- ID:
- ivo://CDS.VizieR/J/AJ/143/102
- Title:
- SHELS galaxies with 0.02<z<0.1
- Short Name:
- J/AJ/143/102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Smithsonian Hectospec Lensing Survey (SHELS) is a dense redshift survey covering a 4deg^2^ region to a limiting R=20.6. In the construction of the galaxy catalog and in the acquisition of spectroscopic targets, we paid careful attention to the survey completeness for lower surface brightness dwarf galaxies. Thus, although the survey covers a small area, it is a robust basis for computation of the slope of the faint end of the galaxy luminosity function to a limiting M_R_=-13.3+5logh. We calculate the faint-end slope in the R band for the subset of SHELS galaxies with redshifts in the range 0.02<=z<0.1, SHELS_0.1_. This sample contains 532 galaxies with R<20.6 and with a median surface brightness within the half-light radius of SB_50,R_=21.82mag/arcsec^2^. We used this sample to make one of the few direct measurements of the dependence of the faint end of the galaxy luminosity function on surface brightness. For the sample as a whole the faint-end slope, {alpha}=-1.31+/-0.04, is consistent with both the Blanton et al. analysis of the Sloan Digital Sky Survey (2005ApJ...631..208B, 2005AJ....129.2562B) and the Liu et al. analysis of the COSMOS field (2008ApJ...672..198L). This consistency is impressive given the very different approaches of these three surveys. A magnitude-limited sample of 135 galaxies with optical spectroscopic redshifts with mean half-light surface brightness, SB_50,R_>=22.5mag/arcsec^2^ is unique to SHELS_0.1_. The faint-end slope is {alpha}_22.5_=-1.52+/-0.16. SHELS_0.1_ shows that lower surface brightness objects dominate the faint-end slope of the luminosity function in the field, underscoring the importance of surface brightness limits in evaluating measurements of the faint-end slope and its evolution.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/872/91
- Title:
- SHELS galaxy sizes using Subaru/HSC imaging
- Short Name:
- J/ApJ/872/91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We explore the relationships between size, stellar mass, and average stellar population age (indicated by D_n_4000 indices) for a sample of ~11000 intermediate-redshift galaxies from the SHELS spectroscopic survey (Geller+ 2014, J/ApJS/213/35) augmented by high-resolution Subaru Telescope Hyper Suprime-Cam imaging. In the redshift interval 0.1<z<0.6, star-forming galaxies are on average larger than their quiescent counterparts. The mass-complete sample of ~3500M_*_>10^10^M_{sun}_ quiescent galaxies shows that the average size of a 10^11^M_{sun}_ quiescent galaxy increases by <~25% from z~0.6 to z~0.1. This growth rate is a function of stellar mass: the most massive (M_*_>10^10^M_{sun}_) galaxies grow significantly more slowly in size than quiescent systems an order of magnitude less massive that grow by 70% in the 0.1<~z<~0.3 redshift interval. For M_*_<10^11^M_{sun}_ galaxies, age and size are anticorrelated at fixed mass; more massive quiescent systems show no significant trend in size with average stellar population age. The evolution in absolute and fractional abundances of quiescent systems at intermediate redshift are also a function of galaxy stellar mass. The suite of evolutionary trends suggests that galaxies more massive than ~10^11^M_{sun}_ have mostly assembled their mass by z~0.6. Quiescent galaxies with lower stellar masses show more complex evolution that is characterized by a combination of individual quiescent galaxy size growth (through mergers) and an increase in the size of newly quenched galaxies joining the population at later times (progenitor bias). The low-mass population (M_*_~10^10^M_{sun}_) grows predominantly as a result of progenitor bias. For more massive (M_*_~5x10^10^M_{sun}_) quiescent galaxies, (predominantly minor) mergers and progenitor bias make more comparable contributions to the size growth. At intermediate redshift, quiescent size growth is mass-dependent; the most massive (M_*_>10^10^M_{sun}_) galaxies experience the least rapid increase in size from z~0.6 to z~0.1.
- ID:
- ivo://CDS.VizieR/J/ApJS/224/11
- Title:
- SHELS: redshift survey of the F1 DLS field
- Short Name:
- J/ApJS/224/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Smithsonian Hectospec Lensing Survey (SHELS) is a complete redshift survey covering two well-separated fields (F1 and F2) of the Deep Lens Survey (DLS). Both fields are more than 94% complete to a Galactic extinction corrected R_0_=20.2. Here, we describe the redshift survey of the F1 field centered at RA=00:53:25.3 and DEC=12:33:55 (J2000); like F2, the F1 field covers ~4deg^2^. The redshift survey of the F1 field includes 9426 new galaxy redshifts measured with Hectospec on the MMT (published here). As a guide to future uses of the combined survey, we compare the mass metallicity relation and the distributions of D_n_4000 as a function of stellar mass and redshift for the two fields. The mass-metallicity relations differ by an insignificant 1.6{sigma}. For galaxies in the stellar mass range 10^10^-10^11^M_{sun}_, the increase in the star-forming fraction with redshift is remarkably similar in the two fields. The seemingly surprising 31%-38% difference in the overall galaxy counts in F1 and F2 is probably consistent with the expected cosmic variance given the subtleties of the relative systematics in the two surveys. We also review the DLS cluster detections in the two fields: poorer photometric data for F1 precluded secure detection of the single massive cluster at z=0.35 that we find in SHELS. Taken together, the two fields include 16055 redshifts for galaxies with R_0_<=20.2 and 20754 redshifts for galaxies with R<=20.6. These dense surveys in two well-separated fields provide a basis for future investigations of galaxy properties and large-scale structure.
- ID:
- ivo://CDS.VizieR/J/A+AS/115/407
- Title:
- Short WSRT HI observations of spiral galaxies
- Short Name:
- J/A+AS/115/407
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained short HI observations of 60 late type spiral galaxies with the Westerbork Synthesis Radio Telescope (WSRT). Several HI properties are presented, including the radial surface density distribution of HI and a position-velocity map. When possible these are compared to those measured from single-dish observations. We confirm earlier results that there is no serious systematic difference between the WSRT and single-dish observations in total flux and linewidths.
- ID:
- ivo://CDS.VizieR/J/ApJ/830/14
- Title:
- SIGMA: Keck spectra of z~2 gal. in CANDELS fields
- Short Name:
- J/ApJ/830/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a survey of the internal kinematics of 49 star-forming galaxies at z~2 in the CANDELS fields with the Keck/MOSFIRE spectrograph, Survey in the near-Infrared of Galaxies with Multiple position Angles (SIGMA). Kinematics (rotation velocity V_rot_ and gas velocity dispersion {sigma}_g_) are measured from nebular emission lines which trace the hot ionized gas surrounding star-forming regions. We find that by z~2, massive star-forming galaxies (logM_*_/M_{sun}_>~10.2) have assembled primitive disks: their kinematics are dominated by rotation, they are consistent with a marginally stable disk model, and they form a Tully-Fisher relation. These massive galaxies have values of V_rot_/{sigma}_g_ that are factors of 2-5 lower than local well-ordered galaxies at similar masses. Such results are consistent with findings by other studies. We find that low-mass galaxies (logM_*_/M_{sun}_<~10.2) at this epoch are still in the early stages of disk assembly: their kinematics are often dominated by gas velocity dispersion and they fall from the Tully-Fisher relation to significantly low values of V_rot_. This "kinematic downsizing" implies that the process(es) responsible for disrupting disks at z~2 have a stronger effect and/or are more active in low-mass systems. In conclusion, we find that the period of rapid stellar mass growth at z~2 is coincident with the nascent assembly of low-mass disks and the assembly and settling of high-mass disks.
3236. SIGRID galaxy sample
- ID:
- ivo://CDS.VizieR/J/AJ/142/83
- Title:
- SIGRID galaxy sample
- Short Name:
- J/AJ/142/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using an optically unbiased selection process based on the HIPASS neutral hydrogen survey, we have selected a sample of 83 spatially isolated, gas-rich dwarf galaxies in the southern hemisphere with cz between 350 and 1650km/s, and with R-band luminosities and HI masses less than that of the Small Magellanic Cloud. The sample is an important population of dwarf galaxies in the local universe, all with ongoing star formation, and most of which have no existing spectroscopic data. We are measuring the chemical abundances of these galaxies, using the integral-field spectrograph on the Australian National University 2.3m telescope, the Wide-Field Spectrograph. This paper describes our survey criteria and procedures, lists the survey sample, and reports on initial observations.
- ID:
- ivo://CDS.VizieR/J/MNRAS/440/843
- Title:
- SIM2D parameters of SDSS-DR7 galaxies
- Short Name:
- J/MNRAS/440/843
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using data from the Sloan Digital Sky Survey (SDSS)-DR7, including structural measurements from 2D surface brightness fits with gim2d, we show how the fraction of quiescent galaxies depends on galaxy stellar mass M*, effective radius Re, fraction of r-band light in the bulge, B/T, and their status as a central or satellite galaxy at 0.01<z<0.2. For central galaxies we confirm that the quiescent fraction depends not only on stellar mass, but also on Re. The dependence is particularly strong as a function of M*/Re^{alpha}^, with {alpha}~1.5. This appears to be driven by a simple dependence on B/T over the mass range 9<log(M*/M_{sun}_)<11.5, and is qualitatively similar even if galaxies with B/T>0.3 are excluded. For satellite galaxies, the quiescent fraction is always larger than that of central galaxies, for any combination of M*, Re and B/T. The quenching efficiency is not constant, but reaches a maximum of ~0.7 for galaxies with 9<log(M*/M_{sun}_)<9.5 and Re<1kpc. This is the same region of parameter space in which the satellite fraction itself reaches its maximum value, suggesting that the transformation from an active central galaxy to a quiescent satellite is associated with a reduction in Re due to an increase in dominance of a bulge component.
- ID:
- ivo://CDS.VizieR/VI/76
- Title:
- Simulation Atlas of Tidal Features in Galaxies
- Short Name:
- VI/76
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The simulation survey of tidally perturbed galaxies provides images of 84 different encounters that vary orbit tilt of companion orbit, perigalacticon distance ratio of primary galaxy mass to companion mass, and the amount of inert matter in the primary galaxy. In total 1764 galaxy images are available in the survey. This data set contains 84 separate simulations, each simulation is run for 1000 time steps, producing image output of the star particles and gas particles separately every 50 time steps. The first 21 images represent the "gas", and the second 21 images represent the "stars". Time steps for matching "gas" and "stars" are the same. There are [256,256] grid points on a Cartesian coordinate system. The renormalized densities are stored as 8-bit floating point numbers. The data have been put into FITS. Each header specifies the parameters for that simulation.
- ID:
- ivo://CDS.VizieR/J/AJ/147/93
- Title:
- Simulation of massive early type galaxies
- Short Name:
- J/AJ/147/93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The next generation of giant-segmented mirror telescopes (>20m) will enable us to observe galactic nuclei at much higher angular resolution and sensitivity than ever before. These capabilities will introduce a revolutionary shift in our understanding of the origin and evolution of supermassive black holes by enabling more precise black hole mass measurements in a mass range that is unreachable today. We present simulations and predictions of the observations of nuclei that will be made with the Thirty Meter Telescope (TMT) and the adaptive optics assisted integral-field spectrograph IRIS, which is capable of diffraction-limited spectroscopy from Z band (0.9{mu}m) to K band (2.2{mu}m). These simulations, for the first time, use realistic values for the sky, telescope, adaptive optics system, and instrument to determine the expected signal-to-noise ratio of a range of possible targets spanning intermediate mass black holes of ~10^4^M_{sun}_ to the most massive black holes known today of >10^10^M_{sun}_. We find that IRIS will be able to observe Milky Way mass black holes out the distance of the Virgo Cluster, and will allow us to observe many more of the brightest cluster galaxies where the most massive black holes are thought to reside. We also evaluate how well the kinematic moments of the velocity distributions can be constrained at the different spectral resolutions and plate scales designed for IRIS. We find that a spectral resolution of ~8000 will be necessary to measure the masses of intermediate mass black holes. By simulating the observations of galaxies found in Sloan Digital Sky Survey DR7, we find that over 10^5^ massive black holes will be observable at distances between 0.005<z<0.18 with the estimated sensitivity and angular resolution provided by access to Z-band (0.9{mu}m) spectroscopy from IRIS and the TMT adaptive optics system. These observations will provide the most accurate dynamical measurements of black hole masses to enable the study of the demography of massive black holes, address the origin of the M_BH_-{sigma} and M_BH_-L relationships, and evolution of black holes through cosmic time.
- ID:
- ivo://CDS.VizieR/J/A+A/622/A128
- Title:
- SINFONI datacube of NGC 1365
- Short Name:
- J/A+A/622/A128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the framework of understanding the gas and stellar kinematics and their relations to AGNs and galaxy evolution scenarios, we present spatially resolved distributions and kinematics of the stars and gas in the central ~800-pc radius of the nearby Seyfert galaxy NGC 1365. We obtained H + K- and K-band near-infrared (NIR) integral-field observations from VLT/SINFONI. Our results reveal strong broad and narrow emission-line components of ionized gas (hydrogen recombination lines Pa{alpha} and Br{gamma}) in the nuclear region, as well as hot dust with a temperature of ~1300K, both typical for type-1 AGNs. From M_BH_-{sigma}* and the broad components of hydrogen recombination lines, we find a black-hole mass of (5-10)x10^6^M_{sun}_. In the central ~800pc, we find a hot molecular gas mass of ~615M , which corresponds to a cold molecular gas reservoir of (2-8)x10^8^M_{sun}_. However, there is a molecular gas deficiency in the nuclear region. The gas and stellar-velocity maps both show rotation patterns consistent with the large-scale rotation of the galaxy. However, the gaseous and stellar kinematics show deviations from pure disk rotation, which suggest streaming motions in the central <200pc and a velocity twist at the location of the ring which indicates deviations in disk and ring rotation velocities in accordance with published CO kinematics. We detect a blueshifted emission line split in Pa{alpha}, associated with the nuclear region only. We investigate the star-formation properties of the hot spots in the circumnuclear ring which have starburst ages of 10Myr and find indications for an age gradient on the western side of the ring. In addition, our high-resolution data reveal further substructure within this ring which also shows enhanced star forming activity close to the nucleus.
