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H-alpha monitoring of OJ 287 in 2005-08
Tekijät: Nilsson K, Takalo LO, Lehto HJ, Sillanpaa A
Kustantaja: EDP SCIENCES S A
Julkaisuvuosi: 2010
Journal: Astronomy and Astrophysics
Tietokannassa oleva lehden nimi: ASTRONOMY & ASTROPHYSICS
Lehden akronyymi: ASTRON ASTROPHYS
Artikkelin numero: ARTN A60
Vuosikerta: 516
Sivujen määrä: 5
ISSN: 0004-6361
DOI: https://doi.org/10.1051/0004-6361/201014198
Tiivistelmä
We present the results of H alpha monitoring of the BL Lac object OJ 287 with the VLT during seven epochs in 2005-08. We were able to detect five previously undetected narrow emission lines,lambda lambda 6548, 6583[NII], lambda 6563H alpha and lambda lambda 6716, 6731 [SII] during at least one of the epochs and a broad H alpha feature during two epochs. The broad H alpha luminosity was a factor similar to 10 lower in 2005-08 than in 1984 when the line was previously detected and a factor similar to 10 lower than what is observed in quasars and Seyfert galaxies at the same redshift. The data are consistent with no change in the position or luminostity of the H alpha line in 2005-08. The width of the H alpha line was 4200 +/- 500 km s(-1), consistent with the width in 1984.
We present the results of H alpha monitoring of the BL Lac object OJ 287 with the VLT during seven epochs in 2005-08. We were able to detect five previously undetected narrow emission lines,lambda lambda 6548, 6583[NII], lambda 6563H alpha and lambda lambda 6716, 6731 [SII] during at least one of the epochs and a broad H alpha feature during two epochs. The broad H alpha luminosity was a factor similar to 10 lower in 2005-08 than in 1984 when the line was previously detected and a factor similar to 10 lower than what is observed in quasars and Seyfert galaxies at the same redshift. The data are consistent with no change in the position or luminostity of the H alpha line in 2005-08. The width of the H alpha line was 4200 +/- 500 km s(-1), consistent with the width in 1984.
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