| Canonical Name: | PKS 1424+240 |
| TeVCat Name: | TeV J1427+238 |
| Other Names: | 7C 1424+2401 |
| Source Type: | HBL |
| R.A.: | 14 27 00 (hh mm ss) |
| Dec.: | +23 47 40 (dd mm ss) |
| Gal Long: | 29.47 (deg) |
| Gal Lat: | 68.21 (deg) |
| Distance: | |
| Flux: | 0.05 (Crab Units) |
| Energy Threshold: | 200 GeV |
| Spectral Index: | 4.2 |
| Extended: | No |
| Discovery Date: | 2009-06 |
| Discovered By: | VERITAS |
| TeVCat SubCat: | Default Catalog |
Source Notes:
Source position and its uncertainty:
From
Acciari et al. (2010):
- RA (J2000): 14h 27m 00s +/- 7s(stat)
- Dec (J2000): 23d 47' 40" +/- 2'(stat)
Source Association:
- spatially consistent with the Fermi-LAT source 0FGL J1427.1+2347 (Abdo et al.
(2009a),
(2009b))
Distance:
The redshift of this object is uncertain.
Current limits place it in the range z = 0.24 - 1.19 (details below).
From
Zahoor et al. (2021):
- In this work, the effect of the absorption of the extragalactic
galactic background light was used to place constraints on the
redshifts of gamma-ray sources.
- "The very high energy (VHE) gamma-ray spectral indices of blazars
show strong correlation with the source redshift. Absence of any such
correlation in low energy gamma rays and X-rays indicate the presence
of Extragalactic Background Light (EBL) induced absorption of VHE
gamma rays. By employing a linear regression analysis, this
observational feature of blazars is used to constrain the redshift of
BL Lac objects which was unknown/uncertain earlier."
- Two different regression relations were used to constrain the source
redshift and the following values were found for PKS 1424+240:
- z = 0.28 +/- 0.13
- z = 0.24 +/- 0.11
From
Rovero et al. (2016):
- "Given the difficulty of measuring spectroscopic redshifts for
BL-Lac objects directly, we aim to establish a reliable redshift value
for this blazar by finding its host group of galaxies."
- "For this, we performed optical spectroscopic observations of thirty
objects in the field of view of PKS 1424+240 using the Gemini MOS."
-" We found a new group of galaxies with eight members at z = 0.6010
+/- 0.003 ... The photometric study indicates that more members are
probably populating this previously uncatalogued group of
galaxies. The probability of PKS 1424+240 being a member of this group
was found to be 98%. The new group of galaxies found at z = 0.6010 +/-
0.003 is very likely hosting PKS 1424+240."
From
Rovero et al. (2015):
- " Redshift determination of BL-Lac objects are difficult to
achieve. We have found that redshift of blazars can be determined by
its association to a galaxy group or cluster. To explore this
possibility for PKS 1424+240, we have carried out spectroscopic
measurements with the Gemini North telescope of galaxies in its field
of view. In this work we present the optical spectrum of PKS 1424+240
and show preliminary results of the blazar environment
characterization. Spectroscopic redshift using the optical spectrum
of PKS 1424+240 could not be determined in this work."
From
Furniss et al. (2013):
- "We present the strict redshift lower limit of z ≥ 0.6035 for PKS
1424+240, set by the detection of Ly-Beta and gamma lines from
intervening hydrogen clouds. This lower limit makes PKS 1424+240 the
most distant VHE-detected source. At this distance, VHE observations
of the source out to energies of 500 GeV probe gamma-ray opacities of
up to tau ~ 5."
From
Yang & Wang (2010):
- an upper limit of 1.19 on the redshift was derived
From
Prandini et al. (2011):
- the redshift is estimated to be 0.24 +/- 0.05
Spectral Properties:
From
Benbow et al. (2015):
- Spectral index: 4.2 +/- 0.3
From
Acciari et al. (2010):
- Spectral index: 3.8 +/- 0.5(stat) +/- 0.3(syst)
Source Classification:
From
Archambault et al. (2014):
- Updated from IBL to HBL on 140506
- "The blazar can be categorized as an high-synchrotron-peaked (HSP)
BL Lac, with a synchrotron peak above 1015 Hz (Abdo et al. 2010) and
an isotropic luminosity above 400 GeV of 1.03 x10e44 erg s−1"
Seen by: MAGIC, VERITAS
-
PKS 1424+240: yet another masquerading BL Lac object as a possible IceCube neutrino source
Padovani, P. et al., arXiv e-prints parXiv:2202.04363 (2022) [LINK]
-
Search for multi-flare neutrino emissions in 10 years of IceCube data from a catalog of sources
IceCube collaboration et al., arXiv e-prints parXiv:2109.05818 (2021) [LINK]
-
Model-independent Redshift Estimation of BL Lac Objects through VHE Observations
Zahoor, Malik et al., arXiv e-prints parXiv:2110.15953 (2021) [LINK]
-
Astrophysical Neutrinos and Blazars
Giommi, Paolo and Padovani, Paolo, Universe 7 p492 (2021) [LINK]
-
Testing two-component models on very-high-energy gamma-ray emitting BL Lac objects
MAGIC Collaboration et al., arXiv e-prints parXiv:2006.04493 (2020) [LINK]
-
Testing CIBER cosmic infrared background measurements and axionlike particles with observations of TeV blazars
Long, G.B. et al., arXiv e-prints parXiv:1912.05309 (2019) [LINK]
-
Long-term optical monitoring of TeV emitting blazars. I. Data analysis
Nilsson, K. et al., A&A 620 pA185 (2018) [LINK]
-
EBL Inhomogeneity and Hard-Spectrum Gamma-Ray Sources
Abdalla, H. and Boettcher, M., ArXiv e-prints p (2017) [LINK]
-
On the redshift of TeV BL Lac objects
Paiano, S. et al., ArXiv e-prints p (2017) [LINK]
-
Effects of Spatial Fluctuations in the Extra Galactic Background Light on Hard Gamma Ray Spectra
Kudoda, A.M. and Faltenbacher, A., ArXiv e-prints p (2017) [LINK]
-
MAGIC detects activity from PKS 1424+240 at very-high-energy gamma rays
Mirzoyan, R., The Astronomer's Telegram 10157 p1 (2017) [LINK]
-
Luminous and high-frequency-peaked blazars: on the origin of the gamma-ray emission from PKS 1424+240
Cerruti, M. et al., ArXiv e-prints p (2017) [LINK]
-
Constraining the redshifts of TeV BL Lac objects
Qin, L. et al., ArXiv e-prints p (2017) [LINK]
-
The BL-Lac gamma-ray blazar PKS 1424+240 associated with a group of galaxies at z=0.6010
Rovero, A.C. et al., ArXiv e-prints p (2016) [LINK]
-
On the origin of the soft photons of the high synchrotron peaked blazar : PKS 1424+240
Kang, S. et al., ArXiv e-prints p (2016) [LINK]
-
Latest MAGIC discoveries pushing redshift boundaries in VHE Astrophysics
Manganaro, M. et al., Journal of Physics Conference Series 718 p052022 (2016) [LINK]
-
VERITAS Observations of Very High Energy Blazars and Potential for Cosmological Insight
Amy Furniss for the VERITAS Collaboration, ArXiv e-prints p (2015) [LINK]
-
Short Timescale Photometric and Polarimetric Behavior of two BL Lacertae Type Objects
Covino, S. et al., ArXiv e-prints p (2015) [LINK]
-
Highlights from the VERITAS AGN Observation Program
Benbow, W. and for the VERITAS Collaboration, ArXiv e-prints p (2015) [LINK]
-
Redshift measurement of the BL-Lac gamma-ray blazar PKS 1424+240
Rovero, A.C. et al., ArXiv e-prints p (2015) [LINK]
-
MAGIC long-term study of the distant TeV blazar PKS 1424+240 in a multiwavelength context
MAGIC Collaboration et al., ArXiv e-prints p (2014) [LINK]
-
An Empirical Determination of the Intergalactic Background Light Using NIR Deep Galaxy Survey Data out to 5 microns and the Gamma-ray Opacity of the Universe
Scully, S.T. et al., ArXiv e-prints p (2014) [LINK]
-
Deep Broadband Observations of the Distant Gamma-Ray Blazar PKS 1424+240
Archambault, S. et al., ApJ 785 pL16 (2014) [LINK]
-
Understanding the TeV emission from a distant blazar PKS 1424+240 in a lepto-hadronic jet model
Yan, D. and Zhang, L., ArXiv e-prints p (2014) [LINK]
-
A self-consistent interpretation of the GeV-TeV emission from a distant blazar PKS 1424+240
Yan, D. et al., ArXiv e-prints p (2014) [LINK]
-
The Firm Redshift Lower Limit of the Most Distant TeV-Detected Blazar PKS 1424+240
Furniss, A. et al., ArXiv e-prints p (2013) [LINK]
-
Impact of oscillations of photons into axion-like particles on the very-high energy gamma-ray spectrum of the blazar PKS1424+240
Meyer, M. and Horns, D., ArXiv e-prints p (2013) [LINK]
-
Understanding the spectrum of a distant blazar PKS 1424+240 and its implications
Essey, W. and Kusenko, A., ArXiv e-prints p (2013) [LINK]
-
Blazars distance indications from Fermi and TeV data
Prandini et al., ArXiv e-prints p (2011) [LINK]
-
Observation of selected IBLs and LBLs with VERITAS
Majumdar, P. and for the VERITAS Collaboration, ArXiv e-prints p (2011) [LINK]
-
Overview of the results from extra-galactic observations with the MAGIC telescopes
Berger, K. and for the MAGIC Collaboration, ArXiv e-prints p (2011) [LINK]
-
VHE Blazar Discoveries with VERITAS
Wystan Benbow for the VERITAS Collaboration, ArXiv e-prints p (2011) [LINK]
-
Constraining blazars distances with combined GeV and TeV data
Prandini et al., ArXiv e-prints p (2011) [LINK]
-
Redshifts of distant blazar limited by Fermi and VHE Gamma-ray observations
Yang, J. and Wang, J., ArXiv e-prints p (2010) [LINK]
-
Discovery of Very High Energy Gamma Rays from PKS 1424+240 and Multiwavelength Constraints on Its Redshift
Acciari, V.A. et al., ApJ 708 pL100-L106 (2010) [LINK]
-
Discovery of VHE Gamma-Ray Emission from the Fermi-LAT Source PKS 1424+240 (Ong)
Ong, R. A. on behalf of the VERITAS Collaboration, ATel 2084 [LINK]
-
MAGIC observes very high energy gamma ray emission from PKS 1424+240
Teshima, M. on behalf of the MAGIC Collaboration, ATel 2098 [LINK]
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