2009A&A...507.1211R


C.D.S. - SIMBAD4 rel 1.7 - 2021.02.27CET14:00:49

2009A&A...507.1211R - Astronomy and Astrophysics, volume 507, 1211-1215 (2009/12-1)

Quenching of the strong aperiodic accretion disk variability at the magnetospheric boundary.

REVNIVTSEV M., CHURAZOV E., POSTNOV K. and TSYGANKOV S.

Abstract (from CDS):

We study power density spectra (PDS) of X-ray flux variability in binary systems, where the accretion flow is truncated by the magnetosphere. PDS of accreting X-ray pulsars, where the neutron star is almost corotating with the accretion disk at the magnetospheric boundary, have a distinct break/cutoff at the neutron star spin frequency. This break can naturally be explained by the ``perturbation propagation'' model, which assumes that at any given radius in the accretion disk stochastic perturbations are introduced in flow with frequencies that are characteristic of this radius. These perturbations are then advected to the region of main energy release leading to a self-similar variability in the X-ray flux P∝f–1...–1.5. The break in the PDS is then a natural manifestation of the transition from the disk to the magnetospheric flow at the frequency characteristic of the accretion disk truncation radius (magnetospheric radius). The proximity of the PDS break frequency to the spin frequency in corotating pulsars strongly suggests that the typical variability timescale in accretion disks is close to the Keplerian one. In transient accreting X-ray pulsars characterized by large variations in the mass accretion rate during outbursts, the PDS break frequency follows the variations in the X-ray flux, reflecting the change in the magnetosphere size with the accretion rate. Above the break frequency, the PDS steepens to close to f–2 law which holds over a broad frequency range. These results suggest that strong f–1...–1.5 aperiodic variability, which is ubiquitous in accretion disks, is not characteristic of magnetospheric flows.

Abstract Copyright:

Journal keyword(s): accretion, accretion disks - instabilities - turbulence - stars: binaries: general - stars: magnetic fields - X-rays: general

Simbad objects: 15

goto Full paper

goto View the reference in ADS

Number of rows : 15

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 V* V635 Cas HXB 01 18 31.9704429246 +63 44 33.071137750 17.05 16.64 15.19 14.34 13.22 B0.2Ve 673 0
2 V* BQ Cam HXB 03 34 59.9116460415 +53 10 23.296351781   17.16 15.42 14.26 13.04 O8.5Ve 411 1
3 V* X Per HXB 03 55 23.0778791365 +31 02 45.045745259 6.090 6.840 6.720     O9.5III 917 0
4 HD 245770 HXB 05 38 54.5749436467 +26 18 56.839215267 9.30 9.84 9.39 8.77 8.30 O9/B0III/Ve 885 0
5 V* GP Vel HXB 09 02 06.8610736194 -40 33 16.896402010 6.85 7.37 6.87 6.31 6.05 B0.5Ia 1385 0
6 V* V779 Cen HXB 11 21 15.0920367078 -60 37 25.627505233   14.4 12.27     O9III/Veq 1004 0
7 V* BP Cru HXB 12 26 37.5607088371 -62 46 13.259605389   12.70 10.66     B1.5Iaeq 614 0
8 V* QV Nor HXB 15 42 23.3633078550 -52 23 09.576918639   16.3 14.5     B0.2Ia:e 379 1
9 V* KZ TrA LXB 16 32 16.79 -67 27 39.3 17.40 18.60 18.5     ~ 533 1
10 V* V2116 Oph Sy* 17 32 02.1544831482 -24 44 44.125962969   20.78 18.4     M6IIIe 652 1
11 V* AM Her AM* 18 16 13.2546541781 +49 52 04.759861155     12.30     M4.5 915 0
12 V* V1223 Sgr DQ* 18 55 02.3109253503 -31 09 49.589704079           ~ 305 0
13 2MASS J19493548+3012317 HXB 19 49 35.4840244577 +30 12 31.775034731   15.16 14.22 13.53 12.88 B0Ve 140 1
14 HD 226868 HXB 19 58 21.6758193269 +35 12 05.782512305 9.38 9.72 8.91 8.42   O9.7Iabpvar 3982 0
15 V* V2246 Cyg HXB 20 32 15.2744631713 +37 38 14.839930326   22.16 19.41 17.32 15.18 B0Ve 382 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2009A&A...507.1211R and select 'bookmark this link' or equivalent in the popup menu


2021.02.27-14:00:49

© Université de Strasbourg/CNRS

    • Contact