The narrow variable components of C iv in NGC 4151 from 1981 to 1987

被引:5
作者
Ulrich, MH
机构
[1] European Southern Observatory, D-85748 Garching
关键词
galaxies; individual; NGC; 4151; jets; nuclei galaxies; Seyfert; ultraviolet;
D O I
10.1093/mnras/281.3.907
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The nucleus of the Seyfert 1 galaxy NGC 4151 undergoes large-amplitude variations and occasionally passes through deep minimum states lasting up to a few months. Two narrow emission lines, L(1) and L(2), variable in intensity on a time-scale of a few days were discovered during International Ultra-violet Explorer (IUE) campaigns at low states in 1981 and 1984 and were identified with components of C IV lambda 1550 blueshifted and redshifted by -6100 km s(-1) and +8500 km s(-1) respectively. We re-analyse in an homogeneous fashion these data and additional unpublished data obtained with IUE in 1986 and 1987. This analysis confirms the previous results and adds to our knowledge on the longer term behaviour of L(1) and L(2). Specifically, (i) at each low state, the two lines re-appear with approximately the same intensity range and variation time-scale as in previous low states, even though in the meantime the nucleus passed through bright episodes with strong continuum and intense broad emission components. (ii) There is no detectable wavelength drift of L(1) and L(2) in 6.7 yr. The observed wavelength of L(1) remains constant at 1522.75 +/- 0.4 Angstrom. (iii) There are correlations between the intensity of L(1) and the intensity of L(2), and between the intensities of the two lines with the continuum flux. These correlations are strongest in 1981 and 1984. We briefly discuss various interpretations and conclude that, at present, none is satisfactory.
引用
收藏
页码:907 / 915
页数:9
相关论文
共 16 条
[1]   THE ULTRAVIOLET CALIBRATION OF THE HUBBLE SPACE TELESCOPE .2. A CORRECTION FOR THE CHANGE IN SENSITIVITY OF THE SWP CAMERA ON THE IUE [J].
BOHLIN, RC ;
GRILLMAIR, CJ .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1988, 66 (02) :209-226
[2]   IUE OBSERVATIONS OF EXTRA-GALACTIC OBJECTS [J].
BOKSENBERG, A ;
SNIJDERS, MAJ ;
WILSON, R ;
BENVENUTI, P ;
CLAVELL, J ;
MACCHETTO, F ;
PENSTON, M ;
BOGGESS, A ;
GULL, TR ;
GONDHALEKAR, P ;
LANE, AL ;
TURNROSE, B ;
WU, CC ;
BURTON, WM ;
SMITH, A ;
BERTOLA, F ;
CAPACCIOLI, M ;
ELVIUS, AM ;
FOSBURY, R ;
TARENGHI, M ;
ULRICH, MH ;
HACKNEY, RL ;
JORDAN, C ;
PEROLA, CG ;
ROEDER, RC ;
SCHMIDT, M .
NATURE, 1978, 275 (5679) :404-414
[3]  
BROMAGE GE, 1985, MON NOT R ASTRON SOC, V215, P1
[4]   A DETAILED STUDY OF THE C-IV-LAMBDA-1550 LINE-PROFILE AND ADJACENT SPECTRAL FEATURES IN NGC-4151 FROM 1978 TO 1983 [J].
CLAVEL, J ;
ALTAMORE, A ;
BOKSENBERG, A ;
BROMAGE, GE ;
ELVIUS, A ;
PELAT, D ;
PENSTON, MV ;
PEROLA, GC ;
SNIJDERS, MAJ ;
ULRICH, MH .
ASTROPHYSICAL JOURNAL, 1987, 321 (01) :251-279
[5]  
CLAVEL J, 1990, MON NOT R ASTRON SOC, V246, P668
[6]   PHOTOGRAPHIC B-BAND MONITORING OF NGC-4151 [J].
GILL, TR ;
LLOYD, C ;
PENSTON, MV ;
SNIJDERS, MAJ .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1984, 211 (01) :31-37
[7]   DETAILED OBSERVATIONS OF NGC-4151 WITH IUE-I LOW DISPERSION DATA UP TO 1979 JANUARY [J].
PENSTON, MV ;
BOKSENBERG, A ;
BROMAGE, GE ;
CLAVEL, J ;
ELVIUS, A ;
GONDHALEKAR, PM ;
JORDAN, C ;
LIND, J ;
LINDEGREN, L ;
PEROLA, GC ;
PETTINI, M ;
SNIJDERS, MAJ ;
TANZI, EG ;
TARENGHI, M ;
ULRICH, MH .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1981, 196 (03) :857-887
[8]  
PEROLA GC, 1982, MNRAS, V196, P857
[9]  
PEROLA GC, 1986, APJ, V306, P568
[10]   SATELLITE EMISSION FEATURES IN 2 SEYFERT-GALAXIES - NEW EVIDENCE THAT RADIO-QUIET AGN POSSESS SUBRELATIVISTIC WINDS [J].
STOCKE, JT ;
SHULL, JM ;
GRANADOS, AE ;
SACHS, ER .
ASTRONOMICAL JOURNAL, 1994, 108 (04) :1178-1185