Astrotomography: Indirect Imaging Methods in Observational Astronomy

TheideaforthisbookoriginatedintheLaSillaobservatorywheretwoofthe editorsweredoingphase-resolvedspectroscopyofsomecataclysmicvariable starsusingtheNTT. Werealizedthatalthoughindirectimagingtechniques suchaseclipsemappingandDopplertomographyhadbeenaroundformore thanadecadeandhadprovidedsomeofthemostinterestingdiscoveries, no bookexistedwhichcoveredthesetechniques. Moreover, nocolloquiumhadever beenorganizedspeci?callyonthesetopics. Theimplementationoftomographic methodsinastrophysics, inordertoprobestructuresonangularscalesofmic- arcseconds, startedabout15yearsagowiththedevelopmentoftheeclipsem- pingmethod. Thismethodisabletoreconstructlightdistributionsineclipsing binariesbyexploitingtheregularobscurationofthelightsourcebyoneofthe binarycomponents. Asimilarapproachtoregulariseddata?ttingleadtoa- rietyofrelatedmethodsinordertoresolvelightdistributionsoftheaccretion ?owsinbinaries, thesurfacestructuresofstarsandtheinnerregionsofactive galaxies. Thescienti?coutputofthesemethodsisconsiderableandtheyare increasinglybecomingversatiletoolsforawidecommunityofresearchers. Aspecialisedworkshopseemedhighlydesirable, sowedecidedtoorganise the?rstinternationalworkshoponastrotomography. Theideaofthemeeting, whichtookplaceinBrusselsinearlyJuly2000, wastobringtogetherresearchers sharinganinterestinapplyingindirectimagingmethodsinastronomy, andto comparethemethodsusedindi?erent?elds. Duringthemeeting, alargeamount oftimewasdevotedtoextensivereviewsofthevariousreconstructiontechniques. Inconjunctionwiththereviews, shortcontributedtalkshighlightedrecent- sultsanddevelopments. Duetothesmallnumberofparticipants,60, therewas plentyofopportunityfordiscussionandinteraction. Moreover, wewantedthat theproceedingsofthismeetingcouldbeusedasahandbookonthesemethods. Thereviewerswerethereforeaskedtoprovideextensiveaccountsoftheir?eld. Theproceedingsthusconsistof13reviewsofabout25pageseachaswellas 15contributedtalksof6?8pages. Awiderangeoftopicsarediscussed, mostly onthepropertiesofaccretion?owsinsemi-detachedbinarysystemsconta- ingacompactstellarremnant. Othertopicsincludethesurfaceandmagnetic ?eldstructureofsinglestars, theshockwavesofMirastars, theaccretion?ows aroundblackholesinbinariesandactivegalacticnucleiandthestructureof Algolsystems. Thelargevarietyofsubjectscoveredisaclearillustrationofthe importancethatindirectimagingtechniqueshavegainedinastrophysics. Anew VI generationofopticaltelescopesandspectrographsiscomingon-linewhichwill pushthepossibilitiesofindirectimagingevenfurther. Inconjunctionwiththat, specialisedinstrumentsandprojectsonexistingtelescopeswilldeliverdatasets withhightimeandwavelengthresolutionstailoredforaccuratemapping- periments. Wehopethattheseproceedingswillprovideahelpfuloverviewfor anyresearcherinterestedinsuchtechniques. Withthesamespiritofproducing morethanjustproceedings, wealsoincludealistofsomeusefulresourceson theInternet. Wealsohopethatthewebpageoftheworkshopwillbekeptalive andbecomeausefulreferenceonastrotomography. Wewouldliketothankalltheparticipantsformakingthisworkshopas- cess, andinparticularallthecontributingreviewauthorsforhavinggenerously agreedtocometothemeetingattheirownexpense, andfortheire?ortsin providingabalancedsetofreviewpapers. Manythankstoallthemembersof thelocalorganisingcommitteeforthehardworkbefore, duringandafterthe workshop. TheBrusselsPlanetariumisthankedforprovidinguswithameeting venueandexcellentsupport. WealsowishtothanktheDirectoroftheRoyal ObservatoryofBelgium, Prof. PaulP aquet, forhise?orts. RobHynesprovided uswithasuperb scienti?cimpression ofaninteractingbinarythatfeaturedon theworkshopposterandvariousotherlocations. Finally, wearegratefulfo- nancialsupportfromprojectG. 0265. 97oftheResearchProgrammeoftheFund forScienti?cResearch Flanders(F. W. O. Vlaanderen). Brussels, Southampton, HenriBo?n, November2000 DannySteeghs, JanCuypers Workshopwebpage: http: //www. astro. oma. be/DopplerWorkshop/ Contents DopplerTomography T. R. Marsh. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 MappingthePeculiarBinaryGPCom L. Morales-Rueda, T. R. Marsh, R. C. North. . . . . . . . . . . . . . . . . . . . . . . . . . . 27 H?-EmissionDopplerTomography ofLong-PeriodCataclysmicVariableStars R. C. North, T. R. Marsh, C. K. J. Moran, U. Kolb, R. C. Smith, R. Stehle. . 33 DopplerTomographyoftheDwarfNovaIYUMa duringQuiescence D. J. Rolfe, T. M. C. Abbott, C. A. Haswell. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 SpiralWavesinAccretionDiscs Observations D. Steeghs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 SpiralWavesinAccretionDiscs Theory H. M. J. Bo?n. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 SpiralShocksinanInviscidSimulationofAccretionFlow inaCloseBinarySystem M. Makita, H. Fujiwara, T. Matsuda, H. M. J. Bo?n. . . . . . . . . . . . . . . . . . . . 88 ImagingtheSecondaryStarsinCataclysmicVariables V. S. Dhillon, C. A. Watson. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 StatisticsofIsolatedEmissionSourcesinCataclysmicVariables C. Tappert, R. Hanuschik. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 TomographyofPolars A. Schwope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 TomographyofMagneticAccretionFlows G. Wynn. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 VIII Contents TheGeometricalCon?gurationofPolars andPossibleReconstructionArtefacts ofEclipseMappingMethods J. Kube. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 SpotMappinginCoolStars A. CollierCameron. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 ImagingtheMa