Access to Astronomical Catalogues

← Click to display the menu
J/A+A/551/A95     Reduced co-added LETGS spectrum of Ark 564     (Ramirez, 2013)

Chandra LETGS observation of the variable NLS1 galaxy Ark 564. Ramirez J.M. <Astron. Astrophys. 551, A95 (2013)> =2013A&A...551A..95R
ADC_Keywords: Galaxies, Seyfert ; X-ray sources ; Spectroscopy Keywords: galaxies: Seyfert - line: identification - quasars: absorption lines Abstract: We present an analysis of the 100ks X-ray spectrum of the narrow-line Seyfert 1 Galaxy Ark 564, taken with the Low Energy Transmission Grating Spectrometer (LETGS) on board Chandra. Using chisquare statistics, several continuum models of the time-averaged spectrum of this object are compared, obtaining a semi-empirical solution for the description of the intrinsic emission continuum and a physical solution for the intrinsic absorption of the system. We find that the 0.1-10keV spectrum can be well described by a power law plus two thermal components that account for the soft step. We are also able to detect and measure several narrow, unresolved absorption lines arising from highly ionized species of C, N, O, and Fe. The material seems to have a velocity consistent with the systemic velocity of the galaxy. This piece of evidence, in addition to the very low observed column density of Nh∼1020cm-2, is in good agreement with the scenario of a transverse biconical outflow with a gas density of n<3x1012cm-3 at distances beyond the broad-line region r>10lt-days, but a dust torus origin cannot be ruled out. Description: This is the 1-D LETGS (Low Energy Transmission Grating Spectrometer on board Chandra) spectrum of Ark 564 observed in April 2008, ObsID: 09151. Objects: ---------------------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------------------- 22 42 39.31 +29 43 31.6 Ark 564 = UGC 12163 ---------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file spectrum.dat 54 1533 LETGS (Low Energy Transmission Grating in Chandra, 0.07-0.2keV) 100ks spectrum of Ark 564
See also: B/chandra : The Chandra Archive Log (CXC, 1999-2012) V/138 : Cross-matched radio/infrared/X-ray sources (Combi+, 2011) VII/173 : Catalogue of Seyfert Galaxies (Lipovetsky+, 1988) J/ApJ/590/73 : RASS AGN sample. II. (Xu+, 2003) J/A+A/418/465 : Mid-infrared and hard X-ray emission in AGN (Lutz+, 2004) J/A+A/495/421 : Catalog of AGN in XMM-Newton archive (CAIXA) (Bianchi+, 2009) J/ApJ/713/L11 : X-ray properties of Seyfert 1 galaxies (Zhou+, 2010) J/AJ/141/129 : Chandra Transmission Grating Data Catalog (Huenemoerder+, 2011) Byte-by-byte Description of file: spectrum.dat
Bytes Format Units Label Explanations
2- 10 F9.5 0.1nm lambda [1.275/122.107] Wavelength (Å) 15- 21 F7.5 0.1nm e_lambda Error on lambda 25- 32 F8.5 10ct/s/nm counts Counts per seconds per spectral bin (1Å) 37- 43 F7.5 10ct/s/nm e_counts Errors on counts 48- 54 F7.5 10ct/s/nm Mcounts Best fit physical model
Acknowledgements: Jose M. Ramirez, josem(at)
(End) Jose M. Ramirez [IVIC, Venezuela] 06-Feb-2013
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

catalogue service