190 likes | 288 Views
Near Infrared Spectroscopy of X-Ray Selected AGNs. Régis Cartier U. Advisor: Malcolm G. Smith. March 2008 La Serena - Chile. Introduction. It has been evident that optical surveys miss a significant fraction of AGNs.
E N D
Near Infrared Spectroscopy of X-Ray Selected AGNs Régis Cartier U. Advisor: Malcolm G. Smith March 2008 La Serena - Chile
Introduction • It has been evident that optical surveys miss a significant fraction of AGNs. • Our AGNs were detected in x-ray and selected using infrared photometry with a combination of two color criteria of J-K>1.7 and r-K > 4 (Glikman et al. 2004) or J-K>2 (Croom et al, 2002).
Data Reduction • The spectra were taken in poor weather conditions with GNIRS on Gemini South (Band 3). • They were reduced using standard IRAF infrared reduction and they have low Signal to Noise (S/N).
Goals • Identify emission lines and use them for further redshift identification. • Characterize and compare spectral properties of these AGNs (e.g. emission lines, continuum, etc...).
Emission Lines and Redshifts Z=0.209 Paβ Hα Paα [S III] HeI+Paγ
Emission Lines and Redshifts Z=0.232 Paβ Hα Paε Paα HeI+Paγ
Comparison with Bright Blue Quasars Glikman et al. 2006 2MP1211
Comparison with Bright Blue Quasars Glikman et al. 2006 2MP2058
Paα/Paβ Ratios • Theoretical calculation for Case B recombination predicts Paα/Paβ ratios between 1.8 (T=104K, Ne=109cm-3, Hummer & Storey, 1987) to 2.08 (T=104K, Ne=102cm-3, Osterbrock, 1989).
Conclusions • We found that they are low redshift red AGNs z ~ 0.2. • We classify 2MP1211 as Type 1 AGN because of their broad emission lines (FWHM > 1500 km/s) and 2MP2058 probably as Type 2 AGN (FWHM~1000 km/s). • Finally by comparing their continua with bright blue quasars (Glikman et al, 2006), we conclude that they are probably dust enshrouded AGNs and we can`t rule out case B recombination for 2MP1211.
Introduction • The quality of north-chilean sky is fundamental for the development of chilean astronomy and for the observatories placed here. • With the aim of beginning a serious and continuous follow up of the sky quality, we have taken images and Sky Quality Meter (SQM) measurements of the sky.
Views From Cerro Grande Cruz del Sur Orion Credits: Malcolm Smith
Measurements Around Tololo Orellana & Warner
Measurements Around Tololo Orellana & Warner.
Summary • We are beginning a serious and complete follow up of the quality of IV Region sky using simple SQM instrument and images. • Based on Tololo measuremets, we are able to detect differences in luminosities of the order of 0.1-0.2 mag.
Thanks to... • NSF and CTIO • Malcolm Smith • Mario Hamuy • Stella Kafka • Susan Ridgway • All Lunch Talk Speakers • All Football Players • Administrative CTIO staff • And ...