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Some Observational Aspects of Compact Galactic X-Ray Sources

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Some Observational Aspects of Compact Galactic X-Ray Sources Cover: A two dimensional picture on the High Resolution Imager taken with the Objective Grating Spectrometer onboard the EINSTEIN observatory of the black hole candidate, the X-ray binary system Cygnus X-l. The central bright spot is the zero order image with on both sides the first order diffracted radiation extending to about 20 A (corresponding to 320 arcsec). N Grafisch bedrijf: Jurriaans B.V. Amsterdam. SOME OBSERVATIONAL ASPECTS OF COMPACT GALACTIC X-RAY SOURCES PROEFSCHRIFT TER VERKRIJGING VAN DE GRAAD VAN DOCTOR IN DE WISKUNDE EN NATUURWETENSCHAPPEN AAN DE RIJKSUNIVERSITEIT TE UTRECHT, OP GEZAG VAN DE RECTOR MAGNIFICUS PROF.DR. O.J. DE JONG, VOLGENS BESLUIT VAN HET COLLEGE VAN DECANEN IN HET OPENBAAR TE VERDEDIGEN OP WOENSDAG 15 DECEMBER 1982 DES NAMIDDAGS TE 4.15 UUR DOOR JOHAN HEISE GEBOREN OP 23 DECEMBER 1942 TE HILVERSUM PROMOTOR PROF. DR.C. DE JAGER Contents Voorwoord 8 Samenvatting 11 Summary 17 I. REVIEWS 19 1.1 Introduction 20 1.2 High Luminosity Galactic X-ray Sources 22 Transient phenomena in galactic X-ray sources 1.3.1 X-ray Burst Sources 31 1.3.2 X-rays from Flare Stars 48 1.3.3 Transient Galactic X-ray Sources 65 Low Luminosity Galactic X-ray Sources 1.4.1 X-rays from isolated Hot White Dwarfs 73 1.4.2 X-ray emission from Cataclysmic Variables 83 II. HIGH LUMINOSITY GALACTIC X-RAY SOURCES 97 11.1 ANS results on X-ray binaries 98 (J.Heise,A.C.Brinkman) 11.2 X-ray observations of Cyg X-l with ANS 1J0 (J.Heise,A.C.Brinkman,J.Schrijver, R.Mewe,A.den Boggende,E.Gronenschild, D.Parsignault,J.Grindlay,E.Schreier, H.Schnopper,H.Gursky) 11.3 High resolution soft X-ray spectra with the Objective JJ5 Grating Spectrometer of the Einstein Observatory (J.Heise,A.Brinkman) III. TRANSIENT PHENOMENA IN GALACTIC X-RAY SOURCES 127 111.1 Evidence for X-ray emission from flare stars 128 (J.Heise,A.Brinkman,J.Schrijver, R.Mewe,E.Gronenschild,A.den Boggende) 111.2 Discovery of intense X-ray bursts 135 from globular cluster NGC 6624 (J.Grindlay,H.Gursky,H.Schnopper, J.Heise,A.Brinkman,J.Schrijver) 111.3 X-ray observations of globular clusters with ANS 144 (J.Grindlay,H.Gursky,D.Parsignault.H.Conn, J.Heise,A.Brinkman) 111.4 ANS observations on the X-ray burster MXB1730-335 152 (J.Heise,A.Brinkman,A.den Boggende, D.Parsignault,J.Grindlay,H.Gursky) 111.5 A short lived transient X-ray source , 158 at high galactic latitude (J.Schrijver,A.Brinkman,J.Heise,A.den Boggende, E. Gronenschild,R.Mewe,J.Grindlay,D.Parsignault) 111.6 Measurements of AO620-00 with ANS 164 (A.Brinkman,J.Heise,A.den Boggende, R.Mewe,E.Gronenschild,J.Schrijver) IV. LOW LUMINOSITY GALACTIC X-RAY SOURCES 169 IV.1 Soft X-rays from Sirius 170 (R.Mewe,J.Heise,E.Gronenschild,A.Brinkman, J.Schrijver and A.den Boggende) IV.2 Detection of X-ray emission from stellar coronae J74 with ANS (R.Mewe,J.Heise,E.Gronenschild,A.Brinkman, J.Schrijver and A.den Boggende) IV.3 Detection of both soft and hard X-ray emission 184 from SS Cygni (J.Heise,R.Mewe,A.Brinkman,E.GronenschiId, A.den Boggende,J.Schrijver, D.Parsignault and J.Grindlay) IV.4 Observation of the ultra-soft X-ray spectrum of HZ 43 J90 (J.Bleeker,J.Davelaar,A.Deerenberg,H.Huizenga, J.Heise,A.Brinkman,Y.Tanaka.S.Hayakawa,K.Yamashita) IV.5 The hot white dwarf HX 43: The helium abundance J98 derived from the ultra soft X-ray spectrum (J.Heise and H.Huizenga) IV.6 A 67 minute period in the soft X-ray emission of 208 EX Hydrae observed with Einstein Observatory (J.Heise,R.Mewe,A.Kruszewski,T.Chlebowski, W.van Dijk and R.Bakker) IV.7 High resolution soft X-ray spectrum of AM Her 225 (J.Heise,A.Kruszewski,T.ChlebowskisR.Mewe, S.Kahn,F.D.Seward) Curriculum Vitae 243 Voorwoord In toenemende mate is het bedrijven van wetenschap een collectieve aangelegenheid. Dit is wel heel duidelijk het geval in het sterrenkun- dig ruimteonderzoek. Hoewel gedragen door de individuele weten- schapper, is onderzoek als in dit proefschrift beschreven alleen moge- lijk dankzij de belangstelling, daadwerkelijke steun en inzet van een groot aantal mensen. In de eerste plaats geldt dit voor de Nederlandse belastingbeta- ler. Uw potentiële nieuwsgierigheid naar de verschijnselen in het heelal en Uw bereidheid deze nieuwsgierigheid te bevredigen door astronomen en astrofysici hun werk te laten doen, maakt het sterren- kundig onderzoek mogelijk. Dankzij Uw bijdrage van (gemiddeld) enkele tientjes per jaar (iets minder dan in landen als Duitsland, Frankrijk en Engeland) kunnen astronomen de technici vragen hun instrumenten buiten de dampkring te brengen. Hoewel U zelf, door straatverlichting en luchtverontreiniging gehinderd, het uitspansel niet of nauwelijks meer kunt zien, blijkt zonneklaar uit waarnemingen vanuit ob- servatoria in afgelegen delen op deze Aarde en vanuit de ruimte: de sterren zijn er nog. Ze stralen helderder dan ooit, zelfs met straling van eertijds onvermoede soorten zoals infrarood-, ultraviolet- en RÖntgenstraling. Over deze laatste stralingssoort gaat dit proef- schrift. Dank voor Uw bijdrage daarin. Ik zal U als vanouds via popu- laire lezingen en artikelen op de hoogte houden van de ontwikkelingen in de RSntgensterrenkunde en de facinerende aspecten van de hoge-ener- gie-astrofysica. De organisatie en verdeling van de door de overheid ter beschik- king gestelde financiële middelen is in handen van de GROC (Geofysica en Ruimte Onderzoek Commissie) en haar voorzitter prof. H. van de Hulst. Deze commisie behartigt de belangen van haar vier werkgroepen, waarvan de werkgroep "Ruimteonderzoek van Zon en Sterren", het Labora- torium voor Ruimteonderzoek te Utrecht er ëën van is(*). Zij onder- handelde met de overheid over de Astronomische Nederlandse Satelliet ANS, pleitte voor het belang van de Röntgenastronomie, keurde onze voorstellen voor experimenten goed, etc,etc. Dit proefschrift was alleen mogelijk dankzij hun bestuurlijke inzet. Het verrichten van astronomisch onderzoek vanuit de ruimte ver- eist het vervaardigen van technologisch hoogwaardige instrumenten. Deze moeten (a) tot het uiterste gaan in technologische mogelijkheden, maar daarbij bovendien (b) bestand zijn tegen de ruwe omstandigheden (*) De andere zijn de werkgroep "Kosmische Straling" te Leiden, de werkgroep "Fotometrie" te Groningen en die van "Satelliet Geodesie" te Delft -8- tijdens de lancering en het daarbij (c) langdurig in de ruimte kunnen uithouden. Dit vereist de intensieve samenwerking van ervaren fysici, electronici, mechanic! en computerdeskundigen, en verder een nauw- keurige planning van een projectleider en de begripvolle begeleiding door de administratieve staf en het secretariaat. Een dergelijk team bestaat op het LRO en ik dank iedereen voor hun medewerking. Speciaal dank ik de leden van de "Rontgen-groep" o.l.v. Bert Brinkman voor hun bijdrage in het verkrijgen van de wetenschappelijke resultaten. Sommige van deze resultaten zijn verkregen uit waarnemingen van de Astronomische Nederlandse Satelliet ANS. Ik heb de samenwerking bij de bouw van deze satelliet tussen de industrie en de astronomie van nabij mogen meemaken en heb daarbij grote waardering gekregen voor de deskundigheid en betrokkenheid van Prof. W. Bloemendal en zijn mede- werkers (Fokker) en van Ir. C. Kramer en zijn groep (Philips). Ook de leden van het team op het European Space Operation Centre ESOC te Darmstadt o.l.v.Ir. M. Lamers (NLR) toonden grote bereidheid tot samenwerking en belangstelling voor de sterrenkunde. Ik heb door hun activiteiten geleerd dat het maken van een satelliet niet alleen een technologisch, maar vooral ook een organisatorisch hoogstandje is. ANS was het eerste project waarvoor het LRO ook verantwoordelijk- heid droeg in de operationele fase, d.w.z. bij het functioneren van de satelliet na de lancering. De satelliet vereiste dagelijks nieuwe instructies en dumpte ook dagelijks de verkregen meetresultaten via de directe computerlijn met het E30C-statlon in Darmstadt. Dankzij de nauwe samenwerking tussen het 'ANS-team' (Bert Brinkman, Rolf Mewe, Hans Schrijver, Ed Gronenschild, Ton den Boggende, Albert Naber en ikzelf), de computerafdeling (Theo Gunsing, Frans Ammerlaan, Frans Werkhoven en Chiel Galama) en de communicatiedeskundige (Annelies Veldkamp) is dit soepel en bevredigend verlopen. Ook de interpretatie van de verkregen astronomische gegevens Is veelal een collectieve zaak, zoals duidelijk blijkt uit het aantal au- teurs van diverse in dit proefschrift opgenomen artikelen. Behalve de eerdergenoemde mensen hebben daar ook toe bijgedragen Johan Bleeker (Leiden), Henk Huizenga (Leiden), Willem van Dijk (Utrecht) en een aantal buitenlandse collega's, waarbij ik in het bijzonder Josh Grind- lay (Cambridge,V.S.) wil noemen. Dit proefschrift kwam tot stand onder leiding van mijn promotor Kees de Jager. Hij speelde, als directeur van het LRO, een belangrijke rol in alle hiervoor genoemde aspecten. Hij is bovendien een belang- rijk stimulator van het astronomische ruimteonderzoek en mede-initia- tiefnemer voor de voorstellen voor de eerste Nederlandse astronomische satelliet ANS. Ik dank hem in het bijzonder voor de stimulerende dis- cussies (ook die met betrekking tot de promotiedatum) en de critische kanttekeningen bij eerdere versies van de manuscripten in dit proef- schrift. Verder ben ik dank verschuldigd aan de direct betrokkenen bij het tot stand komen van dit proefschrift. Dank aan Louise Cramer, die be- wezen heeft dat ook bij gecomputeriseerd typewerk de vaardige hand van een secretaresse onontbeerlijk is. Ik ben het dan ook volledig oneens met de ingelijste tekst boven haar bureau getiteld "Het is ook nooit goed...". Dank aan Hans Braun voor
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