Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2010-11-17
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
(accepted by AJ)
Scientific paper
We present spectroscopy of 76 emission-line galaxies (ELGs) in CDF-S taken with the LDSS3 spectrograph on Magellan Telescope. These galaxies are selected to have emission lines with ACS grism data in the Hubble Space Telescope Probing Evolution and Reionization Spectroscopically (PEARS) grism Survey. The ACS grism spectra cover the wavelength range 6000-9700 \AA\ and most PEARS grism redshifts are based on a single emission line + photometric redshifts from broad-band colors; the Magellan spectra cover a wavelength range from 4000 {\AA} to 9000 {\AA}, and provide a check on redshifts derived from PEARS data. We find an accuracy of $\sigma_z$ = 0.006 for the ACS grism redshifts with only one catastrophic outlier. We probe for AGN in our sample via several different methods. In total we find 7 AGNs and AGN candidates out of 76 galaxies. Two AGNs are identified from the X-ray full-band luminosity, $L_{X-ray,FB}>10^{43}$ erg$\;$s$^{-1}$, the line widths and the power-law continuum spectra. Two unobscured faint AGN candidates are identified from the X-ray full-band luminosity $L_{X-ray,FB}\sim10^{41}$ erg$\;$s$^{-1}$, the hardness ratio and the column density, and the emission-line and X-ray derived SFRs. Two candidates are classified based on the line ratio of [NII]\lambda6584/H$\alpha$ versus [OIII]$\lambda$5007/H$\beta$ (BPT diagram), which are between the empirical and theoretical demarcation curves, i.e, the transition region from star-forming galaxies to AGNs. One AGN candidate is identified from the high-ionization emission line HeII{\AA}4686.
Floyd David
Grogin Norman
Malhotra Sangeeta
Meurer Gerhardt
Pirzkal Norbert
No associations
LandOfFree
Spectroscopic Study of the HST/ACS PEARS Emission-Line Galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Spectroscopic Study of the HST/ACS PEARS Emission-Line Galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spectroscopic Study of the HST/ACS PEARS Emission-Line Galaxies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-534859