J/A+A/545/A68 Optical spectrum of the blazar PKS 0447-439 (Fumagalli+, 2012)
On the redshift of the blazar PKS 0447-439.
Fumagalli M., Furniss A., O'Meara J., Prochaska J.X., Williams D., Farina E.
<Astron. Astrophys. 545, A68 (2012)>
=2012A&A...545A..68F 2012A&A...545A..68F
ADC_Keywords: BL Lac objects ; Spectroscopy
Keywords: galaxies: active - BL Lacertae objects: individual: PKS 0447-439 -
galaxies: distances and redshifts
Abstract:
PKS 0447-439 is one of the BL Lacertae objects that have been detected
at very high energy. There has been a recent report of a lower limit
of z≥1.246 for the redshift of this blazar, challenging the current
paradigm in which very high-energy γ-rays cannot freely
propagate in the z≳1 universe. In this research note, we present a
new MagE/Magellan spectrum of PKS 0447-439 with exquisite
signal-to-noise (S/N>150 at 6500Å). Our analysis confirms the
presence of the previously-reported absorption line at 6280Å, which
we identify, however, with a known telluric absorption, invalidating
the claim that this blazar lies at z>1. Since no other extragalactic
spectral features are detected, we cannot establish a redshift based
on our spectrum.
Description:
MagE/Magellan optical spectrum of the blazar PKS 0447-439 (see Fig. 1
of the paper).
Objects:
-----------------------------------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------------------------------
04 49 24.88 -43 50 09.7 PKS 0447-439 = CRATES J044924-435004
-----------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
spectrum.dat 35 11435 Optical spectrum of the blazar PKS 0447-439
--------------------------------------------------------------------------------
Byte-by-byte Description of file: spectrum.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.4 0.1nm lambda [3500.1/8101] Observed wavelength
15- 22 F8.4 aW/m2/nm Flux Flux (10-16erg/cm2/s/Å)
29- 35 F7.5 aW/m2/nm e_Flux 1 sigma error on Flux
(10-16erg/cm2/s/Å)
--------------------------------------------------------------------------------
Acknowledgements:
Michele Fumagalli, miki(at)ucolick.org
(End) Michele Fumagalli [UCSC], Patricia Vannier [CDS] 11-Aug-2012