Multiwavelength monitoring of the narrow-line Seyfert 1 galaxy Arakelian 564. III. Optical observations and the optical-UV-X-ray connection

O. Shemmer; P. Romano; R. Bertram; W. Brinkmann; S. Collier; K. A. Crowley; E. Detsis; A. V. Filippenko; C. M. Gaskell; T. A. George; M. Gliozzi; M. E. Hiller; T. L. Jewell; S. Kaspi; E. S. Klimek; M. H. Lannon; W. Li; P. Martini; S. Mathur; H. Negoro; H. Netzer; I. Papadakis; I. Papamastorakis; B. M. Peterson; B. W. Peterson; R. W. Pogge; V. I. Pronik; K. S. Rumstay; S. G. Sergeev; E. A. Sergeeva; G. M. Stirpe; C. J. Taylor; R. R. Treffers; T. J. Turner; P. Uttley; M. Vestergaard; K. Von Braun; R. M. Wagner; Z. Zheng

doi:10.1086/323236

Multiwavelength monitoring of the narrow-line Seyfert 1 galaxy Arakelian 564. III. Optical observations and the optical-UV-X-ray connection

O. Shemmer^*, P. Romano, R. Bertram, W. Brinkmann, S. Collier, K. A. Crowley, E. Detsis, A. V. Filippenko, C. M. Gaskell, T. A. George, M. Gliozzi, M. E. Hiller, T. L. Jewell, S. Kaspi, E. S. Klimek, M. H. Lannon, W. Li, P. Martini, S. Mathur, H. NegoroH. Netzer, I. Papadakis, I. Papamastorakis, B. M. Peterson, B. W. Peterson, R. W. Pogge, V. I. Pronik, K. S. Rumstay, S. G. Sergeev, E. A. Sergeeva, G. M. Stirpe, C. J. Taylor, R. R. Treffers, T. J. Turner, P. Uttley, M. Vestergaard, K. Von Braun, R. M. Wagner, Z. Zheng

^*Corresponding author for this work

54 Citations (Scopus)

Abstract

We present the results of a 2 yr long optical monitoring program of the narrow-line Seyfert 1 galaxy Ark 564. The majority of this monitoring project was also covered by X-ray observations (RXTE), and for a period of ∼50 days, we observed the galaxy in UV (HST) and X-rays (RXTE and ASCA) simultaneously with the ground-based observations. Rapid and large-amplitude variations seen in the X-ray band, on a daily and hourly timescale, were not detected at optical and UV wavelengths, which in turn exhibited much lower variability either on short (1 day) or long (several months) timescales. The only significant optical variations can be described as two 2-4 day events with ∼10% flux variations. We detect no significant optical line variations and thus cannot infer a reverberation size for the broad-line region. Similarly, the large X-ray variations seem to vanish when the light curve is smoothed over a period of 30 days. The UV continuum follows the X-rays with a lag of ∼0.4 days, and the optical band lags the UV band by ∼2 days. No significant correlation was found between the entire X-ray data set and the optical band. Focusing on a 20 day interval around the strongest optical event we detect a significant X-ray-optical correlation with similar events seen in the UV and X-rays. Our data are consistent with reprocessing models on the grounds of the energy emitted in this single event. However, several large X-ray flares produced no corresponding optical emission.

Original language	English
Journal	Astrophysical Journal
Volume	561
Issue number	1 PART 1
Pages (from-to)	162-170
Number of pages	9
ISSN	0004-637X
DOIs	https://doi.org/10.1086/323236
Publication status	Published - 1 Nov 2001
Externally published	Yes

Keywords

Galaxies: active
Galaxies: individual (Arakelian 564)
Galaxies: nuclei
Galaxies: Seyfert
X-rays: galaxies

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10.1086/323236Licence: CC BY

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Shemmer, O., Romano, P., Bertram, R., Brinkmann, W., Collier, S., Crowley, K. A., Detsis, E., Filippenko, A. V., Gaskell, C. M., George, T. A., Gliozzi, M., Hiller, M. E., Jewell, T. L., Kaspi, S., Klimek, E. S., Lannon, M. H., Li, W., Martini, P., Mathur, S., ... Zheng, Z. (2001). Multiwavelength monitoring of the narrow-line Seyfert 1 galaxy Arakelian 564. III. Optical observations and the optical-UV-X-ray connection. Astrophysical Journal, 561(1 PART 1), 162-170. https://doi.org/10.1086/323236

Shemmer, O, Romano, P, Bertram, R, Brinkmann, W, Collier, S, Crowley, KA, Detsis, E, Filippenko, AV, Gaskell, CM, George, TA, Gliozzi, M, Hiller, ME, Jewell, TL, Kaspi, S, Klimek, ES, Lannon, MH, Li, W, Martini, P, Mathur, S, Negoro, H, Netzer, H, Papadakis, I, Papamastorakis, I, Peterson, BM, Peterson, BW, Pogge, RW, Pronik, VI, Rumstay, KS, Sergeev, SG, Sergeeva, EA, Stirpe, GM, Taylor, CJ, Treffers, RR, Turner, TJ, Uttley, P, Vestergaard, M, Von Braun, K, Wagner, RM & Zheng, Z 2001, 'Multiwavelength monitoring of the narrow-line Seyfert 1 galaxy Arakelian 564. III. Optical observations and the optical-UV-X-ray connection', Astrophysical Journal, vol. 561, no. 1 PART 1, pp. 162-170. https://doi.org/10.1086/323236

@article{92732669beb14b619ad2dcec5dca6e34,

title = "Multiwavelength monitoring of the narrow-line Seyfert 1 galaxy Arakelian 564. III. Optical observations and the optical-UV-X-ray connection",

abstract = "We present the results of a 2 yr long optical monitoring program of the narrow-line Seyfert 1 galaxy Ark 564. The majority of this monitoring project was also covered by X-ray observations (RXTE), and for a period of ∼50 days, we observed the galaxy in UV (HST) and X-rays (RXTE and ASCA) simultaneously with the ground-based observations. Rapid and large-amplitude variations seen in the X-ray band, on a daily and hourly timescale, were not detected at optical and UV wavelengths, which in turn exhibited much lower variability either on short (1 day) or long (several months) timescales. The only significant optical variations can be described as two 2-4 day events with ∼10% flux variations. We detect no significant optical line variations and thus cannot infer a reverberation size for the broad-line region. Similarly, the large X-ray variations seem to vanish when the light curve is smoothed over a period of 30 days. The UV continuum follows the X-rays with a lag of ∼0.4 days, and the optical band lags the UV band by ∼2 days. No significant correlation was found between the entire X-ray data set and the optical band. Focusing on a 20 day interval around the strongest optical event we detect a significant X-ray-optical correlation with similar events seen in the UV and X-rays. Our data are consistent with reprocessing models on the grounds of the energy emitted in this single event. However, several large X-ray flares produced no corresponding optical emission.",

keywords = "Galaxies: active, Galaxies: individual (Arakelian 564), Galaxies: nuclei, Galaxies: Seyfert, X-rays: galaxies",

author = "O. Shemmer and P. Romano and R. Bertram and W. Brinkmann and S. Collier and Crowley, {K. A.} and E. Detsis and Filippenko, {A. V.} and Gaskell, {C. M.} and George, {T. A.} and M. Gliozzi and Hiller, {M. E.} and Jewell, {T. L.} and S. Kaspi and Klimek, {E. S.} and Lannon, {M. H.} and W. Li and P. Martini and S. Mathur and H. Negoro and H. Netzer and I. Papadakis and I. Papamastorakis and Peterson, {B. M.} and Peterson, {B. W.} and Pogge, {R. W.} and Pronik, {V. I.} and Rumstay, {K. S.} and Sergeev, {S. G.} and Sergeeva, {E. A.} and Stirpe, {G. M.} and Taylor, {C. J.} and Treffers, {R. R.} and Turner, {T. J.} and P. Uttley and M. Vestergaard and {Von Braun}, K. and Wagner, {R. M.} and Z. Zheng",

year = "2001",

month = nov,

day = "1",

doi = "10.1086/323236",

language = "English",

volume = "561",

pages = "162--170",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "Institute of Physics Publishing, Inc",

number = "1 PART 1",

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TY - JOUR

T1 - Multiwavelength monitoring of the narrow-line Seyfert 1 galaxy Arakelian 564. III. Optical observations and the optical-UV-X-ray connection

AU - Shemmer, O.

AU - Romano, P.

AU - Bertram, R.

AU - Brinkmann, W.

AU - Collier, S.

AU - Crowley, K. A.

AU - Detsis, E.

AU - Filippenko, A. V.

AU - Gaskell, C. M.

AU - George, T. A.

AU - Gliozzi, M.

AU - Hiller, M. E.

AU - Jewell, T. L.

AU - Kaspi, S.

AU - Klimek, E. S.

AU - Lannon, M. H.

AU - Li, W.

AU - Martini, P.

AU - Mathur, S.

AU - Negoro, H.

AU - Netzer, H.

AU - Papadakis, I.

AU - Papamastorakis, I.

AU - Peterson, B. M.

AU - Peterson, B. W.

AU - Pogge, R. W.

AU - Pronik, V. I.

AU - Rumstay, K. S.

AU - Sergeev, S. G.

AU - Sergeeva, E. A.

AU - Stirpe, G. M.

AU - Taylor, C. J.

AU - Treffers, R. R.

AU - Turner, T. J.

AU - Uttley, P.

AU - Vestergaard, M.

AU - Von Braun, K.

AU - Wagner, R. M.

AU - Zheng, Z.

PY - 2001/11/1

Y1 - 2001/11/1

N2 - We present the results of a 2 yr long optical monitoring program of the narrow-line Seyfert 1 galaxy Ark 564. The majority of this monitoring project was also covered by X-ray observations (RXTE), and for a period of ∼50 days, we observed the galaxy in UV (HST) and X-rays (RXTE and ASCA) simultaneously with the ground-based observations. Rapid and large-amplitude variations seen in the X-ray band, on a daily and hourly timescale, were not detected at optical and UV wavelengths, which in turn exhibited much lower variability either on short (1 day) or long (several months) timescales. The only significant optical variations can be described as two 2-4 day events with ∼10% flux variations. We detect no significant optical line variations and thus cannot infer a reverberation size for the broad-line region. Similarly, the large X-ray variations seem to vanish when the light curve is smoothed over a period of 30 days. The UV continuum follows the X-rays with a lag of ∼0.4 days, and the optical band lags the UV band by ∼2 days. No significant correlation was found between the entire X-ray data set and the optical band. Focusing on a 20 day interval around the strongest optical event we detect a significant X-ray-optical correlation with similar events seen in the UV and X-rays. Our data are consistent with reprocessing models on the grounds of the energy emitted in this single event. However, several large X-ray flares produced no corresponding optical emission.

AB - We present the results of a 2 yr long optical monitoring program of the narrow-line Seyfert 1 galaxy Ark 564. The majority of this monitoring project was also covered by X-ray observations (RXTE), and for a period of ∼50 days, we observed the galaxy in UV (HST) and X-rays (RXTE and ASCA) simultaneously with the ground-based observations. Rapid and large-amplitude variations seen in the X-ray band, on a daily and hourly timescale, were not detected at optical and UV wavelengths, which in turn exhibited much lower variability either on short (1 day) or long (several months) timescales. The only significant optical variations can be described as two 2-4 day events with ∼10% flux variations. We detect no significant optical line variations and thus cannot infer a reverberation size for the broad-line region. Similarly, the large X-ray variations seem to vanish when the light curve is smoothed over a period of 30 days. The UV continuum follows the X-rays with a lag of ∼0.4 days, and the optical band lags the UV band by ∼2 days. No significant correlation was found between the entire X-ray data set and the optical band. Focusing on a 20 day interval around the strongest optical event we detect a significant X-ray-optical correlation with similar events seen in the UV and X-rays. Our data are consistent with reprocessing models on the grounds of the energy emitted in this single event. However, several large X-ray flares produced no corresponding optical emission.

KW - Galaxies: active

KW - Galaxies: individual (Arakelian 564)

KW - Galaxies: nuclei

KW - Galaxies: Seyfert

KW - X-rays: galaxies

UR - http://www.scopus.com/inward/record.url?scp=0035510776&partnerID=8YFLogxK

U2 - 10.1086/323236

DO - 10.1086/323236

M3 - Journal article

AN - SCOPUS:0035510776

SN - 0004-637X

VL - 561

SP - 162

EP - 170

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 1 PART 1

ER -

Multiwavelength monitoring of the narrow-line Seyfert 1 galaxy Arakelian 564. III. Optical observations and the optical-UV-X-ray connection

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Keywords

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