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Observation Date (UT) Observation Lat

Canonical Name:1ES 2344+514
TeVCat Name:TeV J2347+517
Other Names:
Source Type:HBL
R.A.:23 47 04 (hh mm ss)
Dec.:+51 42 49 (dd mm ss)
Gal Long: 112.89 (deg)
Gal Lat: -9.90 (deg)
Distance: z=0.044
Flux:0.07 (Crab Units)
Energy Threshold:350 GeV
Spectral Index:2.46
Extended:No
Discovery Date:1998-07
Discovered By: Whipple
TeVCat SubCat:Default Catalog

Source Notes:

Source position and its uncertainty:
On 170904 the position was updated from that of Aharonian et al. (2004)
to that from Allen et al. (2017)
From Allen et al. (2017):
- R.A. (J2000): 23h 47m 04s +/- 2s(stat)
- Dec. (J2000): +51d 42' 49" +/- 16" (stat)
- the systematic error on the VERITAS pointing accuracy is <25", which
gives systematic errors on the right ascension of +/- 3s and on the
declination of +/- 25"
From Albert et al. (2007):
- R.A. (J2000): 23h 46m +/- 0.4m (23 46 00)
- Dec. (J2000): 51d 42.6' +/- 1.2' (+51 42 36)
- When the quoted uncertainties are taken into account,
the position remains incompatible with that from NED.
From Aharonian et al. (2004):
- R.A. (J2000): 23 47 04.9
- Dec. (J2000): +51 42 17
- No information on the positional uncertainty is provided.

Spectral Properties:
From Allen et al. (2017):
- Spectral index for different observation periods:
... 2007-2008: 2.43 +/- 0.09 (stat)
... 2008-2015: 2.63 +/- 0.14 (stat)
... 2007-2015: 2.46 +/- 0.06 (stat)
... the systematic error is 0.20
From Acciari et al. (2011):
- Spectral index (flare): 2.43 +/- 0.22(stat) +/- 0.15(syst)
- Spectral index (time-averaged): 2.78 +/- 0.09(stat) +/- 0.15(syst)
From Albert et al. (2007):
- Spectral index: 2.95 +/- 0.12(stat) +/- 0.2(syst)
From Schroedter et al. (2005):
- Spectral index: 2.54 +/- 0.17(stat) +/-0.07(syst)

Flux:
From Allen et al. (2017):
- "The time-averaged event rate for all nights is measured to be (0.20
+/- 0.01) gammas min−1 and the total time-averaged flux above 0.35 TeV
is calculated to be F(E>0.35 TeV) = (7.1 +/- 0.4) × 10−12 cm−2 s −1 or
7% that of the Crab Nebula"
- "The observations, when combined with other VHE observations,
indicate that there is not a steady baseline flux level for the VHE
emission from this object. The observed flickering variability is not
uncommon for BL Lac objects and indicates that the VHE emission is not
from a large scale structure within the galaxy, but instead from a
compact region most probably within the jet, with variability possibly
caused by turbulence in the jet or variations in the electron supply
(see, for example, Howard et al. 2004).
The gamma-ray flux from 1ES 2344+514 is variable.
A summary of its historical gamma-ray flux is provided in Allen et al. (2017):
- "The integral flux is typically less than 10% that of the Crab
Nebula, but day-scale flares of 60% and 50% of the Crab Nebula flux
have been observed (Catanese et al. 1998; Acciari et al. 2011)."
- The MAGIC collaboration observed 1ES 2344+514 in a particularly low
state for ∼20 hours spread across 14 nights (in 2008) as part of a
multiwavelength campaign; it was marginally detected at a level of 3.5
standard deviations above the background and determined to have a flux
approximately 2.5% that of the Crab Nebula (Aleksic et al. 2013)
- "VERITAS detected 1ES 2344+514 at the 20 sigma level in 18 hours of
observations spread across 37 nights in 2007/2008 including a one-day
flare of ∼50% of the Crab Nebula flux on December 7, 2007 (MJD 54441)
(Acciari et al. 2011). Analysis of the data excluding the flare
revealed a low-state flux of ∼7.6% of the Crab Nebula"
- "MAGIC observations in 2005/2006 (27 nights in the interval 2005
August 3 to 2006 January 1) totalling 32 hours provided an 11 sigma
detection with an average flux of ∼10% that of the Crab Nebula" Albert et al. (2007)


Seen by: Whipple, HEGRA, MAGIC, VERITAS
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