1 / 16

Fermi-GBM type I X-ray burst project: An all-sky view of thermonuclear bursts.

Fermi-GBM type I X-ray burst project: An all-sky view of thermonuclear bursts.

odin
Download Presentation

Fermi-GBM type I X-ray burst project: An all-sky view of thermonuclear bursts.

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Fermi-GBM type I X-ray burst project:An all-sky view of thermonuclear bursts. M. Linares (MIT, Rubicon Fellow)V. Connaughton (CSPAR/UAH), P. Jenke (ORAU), A. Camero-Arranz (FECYT), E. Beklen (METU), M. H. Finger (USRA), C. Wilson-Hodge, C. Kouveliotou (NASA/MSFC), A. J. van der Horst (NASA/MSFC/ORAU), D. Chakrabarty (MIT), A. L. Watts (Amsterdam)

  2. World English Dictionary • monitor  — n 1. a person or piece of equipment that warns, checks, controls, or keeps a continuous record of something • Dictionary.com • monitor  — 6. an instrument for detecting dangerous gases, radiation, etc.

  3. Thermonuclear bursts from NS-LMXBs http://www.gsfc.nasa.gov/topstory/2004/0220stardisk.html

  4. Fermi-GBM • Field of view: all unocculted (75%) sky. • X-ray response: down to 8 keV. • Optimal instrument to detect rare & bright thermonuclear bursts.

  5. GBM and X-ray bursts Systematic X-ray burst search and processing at NSSTC & MIT. So far (March 2010 – November 2010): ~346 XRB candidates (~1.3/day)

  6. GBM and X-ray bursts Durations: 20-400 s; Av. net rates: 5-100 c/s (11-27 keV band)

  7. GBM and thermonuclear bursts: 4U 0614+09

  8. GBM and thermonuclear bursts: 4U 0614+09 7 type I X-ray bursts from 4U 0614+09 between March and October, 2010. 51% observation duty cycle: Burst recurrence time = 16 +/- 6 d

  9. GBM and thermonuclear bursts: 4U 0614+09 Kuulkers et al. (2009) 7 GBM bursts in ~8 months!

  10. GBM and thermonuclear bursts: 4U 0614+09

  11. GBM and thermonuclear bursts: 4U 0614+09

  12. GBM and thermonuclear bursts: 4U 0614+09 Falanga et al. (2009) Linares et al. (2009) Long (aka ‘intermediate duration’) type I burst from XTE J1701-407:XRT ~15x longer than BAT

  13. GBM and thermonuclear bursts: 4U 0614+09 Observations of bursts have been strongly biased towards bright (and therefore high Mdot ) states of LMXBs. Recurrence times of low-Mdot bursts have proven extremely difficult to measure. A scenario has been proposed to explain short low-Mdot bursts that involves stable(unstable) hydrogen burning that builds up(ignites) a pure helium layer (Fujimoto et al. 1981; Bildsten 1998). On the other hand, sedimentation of heavy elements is thought to play an important role in the production of long low-Mdot bursts (Peng et al. 2007). GBM is measuring their recurrence time to provide crucial missing info: how much mass is accreted to reach ignition? (see Cir X-1 poster for high Mdot bursts)

  14. MAXI and thermonuclear bursts MAXI: -”Normal” type I bursts. -Well suited to superbursts (duration ~day). -Well sampled long-term accretion rate history.

  15. Summary • GBM: Also an X-ray burst monitor, building a valuable archive of several transient high-energy phenomena. • GBM has opened new ways in the study of thermonuclear bursts, low-Mdot bursts in particular. • 4U 0614+09 bursts every ~16 days during 2010, while Mdot keeps close to 1% Eddington.

  16. Arigato for your attention.

More Related