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WEBT multiwavelength monitoring and XMM-Newton observations of BL Lacertae in 2007-2008. / Raiteri, C. M.; Villata, M.; Capetti, A.; Aller, M. F.; Bach, U.; Calcidese, P.; Gurwell, M. A.; Larionov, V. M.; Ohlert, J.; Nilsson, K.; Strigachev, A.; Agudo, I.; Aller, H. D.; Bachev, R.; Benítez, E.; Berdyugin, A.; Böttcher, M.; Buemi, C. S.; Buttiglione, S.; Carosati, D.; Charlot, P.; Dultzin, D.; Forné, E.; Fuhrmann, L.; Gómez, J. L.; Gupta, A. C.; Heidt, J.; Hiriart, D.; Hsiao, W. S.; Jelínek, M.; Jorstad, S. G.; Kimeridze, G. N.; Konstantinova, T. S.; Kopatskaya, E. N.; Kostov, A.; Kurtanidze, O. M.; Lähteenmäki, A.; Lanteri, L.; Larionova, L. V.; Leto, P.; Latev, G.; Le Campion, J. F.; Ligustri, R.; Lindfors, E.; Marscher, A. P.; Mihov, B.; Nikolashvili, M. G.; Nikolov, Y.; Ovcharov, E.; Principe, D.; Pursimo, T.; Ragozzine, B.; Robb, R. M.; Ros, J. A.; Sadun, A. C.; Sagar, R.; Semkov, E.; Sigua, L. A.; Smart, R. L.; Sorcia, M.; Takalo, L. O.; Tornikoski, M.; Trigilio, C.; Uckert, K.; Umana, G.; Valcheva, A.; Volvach, A.

In: Astronomy and Astrophysics, Vol. 507, No. 2, 04.11.2009, p. 769-779.

Research output: Contribution to journal › Article › peer-review

Harvard

Raiteri, CM, Villata, M, Capetti, A, Aller, MF, Bach, U, Calcidese, P, Gurwell, MA, Larionov, VM, Ohlert, J, Nilsson, K, Strigachev, A, Agudo, I, Aller, HD, Bachev, R, Benítez, E, Berdyugin, A, Böttcher, M, Buemi, CS, Buttiglione, S, Carosati, D, Charlot, P, Dultzin, D, Forné, E, Fuhrmann, L, Gómez, JL, Gupta, AC, Heidt, J, Hiriart, D, Hsiao, WS, Jelínek, M, Jorstad, SG, Kimeridze, GN, Konstantinova, TS, Kopatskaya, EN, Kostov, A, Kurtanidze, OM, Lähteenmäki, A, Lanteri, L, Larionova, LV, Leto, P, Latev, G, Le Campion, JF, Ligustri, R, Lindfors, E, Marscher, AP, Mihov, B, Nikolashvili, MG, Nikolov, Y, Ovcharov, E, Principe, D, Pursimo, T, Ragozzine, B, Robb, RM, Ros, JA, Sadun, AC, Sagar, R, Semkov, E, Sigua, LA, Smart, RL, Sorcia, M, Takalo, LO, Tornikoski, M, Trigilio, C, Uckert, K, Umana, G, Valcheva, A & Volvach, A 2009, 'WEBT multiwavelength monitoring and XMM-Newton observations of BL Lacertae in 2007-2008', Astronomy and Astrophysics, vol. 507, no. 2, pp. 769-779. https://doi.org/10.1051/0004-6361/200912953

APA

Raiteri, C. M., Villata, M., Capetti, A., Aller, M. F., Bach, U., Calcidese, P., Gurwell, M. A., Larionov, V. M., Ohlert, J., Nilsson, K., Strigachev, A., Agudo, I., Aller, H. D., Bachev, R., Benítez, E., Berdyugin, A., Böttcher, M., Buemi, C. S., Buttiglione, S., ... Volvach, A. (2009). WEBT multiwavelength monitoring and XMM-Newton observations of BL Lacertae in 2007-2008. Astronomy and Astrophysics, 507(2), 769-779. https://doi.org/10.1051/0004-6361/200912953

Vancouver

Raiteri CM, Villata M, Capetti A, Aller MF, Bach U, Calcidese P et al. WEBT multiwavelength monitoring and XMM-Newton observations of BL Lacertae in 2007-2008. Astronomy and Astrophysics. 2009 Nov 4;507(2):769-779. https://doi.org/10.1051/0004-6361/200912953

Author

Raiteri, C. M. ; Villata, M. ; Capetti, A. ; Aller, M. F. ; Bach, U. ; Calcidese, P. ; Gurwell, M. A. ; Larionov, V. M. ; Ohlert, J. ; Nilsson, K. ; Strigachev, A. ; Agudo, I. ; Aller, H. D. ; Bachev, R. ; Benítez, E. ; Berdyugin, A. ; Böttcher, M. ; Buemi, C. S. ; Buttiglione, S. ; Carosati, D. ; Charlot, P. ; Dultzin, D. ; Forné, E. ; Fuhrmann, L. ; Gómez, J. L. ; Gupta, A. C. ; Heidt, J. ; Hiriart, D. ; Hsiao, W. S. ; Jelínek, M. ; Jorstad, S. G. ; Kimeridze, G. N. ; Konstantinova, T. S. ; Kopatskaya, E. N. ; Kostov, A. ; Kurtanidze, O. M. ; Lähteenmäki, A. ; Lanteri, L. ; Larionova, L. V. ; Leto, P. ; Latev, G. ; Le Campion, J. F. ; Ligustri, R. ; Lindfors, E. ; Marscher, A. P. ; Mihov, B. ; Nikolashvili, M. G. ; Nikolov, Y. ; Ovcharov, E. ; Principe, D. ; Pursimo, T. ; Ragozzine, B. ; Robb, R. M. ; Ros, J. A. ; Sadun, A. C. ; Sagar, R. ; Semkov, E. ; Sigua, L. A. ; Smart, R. L. ; Sorcia, M. ; Takalo, L. O. ; Tornikoski, M. ; Trigilio, C. ; Uckert, K. ; Umana, G. ; Valcheva, A. ; Volvach, A. / WEBT multiwavelength monitoring and XMM-Newton observations of BL Lacertae in 2007-2008. In: Astronomy and Astrophysics. 2009 ; Vol. 507, No. 2. pp. 769-779.

BibTeX

@article{53230e9176ec489cb97294d960229e15,
title = "WEBT multiwavelength monitoring and XMM-Newton observations of BL Lacertae in 2007-2008",
abstract = "Context. BL Lacertae is the prototype of the blazar subclass named after it. Yet, it has occasionally shown a peculiar behaviour that has questioned a simple interpretation of its broad-band emission in terms of synchrotron plus synchrotron self-Compton (SSC) radiation.Aims. In the 2007-2008 observing season we carried out a new multiwavelength campaign of the Whole Earth Blazar Telescope (WEBT) on BL Lacertae, involving three pointings by the XMM-Newton satellite in July and December 2007, and January 2008, to study its emission properties, particularly in the optical-X-ray energy range.Methods. The source was monitored in the optical-to-radio bands by 37 telescopes. The brightness level was relatively low. Some episodes of very fast variability were detected in the optical bands. Flux changes had larger amplitude at the higher radio frequencies than at longer wavelengths.Results. The X-ray spectra acquired by the EPIC instrument onboard XMM-Newton are well fitted by a power law with photon index Λ ∼ 2 and photoelectric absorption exceeding the Galactic value. However, when taking into account the presence of a molecular cloud on the line of sight, the EPIC data are best fitted by a double power law, implying a concave X-ray spectrum. The spectral energy distributions (SEDs) built with simultaneous radio-to-X-ray data at the epochs of the XMM-Newton observations suggest that the peak of the synchrotron emission lies in the near-IR band, and show a prominent UV excess, besides a slight soft-X-ray excess. A comparison with the SEDs corresponding to previous observations with X-ray satellites shows that the X-ray spectrum is very variable, since it can change from extremely steep to extremely hard, and can be more or less curved in intermediate states. We ascribe the UV excess to thermal emission from the accretion disc, and the other broad-band spectral features to the presence of two synchrotron components, with their related SSC emission. We fit the thermal emission with a black body law and the non-thermal components by means of a helical jet model. The fit indicates a disc temperature ≳20 000K and a luminosity ≳ 6 × 1044 erg s-1.",
keywords = "Galaxies: active, Galaxies: BL Lacertae objects: general, Galaxies: BL Lacertae objects: individual: BL Lacertae, Galaxies: jets",
author = "Raiteri, {C. M.} and M. Villata and A. Capetti and Aller, {M. F.} and U. Bach and P. Calcidese and Gurwell, {M. A.} and Larionov, {V. M.} and J. Ohlert and K. Nilsson and A. Strigachev and I. Agudo and Aller, {H. D.} and R. Bachev and E. Ben{\'i}tez and A. Berdyugin and M. B{\"o}ttcher and Buemi, {C. S.} and S. Buttiglione and D. Carosati and P. Charlot and D. Dultzin and E. Forn{\'e} and L. Fuhrmann and G{\'o}mez, {J. L.} and Gupta, {A. C.} and J. Heidt and D. Hiriart and Hsiao, {W. S.} and M. Jel{\'i}nek and Jorstad, {S. G.} and Kimeridze, {G. N.} and Konstantinova, {T. S.} and Kopatskaya, {E. N.} and A. Kostov and Kurtanidze, {O. M.} and A. L{\"a}hteenm{\"a}ki and L. Lanteri and Larionova, {L. V.} and P. Leto and G. Latev and {Le Campion}, {J. F.} and R. Ligustri and E. Lindfors and Marscher, {A. P.} and B. Mihov and Nikolashvili, {M. G.} and Y. Nikolov and E. Ovcharov and D. Principe and T. Pursimo and B. Ragozzine and Robb, {R. M.} and Ros, {J. A.} and Sadun, {A. C.} and R. Sagar and E. Semkov and Sigua, {L. A.} and Smart, {R. L.} and M. Sorcia and Takalo, {L. O.} and M. Tornikoski and C. Trigilio and K. Uckert and G. Umana and A. Valcheva and A. Volvach",
year = "2009",
month = nov,
day = "4",
doi = "10.1051/0004-6361/200912953",
language = "English",
volume = "507",
pages = "769--779",
journal = "ASTRONOMY & ASTROPHYSICS",
issn = "0004-6361",
publisher = "EDP Sciences",
number = "2",

}

RIS

TY - JOUR

T1 - WEBT multiwavelength monitoring and XMM-Newton observations of BL Lacertae in 2007-2008

AU - Raiteri, C. M.

AU - Villata, M.

AU - Capetti, A.

AU - Aller, M. F.

AU - Bach, U.

AU - Calcidese, P.

AU - Gurwell, M. A.

AU - Larionov, V. M.

AU - Ohlert, J.

AU - Nilsson, K.

AU - Strigachev, A.

AU - Agudo, I.

AU - Aller, H. D.

AU - Bachev, R.

AU - Benítez, E.

AU - Berdyugin, A.

AU - Böttcher, M.

AU - Buemi, C. S.

AU - Buttiglione, S.

AU - Carosati, D.

AU - Charlot, P.

AU - Dultzin, D.

AU - Forné, E.

AU - Fuhrmann, L.

AU - Gómez, J. L.

AU - Gupta, A. C.

AU - Heidt, J.

AU - Hiriart, D.

AU - Hsiao, W. S.

AU - Jelínek, M.

AU - Jorstad, S. G.

AU - Kimeridze, G. N.

AU - Konstantinova, T. S.

AU - Kopatskaya, E. N.

AU - Kostov, A.

AU - Kurtanidze, O. M.

AU - Lähteenmäki, A.

AU - Lanteri, L.

AU - Larionova, L. V.

AU - Leto, P.

AU - Latev, G.

AU - Le Campion, J. F.

AU - Ligustri, R.

AU - Lindfors, E.

AU - Marscher, A. P.

AU - Mihov, B.

AU - Nikolashvili, M. G.

AU - Nikolov, Y.

AU - Ovcharov, E.

AU - Principe, D.

AU - Pursimo, T.

AU - Ragozzine, B.

AU - Robb, R. M.

AU - Ros, J. A.

AU - Sadun, A. C.

AU - Sagar, R.

AU - Semkov, E.

AU - Sigua, L. A.

AU - Smart, R. L.

AU - Sorcia, M.

AU - Takalo, L. O.

AU - Tornikoski, M.

AU - Trigilio, C.

AU - Uckert, K.

AU - Umana, G.

AU - Valcheva, A.

AU - Volvach, A.

PY - 2009/11/4

Y1 - 2009/11/4

N2 - Context. BL Lacertae is the prototype of the blazar subclass named after it. Yet, it has occasionally shown a peculiar behaviour that has questioned a simple interpretation of its broad-band emission in terms of synchrotron plus synchrotron self-Compton (SSC) radiation.Aims. In the 2007-2008 observing season we carried out a new multiwavelength campaign of the Whole Earth Blazar Telescope (WEBT) on BL Lacertae, involving three pointings by the XMM-Newton satellite in July and December 2007, and January 2008, to study its emission properties, particularly in the optical-X-ray energy range.Methods. The source was monitored in the optical-to-radio bands by 37 telescopes. The brightness level was relatively low. Some episodes of very fast variability were detected in the optical bands. Flux changes had larger amplitude at the higher radio frequencies than at longer wavelengths.Results. The X-ray spectra acquired by the EPIC instrument onboard XMM-Newton are well fitted by a power law with photon index Λ ∼ 2 and photoelectric absorption exceeding the Galactic value. However, when taking into account the presence of a molecular cloud on the line of sight, the EPIC data are best fitted by a double power law, implying a concave X-ray spectrum. The spectral energy distributions (SEDs) built with simultaneous radio-to-X-ray data at the epochs of the XMM-Newton observations suggest that the peak of the synchrotron emission lies in the near-IR band, and show a prominent UV excess, besides a slight soft-X-ray excess. A comparison with the SEDs corresponding to previous observations with X-ray satellites shows that the X-ray spectrum is very variable, since it can change from extremely steep to extremely hard, and can be more or less curved in intermediate states. We ascribe the UV excess to thermal emission from the accretion disc, and the other broad-band spectral features to the presence of two synchrotron components, with their related SSC emission. We fit the thermal emission with a black body law and the non-thermal components by means of a helical jet model. The fit indicates a disc temperature ≳20 000K and a luminosity ≳ 6 × 1044 erg s-1.

AB - Context. BL Lacertae is the prototype of the blazar subclass named after it. Yet, it has occasionally shown a peculiar behaviour that has questioned a simple interpretation of its broad-band emission in terms of synchrotron plus synchrotron self-Compton (SSC) radiation.Aims. In the 2007-2008 observing season we carried out a new multiwavelength campaign of the Whole Earth Blazar Telescope (WEBT) on BL Lacertae, involving three pointings by the XMM-Newton satellite in July and December 2007, and January 2008, to study its emission properties, particularly in the optical-X-ray energy range.Methods. The source was monitored in the optical-to-radio bands by 37 telescopes. The brightness level was relatively low. Some episodes of very fast variability were detected in the optical bands. Flux changes had larger amplitude at the higher radio frequencies than at longer wavelengths.Results. The X-ray spectra acquired by the EPIC instrument onboard XMM-Newton are well fitted by a power law with photon index Λ ∼ 2 and photoelectric absorption exceeding the Galactic value. However, when taking into account the presence of a molecular cloud on the line of sight, the EPIC data are best fitted by a double power law, implying a concave X-ray spectrum. The spectral energy distributions (SEDs) built with simultaneous radio-to-X-ray data at the epochs of the XMM-Newton observations suggest that the peak of the synchrotron emission lies in the near-IR band, and show a prominent UV excess, besides a slight soft-X-ray excess. A comparison with the SEDs corresponding to previous observations with X-ray satellites shows that the X-ray spectrum is very variable, since it can change from extremely steep to extremely hard, and can be more or less curved in intermediate states. We ascribe the UV excess to thermal emission from the accretion disc, and the other broad-band spectral features to the presence of two synchrotron components, with their related SSC emission. We fit the thermal emission with a black body law and the non-thermal components by means of a helical jet model. The fit indicates a disc temperature ≳20 000K and a luminosity ≳ 6 × 1044 erg s-1.

KW - Galaxies: active

KW - Galaxies: BL Lacertae objects: general

KW - Galaxies: BL Lacertae objects: individual: BL Lacertae

KW - Galaxies: jets

UR - http://www.scopus.com/inward/record.url?scp=70450207356&partnerID=8YFLogxK

U2 - 10.1051/0004-6361/200912953

DO - 10.1051/0004-6361/200912953

M3 - Article

AN - SCOPUS:70450207356

VL - 507

SP - 769

EP - 779

JO - ASTRONOMY & ASTROPHYSICS

JF - ASTRONOMY & ASTROPHYSICS

SN - 0004-6361

IS - 2

ER -

ID: 88378689