NDLI: Long-term periodicity in LS I +61°303 as beat frequency between orbital and precessional rate

Content Provider	EDP Sciences
Author	M. Massi F. Jaron
Abstract	Context. In the binary system LS I +61°303 the peak flux density of the radio outburst, which is related to the orbital period of 26.4960 ± 0.0028d, exibits a modulation of 1667 ± 8 d. The radio emission at high spatial resolution appears structured in a precessing jet with a precessional period of 27−28 d.Aims. How close is the precessional period of the radio jet to the orbital period? Any periodicity in the radio emission should be revealed by timing analysis. The aim of this work is to establish the accurate value of the precessional period.Methods. We analyzed 6.7 years of the Green Bank Interferometer database at 2.2 GHz and 8.3 GHz with the Lomb-Scargle and phase dispersion minimization methods and performed simulations.Results. The periodograms show two periodicities, P_{1_{= 26.49 ± 0.07d (ν_{1_{= 0.03775 d^{-1^{) and P_{2_{= 26.92 ± 0.07d (ν_{2_{= 0.03715 d^{-1^{). Whereas radio outbursts have been known to have nearly orbital occurrence P_{1_{with timing residuals exhibiting a puzzling sawtooth pattern, we probe in this paper that they are actually periodical outbursts and that their period is P_{average_{= 2/(ν_{1_{+ ν_{2_{) = 26.70 ± 0.05 d. The period P_{average_{as well as the long-term modulation P_{beat_{= 1/(ν_{1_{− ν_{2_{) = 1667 ± 393 d result from the beat of the two close periods, the orbital P_{1_{and the precessional P_{2_{periods.Conclusions. The precessional period, indicated by the astrometry to be of 27–28 d, is P_{2_{= 26.92 d. The system LS I +61°303 seems to be one more case in astronomy of beat, i.e., a phenomenon occurring when two physical processes create stable variations of nearly equal frequencies. The very small difference in frequency creates a long-term variation of period 1/(ν_{1_{− ν_{2_{). The long-term modulation of 1667 d results from the beat of the two close orbital and precessional rates.}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}
Page Count	8
File Format	HTM / HTML PDF
ISSN	00046361
Alternate Webpage(s)	https://www.aanda.org/articles/aa/abs/2013/06/aa19685-12/aa19685-12.html
e-ISSN	14320746
Journal	Astronomy & Astrophysics
Volume Number	554
DOI	10.1051/0004-6361/201219685
Language	English
Publisher	EDP Sciences
Publisher Date	2013-06-01
Access Restriction	Open
Rights Holder	© ESO, 2013
Subject Keyword	radio continuum: stars X-rays: binaries gamma rays: stars X-rays: individuals: LSI+61303 radio continuum: stars / X-rays: binaries / gamma rays: stars / X-rays: individuals: LSI+61303
Content Type	Text
Resource Type	Article
Subject	Astronomy and Astrophysics Space and Planetary Science

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Long-term OVRO monitoring of LS I +61°303: confirmation of the two close periodicities

Understanding the periodicities in radio and GeV emission from LS I +61°303

Implications of the radio spectral index transition in LS I +61°303 for its INTEGRAL data analysis

VLBA images of the precessing jet of LS I +61°303

LS I +61303 in the context of microquasars

Super-orbital variability of LS I +61°303 at TeV energies

Evidence of coupling between the thermal and nonthermal emission in the gamma-ray binary LS I +61 303

Hints for a fast precessing relativistic radio jet in LS I +61°303

The gamma-ray source LSI +61°303 — I. RXTE/ASM observations

Long-term periodicity in LS I +61°303 as beat frequency between orbital and precessional rate

Similar Documents

Long-term OVRO monitoring of LS I +61°303: confirmation of the two close periodicities

Understanding the periodicities in radio and GeV emission from LS I +61°303

Implications of the radio spectral index transition in LS I +61°303 for its INTEGRAL data analysis

VLBA images of the precessing jet of LS I +61°303

LS I +61303 in the context of microquasars

Super-orbital variability of LS I +61°303 at TeV energies

Evidence of coupling between the thermal and nonthermal emission in the gamma-ray binary LS I +61 303

Hints for a fast precessing relativistic radio jet in LS I +61°303

The gamma-ray source LSI +61°303 — I. RXTE/ASM observations

Long-term periodicity in LS I +61°303 as beat frequency between orbital and precessional rate