| Canonical Name: | 1ES 1215+303 |
| TeVCat Name: | TeV J1217+301 |
| Other Names: | ON 325, B2 1215+30, VER J1217+301 |
| Source Type: | HBL |
| R.A.: | 12 17 48.5 (hh mm ss) |
| Dec.: | +30 06 06 (dd mm ss) |
| Gal Long: | 189.01 (deg) |
| Gal Lat: | 82.05 (deg) |
| Distance: | z=0.131 |
| Flux: | 0.035 (Crab Units) |
| Energy Threshold: | 250 GeV |
| Spectral Index: | |
| Extended: | No |
| Discovery Date: | 2011-01 |
| Discovered By: | MAGIC |
| TeVCat SubCat: | Default Catalog |
Source Notes:
Source position and its uncertainty:
TeV source position added on 131028; prior to that, the position from
NED was used
From
VERITAS Collaboration (2013):
- R.A. (J2000): 12h 17m 48.5s +/- 1.7s (stat)
- Dec. (J2000): +30d 06' 06" +/- 25"
- Systematic uncertainty: 50"
Distance:
171017: The redshift was updated from z=0.13 to z=0.131
From
Piano et al. 2017:
- "we secured a high quality optical spectrum (SNR approx. 300) in
which we detect two emission lines: [OII] 3727 Angstroms,
[OIII] 5007 Angstroms at z = 0.131 (see also Table 5) confirming
the low redshift previously reported."
Note: in the abstract the redshift is listed as z=0.129; in Table 4
the emission lines are listed as lying at redshift of z=0.129
-
White et al. (2000) give z=0.237
-
Akiyama et al. (2003) give z=0.130
Triggered observations:
- From
ATel 3100: "The MAGIC observations were triggered by
an optical high-state of the source, reported by the
Tuorla blazar
monitoring program".
Spectral Properties:
From
VERITAS Collaboration (2013):
- Spectral index: 3.6 +/- 0.4(stat) +/- 0.3(syst)
From
Aleksic et al. (2012):
- Spectral index: 2.96 +/- 0.14(stat) +/- 0.15(syst)
From
Prokoph et al. (2012):
- Spectral index: 3.6 +/- 0.5
Flux :
From
VERITAS Collaboration (2013):
- during the 2011 season:
- 3.4% of the Crab Nebula flux
- "no evidence for deviation from a steady flux" was found. "No
significant flux variations within any monthly bin were detected
either."
- data available outside the 2011 season (2008/9 and 2012):
- an upper limit was placed on the TeV flux during 2008/9
- during 2012 a flux at the leve of 1.2% of the Crab Nebula flux was
detected
- "The hypothesis of a constant flux between the three seasons is
excluded at the level of 4.5 sigma."
From
Prokoph et al. (2012):
- a flux at the level of about 3% of that of the Crab is reported above 200 GeV
From
Aleksic et al. (2012):
- the flux corresponds to about 3.5% of the Crab Nebula flux
From
Benbow et al. (2011):
- a flux at the level of 1% that of the Crab is reported
From
Mariotti (2011):
- a flux at the level of (2.0 +/- 1.0)% that of the Crab is reported
Classification:
Initially, this source was classified as an LBL in TeVCat. It has been
updated (121113) to a HBL based on its classification in
the
Fermi
2nd AGN Catalog (Ackermann et al. 2012)
From
Valverde et al. (2020):
- "In many ways, 1ES 1215+303 shows typical features of a classical
HBL source: it has an FR I radio jet (Giroletti et al. 2006) at the
kpc scale, with multiple stationary radiocomponents as can be seen
from VLBI (
Hervet et al. 2016;
Piner & Edwards 2018). It does not show
a thermal accretion disk signature in the blue-UV, nor does it exhibit
strong inverse-Compton dominance in the broadband SED."
- "An unusual feature, however, is the dramatic change of the
synchrotron bump (shape and peak frequency) between low and high
activity states. The high state, as observed in the 2017 flare and
post-flare SED, presents a synchrotron peak between the UV and soft
X-rays, typical of HBLs."
- "Due to the relative flatness of the synchrotron bump, it is
difficult to determine the precise peak frequency value, but the
favored post-flare model shows a synchrotron peak at log_10(nu_peak)
of 15.75. The low state is characterized by a much more constrained
peak frequency, of log_10(nu_peak of 14.49 +0.17 -0.54 from the model,
with boundaries from the IR and optical data—consistent with the
results of
Nilsson et al. (2018), based on the Roma-BZCAT Multifrequency
Catalog up to 2012. Thus, if only this low state were considered, this
source would be classified as an IBL."
Information on the jet:
From
Lister et al. (2019):
- "All three innermost features of this low redshift BL Lac object
(z = 0.131) show small but significant inward motion of approximately
25 micro-as y-1 (0.2 c)."
Seen by: MAGIC, VERITAS
-
Study of the long-term Very High Energy emission of the blazars 1ES 1215+3031 and VER J0521+211 with the HAWC gamma-ray observatory
Urena-Mena, Fernando et al., arXiv e-prints parXiv:2310.02468 (2023) [LINK]
-
A decade of multi-wavelength observations of the TeV blazar 1ES 1215+303: Extreme shift of the synchrotron peak frequency and long-term optical-gamma-ray flux increase
Valverde, Janeth et al., ApJ v891 (2) p170 (2020) [LINK]
-
Nature of gamma-ray variability in blazars
Bhatta, Gopal and Dhital, Niraj, arXiv e-prints parXiv:1911.08198 (2019) [LINK]
-
Long-term Variability Study of the Blazar B2 1215+30 at Gamma-Ray Energies
Noto, G., Valverde J., Horan D., Mukherjee, R. on behalf of the VERITAS and Fermi-LAT Collaborations, 230th AAS Austin, TX, June, 2017 230 p1 (2017) [LINK]
-
Long-term optical monitoring of TeV emitting blazars. I. Data analysis
Nilsson, K. et al., A&A 620 pA185 (2018) [LINK]
-
A luminous and isolated gamma-ray flare from the blazar B2 1215+30
VERITAS Collaboration et al., ArXiv e-prints p (2017) [LINK]
-
On the redshift of TeV BL Lac objects
Paiano, S. et al., ArXiv e-prints p (2017) [LINK]
-
Fermi LAT detection of a GeV gamma-ray flare from the high-energy peaked BL Lac object 1ES 1215+303 (B2 1215+30, ON 325)
Ciprini, S., The Astronomer's Telegram 10270 p1 (2017) [LINK]
-
Temporal analysis of an unprecedented data set for the gamma-ray blazar 1ES 1215+303: Fermi-LAT and VERITAS light curves spanning ten years
Valverde, J. et al., ArXiv e-prints p (2017) [LINK]
-
Observations of low- and intermediate-frequency-peaked BL Lacs above 100 GeV with VERITAS
Errando, M. for the VERITAS Collaboration, ArXiv e-prints p (2013) [LINK]
-
Long term observations of B2 1215+30 with VERITAS
VERITAS collaboration et al., ArXiv e-prints p (2013) [LINK]
-
Discovery of VHE gamma-rays from the blazar 1ES 1215+303 with the MAGIC telescopes and simultaneous multi-wavelength observations
Aleksic, J. et al., A&A 544 pA142 (2012) [LINK]
-
Observations of very high energy emission from B2 1215+30 with VERITAS
Prokoph, H. and for the VERITAS Collaboration, ArXiv e-prints p (2012) [LINK]
-
Discovery of Very High Energy Gamma-Ray Emission from 1ES 1215+303 by MAGIC
Mariotti, M., The Astronomer's Telegram 3100 p1-+ (2011) [LINK]
-
NIR brightening of the Gamma Ray Source 1ES 1215+303
Carrasco, L. et al., The Astronomer's Telegram 3281 p1-+ (2011) [LINK]
-
Rapid optical variability of TeV blazars
Gopal-Krishna 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]
-
Highlights of the VERITAS Blazar Observation Program
Wystan Benbow for the VERITAS Collaboration, ArXiv e-prints p (2011) [LINK]
-
Observation of the BL Lac objects 1ES 1215+303 and 1ES 1218+304 with the MAGIC telescopes
Colin, P. et al., ArXiv e-prints p (2011) [LINK]
-
MAGIC Telescopes observation of the BL Lac objects 1ES 1215+303 and 1ES 1218+304
Lombardi, S. et al., ArXiv e-prints p (2011) [LINK]
-
Connection Between Optical and VHE Gamma-ray Emission in Blazar Jets
Reinthal, R. et al., ArXiv e-prints p (2011) [LINK]
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