- 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.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/366/480
- Title:
- Emission-line properties of Seyfert 2 nuclei
- Short Name:
- J/MNRAS/366/480
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the third paper of a series devoted to the study of the global properties of Joguet's sample (2001A&A...380...19J) of 79 nearby galaxies observable from the southern hemisphere, of which 65 are Seyfert 2 galaxies. We use the population synthesis models of Paper II (Cid Fernandes et al., 2004MNRAS.355..273C) to derive 'pure' emission-line spectra for the Seyfert 2 galaxies in the sample, and thus explore the statistical properties of the nuclear nebular components and their relation to the stellar populations.
- ID:
- ivo://CDS.VizieR/J/ApJ/865/56
- Title:
- Emission line & R-band continuum LCs of 17 QSOs
- Short Name:
- J/ApJ/865/56
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present reverberation mapping (RM) results for 17 high-redshift, high-luminosity quasars with good-quality R-band and emission-line light curves. We are able to measure statistically significant lags for Ly{alpha} (11 objects), Si IV (5 objects), C IV (11 objects), and C III] (2 objects). Using our results and previous lag determinations taken from the literature, we present an updated C IV radius-luminosity relation and provide for the first time radius-luminosity relations for Ly{alpha}, Si IV, and C III]. While in all cases the slopes of the correlations are statistically significant, the zero points are poorly constrained because of the lack of data at the low- luminosity end. We find that the emissivity-weighted distances from the central source of the Ly{alpha}, Si IV, and C III] line-emitting regions are all similar, which corresponds to about half that of the H{beta} region. We also find that 3/17 of our sources show an unexpected behavior in some emission lines, two in the Ly{alpha} light curve and one in the Si IV light curve, in that they do not seem to follow the variability of the UV continuum. Finally, we compute RM black hole (BH) masses for those quasars with highly significant lag measurements and compare them with C IV single-epoch (SE) mass determinations. We find that the RM-based BH mass determinations seem smaller than those found using SE calibrations.
- 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.
- ID:
- ivo://CDS.VizieR/J/A+AS/112/35
- Title:
- Emission lines from giant HII regions
- Short Name:
- J/A+AS/112/35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have computed theoretical models of the emission line spectra of giant extragalactic HII regions (GEHR) in which a single star cluster is assumed to be responsible for the ionization. In this paper we present the synthetic emission line spectra of the ionized regions.
- ID:
- ivo://CDS.VizieR/J/A+A/560/A69
- Title:
- Emission lines in a flare of AB Dor A
- Short Name:
- J/A+A/560/A69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a identification catalog of chromospheric emission lines in the optical range for two flares on AB Dor A, with event 1 being larger than event 3. An additional flare event 2 is not described here because of its overlap with event 1. All lines are identified in an flare- only spectrum, i.e. with a quiescent spectrum subtracted. The data were obtained with ESO's Kueyen telescope equipped with the UVES spectrograph on November 25/26 in 2009. The instrument was operated in dichroic mode (spectral coverage from 3720 to 4945 and from 5695 to 9465 AA). We tabulate measured wavelength, line flux and FWHM for every line and also provide the rest wavelength from the Moore catalog which was used for identification (Moore, 1972, Nat. Stand. Ref. Data. Ser., 40). Few lines were identified with the NIST database.
- ID:
- ivo://CDS.VizieR/J/other/JAD/14.3
- Title:
- Emission lines in 32 Cygni
- Short Name:
- J/other/JAD/14.3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- I identify the profusion of emission lines seen in IUE spectra of 32 Cyg (K4-5 Ib+B6-7 IV-V) during total eclipse. With the exception of a very few weak lines, all of these are also seen in zeta Aur during its eclipse, and the stronger features appear in 31 Cyg. Seventy-four percent of these emission lines can be attributed to FeII. Few are intrisically weaker than gf~0.01. Other spectra definitely present are CII, NI, OI, SiII, MgII, SII, CrII, NiII, AlII, AlIII, FIII, SiIV, and CIV. No emission lines of the neutral metals, except for fluorescent FeI UV44, are unambiguously detected; specifically, lines of CI, SiI, or SI were not detected in the spectrum.
- ID:
- ivo://CDS.VizieR/J/A+A/507/881
- Title:
- Emission lines in EX Lup optical spectrum
- Short Name:
- J/A+A/507/881
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A high-resolution optical spectrum of EX Lupi was obtained on 2007 July 30 with FEROS at the 2.2m MPG/ESO telescope in ESO La Silla, Chile. The spectrum shows several emission lines in addition to the photospheric absorption features characteristic of the young late-type star. Here we present all emission lines identified in the spectrum, the observed wavelengths and equivalent widths in Angstrom and the full widths at half maximum in km/s, determined by Gaussian fitting. The most prominent emission lines are the Balmer lines of the hydrogen, the H and K lines and the infrared triplet of the ionized calcium, and the helium lines at 5875 and 6678 Angstrom, and in addition more than 200 weak, narrow metallic lines could be identified using Moore's (1945, Contrib. Princeton Univ. Obs., No. 20) multiplet tables.
- ID:
- ivo://CDS.VizieR/J/A+A/418/1073
- Title:
- Emission lines in optical spectrum of 3 Cen A
- Short Name:
- J/A+A/418/1073
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Weak emission lines in the optical spectrum of the helium-weak chemically peculiar star 3 Cen A are tabulated. The observed wavelengths, line identification information and equivalent widths are presented based on data obtained with the ESO 1.5m telescope and FEROS instrument (16-17 May 2000) and the VLT with UVES spectrograph (24 June 2001). Table 2 is a listing of all recorded emission lines arranged by wavelength and including unidentified features. Table 3 arranges the identified lines according to their ion and multiplet.
- ID:
- ivo://CDS.VizieR/J/ApJ/599/886
- Title:
- Emission lines of radio-loud AGN
- Short Name:
- J/ApJ/599/886
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the completion of a survey of radio-loud active galactic nuclei (AGNs) begun in an earlier paper (Eracleous & Halpern, 1994ApJS...90....1E) with the main goal of finding and studying broad, double-peaked Balmer lines. We present H{alpha} spectra of 13 more broad-lined objects, including three with double-peaked H{alpha} profiles. The final sample includes 106 radio-loud AGNs. In our final census 20% of objects have H{alpha} lines with double peaks or twin shoulders (the "double-peaked emitters"), and of these 60% (the disklike emitters) can be fitted quite well with a model attributing the emission to a circular, relativistic, Keplerian disk. In four objects where broad H{beta} and Mg II lines have been observed, we compare the profiles with models of photoionized accretion disks and find them to be in reasonable agreement.
