Parsec-scale properties of Markarian 501

被引：187

作者：

Giroletti, M

Giovannini, G

Feretti, L

Cotton, WD

Edwards, PG

Lara, L

Marscher, AP

Mattox, JR

Piner, BG

Venturi, T

机构：

[1] CNR, Ist Radioastron, I-40129 Bologna, Italy

[2] Univ Bologna, Dipartimento Astron, I-40127 Bologna, Italy

[3] Natl Radio Astron Observ, Charlottesville, VA 22903 USA

[4] Inst Space & Astronaut Sci, Kanagawa 2298510, Japan

[5] Univ Granada, Dept Fis Teor & Cosmos, E-18071 Granada, Spain

[6] CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain

[7] Boston Univ, Inst Astrophys Res, Boston, MA 02215 USA

[8] Francis Marion Univ, Dept Phys & Astron, Florence, SC 29501 USA

[9] Whittier Coll, Dept Phys & Astron, Whittier, CA 90608 USA

来源：

ASTROPHYSICAL JOURNAL | 2004年 / 600卷 / 01期

关键词：

BL Lacertae objects : individual (Markarian 501); galaxies : active; galaxies : jets; galaxies : nuclei;

D O I：

10.1086/379663

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present the results of a high angular resolution study of the BL Lac object Markarian 501 in the radio band. We consider data taken at 14 different epochs, ranging between 1.6 and 22 GHz in frequency, and including new Space VLBI observations obtained on 2001 March 5 and 6 at 1.6 and 5 GHz. We study the kinematics of the parsec-scale jet and estimate its bulk velocity and orientation with respect to the line of sight. Limb-brightened structure in the jet is clearly visible in our data, and we discuss its possible origin in terms of velocity gradients in the jet. Quasi-simultaneous, multiwavelength observations allow us to map the spectral index distribution and to compare it to the jet morphology. Finally, we estimate the physical parameters of the parsec-scale jet.

引用

页码：127 / 140

页数：14

共 43 条

[11]

Feretti L, 1999, ASTRON ASTROPHYS, V341, P29

[12]

FERETTI L, 1984, ASTRON ASTROPHYS, V139, P55

[13] VLBA observations of radio reference frame sources .2. Astrometric suitability based on observed structure [J].

Fey, AL ;

Charlot, P .

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1997, 111 (01) :95-142

[14]

Ficarra A., 1985, Astronomy & Astrophysics Supplement Series, V59, P255

[15] The radio jet velocities at high resolution [J].

Giovannini, G .

NEW ASTRONOMY REVIEWS, 2003, 47 (6-7) :551-555

[16]

GIOVANNINI G, 1988, ASTRON ASTROPHYS, V199, P73

[17] VLBI observations of a complete sample of radio galaxies: 10 years later [J].

Giovannini, G ;

Cotton, WD ;

Feretti, L ;

Lara, L ;

Venturi, T .

ASTROPHYSICAL JOURNAL, 2001, 552 (02) :508-526

[18]

Giovannini G, 1999, ASTR SOC P, V159, P439

[19] Overview and initial results of the very long baseline interferometry space observatory programme [J].

Hirabayashi, H ;

Hirosawa, H ;

Kobayashi, H ;

Murata, Y ;

Edwards, PG ;

Fomalont, EB ;

Fujisawa, K ;

Ichikawa, T ;

Kii, T ;

Lovell, JEJ ;

Moellenbrock, GA ;

Okayasu, R ;

Inoue, M ;

Kawaguchi, N ;

Kameno, S ;

Shibata, KM ;

Asaki, Y ;

Bushimata, T ;

Enome, S ;

Horiuchi, S ;

Miyaji, T ;

Umemoto, T ;

Migenes, V ;

Wajima, K ;

Nakajima, J ;

Morimoto, M ;

Ellis, J ;

Meier, DL ;

Murphy, DW ;

Preston, RA ;

Smith, JG ;

Tingay, SJ ;

Traub, DL ;

Wietfeldt, RD ;

Benson, JM ;

Claussen, MJ ;

Flatters, C ;

Romney, JD ;

Ulvestad, JS ;

D'Addario, LR ;

Langston, GI ;

Minter, AH ;

Carlson, BR ;

Dewdney, PE ;

Jauncey, DL ;

Reynolds, JE ;

Taylor, AR ;

McCulloch, PM ;

Cannon, WH ;

Gurvits, LI .

SCIENCE, 1998, 281 (5384) :1825-1829

[20] The VLBI space observatory programme and the radio-astronomical satellite HALCA [J].