Timing and spectral properties of the X-ray emission from the blazar 1ES 1426+428

Fidelis, V. V.; Yakubovskyi, D. A.; Voytkova, Yu. V.

doi:10.1134/s1063773709090011

Cited by 4 publications

(2 citation statements)

References 17 publications

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“…The XMM-Newton space observatory, thanks to its large collecting area the ability to make long uninterrupted observations, has provided important information for the multiwavelength study of blazars (e.g., Raiteri et al 2006;Fidelis et al 2009;Kalita et al 2015;Bhagwan et al 2016). Data collected by XMM-Newton European Photon Imaging Camera (EPIC), available for fields containing 64 ABC sources, Notes.…”

Section: Xmm-newton-epicmentioning

confidence: 99%

A new multiwavelength census of blazars

Paggi

Bonato

Raiteri

et al. 2020

A&A

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Context. Blazars are the rarest and most powerful active galactic nuclei. They play a crucial and expanding role in the multifrequency and multimessenger astrophysics of today. Dominating the high-energy extragalactic sky, they have been recently associated with high-energy astrophysical neutrinos and they may be among the accelerators of the ultra-high energy cosmic rays. Current blazar catalogs, however, are incomplete and they are depleted, in particular, at low Galactic latitudes. Aims. Our study is aimed at augmenting the current blazar census, starting from a sample of ALMA calibrators that provides more homogeneous sky coverage, especially at low Galactic latitudes, to build a catalog of blazar candidates that can provide candidate counterparts to unassociated γ-ray sources and sources of high-energy neutrino emission or ultra-high energy cosmic rays. Methods. Based on the ALMA Calibrator Catalog, we compiled a selection of 1580 ALMA Blazar Candidates (ABCs) for which we collected multiwavelength information, including Gaia photometric, parallax, and proper motion data, as well as SDSS and LAMOST photometric and spectral data, WISE photometric data, X-ray (Swift-XRT, Chandra-ACIS and XMM-Newton-EPIC) count-rates and spectra, and Fermi-LAT fluxes and spectral slopes. We also compared our ALMA Blazar Candidates with existing blazar catalogs, such as 4FGL, 3HSP, WIBRaLS2, and the KDEBLLACS. Results. The ABC catalog fills in the gaps with regard to low Galactic latitude sources in current blazar catalogs. By cross-matching this catalog with Gaia DR2, SDSS DR12, LAMOST DR5, AllWISE, and 4FGL catalogs, we obtained 805, 295, 31, 1311, and 259 matches, respectively. ALMA Blazar Candidates are significantly dimmer than known blazars in the Gaia g band, while the difference in the Gaia b − r color between the two populations is less pronounced. Also, ABC sources appear bluer in SDSS than known blazars, although with low statistical significance. Most ABCs classified as QSO and BL Lac fall into the SDSS color regions of low redshift quasars, with some QSOs entering the regions of higher redshift quasars. We collected 110 optical spectra in SDSS DR12 and LAMOST DR5, which mostly classify the corresponding sources as QSO (98), while 12 sources turned out to be galactic objects. Regarding the WISE colors, we found that ABC sources are significantly bluer than known blazars in the w2 − w3 and w3 − w4 colors. In X-ray, we detected 173 ABCs and we were able to extract X-ray spectra for 92 of them. Our sources are, on average, similar in the X-ray band to known blazars in terms of count rates and spectral slopes, implying that our sample covers the same region of the blazar parameter space in this band. A comparison of γ-ray properties shows that the ABCs are, on average, dimmer and that their γ-ray spectra are softer than known blazars, indicating a significant contribution on the part of FSRQ sources. Making use of WISE colors, we classified 715 ABCs as candidate γ-ray blazar of different classes. Conclusions. We built a new catalog of 1580 candidate blazars with a rich multiwavelength data-set, filling in the gaps for low Galactic latitude sources in current blazar catalogs. This will be particularly important for the identification of the source population of high-energy neutrinos or ultra-high energy cosmic rays, or to verify the Gaia optical reference frame. In addition, ALMA Blazar Candidates can be investigated both through optical spectroscopic observation campaigns or through repeated photometric observations for variability studies. In this context, the data collected by the upcoming LSST surveys will provide a key tool for investigating the possible blazar nature of these sources.

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Section: Xmm-newton-epicmentioning

confidence: 99%

A new multiwavelength census of blazars

Paggi

Bonato

Raiteri

et al. 2020

A&A

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“…The observation data of blazars show that they vary over different time scales, which can be roughly divided into three classes: intra-day variability (IDV) or micro-variability, short term outbursts and long term trends (Fan 2005). Variability of blazars in radio to optical bands on diverse time scales have been reported in a large number of papers (see Fan 2005;Takalo et al 2008;Heidt & Wagner 1996;Sillanpää et al 1996a,b;Bai et al 1999;Fan et al 1998aFan et al , 2007Fan et al , 2009aQian et al 2000Qian et al , 2002Qian et al , 2004Aller et al 2003;Tao et al 2008;Romero et al 2002;Xie et al 2002a,b;Gupta et al 2008a,b;Cellone et al 2007;Ciprini et al 2007;Kurtanidze 2008;Raiteri et al 2008;Villata et al 2008;Valtonen et al 2008;Dai et al 2001Dai et al , 2009Fidelis et al 2009;Boettcher et al 2009 and references therein). The variability time scale of years gives the long term variation information and even some information about the central structure of the source.…”

Section: Introductionmentioning

confidence: 97%

Long-term variation time scales in OJ 287

Fan¹,

Liu²,

Qian³

et al. 2010

Res. Astron. Astrophys.

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The light curve data from 1894 to 2008 are compiled for the BL Lacertae object OJ 287 from the available literature. Periodicity analysis methods (the Discrete Correlation Function-DCF, the Jurkevich method, the power spectral (Fourier) analysis, and the CLEANest method) are performed to search for possible periodicites in the light curve of OJ 287. Significance levels are given for the possible periods. The analysis results confirm the existence of the 12.2 ± 0.6 yr time scale and show a hint of a ∼53 yr time scale. The 12.2±0.6 yr period is used as the orbital period to investigate the supermassive binary black hole system parameters.

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Variability of Blazars

Jiang

Liu

et al. 2011

J Astrophys Astron

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Variability is one of the characteristics of blazars. The rapid variability is superposed on the long term variation. In this work, the variability on different time scales, such as intra-day (IDV), short-term (STV) and long-term (LTV) variations are presented for some sources. We also presented our own observations of some selected objects, for which the historical data were compiled for periodicity analysis using several methods. The parameters of the binary black hole system OJ 287 are determined.

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Timing and spectral properties of the X-ray emission from the blazar 1ES 1426+428

Cited by 4 publications

References 17 publications

A new multiwavelength census of blazars

A new multiwavelength census of blazars

Long-term variation time scales in OJ 287

Variability of Blazars

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