2012MNRAS.425....8I

2012MNRAS.425....8I - Mon. Not. R. Astron. Soc., 425, 8-20 (2012/September-1)

Light-curve dip production through accretion stream–accretion disc impact in the HZ Her/Her X-1 binary star system.

We discuss the production of Hercules X-1's (Her X-1) light-curve dips through accretion stream impact on the disc. We model the binary system geometry, the position of the line of sight relative to the impact site and the effect of several binary system parameters on the occurrence phases of dips. Our input accretion disc models have been validated by observations. The accretion stream geometry is calculated from first principles and it is consistent with theoretical studies and observations.

Our model explains the marching dip effect and several other features of the 35-d phase–orbital phase graph. The outer accretion disc radius has the greatest effect on the timing of dips, while the mass ratio, L1's coordinates, the orbital inclination and separation, and the inner accretion disc radius have negligible effects. We find that dip production occurs for distances from impact to the line of sight of under 2 percent of the orbital separation.

We consider the possibility of disc penetration by the stream and find that it is required to reproduce correctly the marching dip effect and the complex trends of the dips observed by the Rossi X-ray Timing Explorer/Proportional Counter Array. In particular, the model explains the properties of pre-eclipse, anomalous, post-eclipse, main-high-state, short-high-state and low-state dips, and shows that they are all produced by the same mechanism.

Abstract Copyright: 2012 The Authors Monthly Notices of the Royal Astronomical Society 2012 RAS

Journal keyword(s): stars: neutron - pulsars: individual: Her X-1 - X-rays: binaries

N	Identifier	Otype	ICRS (J2000) RA	ICRS (J2000) DEC	Mag U	Mag B	Mag V	Mag R	Mag I	Sp type	#ref 1850 - 2026	#notes
1	V* HZ Her	LXB	16 57 49.8110126616	+35 20 32.486555472	11.90	14.89	13.63	13.88		B3/6ep	2172	0

Annotations :
Annotations allow a user to add a note or report an error concerning the astronomical object and its data. It requires registration to post a note. See description .
Please, have a look at Best practices. The list of all annotations to SIMBAD objects can be found here .

To bookmark this query, right click on this link: simbad:objects in 2012MNRAS.425....8I and select 'bookmark this link' or equivalent in the popup menu

`X Her X-1`	`GCRV 27254`	`RE J1657+352`	`4U 1656+35`
`2A 1655+353`	`GCRV 27255`	`RE J165750+352105`	*`V HZ Her`**
`3A 1656+353`	`GCRV 27253`	`ROTSE1 J165749.74+352032.4`	`WEB 14036`
`AN 142.1936`	`GSC 02598-01298`	`2RXP J165749.4+352033`	`2XMM J165749.8+352032`
`1AXG J165750+3520`	`1H 1656+354`	`RX J1657.8+3521`	`1XRS 16560+354`
`BPS BS 16552-0071`	`H 1656+354`	`RX J1657.8+3520`	`XSS J16581+3522`
`CRTS J165749.7+352032`	`H 1657+35`	`1RXS J165749.6+352022`	`ZTF J165749.81+352032.4`
`2E 1656.0+3525`	`INTREF 730`	`SBC7 602`	`[BM83] X1656+354`
`2E 3791`	`Lan 78`	`SBC9 937`	`[FS2003] 0862`
`1ES 1656+35.4`	`1M 1656+354`	`SDSS J165749.81+352032.4`	`[KRL2007b] 211`
`2EUVE J1657+35.3`	`2MASS J16574981+3520323`	`SRGA J165749.5+352028`	`[ZEH2003] RX J1657.8+3520 1`
`EUVE J1657+35.3`	`2MAXI J1658+353`	`1SWASP J165749.80+352032.8`	`AAVSO 1654+35`
`FBS B 587`	`PBC J1657.8+3520`	`SWIFT J1657.7+3518`	`Gaia DR3 1338822021487330304`
`FBS 1656+354`	`RBS 1614`	`TIC 341738544`	`Gaia DR2 1338822021487330304`
`GAT 227`	`2RE J1657+352`	`2U 1705+34`
`GCRV 27256`	`2RE J165750+352053`	`3U 1653+35`

`2E 3791`	`EUVE J1657+35.3`	`FBS B 587`	`FBS 1656+354`	`GSC 02598-01298`
`Lan 78`	`2MASS J16574981+3520323`	`2RE J1657+352`	`2RE J165750+352053`	`1RXS J165749.6+352022`
`SDSS J165749.81+352032.4`	*`V HZ Her`**	`Gaia DR3 1338822021487330304`	`Gaia DR2 1338822021487330304`