H1426+428
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| H1426+428 | |
|---|---|
 The BL Lac object H1426+428. | |
| Observation data (J2000.0 epoch) | |
| Constellation | Boötes |
| Right ascension | 14h 28m 32.60s |
| Declination | +42° 40′ 20.97″ |
| Redshift | 0.129265 |
| Heliocentric radial velocity | 38,753 km/s |
| Distance | 1.911 Gly (585.91 Mpc) |
| Apparent magnitude (V) | 16.45 |
| Apparent magnitude (B) | 16.95 |
| Characteristics | |
| Type | BL LAC |
| Other designations | |
| 1ES 1426+428, LEDA 2203750, 4FGL J1428.5+4240, 1ES 1426+42.8, TeV J1428+426, 1RXS J142832.6+424028, RX J1428.5+4240 | |
H1426+428 also known as 1ES 1426+428, is a high-frequency peaked BL Lacertae object (HBL)[1][2] located in the constellation of Boötes. It is located at a relatively high[3] redshift of (z) 0.129,[4] and was discovered in 1984 by astronomers who presented a catalogue of X-ray sources taken with the HEAO 1 satellite.[5]
H1426+428 is classified as a blazar.[6] It is also a distant source of TeV gamma rays.[7][8] It has low power and a synchrotron peak that is above 100 KeV.[6][9] Furthermore, H1426+428 is possibly hosted in an elliptical galaxy and is luminous in X-ray bands. It has a 2-6 keV luminosity of ~1044 erg s−1.[10]
The gamma emission in H1426+428 is found to have an average flux. Its spectrum is very steep and shows a differential spectral index of γ = -3.60 ± 0.57, when observed by the Cosmic Anisotropy Telescope (CAT) in Very High energy gamma ray bands between 1998 and 2000.[11] This steep spectrum is mainly contributed by the absorption of gamma rays in the intergalactic medium[12] or by diffused cosmic infrared background.[11]
In 2002, H1426+428 exhibited variability in the 3-24 keV X-ray spectra.[13] However in 2006, it was in a period of X-ray inactivity, showing no gamma rays, when observed by CELESTE Cherenkov telescope .[14] The Tev activity in H1426+428 only increased just before 2008, with it experiencing flare activity for four days in 2009.[15] A long-term X-ray flare was detected in H1426+428 in January 2021 by the X-ray telescope onboard Neil Gehrels Swift Observatory.[16] This was followed by a very high energy gamma ray flux in March 2021.[17]
H1426+428 has a compact radio core with a ~ 17 mJy flux density. In additional, it has a faint radio jet extending towards northwest with a project position angle of -25°.[18] There is also a faint radio halo that is surrounding the radio core as well[19] but it has weak radio and optical polarization.[20]
