Astrotomography

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. PaulPˆaquet,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 ImagingtheMagneticTopologiesofCoolActiveStars J. -F. Donati. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 Di?erentialRotationofCloseBinaryStars: ApplicationtoHR1099 P. Petit, J. -F. Donati, G. A. Wade, J. D. Landstreet, J. M. Oliveira, S. L. S. Shorlin,T. A. A. Sigut,A. C. Cameron. . . . . . . . . . . . . . . . . . . . . . . . . . 232 MagneticDopplerImagingofChemicallyPeculiarStars N. Piskunov,O. Kochukhov. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 StokesImagingoftheAccretionRegion inMagneticCataclysmicVariables S. Potter,E. Romero-Colmenero,D. A. H. Buckley,M. Cropper, P. Hakala. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 DopplerImagesoftheMDwarfRE1816+541 J. R. Barnes,A. CollierCameron. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252 TheMethodofSpectraDisentangling andItsLinkstoDopplerTomography P. Hadrava. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .