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About the discovery of X-ray bursts 35 years ago

About the discovery of X-ray bursts 35 years ago. John Heise’s After Dinner speech X-ray burst workshop Leiden 2010. SRON-Utrecht. SAS-3 1975. ANS 1974. Vela-5 1969. many high-energy satellites in the period 1960-1975. UHURU 1971. 1975. 1960. Mostly “scanning” satellites.

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About the discovery of X-ray bursts 35 years ago

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  1. About the discovery of X-ray bursts35 years ago John Heise’s After Dinner speech X-ray burst workshop Leiden 2010 SRON-Utrecht

  2. SAS-31975 ANS 1974 Vela-5 1969 many high-energy satellites in the period 1960-1975 UHURU 1971 1975 1960

  3. Mostly “scanning” satellites • small fraction of time “on source” • but seeing large fraction of the sky • rare phenomenae better seen while pointing • ANS, the Astronomical Netherlands Satellite the first X-ray pointing satellite

  4. ANS, 1974-1976, the first 3-axis stabilized X-ray satellite • for X-ray & UV • with unfavorable orbit: ANS Instruments: SRON-Utrecht SXX 0.2 – 0.25 keV 1-7 keV Harvard+MIT HXX 2-25 keV bragg-crystal spectr. Groningen UV-telescope SXX: John Heise HXX: Gursky, Grindlay bragg: Schnopper,

  5. X-ray bursts discovered for the wrong reasonNGC 6624, a centrally condensed globular cluster In 1974 thought (Bahcall) to contain a Central Black Hole of ~100-1000 Msun characteristics of BHs were thought to be ● soft spectrum ● variability errorbox 3U1820-30

  6. In 1974: 1 candidate Black Hole: Cyg X-1exhibiting millisec bursts 1974 Rothschild et al. ~millisec bursts (for ~1 Msun) so possibly Expecting ~sec bursts (for ~1000 Msun)

  7. ANS planning:visibility per source ~1 day/cos(lat) summer 1974 (after visit John Bahcall) Heise planned observations for 3U1820-30 around 28 september 1974 swapping time with the UV-experiment t maximize exposure time with window

  8. Data analysis nov 1975 35 years ago

  9. nov 1975 discovery of 2 X-ray Bursts in 3U 1820-30 ANS-data ANS data arrived in nov 1975 Data reduction with Josh Grindlay, Harvard: Grindlay & Heise, 1975 (IAU-circular) Grindlay et al, 1976 NGC6624 3U1820-30 10 s

  10. dec 1975: energy explosions in spaceDutch press:sensational discovery with “ANS” “ANS” Astronomical Netherlands Satellite 1974-1976

  11. main concern in the beginning:background particle events? • SXX and HXX different respons to high-energy particles • collimators were slightly offset and ratio was consistent with celestial source NO:

  12. others were less concernedabout the possibility of bg-events COSMOS 428 1975 1960

  13. Background events?Hard “bursts” seen everywhere since 1971! But these were background Kosmos 428 satellite, IKI, Moscow Babushkina Kudryavtsev Melioranskii Walter Lewin 1977: correlated with geoposition (all near van Allen belts)

  14. Thermonuclear explanationof X-ray bursts ● 1975, Hansen and van Horn “Nuclear fusion in accreting neutron star envelopes” ● 1976, first mentioned in the context of X-ray bursts by Laura Maraschi (Milaan) ● 1976, Woosley and Taam Thermonuclear explosions on Neutron Stars ● 1976, Jean Swank BB emission size consistent with NS

  15. What about the Vela-5A/B short transients? Including the “Norma burster” position accuracy ~6 degree Walter Lewin in reviews: ignored by definition (Def. : X-ray bursts have rise times ~1 sec, not seen in Vela-bursts)

  16. Other Fast Transients in X-rays ● Other satellites (Ariel V etc) discovered fast Transients also at high galactic latitude ● What is the nature of these sources? some may be Gamma Ray Bursts some may be related with flare stars ● The study required the use of wide field imaging in X-rays with long exposure times: just sit and wait till a transient occurred within the FOV

  17. Wide Field Cameras in X-rays To localize new fast Transients and establish there nature SRON-Utrecht invested in Coded Mask Camera’s

  18. Wide Field Cameras in X-rays 1980 5 WFCs? new Dutch satellite TIXTE? TIXTE: S/C concept 1982 4 WFCs? new ESA satellite X80? 1981 COMIS/TTM om MIR-station a pilot study with 1 WFC? WFC’s 1983 3 WFCs? Dutch-Italian satellite WFC’s 1985 2 WFCs! Dutch-Italian SAX satellite YES! Launched 1987

  19. GRB970228 40o 40o significance→ Burst Cyg X-1 exposure 52 ksec 30 sec 48 ksec 3ox3o 3ox3o 3ox3o biggest succes:arcmin localization of GRBs WFC GRB GRB960720

  20. WFC view on the Galactic Center SAXJ1808-36 discovery of new neutron stars

  21. WFC discovery of superbursts a new thermonuclear burning regime E~1039 ergs X-ray Burst Röntgen-intensiteit→ X-ray intensity → KS1731-26 time → E~1042 ergs Superburst hardness→ 4U1735-44 Cornelisse et al. 2001

  22. Tod’s discovery of burst oscillations Xray-burst publications per year data Jean in ‘t Zand 1976 2005 1985 1995

  23. Top of most cited papers Wallace & Woosley (1981): 372 (TH, Explosive hydrogen burning) Lewin et al. (1993): 284 (Space Science Review) Strohmayer et al (1996): 283 (OBS, Discovery burst oscillations) Grindlay et al. (1976) 198 (OBS, discovery paper) Lewin et al. (1981): 181 (Space Science Review) Woosley & Taam (1976): 174 (TH, 1st interpretation) Fujimoto et al. (1981): 165 (TH, Accretion regimes for bursting) Chakrabarty et al. (2003): 164 (OBS, burst.osc. pulsar in J1808) Schatz et al. (2001): 158 (TH, endpoint of rp process) Ayasli et al. (1982): 152 (TH) Kuulkers et al. (2003): 125 (OBS, PRE bursts in Globular clusters) Swank et al. (1977): 116 (BB emission size consistent with NS) Joss et al. (1977): 107 (TH) Strohmayer et al. (2002): 104 (OBS, Superburst from 4U 1820-30)

  24. most productive authors nr as first author (Citation score) Lewin: 41 (20) van Paradijs: 21 (23) Strohmayer: 34 (29) Grindlay: 15 (26) in 't Zand: 14 (23) Kuulkers: 13 (19) Taam: 13 (23) Swank: 10 (17) Hoffman: 10 (21) Cumming: 11 (18)

  25. Conclusion X-ray burst astronomy is a thriving field with a promise to extract fundamental NS-data

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