Hercules X-1

Hercules X-3
Hercules X-3
	Star
Observational data; ( Epoch J2000.0 )
Type of	Pulsar
Right ascension
Declination
Visible magnitude ( V )	13.83
Constellation	Hercules
Specifications
Spectral class	DA
Other designations
	4U 1656 + 35, HZ Her
Information in databases
SIMBAD

Hercules X-1 ( Hercules X-1 , Her X-1 , 4U1656 + 35 ) is an X-ray dual source of intermediate power, first explored by the Uhuru satellite. It consists of a neutron star , to which accretion of matter from an ordinary star (HZ Her) occurs, probably due to the filling of a Roche lobe with a star.

Content

Intermediate Mass X-ray Double Star

Hercules X-1 is a prototype of massive X-ray binaries, although it is located on the border (about 2 solar masses ) between high- and low-mass X-ray binaries ^[2] .

An intermediate-mass X-ray double is a binary stellar system in which one of the components is a neutron star or a black hole . The other component is an intermediate mass star ^[3] .

Intensity

This light curve of the source Hercules X-1 shows variability on large and medium scales. Each pair of vertical lines marks the eclipse of a compact object with a companion star. In this case, the companion is a star with a mass twice the solar one and a radius of about 4 radii of the Sun. Eclipses indicate a system orbital period of 1.7 days.

The source has a complex variability, the pulsation with a period of 1.24 seconds is associated with the rotation of a neutron star, eclipses every 1.70 days show the orbital period of a double star, variations with a period of 35 days associated with the precession of the accretion disk are also observed. Observations show that the system has a curved accretion disk with retrograde precession, which affects the HZ X-ray illumination of Hercules and the Earth. ^[2]

Observations on the Uhuru apparatus revealed the presence of pulsations in the X-ray range with a period of 1.2 seconds, which confirmed the presence of a rapidly rotating neutron star. Figure taken from the work of Charles and Seward.

A ripple period of 1.24 seconds is evident from observations. A sharp break of ~ 24 keV in the flat spectrum of the object provides evidence of the presence of radiation transfer effects associated with a magnetized plasma near the surface of a neutron star.

15-second signal samples obtained in 1973 when observing three of the brightest dual radio sources in the Milky Way: Hercules X-1 (period 1.7 days), Cygnus X-3 (0.2 days) and Cygnus X-1 (5.6 days.).

The spectra of the source Hercules X-1, obtained by OSO 8.

Opening Her X-1

The announcement of the discovery of the source Hercules X-1 during observations on the Uhuru satellite was made at the conference "1971-72 Winter Meeting of the High-Energy Astrophysics Division AAS" held in San Juan . ^[4] The discovery of a periodically pulsating X-ray source itself occurred in November 1971. ^[five]

Location

The position of Hercules x-1 was undefined due to Uhuru satellite sensor errors and was reported as ^[5] for the era J1950 RA 17 ^h 05 ^m Dec 34 ° 52 'according to Uhuru and 16 ^h 56.7 ^m Dec 35 ° 35' ^[6] according to OSO 7 . However, there is only one weak X-ray source (2U 1735 + 43) within 10 ° of Hercules X-1. ^[7] However, four radio sources were detected within the overlap area of an object according to Uhuru and OSO 7 : (1) RA 16 ^h 56 ^m 50.75 ^s Dec 35 ° 14'33 ± 3 "as a double point source, separated by a distance of 17 ± 2 ", (2) RA 16 ^h 57 ^m 10.65 ^s Dec 35 ° 21'35 ± 3" within 6 ± 3 "images of a star, (3) RA 16 ^h 57 ^m 35.72 ^s Dec 35 ° 15'19 ± 3" not visible as a star in the Palomar sky survey, (4) RA 16 ^h 58 ^m 39.17 ^s Dec 35 ° 10'53 ± 3 "was found near the overlap area according to Uhuru and OSO 7. ^[8] At that time, the researchers could not detect that the manifestations of Hercules X-1 in the radio are similar periodically m changes in the manifestations in the X-ray range (a period of 36 days), although no satisfactory astrophysical reasons for such a correlation were proposed. ^{[8] The} four sources mentioned above were observed during several phases of the eclipses of the x-ray source. No corresponding eclipses were detected in the radio band. At that time, Doxy ^[8] showed that additional observations should be made in the radio range (especially during periods of strong X-ray radiation from Hercules X-1), and the position of the source should be clarified.

In 1973, Buckell and Buckell ( Eng. Bahcall ) determined that HZ Hercules has a light curve corresponding to Hercules X-1 at a fixed source position.

Notes

↑ ¹ ² ³ ⁴ SIMBAD
² ¹ ² Priedhorsky WC, Holt SS Long term cycles in cosmic X-ray sources (unknown) // Space Sci Rev .. - 1987. - Vol. 45 , no . 3-4 . - p . 291-348 . - DOI : 10.1007 / BF00171997 . - .
↑ Podsiadlowski P., Rappaport S., Pfahl E. Evolutionary Binary Sequences for Low- and Intermediate-Mass X-ray Binaries (eng.) // The Astrophysical Journal : journal. - IOP Publishing , 2001. - Vol. 565 , no. 2 - P. 1107 . - DOI : 10.1086 / 324686 . - . - arXiv : astro-ph / 0107261 .
↑ Schreier E., Levinson R., Gursky H., Kellogg E., Tananbaum H., Giacconi R. Evidence for the Centaurus X-3 from UHURU X-Ray Observations (English) // Ap J.: journal. - 1972. - March ( vol. 172 , no. 3 ). - P. L79 — L89 . - DOI : 10.1086 / 180896 . - .
² ¹ ² Tananbaum H., Gursky H., Kellogg EM, Levinson R., Schreier E., Giacconi R. Discovery of Hercules from UHURU (English) // Ap J: journal. - 1972. - Vol. 174 . - P. L143-9 . - DOI : 10.1086 / 180968 . - .
↑ Clark GW, Bradt HV, Lewin WH, Schnopper HW, Sprott G. X-ray Astronomy: Uhuru Dominates Madrid Meeting (unknown) // Nature .. - 1972. - V. 237 , No. 5355 . - p . 369 . - DOI : 10.1038 / 237369a0 . - .
↑ Giacconi R., Murray S., Gursky H., Kellogg E., Schreier E., Tananbaum T. The UHURU catalog of X-ray sources (unknown) // Ap J. - 1972. - T. 178 . - p . 281 . - DOI : 10.1086 / 151790 . - .
² ¹ ² ³ Doxsey R., Murthy GT, Rappaport S., Spencer J., Zaumen W. Radio Search for the X-Ray Source in Hercules (Eng.) // Ap J.: journal. - 1972. - August ( vol. 176 , no. 8 ). - P. L15-8 . - DOI : 10.1086 / 181010 . - .

[SIMBAD-1] ¹ ² ³ ⁴ SIMBAD

[Priedhorsky-2] ² ¹ ² Priedhorsky WC, Holt SS Long term cycles in cosmic X-ray sources (unknown) // Space Sci Rev .. - 1987. - Vol. 45 , no . 3-4 . - p . 291-348 . - DOI : 10.1007 / BF00171997 . - .

[Podsiadlowski-3] Podsiadlowski P., Rappaport S., Pfahl E. Evolutionary Binary Sequences for Low- and Intermediate-Mass X-ray Binaries (eng.) // The Astrophysical Journal : journal. - IOP Publishing , 2001. - Vol. 565 , no. 2 - P. 1107 . - DOI : 10.1086 / 324686 . - . - arXiv : astro-ph / 0107261 .

[Schreier-4] Schreier E., Levinson R., Gursky H., Kellogg E., Tananbaum H., Giacconi R. Evidence for the Centaurus X-3 from UHURU X-Ray Observations (English) // Ap J.: journal. - 1972. - March ( vol. 172 , no. 3 ). - P. L79 — L89 . - DOI : 10.1086 / 180896 . - .

[Tananbaum-5] ² ¹ ² Tananbaum H., Gursky H., Kellogg EM, Levinson R., Schreier E., Giacconi R. Discovery of Hercules from UHURU (English) // Ap J: journal. - 1972. - Vol. 174 . - P. L143-9 . - DOI : 10.1086 / 180968 . - .

[Clark-6] Clark GW, Bradt HV, Lewin WH, Schnopper HW, Sprott G. X-ray Astronomy: Uhuru Dominates Madrid Meeting (unknown) // Nature .. - 1972. - V. 237 , No. 5355 . - p . 369 . - DOI : 10.1038 / 237369a0 . - .

[Giacconi72-7] Giacconi R., Murray S., Gursky H., Kellogg E., Schreier E., Tananbaum T. The UHURU catalog of X-ray sources (unknown) // Ap J. - 1972. - T. 178 . - p . 281 . - DOI : 10.1086 / 151790 . - .

[Doxsey-8] ² ¹ ² ³ Doxsey R., Murthy GT, Rappaport S., Spencer J., Zaumen W. Radio Search for the X-Ray Source in Hercules (Eng.) // Ap J.: journal. - 1972. - August ( vol. 176 , no. 8 ). - P. L15-8 . - DOI : 10.1086 / 181010 . - .