Sarch for thrmonuclar x-ray bursts with Intgral, Vinna Tchnical Univrsity Tutors: Clia Sanchz & Erik Kuulkrs
Contnts What? X-ray binaris X-ray bursts Intgral and its instrumnts Why? th Galactic Bulg Monitoring Program IBIS and its advantags vs. JEMX How? Sarch for bursts in dtctor lightcurvs rconstruct a snapshot of th burstr dtrmin th burst proprtis
Low mass X-ray binaris LMXBs consist of a compact objct black hol or nutron star, and a low mass companion (old star or whit dwarf ). Mass transfr via Roch-lob ovrflow Proprtis of LMXBs : Accrtion disk bright radiation hatd disk mattr that hits CO Luminosity 250 to 25000 L sol orbital priods 11 min to 17 d soft X-ray spctra (kt 10 kv) ~ 160 known, 130 in Milky Way Pictur of th Galactic Plan in X-rays
Typ I X-ray bursts Thrmonuclar burning on th surfac of a NS Accumulation of ful on th NS surfac (accrtion) Cration of a thin shll gtting dnsr and hottr Thin shll Instability triggrs thrmonuclar runaway Proprtis of Typ I bursts: accumulation for svral hours to days burst durations ~ 10 100 sc (dpnds on ful-mix) nrgy rlas is nuclar, not gravitational ~ 70 LMXBs known to b Burstrs Lightcurvs of an X-ray burst in diffrnt
Intgral and on-board Instrumnts Th Intrnational Gamma Ray Astrophysics Laboratory Th mission: Obsrvation of Gamma Ray Phnomna combining fin spctroscopy with imaging and positioning of th sourcs. Scinc goals: Compact objcts Binaris, Black Hol Candidats, Extragalactic sourcs AGNs, Syfrt Galaxis, Stllar objcts Wolf Rayt Stars, Nova, Suprnova, Obsrvation of Galactic Plan and Cntr Rgion Dtction of Gamma Ray Bursts Th Instrumnts: IBIS Imagr on Board th Intgral Satllit - high rs Imags of Gamma-ray objcts - Fild of Viw 9 x 9-12 arcmin angular rs ISGRI Intgral soft gamma-ray Imagr CdT smiconductor dtctor 15 500 kv PICsIT Pixllatd Imagr CsI Tlscop CsI scintillator crystals 200 kv 10 MV JEMX Joint Europan Monitor for X-rays - High rs Imags in th X-ray band - FOV 4.8 diamtr - 3-35 kv -3 arcmin angular rs th IBIS dtctor array Morovr SPI, a spctromtr, and OMC
Th Galactic Bulg Monitoring Program Monitoring of th Galactic Bulg Rgion with INTEGRAL, it is a rich host of variabl X- and Gamma-ray point sourcs Obsrv th rgion rgularly at hard X-rays and Gamma-rays, ~ vry 3 days (12.6 ks) invstigat th sourc variability and transint activity on short and long tim scals 3 Sasons of Obsrvations (Rvolutions 288-492) Total Covrag around th Galactic Cntr of 29 with IBIS/ISGRI 6 with JEMX IBIS has a widr FOV than JEMX! It covrs about half of th total X-ray binary population Rv 287-429 IBIS/ISGRI 20-60 kv Mosaic Imag
Burst Dtction Typ I bursts ar mainly sn in soft X-rays obsrvd BB tmpraturs : 1-3 kv JEMX In th 3 sasons of th monitorig program JEMX saw 110 Typ I X-ray bursts! W want to look at thm with IBIS! widr FOV W look at th IBIS/ISGRI Dtctor Lightcurvs of a singl obsrvation: Cration of Histograms bin = 1-2 s Computation of avrag count rat N and th corrsponding standard dviation σ whn condition N " N! 6 ó for count rat N in on bin holds... Burst!
Imag Rconstruction W dfin a Good Tim Intrval which includs only th tim of th burst Cration of sky imag of th momnt of th burst with OSA (Offlin Scinc Analysis Softwar, V 6.0). th burst of Rv 351, obsrvation 25 in th histogram Sky Imag (significanc) of th momnt of th burst. Sky Imag (significanc) with intgration tim of th whol
Dtrmining burst proprtis Th burst shap is givn by th following formula : Fast ris with xponntial dcay W fit this xponntial dcay to burst shaps in th histograms:! t n+h " ô n... avrag count rat h... hight of th burst abov avarag τ... man liftim Calculation of th intgratd flux E b of th burst vnt
Projct Status First Rsults: W wr abl to idntify th sourcs of 56 bursts within th data of 3 sasons (MJD 53419-54032) of th GBMP by now: Th bursts com from 8 diffrnt sourcs 35 bursts (62%) com from only on sourc, GX 354-0 SGR 1806-20 is a soft Gamma-ray rpatr, not a typ I X-ray burstr still to do: OSA didn t find anything, but w hav a possibl Sourc idntify what OSA lft ovr! w focusd on th high significant bursts (>6) du to imag rconstruction. idntify as wll th faintr ons dtrmin thir proprtis Sourc Rv ScW IJD GX 354-0 288 15 1878.422 1A 1742-294 289 10 1881.199 GX 354-0 293 8 1893.127 GX 354-0 294 7 1896.092 4U 1722-30 295 34 1900.205 GX 354-0 296 40 1902.893 GX 354-0 298 4 1908.001 GX 354-0 299 4 1910.995 GX 354-0 302 8 1920.055 GX 354-0 303 22 1923.422 4U 1722-30 304 2 1925.902 GX 354-0 304 4 1925.941 GX 5-1 305 34 1930.266 SGR 1806-20 347 20 2055.036 SGR 1806-20 348 51 2059.356 GX 354-0 350 9 2063.681 GX 354-0 351 25 2067.355 GX 5-1 359 66 2092.066 GX 354-0 359 69 2092.131 GX 354-0 360 97 2095.855 GX 354-0 361 48 2098.052 GX 354-0 362 6 2099.488 4U 1722-30 364 2 2105.383 GX 354-0 365 69 2109.871 SAX J1747.0-2853 366 7 2111.462 NEW 370 68 2125.705 GX 5-1 370 69 2125.721 GX 354-0 410 3 2242.895 4U 1722-30 411 23 2246.413 4U 1722-30 417 67 2265.463 SAX J1747.0-2853 417 70 2265.529 GX 354-0 420 31 2273.608 GX 354-0 421 4 2275.791 4U 1722-30 428 5 2296.759 GX 354-0 429 104 2302.101 4U 1722-30 469 5 2419.303 GX 354-0 470 1 2422.194 SGR 1806-20 470 3 2422.249 GX 354-0 470 7 2422.329 GX 354-0 472 24 2428.959 GX 354-0 473 2 2431.188 GX 354-0 474 3 2434.202 SGR 1806-20 474 4 2434.209 GX 354-0 475 51 2438.552 GX 354-0 476 14 2440.512 GX 354-0 478 14 2446.473 GX 354-0 480 10 2452.368 GX 354-0 480 16 2452.504 GX 354-0 481 8 2455.208
Problms with Imag Rconstruction IBIS is a Codd Mask Instrumnt Imags of sourcs hav to b rconstructd by Th Analysis Softwar! Problms with OSA: A crtain amount of photon counts (xposur tim) is ncssary so imag rconstruction works Nw sourcs arn t always found by th Softwar, spcially in th partially codd FOV can b found by looking for ghosts in th imag Imag of a potntial nw sourc not dtctd By OSA. It s ghosts whr not automatically rmovd during Imag Rconstruction.
Thank You!
CODED MASK TECHNIQUE NO MIRRORS IN GAMMA RAYS NO OPTICAL IMAGES CODED MASK: Mask th aprtur of th tlscop Masur its shadow on th dtctor orintation of th satllit & analysis of data from th dtctor dtrmin position & intnsity of sourcs imag of th obsrvd sky: a. Codd mask b. Dtctor c. Fild of viw
ANTI-COINCIDENCE SYSTEM Blockd photon Valid photon MASK Vtod photon or particl ANTI-COINCIDENCE