Seminaria

Dnia 2025-11-04 o godzinie 13:15 w Sali 2011 Wydziału Fizyki UwB, mgr Laetitia Gibaud z Katedry Astrofizyki i Fizyki Teoretycznej na Wydziale Fizyki UwB wygłosi wykład pt:

„Investigating the X-ray weak, emission-line deficient quasar SDSS J101353.45+492758.1”

Serdecznie zapraszamy

Andrzej Maziewski

Jerzy Przeszowski

„Investigating the X-ray weak, emission-line deficient quasar SDSS J101353.45+492758.1”

mgr Laetitia Gibaud

Katedry Astrofizyki i Fizyki Teoretycznej na Wydziale Fizyki UwB

Szkoła doktorska nauk ścisłych i przyrodnicznych UwB

Weak emission-line quasars (WLQs) represent an intriguing subclass of active galactic nuclei (AGN), characterized by unusually faint or absent high-ionization emission lines [1, 4, 6] despite luminous quasar-like continua [7]. SDSS J101353.45+492758.1 stands out as a particularly extreme case, exhibiting a nearly lineless UV–optical spectrum and an exceptionally low X-ray flux. We analyze the broad-band spectral energy distribution (SED) of this source using both relativistic thin-disk model zkerrbb [3] and multi-component AGN models agnsed [2]. Both approaches yield consistent black hole mass MBH ≈ 2 × 109 M⊙ and accretion rate ( ˙m ≈ 0.1), comparable to typical luminous quasars. The fits require a strongly suppressed or absent hot corona, while adding a warm, optically thick Comptonizing region improves the match to the data. These results favor an intrinsically X-ray weak source, though scenarios involving shielding gas [8, 5] cannot be ruled out. The observed weakness of high-ionization lines, combined with the inferred coronal properties, points to unusual conditions in the broad line region (BLR). This source provides a unique window into the physical diversity of WLQs and the coupling between the accretion flow, corona, and line-emitting gas.

References:

[1] A. M. Diamond-Stanic et al., 2009, ApJ, 699, pp. 782–799.
[2] A. Kubota et al., 2018, MNRAS, 480, pp. 1247–1262.
[3] L.-X. Li et al., 2005, ApJS, 157, pp. 335–370.
[4] J. C. McDowell et al., 1995, ApJ, 450, p. 585.
[5] Q. Ni et al., 2018, MNRAS, 480, pp. 5184–5202.
[6] R. M. Plotkin et al., 2010, ApJ, 721, pp. 562–575.
[7] O. Shemmer et al., 2009, ApJ, 696, pp. 580–590.
[8] J. Wu et al., 2011, ApJ, 736, p. 28.