| Canonical Name: | PKS 0447-439 |
| TeVCat Name: | TeV J0449-438 |
| Other Names: | 0FGL J0449.7-4348 |
| Source Type: | HBL |
| R.A.: | 04 49 28.2 (hh mm ss) |
| Dec.: | -43 50 12 (dd mm ss) |
| Gal Long: | 248.81 (deg) |
| Gal Lat: | -39.91 (deg) |
| Distance: | z=0.343 |
| Flux: | 0.03 (Crab Units) |
| Energy Threshold: | 250 GeV |
| Spectral Index: | 3.89 |
| Extended: | No |
| Discovery Date: | 2009-12 |
| Discovered By: | H.E.S.S. |
| TeVCat SubCat: | Default Catalog |
Source Notes:
Source position and its uncertainty:
From
H.E.S.S. Collaboration (2013):
- R.A. (J2000): 04h 49m 28.2s +/- 1.4s(stat) +/- 1s(syst)
- Dec. (J2000): -43d 50' 12" +/- 15"(stat) +/- 18"(syst)
From
Zech et al. (2010):
- R.A. (J2000): 04h 49m 29.9s
- Dec. (J2000): -43d 50' 09"
- no positional uncertainty information available
From
Raue et al.(2009):
- RA (J2000): 04h49m24.7s
- Dec (J2000): -43d50'09"
- no positional uncertainty information available
Spectral Information:
From
H.E.S.S. Collaboration (2013):
- Spectral index: 3.89 +/- 0.37(stat) +/- 0.22(syst)
From
Zech et al. (2010):
- Spectral index: 4.36 +/- 0.49
Flux:
From
H.E.S.S. Collaboration (2013):
- The flux measured above 250 GeV was ∼3% of the flux from the Crab
Nebula measured with H.E.S.S above the same threshold.
Association and redshift:
The redshift of this source is uncertain - it was changed from z=0.2
to unknown in TeVCat on 130308 and then to z=0.343 on 141212 (
Muriel et al. 2014).
From
Muriel et al. (2014):
- "We identified a group of galaxies that was not previously cataloged
at z = 0.343 with seven members, a virial radius of 0.42 Mpc, and a
velocity dispersion of 622 km s^-1. We found that the probability of
the host galaxy of PKS 0447-439 to be a member of the new group is >=
97%. Therefore, we propose to adopt z = 0.343 +/- 0.002 as the most
likely redshift for PKS 0447-439."
From
Zhou et al. (2013):
- "The redshift of PKS 0447-439 is also estimated in our fitting, and
z = 0.16 +/- 0.05 for Log Parabola case and z = 0.17 +/- 0.04 for
Broken Power Law case."
From
Rovero et al. (2013):
- "In this work we present a new optical spectrum of PKS 0447-439, and
report on the analysis and results of such observations. Even with
this significantly high quality signal we were not able to identify
any spectral features to allow an estimation of the redshift. In
agreement with other recent studies, we identify the Mg II line
reported previously as originated in the Earth's atmosphere, and
conclude the lower limit of the redshift (z>1.246) is incorrect. More
interestingly, we could not identify the Ca II absorption lines used
to report a redshift of 0.205."
From
H.E.S.S. Collaboration (2013):
- "A firm upper limit of z <0.59 on the redshift of PKS 0447−439 is
derived from the combined Fermi-LAT and H.E.S.S. data, given the
assumptions that there is no upturn in the intrinsic spectrum above
the Fermi-LAT energy range and that absorption on the Extragalactic
Background Light (EBL) is not weaker than the lower limit provided by
current models."
From
Pita et al. (2012):
- "z >= 1.26 invalidated, 0.205 not confirmed"
From
Fumagalli et al. (2012):
- "Our analysis confirms the presence of the previously-reported
absorption line at 6280 Å, 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."
From
Raue et al. (2010):
- "0FGL J0449.7-4348 has been associated with PKS 0447-439,
which has been associated with a BL Lac object located at a
redshift of z ~ 0.2 (
Perlman et al., 1998).
Note that PKS 0447-439 has also been associated with a Seyfert 1
galaxy located at a redshift of z=0.107 (
Craig & Fruscione, 1997)."
Landt & Bignall (2008) put lower limit on redshift: z>0.176
From
Zech et al. (2010):
- "The redshift of PKS 0447−439 is not well known. A value of
z approx. 0.205 was claimed by
Perlman et al. (1998),
but is based on
very weak spectral features and has not been independently
confirmed. The most recent study by
Landt & Bignall (2008)
provides only a lower limit of 0.176 based on photometric estimates.
It should be noted that the value of z=0.107 provided by the
SIMBAD database and based on
Craig & Fruscione (1997) is incorrect
(private communication with H. Landt and M. Veron-Cetty)."
From
Prandini et al. (2011):
- "Using the recent TeV spectrum measured by H.E.S.S. we obtain for
PKS 0447-439 a z* value of 0.357 +/- 0.065. The corresponding
reconstructed redshift is z = 0.20 +/- 0.05, which is our estimate on the
source distance."
Seen by: H.E.S.S.
-
The Gamma-Ray and Optical Variability Analysis of the BL Lac Object 3FGL J0449.4-4350
Yang, Xing et al., PASP 132 p044101 (2020) [LINK]
-
Studies of extragalactic background light with TeV BL Lacertae objects
Longhua, Qin et al., MNRAS 499 p2662-2671 (2020) [LINK]
-
Evaluating Quasi-Periodic Variations in the gamma-ray Lightcurves of Fermi-LAT Blazars
Ait Benkhali, F. et al., arXiv e-prints p (2019) [LINK]
-
Target of Opportunity Observations of Blazars with H.E.S.S
Schussler, F. et al., ArXiv e-prints p (2017) [LINK]
-
The BL-Lac gamma-ray blazar PKS 0447-439 as a probable member of a group of galaxies at z=0.343
Muriel, H. et al., ArXiv e-prints p (2014) [LINK]
-
Discovery of TeV gamma-ray emission from PKS 0447-439 and derivation of an upper limit on its redshift
H.E.S.S. Collaboration et al., ArXiv e-prints p (2013) [LINK]
-
Spontaneously gamma-ray spectra from compact sources
Petropoulou, M. et al., ArXiv e-prints p (2013) [LINK]
-
On the redshift of the gamma-ray blazar PKS 0447-439: Optical spectroscopy using Gemini observations with high S/N ratio
Rovero, A.C. et al., ArXiv e-prints p (2013) [LINK]
-
Emitting Electron Spectra and Acceleration Processes in the Jet of PKS 0447-439
Zhou, Y. et al., ArXiv e-prints p (2013) [LINK]
-
Spectroscopy of High Energy BL Lac Objects with X-shooter on the VLT
Pita, S. et al., ArXiv e-prints p (2013) [LINK]
-
On the redshift of the blazar PKS 0447-439
Fumagalli, M. et al., A&A 545 pA68 (2012) [LINK]
-
Discovery of VHE emission from PKS 0447-439 with H.E.S.S. and MWL studies
Zech, A. and others, Proceeding from the 25th Texas Symposium on Relativistic Astrophysics (Heidelberg, Germany, 2010) [LINK]
-
On the redshift of the TeV blazar PKS 0447-439. An independent estimate, combining GeV and TeV spectra
E. Prandini et al., ArXiv e-prints p (2011) [LINK]
-
H.E.S.S. discovers VHE emission from the Fermi LAT source PKS 0447-439
M. Raue, B. Behera, A. Charbonnier, B. Giebels, M. Hauser, K. Kosack, M. Punch, H.-S. Zechlin for the H.E.S.S. collaboration, ATel 2350 (2009) [LINK]
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