Homework–andotherhousekeepingma4ers

•  Homeworkisdueat3:30PMWednesday(oftheweekfollowingaclass)insteadofMonday.

•  TurnintotheAstronomyMailRoom(CSS1204)thatclosesat4:30.

•  AlternaDvely,turnintousinourofficeorinclass.•  HomeworkwillbereturnedthefollowingMonday(two

weeksaIeritishandedout),solatehomework(witha20%/daypenalty)mustbeinbeforeclassonthatday.

•  ThelowestHWscorewillbedropped.•  HWsoluDonswillbepostedonthewebsiteaIerallofthe

assignmentsarecompleted.•  ThisinformaDonisontheupdatedsyllabus–seee‐mail

a4achment,classwebsite.•  Thewebsitealsohasalllecturenotes,labs,andassignments.

HighEnergyDatabasesandCatalogs

AccessingPublicDataontheWeb

•  Sources:facility/missionsites,dedicatedarchives,linksfromelectronicjournalarDcles

•  Content:rawand/orprocesseddata,auxiliarydata(e.g.,calibraDon),reducDonandanalysistools,dataproducts(images,spectra),catalogs

AccessingPublicDataontheWeb

Usage:(1) ReaddocumentaDon(manuals,helpfiles,

tutorials).

(2)IdenDfytheobject(s)orregion(s)ofinterest.

(3)IDthetypeofdatarequired(including

wavelengthregime).

(4)Downloadwhatyouneed.

NASA/IPACExtragalac<cDatabase(NED)

NEDisbuildaroundamasterlistofextragalac9cobjectssearchablebynameorregion.Collectedare…

•  Sourcenames•  PosiDonsandtheirCoordinates•  RedshiIsandradialvelociDes•  OpDcaldiametersandmagnitudes•  Imagesfrom(ground‐based)opDcalandIRall‐skysurveys•  Spectra•  Bibliographicreferences

NEDisagoodstarDngpointifoneisinterestedinaparDcularextragalacDcobject.

NASA/IPACExtragalac<cDatabase(NED)

NEDhasfivebroadsecDons•  Objects•  Data•  Literature•  Tools•  Info–checkouttheintro,FAQ,overview

NASA/IPACExtragalac<cDatabase(NED)

InaddiDonto“staDc”data,NEDalsoprovides•  Calculatorsandothertools.•  CoordinatetransformaDons•  ExDncDoncalculator•  Cosmologycalculators•  Plodngtools•  Batchjobs•  Muchmore…

Re‐analysis‐‐newmethods,calibraDonNewfocus‐‐• partofauniformsample• lookforsomenewphenomenondiscoveredelsewhere• lookforvariabilitycomparedtodataelsewhen• lookforcounterpartstosourcesatotherwavelengths

Data“Archives”• SiteswheredataarestoredaresomeDmescalledarchives.• OIen,aIersomeproprietaryperiod(say,oneyear)thedatabecomepubliclyaccessible,andmaybedownloaded.

Whyanalyzearchivaldata?

QuesDonstoConsider

• WhatdocumentaDonisavailable?• WhatfilesdoIneed?• Isthedatapreprocessed?• Isthedatacalibrated?• Whatformatisthedatain?• WhatsoIwaredoIneedtousethedata?• WhodoIacknowledgewhenIpublishthedata?

HighEnergyAstrophysicsScienceArchiveResearchCenter(HEASARC)

AccesstootherNASAarchives,suchasNED

TheinterfacetotheHEASARCarchiveIscalledBrowse.

OnecommonlysearchesbyobjectnameorposiDon.Onemayspecifyasearchradius,aswellasthemissionsandcatalogstobequeried.

Ifnomissionorcatalogisselected,onegetsalistofallofthepossibleselecDonswithentrieslocatedontheskywithinthesearchradius.Fromamongthese,wechoosetoviewthetableofobservaDonsfromthe X‐rayObservatory.

Thisreturnsonetable‐‐themasterdatabaseofallcompletedandplannedChandraobservaDons‐‐inthisinstance,whichleadsusto…

…thelistofobservaDons,fromwhichweselectthelongestandmostrecentlyarchivedobservaDon

Theseareavailable

WecannowpreviewthedataandretrievetherequestedFITSfiles….

…andcreateasingletarfilecontainingallofthesefiles.

Thetarfilewiththerequesteddataisnowavailablefordownloading.

loew%tar‐xvfw3browse‐172321.tar9517/primary/acisf09517N001_cntr_img2.fits.gzloew%mv9517/primary/acisf09517N001_cntr_img2.fits.gz.loew%ls9517primaryloew%ls9517/primaryloew%rm‐r‐i9517examinefilesindirectory9517?yexaminefilesindirectory9517/primary?yremove9517/primary?yremove9517?Yloew%ls9517ls:9517:Nosuchfileordirectoryloew%rm‐iw3browse‐172321.tarremovew3browse‐172321.tar?yloew%gunzipacisf09517N001_cntr_img2.fits.gzloew%ls*.fitsacisf09517N001_cntr_img2.fitsds9acisf09517N001_cntr_img2.fits&

Inthedirectorywherethedatawasdownloaded(here``loew’’),unpackthetarfile.Movetheimagefitsfilebacktotheoriginaldirectoryanduncompressit,dele@ngunneededsubdirectories.(Alterna@vely,cd9517/primary,andworkinthatdirectory).

StepsleadingfromthedownloadtoopeningtheimageFITSfilewithds9‐‐acombinaDonofUNIXpracDceand“Ddying”up.

OverlayingX‐raycontoursonanop@calimage–step‐by‐step

See,also,h4p://cxc.harvard.edu/ciao/threads/ds9/.(whichhasalinktods9manuals)

ChandraX‐rayimageoftheNGC5813ellipDcalgalaxy

zoomtofit

rescalecolorsusingzscale

changecolor

smooth[analysis–>smoothparameters]

rescalecolors

x‐raycontours[analysis–>contourparameters]savetheseinafile[analysis–>contourparameters–>file–>savecontours]

LoadDSSopDcalimage[analysis–>imageservers–>STSCI‐DSSI/II](automaDcallyDled)

rescalecolorsinopDcalimage

WCS‐alignimages[Frame–>MatchFrames–>WCS]

rescalecolorsinopDcalimage

overlayopDcalcontoursonopDcalimage

clearopDcalcontours

overlayx‐raycontoursonopDcalimage[analysis–>contourparameters–>file–>loadcontours]

AQuickLookatRegionsandCatalogsinDS9

TheframewiththesmoothedX‐rayimage,contourscleared.

Placeacircle(thedefaultregionshape)aroundapointsource.Adjustthecenterandradius(to10’’),andexpresstheseinsexagesimalWCScoordinates[region–>getinforma9on].

savetheseinafile[region–>saveregions],andthenremovefromtheimage[region–>deleteallregions]

Reloadthesavedregion[region–>loadregions]

OverplotsourceposiDonsretrievedfromtheFIRSTradiosurvey,usingbluecrosspointsymbols[analysis–>catalogs–>radio–>firstsurvey]