- ID:
- ivo://CDS.VizieR/J/A+A/379/798
- Title:
- ELAIS H{alpha} emitting galaxies
- Short Name:
- J/A+A/379/798
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out a survey searching for H{alpha} emitting galaxies at z~0.24 using a narrow band filter tuned with the redshifted line. The total sky area covered was 0.19 square degrees within the redshift range 0.228 to 0.255 in a set of four fields in the ELAIS-N1 zone. This corresponds to a volume of 9.8x10^3^Mpc^3^ and a look-back time of 3.6Gyr when H=50km/s/Mpc and q=0.5 are assumed. A total of 52 objects are selected as candidates for a broad band limiting magnitude of I~22.9, plus 16 detected only in the narrow band image for a narrow band limiting magnitude for object detection of 21.0. The threshold detection corresponds to about 20{AA} equivalent width with an uncertainty of ~+/-10{AA}. Point-like objects (15) were excluded from our analysis using CLASS_STAR parameter from SExtractor. The contamination from other emission lines such as [O II]{lambda}3727, H{beta} and [OIII]{lambda}{lambda}4959,5007 at redshifts 1.2, 0.66 and 0.61 respectively is estimated, and found to be negligible at the flux limits of our sample. We find an extinction-corrected H{alpha} luminosity density of (5.4+/-1.1)x10^39^erg/s/Mpc^3^. Our survey for H{alpha} emitting galaxies was carried out using the focal reducer CAFOS at the 2.2 m telescope in CAHA (Centro Astronomico Hispano-Aleman, Almeria, Spain). This instrument is equipped with a 2048x2048 Site#1d CCD with 24{mu}m pixels (0.53" on the sky), which covers a circular area of 16'diameter.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/135/1580
- Title:
- Element abundances in ten red giants of Car dSph
- Short Name:
- J/AJ/135/1580
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained high-resolution spectroscopy of ten red giants in the Carina dwarf spheroidal (dSph) galaxy with the ultraviolet and visual echelle spectrograph at the European Southern Observatory Very Large Telescope in order to study the detailed chemical evolution of this Galactic satellite. Here we present the abundances of O, Na, Mg, Si, Ca, Ti, and Fe.
- ID:
- ivo://CDS.VizieR/J/A+A/465/185
- Title:
- Element abundances of 7 stars of NGC 6253
- Short Name:
- J/A+A/465/185
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out a big FLAMES survey of 10 Galactic open clusters aiming at different goals. One of them is the determination of chemical abundances, in order to put constraints on the radial metallicity gradient in the disk and its evolution. One of the sample clusters is the very metal rich NGC 6253. We have obtained UVES high resolution spectra of seven candidate clusters members (from the turn off up to the red clump) with the goal of determining the chemical composition of NGC 6253 and to investigate its origin and role in the interpretation of the radial metallicity gradient in the disk.
- ID:
- ivo://CDS.VizieR/J/MNRAS/365/454
- Title:
- Emission line analysis of HII galaxies
- Short Name:
- J/MNRAS/365/454
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a statistical study of a very large sample of HII galaxies taken from the literature. We focus on the differences in several properties between galaxies that show the auroral line [OIII]{lambda}4363 and those that do not present this feature in their spectra.
- ID:
- ivo://CDS.VizieR/J/ApJS/192/5
- Title:
- Emission-line galaxies from HETDEX pilot survey
- Short Name:
- J/ApJS/192/5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of emission-line galaxies selected solely by their emission-line fluxes using a wide-field integral field spectrograph. This work is partially motivated as a pilot survey for the upcoming Hobby-Eberly Telescope Dark Energy Experiment. We describe the observations, reductions, detections, redshift classifications, line fluxes, and counterpart information for 397 emission-line galaxies detected over 169arcmin^2^ with a 3500-5800{AA} bandpass under 5{AA} full-width-half-maximum (FWHM) spectral resolution. The survey's best sensitivity for unresolved objects under photometric conditions is between 4 and 20x10^-17^erg/s/cm^2^ depending on the wavelength, and Ly{alpha} luminosities between 3x10^42^ and 6x10^42^erg/s are detectable. This survey method complements narrowband and color-selection techniques in the search of high-redshift galaxies with its different selection properties and large volume probed. The four survey fields within the COSMOS, GOODS-N, MUNICS, and XMM-LSS areas are rich with existing, complementary data. We find 105 galaxies via their high-redshift Ly{alpha} emission at 1.9<z<3.8, and the majority of the remainder objects are low-redshift [OII]3727 emitters at z<0.56. The classification between low- and high-redshift objects depends on rest-frame equivalent width (EW), as well as other indicators, where available. Based on matches to X-ray catalogs, the active galactic nuclei fraction among the Ly{alpha} emitters is 6%. We also analyze the survey's completeness and contamination properties through simulations. We find five high-z, highly significant, resolved objects with FWHM sizes >44arcmin^2^ which appear to be extended Ly{alpha} nebulae. We also find three high-z objects with rest-frame Ly{alpha} EW above the level believed to be achievable with normal star formation, EW0>240{AA}.
- ID:
- ivo://CDS.VizieR/J/AJ/138/1022
- Title:
- Emission-line galaxies from HST PEARS survey
- Short Name:
- J/AJ/138/1022
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of a search for emission-line galaxies (ELGs) in the southern fields of the Hubble Space Telescope Probing Evolution And Reionization Spectroscopically (PEARS) grism survey. The PEARS South Fields consist of five Advanced Camera for Surveys pointings (including the Hubble Ultra Deep Field) with the G800L grism for a total of 120 orbits, revealing thousands of faint object spectra in the GOODS-South region of the sky. ELGs are one subset of objects that are prevalent among the grism spectra. Using a two-dimensional detection and extraction procedure, we find 320 emission lines originating from 226 galaxy "knots" within 192 individual galaxies. Line identification results in 118 new grism-spectroscopic redshifts for galaxies in the GOODS-South Field. We measure emission-line fluxes using standard Gaussian fitting techniques. The star formation rates of the ELGs are presented, as well as a sample of distinct giant star-forming regions at z~0.1-0.5 across individual galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/772/48
- Title:
- Emission-line galaxies from PEARS. II.
- Short Name:
- J/ApJ/772/48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a full analysis of the Probing Evolution And Reionization Spectroscopically (PEARS) slitess grism spectroscopic data obtained with the Advanced Camera for Surveys on board Hubble Space Telescope. PEARS covers fields within both the Great Observatories Origins Deep Survey (GOODS) North and South fields, making it ideal as a random survey of galaxies, as well as the availability of a wide variety of ancillary observations complemented by the spectroscopic results. Using the PEARS data, we are able to identify star-forming galaxies (SFGs) within the redshift volume 0<z<1.5. Star-forming regions in the PEARS survey are pinpointed independently of the host galaxy. This method allows us to detect the presence of multiple emission-line regions (ELRs) within a single galaxy. We identified a total of 1162 H{alpha}, [OIII], and/or [OII] emission lines in the PEARS sample of 906 galaxies to a limiting flux of ~10^-18^erg/s/cm2. The ELRs have also been compared to the properties of the host galaxy, including morphology, luminosity, and mass. From this analysis, we find three key results: (1) the computed line luminosities show evidence of a flattening in the luminosity function with increasing redshift; (2) the star-forming systems show evidence of complex morphologies with star formation occurring predominantly within one effective (half-light) radius. However, the morphologies show no correlation with host stellar mass. (3) Also, the number density of SFGs with M_*_>=10^9^M_{sun}_ decreases by an order of magnitude at z<=0.5 relative to the number at 0.5<z<0.9, supporting the argument of galaxy downsizing.
- ID:
- ivo://CDS.VizieR/J/ApJ/888/79
- Title:
- Emission-line galaxies from the FIGS survey
- Short Name:
- J/ApJ/888/79
- Date:
- 25 Oct 2021 10:14:43
- Publisher:
- CDS
- Description:
- We present a catalog of 208 0.3<z<2.1 emission-line galaxies (ELGs) selected from 1D slitless spectroscopy obtained using Hubble's WFC3 G102 grism, as part of the Faint Infrared Grism Survey. We identify ELG candidates by searching for significant peaks in all continuum-subtracted G102 spectra and, where possible, confirm candidates by identifying consistent emission lines in other available spectra or with published spectroscopic redshifts. We provide derived emission-line fluxes and errors, redshifts, and equivalent widths for H{alpha}{lambda}6563, [OIII]{lambda}{lambda}4959,5007, and [OII]{lambda}3727 emission lines, for ELGs down to AB(F105W)>28 and >10^-17^erg/cm^2^/s line flux. We use the resulting line catalog to investigate a possible relationship between line emission and a galaxy's environment. We use seventh-nearest-neighbor distances to investigate the typical surroundings of ELGs compared to non-ELGs, and we find that [OIII] emitters are preferentially found at intermediate galaxy densities near galaxy groups. We characterize these ELGs in terms of the galaxy specific star formation rate (SFR) versus stellar mass and find no significant influence of environment on that relation. We calculate SFRs and find no dependence of SFR on local galaxy surface density for 0.3<z<0.8 H{alpha} emitters and for 0.8<z<1.3 [OIII] emitters. We find similar rates of close-pair interaction between ELGs and non-ELGs. For galaxy surface densities {Sigma}<=30Mpc^-2^, we find no consistent effect of environment on star formation.
- ID:
- ivo://CDS.VizieR/J/AJ/143/145
- Title:
- Emission-line objects from ALFALFA H{alpha} survey
- Short Name:
- J/AJ/143/145
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- During a wide-field narrowband H{alpha} imaging survey, we noted the presence of numerous isolated emission-line point sources in the data. These objects could represent ultra-low-luminosity galaxies at low-redshift (detection via H{alpha}), isolated extragalactic HII regions associated with the galaxy targeted by the original observation, or background galaxies or QSOs where strong emission lines (most often [OIII]{lambda}5007) redshift into our narrowband filter. We have carried out a systematic search for these "H{alpha} dots" in over 200 15x15arcmin fields. To date we have cataloged 61 candidate emission-line sources in roughly 11.7deg^2^. The sample has a median R magnitude of 19.5, and detects objects as faint as R=22.6. Follow-up spectroscopy reveals that ~85% of the candidates are bona fide emission-line objects, with roughly 60% of the real sources being lower-redshift objects (detection via H{alpha}) and 40% being higher-redshift objects detected via [OIII] emission or some other emission line. Here we present the results of our initial survey and follow-up spectroscopy. We use our sample to study the properties (including star-formation rates and metal abundances) of low-luminosity star-forming galaxies in the nearby universe and of low-metallicity star-forming galaxies at z~0.33.
- ID:
- ivo://CDS.VizieR/J/MNRAS/448/2900
- Title:
- Emission lines for SDSS Coronal-Line Forest AGNs
- Short Name:
- J/MNRAS/448/2900
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We introduce Coronal-Line Forest active galactic nuclei (CLiF AGN), AGN which have a rich spectrum of forbidden high-ionization lines (FHILs, e.g. [FeVII], [FeX] and [NeV]), as well as relatively strong narrow (~300 km/s) H{alpha} emission when compared to the other Balmer transition lines. We find that the kinematics of the CLiF emitting region are similar to those of the forbidden low-ionization emission-line (FLIL) region. We compare emission line strengths of both FHILs and FLILs to cloudy photoionization results and find that the CLiF emitting region has higher densities (10^4.5^<n_H_<10^7.5^/cm^3^) when compared to the FLIL emitting region (10^3.0^<n_H_<10^4.5^/cm^3^). We use the photoionization results to calculate the CLiF regions radial distances (0.04<R_CLiF_<32.5 pc) and find that they are comparable to the dust grain sublimation distances (0.10<R_SUB_<4.3 pc). As a result, we suggest that the inner torus wall is the most likely location of the CLiF region, and the unusual strength of the FHILs is due to a specific viewing angle giving a maximal view of the far wall of the torus without the continuum being revealed.
