCS-red-ext shows similar intrinsic scatter in the {sigma}p-{lambda} relation as the HeCS-red sample, but the range of {sigma}p at fixed richness increases to 3x. We evaluate the membership probability estimates Pmem for individual galaxies provided by redMaPPer. The spectroscopic membership fraction is larger than Pmem for 0.05<=P_mem_<=0.7; conversely, the spectroscopic membership fraction is smaller than P_mem_ at P_mem_>=0.8. We compare spectroscopic richness estimates with redMaPPer richness estimates and find good agreement on average, but a range of a factor of two in spectroscopic richness at fixed redMaPPer richness. Overall, within the high-richness and low-redshift cut of our sample, spectroscopically estimated parameters such as velocity dispersion correlate well with photometric richness estimates, although the relations contain substantial scatter.
- ID:
- ivo://CDS.VizieR/J/ApJS/218/10
- Title:
- HET Massive Galaxy Survey (HETMGS)
- Short Name:
- J/ApJS/218/10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted an optical long-slit spectroscopic survey of 1022 galaxies using the 10m Hobby-Eberly Telescope (HET) at McDonald Observatory. The main goal of the HET Massive Galaxy Survey (HETMGS) is to find nearby galaxies that are suitable for black hole mass measurements. In order to measure accurately the black hole mass, one should kinematically resolve the region where the black hole dominates the gravitational potential. For most galaxies, this region is much less than an arcsecond. Thus, black hole masses are best measured in nearby galaxies with telescopes that obtain high spatial resolution. The HETMGS focuses on those galaxies predicted to have the largest sphere-of-influence, based on published stellar velocity dispersions or the galaxy fundamental plane. To ensure coverage over galaxy types, the survey targets those galaxies across a face-on projection of the fundamental plane. We present the sample selection and resulting data products from the long-slit observations, including central stellar kinematics and emission line ratios. The full data set, including spectra and resolved kinematics, is available online. Additionally, we show that the current crop of black hole masses are highly biased toward dense galaxies and that especially large disks and low dispersion galaxies are under-represented. This survey provides the necessary groundwork for future systematic black hole mass measurement campaigns.
- ID:
- ivo://CDS.VizieR/J/ApJ/871/17
- Title:
- HI and CO observations of M33 interstellar medium
- Short Name:
- J/ApJ/871/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We utilize the multi-wavelength data of M33 to study the origin of turbulence in its interstellar medium. We find that the HI turbulent energy surface density inside 8kpc is ~1-3x10^46^erg/pc^2^, and has no strong dependence on galactocentric radius because of the lack of variation in HI surface density and HI velocity dispersion. Then, we consider the energies injected by supernovae (SNe), the magneto-rotational instability (MRI), and the gravity-driven turbulence from accreted materials as the sources of turbulent energy. For a constant dissipation time of turbulence, the SNe energy can maintain turbulence inside ~4kpc radius (equivalent to ~0.5R_25_), while the MRI energy is always smaller than the turbulent energy within 8kpc radius. However, when we let the dissipation time to be equal to the crossing time of turbulence across the HI scale height, the SNe energy is enough to maintain turbulence out to 7kpc radius, and the sum of SNe and MRI energies is able to maintain turbulence out to 8kpc radius. Due to lack of constraint in the mass accretion rate through the disk of M33, we cannot rule out the accretion driven turbulence as a possible source of energy. Furthermore, by resolving individual giant molecular clouds in M33, we also show that the SNe energy can maintain turbulence within individual molecular clouds with ~1% of coupling efficiency. This result strengthens the proposition that stellar feedback is an important source of energy to maintain turbulence in nearby galaxies.
- ID:
- ivo://CDS.VizieR/VII/213
- Title:
- Hickson's Compact groups of Galaxies
- Short Name:
- VII/213
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog of groups (file "groups.dat") is a list of 100 compact groups of galaxies identified by a systematic search of the Palomar Observatory Sky Survey red prints. Each group contains four or more galaxies, has an estimated mean surface brightness brighter than 26.0 magnitude per arcsec^2^ and satisfies an isolation criterion. Dynamical parameters were derived for 92 of the 100 groups, which are listed in file "dynamics.dat"; the Hubble constant was assumed to be Ho=100km/s/Mpc. Data about individual galaxies in these groups are merged into the "galaxies.dat" file; these data include photometric parameters, morphology, redshifts and absolute magnitudes originally published in four different papers. They result from CCD observations at CFHT (Canada-France-Hawaii Telescope) in 1983-1985. Redshifts were observed at the 1.5m telescope of the F.L. Whipple Observatory on Mt. Hopkins, Arizona, over the period 1984-1986, in wavelength range 470-710nm; the remaining fainter galaxies were observed with the CFHT.
- ID:
- ivo://CDS.VizieR/J/ApJ/772/45
- Title:
- Hi-GAL obs.: star formation in the third quadrant
- Short Name:
- J/ApJ/772/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first Herschel PACS and SPIRE photometric observations in a portion of the outer Galaxy (216.5{deg}<~l<~225.5{deg} and -2{deg}<~b<~0{deg}) as a part of the Hi-GAL survey. The maps between 70 and 500{mu}m, the derived column density and temperature maps, and the compact source catalog are presented. NANTEN CO(1-0) line observations are used to derive cloud kinematics and distances so that we can estimate distance-dependent physical parameters of the compact sources (cores and clumps) having a reliable spectral energy distribution that we separate into 255 proto-stellar and 688 starless sources. Both typologies are found in association with all the distance components observed in the field, up to ~5.8kpc, testifying to the presence of star formation beyond the Perseus arm at these longitudes. Selecting the starless gravitationally bound sources, we identify 590 pre-stellar candidates. Several sources of both proto- and pre-stellar nature are found to exceed the minimum requirement for being compatible with massive star formation based on the mass-radius relation. For the pre-stellar sources belonging to the Local arm (d<~1.5kpc) we study the mass function whose high-mass end shows a power law N(logM){propto}M^-1.0+/-0.2^. Finally, we use a luminosity versus mass diagram to infer the evolutionary status of the sources, finding that most of the proto-stellar sources are in the early accretion phase (with some cases compatible with a Class I stage), while for pre-stellar sources, in general, accretion has not yet started.
- ID:
- ivo://CDS.VizieR/J/ApJ/817/2
- Title:
- High angular resolution spectroscopy of NGC 1277
- Short Name:
- J/ApJ/817/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The nearby lenticular galaxy NGC 1277 is thought to host one of the largest black holes known, however the black hole mass measurement is based on low spatial resolution spectroscopy. In this paper, we present Gemini Near-infrared Integral Field Spectrometer observations assisted by adaptive optics. We map out the galaxy's stellar kinematics within ~440pc of the nucleus with an angular resolution that allows us to probe well within the region where the potential from the black hole dominates. We find that the stellar velocity dispersion rises dramatically, reaching ~550km/s at the center. Through orbit-based, stellar-dynamical models we obtain a black hole mass of (4.9+/-1.6)x10^9^M_{sun}_ (1{sigma} uncertainties). Although the black hole mass measurement is smaller by a factor of ~3 compared to previous claims based on large-scale kinematics, NGC 1277 does indeed contain one of the most massive black holes detected to date, and the black hole mass is an order of magnitude larger than expectations from the empirical relation between black hole mass and galaxy luminosity. Given the galaxy's similarities to the higher redshift (z~2) massive quiescent galaxies, NGC 1277 could be a relic, passively evolving since that period. A population of local analogs to the higher redshift quiescent galaxies that also contain over-massive black holes may suggest that black hole growth precedes that of the host galaxy.
