CDS

2015A&A...575A..58M

Query : 2015A&A...575A..58M

2015A&A...575A..58M - Astronomy and Astrophysics, volume 575A, 58-58 (2015/3-1)

Origin of the X-ray off-states in Vela X-1.

MANOUSAKIS A. and WALTER R.

Abstract (from CDS):

Vela X-1 is the prototype of the classical super-giant high mass X-ray binary systems. Recent continuous and long monitoring campaigns revealed a large hard X-rays variability amplitude with strong flares and off-states. This activity has been interpreted by invoking clumpy stellar winds and/or magnetic gating mechanisms. We investigate whether the observed behavior may be explained by unstable hydrodynamic flows close to the neutron star instead of by the more exotic phenomena. We used the hydrodynamic code VH-1 to simulate the flow of the stellar wind with high temporal resolution and to compare the predicted accretion rate with the observed light curves. The simulation results are similar to the observed variability. Off-states are predicted with a duration of 5 to 120 min corresponding to transient low-density bubbles forming around the neutron star. Oscillations of the accretion rate with a typical period of ∼6800 s are generated in our simulations and observed. They correspond to the complex motion of a bow shock, moving either toward or away from the neutron star. Flares are also produced by the simulations up to a level of 1037erg/s. We have qualitatively reproduced the hard X-ray variations observed in Vela X-1 with hydrodynamic instabilities predicted by a simple model. More sophisticated phenomena, such as clumpy winds or the magnetic gating mechanism, are not excluded, but are not required either to explain the basic phenomenology.

Abstract Copyright: ∼

Journal keyword(s): X-rays: binaries - accretion, accretion disks - hydrodynamics - stars: winds, outflows - X-rays: individuals: Vela X-1

Simbad objects: 1

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Number of rows : 1
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023 		#notes
1 V* GP Vel HXB 09 02 06.8608812864 -40 33 16.899168060 6.85 7.37 6.87 6.31 6.05 B0.5Ia 1469 0

Query : 2015A&A...575A..58M

Basic data :
V* GP Vel -- High Mass X-ray Binary
Origin of the objects types :

(Ref) Object type as listed in the reference "Ref"
(acronym) Object type linked to the acronym according to the original reference
() Anterior to 2007, before we can link the objet type to a reference, or given by the CDS team in some particular cases

Other object types: 		* (1971PW&SO,HD,...), X (3A,EXMS,...), HXB (2013ApJS), SB* (SBC7,SBC9), gam (INTEGRAL1,INTREF), Psr (2007ApJS), V* (V*), UV (TD1), NIR (2MASS)
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
ICRS coord. (ep=J2000) : 		09 02 06.8608812864 -40 33 16.899168060 (Optical) [ 0.0109 0.0127 90 ] A 2020yCat.1350....0G
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
FK4 coord. (ep=B1950 eq=1950) : 		09 00 13.2325024557 -40 21 24.973433844 [ 0.0109 0.0127 90 ]
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
Gal coord. (ep=J2000) : 		263.0582982724309 +03.9298526194060 [ 0.0109 0.0127 90 ]
Syntax of proper motions is : "pm-ra pm-dec [error ellipse] quality bibcode"
  • pm-ra : mu-ra*cos(dec) (expressed in the ICRS system in mas/yr)
  • pm-dec : mu-dec (expressed in the ICRS system in mas/yr)
  • [error ellipse] : error major axis and minor axis (in mas), orientation angle (in deg)
  • quality : flag of quality (A=best quality -> E=worst quality, {� } =unknown quality)
  • bibcode : bibcode of the proper motion reference
Proper motions mas/yr : 		-4.822 9.282 [0.015 0.016 90] A 2020yCat.1350....0G
Syntax of radial velocity (or/and redshift) is : "value [error] (wavelength) quality bibcode"
  • value : radial velocity or/and redshift (Heliocentric frame) according to your Output Options
    (redshift may be not displayed if the data value is <0 and the database inside value is a radial velocity)
  • [error] : error of the corresponding value displayed before
  • (wavelength) : wavelength range of the measurement : Rad, mm, IR, Opt, UV, Xray, Gam or  '∼'(unknown)
  • quality : flag of quality ( A=best quality -> E=worst quality, {� } =unknown quality)
  • bibcode : bibcode of the value's origin
Radial velocity / Redshift / cz : 		V(km/s) -3.20 [0.9] / z(~) -0.000011 [0.000003] / cz -3.20 [0.90]
   A 2004A&A...424..727P
Syntax of parallax is : 'value quality [error] bibcode'
  • value : parallax value
  • quality : flag of quality (A=best quality -> E=worst quality, {� } =unknown quality)
  • [error] : mean error
  • bibcode : bibcode of the parallax reference
Parallaxes (mas): 		0.4962 [0.0152] A 2020yCat.1350....0G
Spectral type is made of 3 parts: %coding is composed of 4 parts :
  • the spectral type, which is made of a temperature class, eventually a luminosity class (roman number) and/or spectral peculiarities;
  • a quality letter: A=best quality→E=worst quality, {� } =unknown quality %
  • a quality letter: A=best quality -> E=worst quality, {� } =unknown quality
  • bibcode : bibcode of the spectral type reference
Spectral type: 		B0.5Ia C 1978MSS...C02....0H
Syntax of fluxes (or magnitudes) is : "filter-name (System) flux-value [error] quality MultVarFlags bibcode"
  • filter-name : U, B, V, R, I, G, J, H, K, u, g, r, i, z
  • (System) : may be AB (default is Vega)
  • flux-value : value of flux or magnitude
  • [error] : error value
  • quality : flag of quality of the flux value ( A=best quality -> E=worst quality, {� } =unknown quality)
  • MultVarFlags : Mult is zero or one char (J) for joined photometry ; Var can be zero or two chars (V[0-4])
  • bibcode : bibcode of the flux reference
Fluxes (9) :
U 6.85 [~] C 2002yCat.2237....0D
B 7.37 [~] C 2002yCat.2237....0D
V 6.87 [~] C 2002yCat.2237....0D
R 6.31 [~] C 2002yCat.2237....0D
G 6.735128 [0.003033] C 2020yCat.1350....0G
I 6.05 [~] C 2002yCat.2237....0D
J 5.833 [0.020] C 2003yCat.2246....0C
H 5.705 [0.034] C 2003yCat.2246....0C
K 5.596 [0.024] C 2003yCat.2246....0C
SIMBAD within arcmin
', {sourceSize:12, color:'#30a090'})); aladin.on('objectClicked', function(object) { var objName=object.data.MAIN_ID; aladin.showPopup(object.ra,object.dec,'',''+ objName+''); });" title="Show Simbad objects"> Overlay Simbad points in this preview
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within arcsec The VizieR photometry tool allows for easy visualization of photometry points extracted around the Simbad position from photometry-enabled catalogues in VizieR.
The search radius has to be specified by the user. It is currently limited to a maximum of 30 arcsec. It depends mostly on the precision or quality of the coordinates (SIMBAD and VizieR catalogs), the resolution of the images from which the sources were extracted, source extent, and source crowding.
Suggestions are: crowded field: 0.5 to 1.5 arcsec, 3 arcsec otherwise; uncertain coordinates (SIMBAD quality E or coordinates without reference): 5 to 30 arsec (risky!). sed-help-icon

Hierarchy : number of linked objects
whatever the membership probability is (see description here ) :

: 1 : 11482 Display criteria :

The link on the acronym of the identifiers give access to the information for this acronym in the dictionary of nomenclature.
Identifiers (55) :
An access of full data is available using the icon Vizier near the identifier of the catalogue

HD 77581 H 0900-403 SBC7 366 uvby98 100077581
3A 0900-403 HIC 44368 SBC9 552 V* GP Vel
ALS 1227 HIP 44368 SKY# 17441 WEB 8506
CD-40 4838 INTEGRAL1 7 SWIFT J0902.1-4034 1XRS 09002-403
CPC 0 6891 INTREF 374 SWIFT J0902.1-4033 X Vel X-1
CPD-40 3072 JP11 1751 TD1 13466 X Vel XR-1
EXMS B0900-403 LS 1227 TIC 191450569 [BM83] X0900-403
GC 12502 1M 0900-403 TYC 7681-2303-1 [FS2003] 0495
GCRV 25807 2MASS J09020686-4033168 2U 0900-40 [KCS2016] J090206.86-403316.9
GEN# +1.00077581 MCW 1168 3U 0900-40 [KRL2007b] 72
GSC 07681-02303 PBC J0902.1-4033 4U 0900-40 Gaia DR3 5620657678322625920
GX 263+03 PPM 313886 UBV M 15041 Gaia DR1 5620657674020935808
1H 0859-403 1RXS J090207.0-403311 UBV 8734 Gaia DR2 5620657678322625920
Hbg 267 SAO 220767 UCAC4 248-031728

References (1469 between 1850 and 2023) (Total 1469)
Simbad bibliographic survey began in 1850 for stars (at least bright stars) and in 1983 for all other objects (outside the solar system).
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                Reference summaries :

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Collections of Measurements


velocities : 7    distance : 3    PLX : 4    PM : 5    MK : 8   

   

Observing logs


herschel : 2    ISO : 5    IUE : 88   

   

External archives :

Archive data at HEASARC - High-Energy Astrophysics Science Archive Research Center

Data at NED - NASA/IPAC Extragalactic Database : V* GP Vel

Link by name to the catalogue in VizieR :

HD 77581 ALS 1227 CD-40 4838 CPD-40 3072 GSC 07681-02303
HIC 44368 HIP 44368 LS 1227 2MASS J09020686-4033168 PPM 313886
1RXS J090207.0-403311 SAO 220767 TD1 13466 TYC 7681-2303-1 UCAC4 248-031728
uvby98 100077581 V* GP Vel Gaia DR3 5620657678322625920 Gaia DR1 5620657674020935808 Gaia DR2 5620657678322625920

Search by coordinates in Vizier (radius: 5 arcsec)

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Please, have a look at Best practices. The list of all annotations to SIMBAD objects can be found here .

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2023.05.29-14:11:49

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