- ID:
- ivo://CDS.VizieR/J/A+A/578/A105
- Title:
- EELGs out to z~1 in zCOSMOS
- Short Name:
- J/A+A/578/A105
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present line measurements and physical properties of a sample of 165 extreme emission-line galaxies (EELGs) in the zCOSMOS 20k-Bright Survey (Lilly et al., 2009, Cat. J/ApJS/184/218). The zCOSMOS spectra consist of ~1h integrations in the medium resolution LRRED grism setting (R~600 with 2.5{AA}/pixel), covering a wavelength range 5550<{lambda}<9650{AA}. Measured emission-line fluxes are given in units of 10^-17^erg/s/cm^2^. Flux errors have been derived following Perez-Montero et al. (2013A&A...549A..25P) and Amorin et al. (2012ApJ...749..185A and 2012ApJ...754L..22A). No extinction correction has been applied to these fluxes. For each galaxy the reddening constant, c(H{beta}), is presented. These values and their corresponding uncertainties have been derived from the H{alpha}/H{beta} or H{gamma}/H{beta} ratios, whenever possible. A reddening constant derived from the SED best-fitting was adopted for (a) those galaxies where the computation of c(H{beta}) from emission lines is not possible because of the lack of lines, or (b) the corresponding line ratio produces a negative extinction correction (i.e., Ha/Hb<2.82 or Hg/Hb<0.47, assuming Case B recombination with T_e_=2*10^4K, n_e_=100cm^-3^). Stellar mass and 1{sigma} uncertainties have been obtained from SED fitting (Bolzonella et al., 2010A&A...524A..76B) after removal of the flux contribution from strong emission lines.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/599/A83
- Title:
- ELG and AGN in WINGS clusters
- Short Name:
- J/A+A/599/A83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the analysis of the emission line galaxies members of 46 low-redshift (0.04<z<0.07) clusters observed by WINGS (WIde-field Nearby Galaxy cluster Survey; Fasano et al., 2006A&A...445..805F). Emission line galaxies were identified following criteria that are meant to minimize biases against non-star-forming galaxies and classified employing diagnostic diagrams. We examined the emission line properties and frequencies of star-forming galaxies, transition objects, and active galactic nuclei (AGNs: LINERs and Seyferts), unclassified galaxies with emission lines, and quiescent galaxies with no detectable line emission. A deficit of emission line galaxies in the cluster environment is indicated by both a lower frequency, and a systematically lower Balmer emission line equivalent width and luminosity with respect to control samples; this implies a lower amount of ionized gas per unit mass and a lower star formation rate if the source is classified as Hii region. A sizable population of transition objects and of low-luminosity LINERs (~10-20% of all emission line galaxies) are detected among WINGS cluster galaxies. These sources are a factor of 1.5 more frequent, or at least as frequent, as in control samples with respect to Hii sources. Transition objects and LINERs in clusters are most affected in terms of line equivalent width by the environment and appear predominantly consistent with so-called retired galaxies. Shock heating can be a possible gas excitation mechanism that is able to account for observed line ratios. Specific to the cluster environment, we suggest interaction between atomic and molecular gas and the intracluster medium as a possible physical cause of line-emitting shocks.
- ID:
- ivo://CDS.VizieR/J/A+AS/116/43
- Title:
- Emission-line galaxies nearby voids.
- Short Name:
- J/A+AS/116/43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the observational results of our search for emission-line galaxies (ELG) towards nearby voids. In order to find ELG, we started a survey using the IIIa-J objective prism plates from the Hamburg QSO Survey. The plates are digitized and an automatic procedure was applied to select the candidates. Digitized direct plates were used to determine coordinates and to reject overlaps between spectra. The accuracy of the coordinates is +/-2". A total area of 1248deg^2^ was scanned, distributed in four different regions. All the selected objects were observed with follow-up spectroscopy. We have obtained a final sample of 203 objects, of which 196 are emission-line galaxies, four are galaxies with absorption lines and three are QSOs. Almost half of our objects are newly discovered ones and three quarters of the given redshifts are new. Our sample contains mainly high ionization galaxies and is less sensitive in the detection of low-ionization objects. The apparent magnitudes, as derived from the objective prism plates, range between 15.0<=B<=19.5. The sample is dominated by nearby galaxies, with a peak in the redshift distribution at cz=4500 km/s.
- ID:
- ivo://CDS.VizieR/J/ApJ/812/89
- Title:
- Environmental COntext (ECO) catalog
- Short Name:
- J/ApJ/812/89
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the relationships between galaxy environments and galaxy properties related to disk (re)growth, considering two highly complete samples that are approximately baryonic mass limited into the high-mass dwarf galaxy regime, the Environmental COntext (ECO) catalog (data release herein) and the B-semester region of the REsolved Spectroscopy Of a Local VolumE (RESOLVE) survey. We quantify galaxy environments using both group identification and smoothed galaxy density field methods. We use by-eye and quantitative morphological classifications plus atomic gas content measurements and estimates. We find that blue early-type (E/S0) galaxies, gas-dominated galaxies, and UV-bright disk host galaxies all become distinctly more common below group halo mass ~10^11.5^M_{sun}_, implying that this low group halo mass regime may be a preferred regime for significant disk growth activity. We also find that blue early-type and blue late-type galaxies inhabit environments of similar group halo mass at fixed baryonic mass, consistent with a scenario in which blue early-types can regrow late-type disks. In fact, we find that the only significant difference in the typical group halo mass inhabited by different galaxy classes is for satellite galaxies with different colors, where at fixed baryonic mass red early- and late-types have higher typical group halo masses than blue early- and late-types. More generally, we argue that the traditional morphology-environment relation (i.e., that denser environments tend to have more early-types) can be largely attributed to the morphology-galaxy mass relation for centrals and the color-environment relation for satellites.
- ID:
- ivo://CDS.VizieR/J/AJ/114/850
- Title:
- Errors in the FK5 Catalog
- Short Name:
- J/AJ/114/850
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents new positions for 689 FK5 stars determined directly in the extragalactic reference system from CCD scan observations made with the Flagstaff Astrometric Scanning Transit Telescope (FASTT). All the observations were made in 1994-1996 with an accuracy of ~+/-40mas in each coordinate. When these positions are compared with their counterparts in the FK5 catalog, systematic errors in the FK5 are found that vary in both right ascension and declination and can be as large as 100 mas in magnitude. No magnitude-dependent errors in the FK5 were found. Moreover, the true error in FK5 star positions is determined to be ~+/-80mas in both coordinates or two times the expected catalog positional errors. There is an excellent agreement between the systematic errors in the FK5 found in this paper and those presented in Lindegren et al. (1995A&A...304...44L) comparing FK5 and Hipparcos 30-month star positions. By comparing corresponding FASTT and FK5 star positions, the link between the optical and extragalactic reference frames was determined and is given by the following rotations ({omega}_x_,{omega}_y_,{omega}_z_) = (3+/-5, 25+/-5, 16+/-4) (s.e.) mas, which agree well with previous determinations made by other investigators. Two of the rotations ({omega}_y_,{omega}_z_) are significantly larger than their standard errors and, therefore, presumably real. Finally, since these rotations are small (<=25mas), the FK5 and extragalactic reference frames must be closely aligned to one another.
- ID:
- ivo://CDS.VizieR/J/A+A/444/365
- Title:
- ESO Distant Cluster Survey, EDisCS
- Short Name:
- J/A+A/444/365
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the ESO Distant Cluster Survey (EDisCS) a survey of 20 distant galaxy clusters with redshifts ranging from 0.4 to 0.8. Candidate clusters were chosen from among the brightest objects identified in the Las Campanas Distant Cluster Survey (LCDCS), half with estimated redshift z_est_~0.5 and half with z_est_~0.8. They were confirmed by identifying red sequences in moderately deep two colour data from VLT/FORS2. For confirmed candidates we have assembled deep three-band optical photometry using VLT/FORS2, deep near-infrared photometry in one or two bands using NTT/SOFI, deep optical spectroscopy using VLT/FORS2, wide field imaging in two or three bands using the ESO Wide Field Imager, and HST/ACS mosaic images for 10 of the most distant clusters. This first paper presents our sample and the VLT photometry we have obtained. We present images, colour magnitude diagrams and richness estimates for our clusters, as well as giving redshifts and positions for the brightest cluster members. Subsequent papers will present our infrared photometry, spectroscopy, HST and wide-field imaging, as well as a wealth of further analysis and science results. Our reduced data become publicly available as these papers are accepted.
227. ESO Slice Project
- ID:
- ivo://CDS.VizieR/J/A+AS/130/323
- Title:
- ESO Slice Project
- Short Name:
- J/A+AS/130/323
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ESO Slice Project (ESP) is a galaxy redshift survey in a region near the South Galactic Pole (see Vettolani et al., 1997A&A...325..954V; Zucca et al., 1997A&A...326..477Z). It extends over a strip 22(RA)x1(DEC) square degrees, plus a nearby area of 5x1 square degrees, 5 degrees west of the main strip. The right ascension limits are 22h30m and 01h20m, at a mean declination of -40{deg}15' (B1950). We have covered this region with a regular grid of adjacent circular fields, with a diameter of 32arcmin each, corresponding to the field of view of the multifiber spectrograph OPTOPUS at the 3.6m ESO telescope. The total solid angle of the spectroscopic survey is 23.2 square degrees. The galaxy catalogue has been extracted from the Edinburgh-Durham Southern Galaxy catalogue (Heydon-Dumbleton et al., 1989MNRAS.238..379H) which has been obtained from COSMOS (MacGillivray & Stobie, 1984VA.....27..433M) scans of SERC J survey plates. The number of objects in the photometric ESP sample is 4487. The spectroscopic survey is about 85% complete to the limiting magnitude bJ=19.4, and consists of 3342 galaxies + 1 QSO with redshift determination. The ESP survey is intermediate between shallow, wide angle samples and very deep, one--dimensional pencil beams. Table 2 lists the fields observed with OPTOPUS and their properties: the numbers listed in this table can be used to compute the redshift completeness of each fields, following eq.(2) of the paper. Table 3 provides the catalogue, with galaxies sorted in right ascension. The catalogue with additional information and updates can also be found at the following URL: http://boas5.bo.astro.it/~cappi/esokp.html
- ID:
- ivo://CDS.VizieR/VII/34C
- Title:
- ESO/Uppsala Survey of the ESO(B) Atlas
- Short Name:
- VII/34C
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The survey is a joint project undertaken by the European Southern Observatory (ESO) and the Uppsala Observatory to provide a systematic and homogeneous search of the ESO(B) Atlas (also known as the Quick Blue Survey). The ESO(B) Atlas, taken with the ESO 1-m Schmidt telescope at La Silla, Chile, covers 606 fields from -90 to -20 degrees of declination. The fields are similar in size and scale to those of the Palomar Observatory Sky Survey. Unsensitized IIa-O plates and a 2-mm GG385 filter were used to give a passband similar to the Johnson B color. The actual search was conducted at the Uppsala Observatory and resulted in a list of nonstellar objects including all NGC and IC galaxies between -20 and -30 degrees declination, all galaxies down to a limiting diameter of 1.0 arcmin, all disturbed galaxies as faint as possible, all star clusters in the Catalog of Star Clusters and Associations (Alter et al. 1970) and smaller and fainter clusters if recognizable and all planetary nebulae listed in the available catalogs. The catalog includes coordinates, identifications, diameters, position angles, morphological types, classifications, magnitudes, colors, and radial velocities.
- ID:
- ivo://CDS.VizieR/J/A+A/644/A67
- Title:
- EUV estimates from CaII H&K activity
- Short Name:
- J/A+A/644/A67
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Atmospheric escape is an important factor shaping the exoplanet population and hence drives our understanding of planet formation. Atmospheric escape from giant planets is driven primarily by the stellar X-ray and extreme- ultraviolet (EUV) radiation. Furthermore, EUV and longer wavelength UV radiation power disequilibrium chemistry in the middle and upper atmosphere. Our understanding of atmospheric escape and chemistry, therefore, depends on our knowledge of the stellar UV fluxes. While the far-ultraviolet fluxes can be observed for some stars, most of the EUV range is unobservable due to the lack of a space telescope with EUV capabilities and, for the more distant stars, to interstellar medium absorption. Thus, it becomes essential to have indirect means for inferring EUV fluxes from features observable at other wavelengths. We present here analytic functions for predicting the EUV emission of F, G, K, and M-type stars from the log R'HK activity parameter that is commonly obtained from ground-based optical observations of the Ca II H&K lines. The scaling relations are based on a collection of about 100 nearby stars with published log R'HK and EUV flux values, where the latter are either direct measurements or inferences from high-quality far-ultraviolet (FUV) spectra. The scaling relations presented here return EUV flux values with an accuracy of about three, which is slightly lower than that of other similar methods based on FUV or X-ray measurements.
- ID:
- ivo://CDS.VizieR/J/A+A/585/A5
- Title:
- Exoplanet hosts/field stars age consistency
- Short Name:
- J/A+A/585/A5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Transiting planets around stars are discovered mostly through photometric surveys. Unlike radial velocity surveys, photometric surveys do not tend to target slow rotators, inactive or metal-rich stars. Nevertheless, we suspect that observational biases could also impact transiting-planet hosts. This paper aims to evaluate how selection effects reflect on the evolutionary stage of both a limited sample of transiting-planet host stars (TPH) and a wider sample of planet-hosting stars detected through radial velocity analysis. Then, thanks to uniform derivation of stellar ages, a homogeneous comparison between exoplanet hosts and field star age distributions is developed. Stellar parameters have been computed through our custom-developed isochrone placement algorithm, according to Padova evolutionary models. The notable aspects of our algorithm include the treatment of element diffusion, activity checks in terms of logR'_HK_ and vsini, and the evaluation of the stellar evolutionary speed in the Hertzsprung-Russel diagram in order to better constrain age. Working with TPH, the observational stellar mean density {rho}_*_ allows us to compute stellar luminosity even if the distance is not available, by combining {rho}_* with the spectroscopic logg. The median value of the TPH ages is ~5Gyr. Even if this sample is not very large, however the result is very similar to what we found for the sample of spectroscopic hosts, whose modal and median values are [3, 3.5)Gyr and ~4.8Gyr, respectively. Thus, these stellar samples suffer almost the same selection effects. An analysis of MS stars of the solar neighbourhood belonging to the same spectral types bring to an age distribution similar to the previous ones and centered around solar age value. Therefore, the age of our Sun is consistent with the age distribution of solar neighbourhood stars with spectral types from late F to early K, regardless of whether they harbour planets or not. We considered the possibility that our selected samples are older than the average disc population.
