2024A&A...682A.114M

Query : 2024A&A...682A.114M

2024A&A...682A.114M - Astronomy and Astrophysics, volume 682A114 (2024/2-1)

Multi-year characterisation of the broad-band emission from the intermittent extreme BL Lac 1ES 2344+514.

MAGIC COLLABORATION, ABE H., ABE S., ACCIARI V.A., AGUDO I., ANIELLO T., ANSOLDI S., ANTONELLI L.A., ARBET ENGELS A., ARCARO C., ARTERO M., ASANO K., BAACK D., BABIC A., BAQUERO A., BARRES DE ALMEIDA U., BATKOVIC I., BAXTER J., BECERRA GONZALEZ J., BERNARDINI E., BERNETE J., BERTI A., BESENRIEDER J., BIGONGIARI C., BILAND A., BLANCH O., BONNOLI G., BOSNJAK Z., BURELLI I., BUSETTO G., CAMPOY-ORDAZ A., CAROSI A., CAROSI R., CARRETERO-CASTRILLO M., CASTRO-TIRADO A.J., CHAI Y., CIFUENTES A., CIKOTA S., COLOMBO E., CONTRERAS J.L., CORTINA J., COVINO S., D'AMICO G., D'AMMANDO F., D'ELIA V., DA VELA P., DAZZI F., DE ANGELIS A., DE LOTTO B., DEL POPOLO A., DELFINO M., DELGADO J., DELGADO MENDEZ C., DEPAOLI D., DI PIERRO F., DI VENERE L., DOMINIS PRESTER D., DORNER D., DORO M., ELSAESSER D., EMERY G., ESCUDERO J., FARINA L., FATTORINI A., FOFFANO L., FONT L., FUKAMI S., FUKAZAWA Y., GARCIA LOPEZ R.J., GASPARYAN S., GAUG M., GIESBRECHT PAIVA J.G., GIGLIETTO N., GIORDANO F., GLIWNY P., GRAU R., GREEN J.G., HADASCH D., HAHN A., HECKMANN L., HERRERA J., HRUPEC D., HUTTEN M., IMAZAWA R., INADA T., IOTOV R., ISHIO K., JIMENEZ MARTINEZ I., JORMANAINEN J., KERSZBERG D., KLUGE G.W., KOBAYASHI Y., KOUCH P.M., KUBO H., KUSHIDA J., LAINEZ LEZAUN M., LAMASTRA A., LEONE F., LINDFORS E., LINHOFF L., LOMBARDI S., LONGO F., LOPEZ-MOYA M., LOPEZ-ORAMAS A., LOPORCHIO S., LORINI A., MACHADO DE OLIVEIRA FRAGA B., MAJUMDAR P., MAKARIEV M., MANEVA G., MANG N., MANGANARO M., MARIOTTI M., MARTINEZ M., MARTINEZ-CHICHARRO M., MAS-AGUILAR A., MAZIN D., MENCHIARI S., MENDER S., MICELI D., MIENER T., MIRANDA J.M., MIRZOYAN R., MOLERO GONZALEZ M., MOLINA E., MONDAL H.A., MORALEJO A., MORCUENDE D., NAKAMORI T., NANCI C., NEUSTROEV V., NIGRO C., NIKOLIC L., NISHIJIMA K., NJOH EKOUME T., NODA K., NOZAKI S., OHTANI Y., OKUMURA A., OTERO-SANTOS J., PAIANO S., PALATIELLO M., PANEQUE D., PAOLETTI R., PAREDES J.M., PAVLOVIC D., PERSIC M., PIHET M., PIROLA G., PODOBNIK F., PRADA MORONI P.G., PRANDINI E., PRINCIPE G., PRIYADARSHI C., RHODE W., RIBO M., RICO J., RIGHI C., SAHAKYAN N., SAITO T., SATALECKA K., SATURNI F.G., SCHLEICHER B., SCHMIDT K., SCHMUCKERMAIER F., SCHUBERT J.L., SCHWEIZER T., SCIACCALUGA A., SITAREK J., SPOLON A., STAMERRA A., STRISKOVIC J., STROM D., SUDA Y., TAJIMA H., TAKEISHI R., TAVECCHIO F., TEMNIKOV P., TERAUCHI K., TERZIC T., TESHIMA M., TOSTI L., TRUZZI S., TUTONE A., UBACH S., VAN SCHERPENBERG J., VENTURA S., VERGUILOV V., VIALE I., VIGORITO C.F., VITALE V., WALTER R., WUNDERLICH C., YAMAMOTO T. (The Multi-wavelength Collaborators), PERRI M., VERRECCHIA F., LETO C., DAS S., CHATTERJEE R., RAITERI C.M., VILLATA M., SEMKOV E., IBRYAMOV S., BACHEV R., STRIGACHEV A., DAMLJANOVIC G., VINCE O., JOVANOVIC M.D., STOJANOVIC M., LARIONOV V.M., GRISHINA T.S., KOPATSKAYA E.N., LARIONOVA E.G., MOROZOVA D.A., SAVCHENKO S.S., TROITSKIY I.S., TROITSKAYA Y.V., VASILYEV A.A., CHEN W.P., HOU W.J., LIN C.S., TSAI A., JORSTAD S.G., WEAVER Z.R., ACOSTA-PULIDO J.A., CARNERERO M.I., CAROSATI D., KURTANIDZE S.O., KURTANIDZE O.M., JORDAN B., IVANIDZE R.Z., GAZEAS K., VRONTAKI K., HOVATTA T., LIODAKIS I., READHEAD A.C.S., KIEHLMANN S., ZHENG W., FILIPPENKO A.V. and FALLAH RAMAZANI V.

Abstract (from CDS):

Aims. The BL Lac 1ES 2344+514 is known for temporary extreme properties characterised by a shift of the synchrotron spectral energy distribution (SED) peak energy ν_synch, p_ above 1 keV. While those extreme states have only been observed during high flux levels thus far, additional multi-year observing campaigns are required to achieve a coherent picture. Here, we report the longest investigation of the source from radio to very high energy (VHE) performed so far, focussing on a systematic characterisation of the intermittent extreme states.
Methods. We organised a monitoring campaign covering a 3-year period from 2019 to 2021. More than ten instruments participated in the observations in order to cover the emission from radio to VHE. In particular, sensitive X-ray measurements by XMM-Newton, NuSTAR, and AstroSat took place simultaneously with multi-hour MAGIC observations, providing an unprecedented constraint of the two SED components for this blazar.
Results. While our results confirm that 1ES 2344+514 typically exhibits ν_synch, p_ > 1 keV during elevated flux periods, we also find periods where the extreme state coincides with low flux activity. A strong spectral variability thus happens in the quiescent state, and is likely caused by an increase in the electron acceleration efficiency without a change in the electron injection luminosity. On the other hand, we also report a strong X-ray flare (among the brightest for 1ES 2344+514) without a significant shift of ν_synch, p_. During this particular flare, the X-ray spectrum is among the softest of the campaign. It unveils complexity in the spectral evolution, where the common harder-when-brighter trend observed in BL Lacs is violated. By combining Swift-XRT and Swift-UVOT measurements during a low and hard X-ray state, we find an excess of the UV flux with respect to an extrapolation of the X-ray spectrum to lower energies. This UV excess implies that at least two regions significantly contribute to the infrared/optical/ultraviolet/X-ray emission. Using the simultaneous MAGIC, XMM-Newton, NuSTAR, and AstroSat observations, we argue that a region possibly associated with the 10 GHz radio core may explain such an excess. Finally, we investigate a VHE flare, showing an absence of simultaneous variability in the 0.3-2 keV band. Using time-dependent leptonic modelling, we show that this behaviour, in contradiction to single-zone scenarios, can instead be explained by a two-component model.

Abstract Copyright: © The Authors 2024

Journal keyword(s): radiation mechanisms: non-thermal - galaxies: active - BL Lacertae objects: individual: 1ES 2344+514

Simbad objects: 9

Full paper

View the references in ADS

Number of rows : 9

N	Identifier	Otype	ICRS (J2000) RA	ICRS (J2000) DEC	Mag U	Mag B	Mag V	Mag R	Sp type	#ref 1850 - 2026	#notes
1	RX J0232.8+2017	BLL	02 32 48.6148874688	+20 17 17.486717388			18.00	13.96	~	387	1
2	QSO B0235+1624	BLL	02 38 38.93010450	+16 36 59.2745528		16.46	15.50	15.92	~	1614	2
3	M 1	SNR	05 34 31.8	+22 01 03					~	6516	1
4	RX J0710.5+5908	BLL	07 10 30.0683697888	+59 08 20.371772544		17.38	16.52	15.1	~	249	1
5	Z 184-50	BLL	11 04 27.3140835504	+38 12 31.798495872		13.50	12.90	8.31	~	2841	1
6	3C 286	Sy1	13 31 08.2883506368	+30 30 32.960091564		17.51	17.25		~	4558	2
7	RX J1428.5+4240	BLL	14 28 32.6090008440	+42 40 21.048123396		16.95	16.45	14.4	~	549	1
8	Z 225-7	BLL	16 53 52.21668403	+39 45 36.6088754	14.09	14.15	13.29	8.26	~	2304	2
9	QSO B2344+514	BLL	23 47 04.8372110928	+51 42 17.877513168			15.50	10.7	~	500	1

To bookmark this query, right click on this link: simbad:objects in 2024A&A...682A.114M and select 'bookmark this link' or equivalent in the popup menu