Access to Astronomical Catalogues

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
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