Integral)Field)Spectroscopy)of)High6Redshi8)Galaxies)with)the)E6ELT)spectrograph)HARMONI)

S.)Kendrew1,)S.)Zieleniewski1,)N.)ThaIe1,)J.)Devriendt1,))R.)Houghton1,))T.)Fusco2,)M.)Tecza1,)F.)Clarke1,)K.)O’Brien1)

1University+of+Oxford,+2ONERA+7+Paris+sarah.kendrew@astro.ox.ac.uk++

ABSTRACT)We+ present+ here+ first+ results+ of+ novel+ simulated+ integral+ field+spectroscopic+observaHons+of+ a+ z+ =+ 3+ galaxy+with+HARMONI,+ a+first+ light+ instrument+ for+ the+ 397m+ European+ Extremely+ Large++Telescope.+ Instead+ of+ extrapolaHng+ exisHng+ observaHons+ to+++higher+ z,+ our+ study+ is+ based+ on+ output+ from+ cosmological+simulaHons+with+the+grid7based+adapHve+mesh+refinement+code+RAMSES.+ + Using+ the+ physical+ properHes+ of+ the+ RAMSES+ star+++parHcles+ in+ combinaHon+ with+ stellar+ populaHon+ synthesis++models,+ we+ produced+ a+ 3D+ spectral+ cube+ of+ the+ galaxy’s+starlight.+

A+ HARMONI+ observaHon+ of+ this+ galaxy+ was+ simulated+ using+ a+dedicated+soUware+tool.+We+show+here+details+of+the+input+data+and+ spaHal+ and+ spectral+ light+ properHes,+ and+ simulated+observaHons+ with+ HARMONI.+ This+ work+ will+ demonstrate+ how+HARMONI+will+extend+the+resolved+spectroscopic+and+kinemaHc++study+ of+ galaxies+ to+ the+ early+ Universe,+ and+ show+ how+predicHons+ from+ advanced+ cosmological+ codes+ will+ be+ tested+observaHonally+ at+ high+ redshiUs+ with+ next7generaHon+instruments.++

HARMONI:)INTEGRAL)FIELD)SPECTROSCOPY)WITH)THE)E6ELT)

+The+HARMONI+instrument+(PI:+N.+ThaXe;+[1])+will+provide+IFS+at+visible+and+near7IR+wavelengths+on+the+E7ELT.+Assisted+by+single+conjugate+and+laser+tomographic+AO+(SCAO;+LTAO),+HARMONI+will+achieve+unprecedented+spaHal+resoluHon+over+a+ 6.4+ x+ 9.1”+ field+ of+ view.+ Key+ science+ with+ HARMONI+ covers+ many+ areas+ in+astrophysics,+ from+ characterizaHon+ of+ extrasolar+ panets+ to+ studies+ of+ high7redshiU+galaxies.+To+esHmate+the+scienHfic+performance+of+HARMONI+and+support+the+instrument+design,+ a+ simulator+ was+ developed+ that+ produces+ realisHc+ output+ data+ cubes+[2,3].++

A)SIMULATED)GALAXY)AT)Z=3))SimulaHons+ of+ cosmic+ structure+ formaHon+ allow+ us+ to+ study+ the+ origin+ and+evoluHon+ of+ galaxies+ through+ cosmic+ history.+ Such+ simulaHons+ today+ have+sufficient+ spaHal+ and+ mass+ resoluHon+ to+ make+ quanHtaHve+ observaHonal+predicHons,+and+indeed+pose+challenges+to+the+ΛCDM+paradigm+[4].+We+use+here+output+ from+ one+ such+ simulaHon,+ using+ the+ RAMSES+ code+ [5],+ to+ produce+ a+spectral+ cube+ of+ a+ star7forming+ galaxy+ at+ z+ =+ 3,+ which+ will+ consHtute+ a+ typical+observaHonal+target+for+HARMONI.++Input)Data)We+extracted+a+4+x+1010+Msolar+star7forming+galaxy+from+a+RAMSES+simulaHon+run+terminated+ at+ z+ =+ 3,+ in+ a+ 10+ x+ 10+ kpc+box,+ corresponding+ roughly+ to+ 3+ effecHve+radii.+The+galaxy+is+described+by+2.5+x+106+star,+gas+and+dark+maXer+parHcles;+Fig.+1+shows+the+dark+maXer+and+gas+(baryonic)+density+and+Fig.+2+the+radial+profiles+of+mass+ and+ density,+ as+ well+ as+ properHes+ of+ the+ stars’+ metallicity+ and+ formaHon+history.+ Analysis+ of+ the+ RAMSES+ data+ was+ performed+ using+ Python+ package+pynbody+[6].++

Fig.) 1:+Dark+maXer+density+plot+ (L)+&+detailed+ gas+density+plot+ (R)+ for+ the+ a+ star7forming+galaxy+ at+ z=3,+ as+produced+ in+ cosmological+ simulaHons+with+ the+RAMSES+AMR+code+[5].+

Stellar)popula[ons)We+employ+the+stellar+populaHon+synthesis+models+of+Bruzual+&+Charlot+[BC03;+7],+assuming+a+Salpeter+IMF,+to+construct+the+spaHal+and+spectral+light+profile+of+the+ galaxy.+ Using+ the+ RAMSES+ output,+ each+ star+ parHcle+ was+ assigned+ a+ BC03+model+ spectrum+ based+ on+ its+mass,+ age+ and+metallicity+ and+ corrected+ for+ the+parHcles’+ radial+ velociHes.+ From+ the+ angular+ co7moving+ distance+ at+ z+ =+ 3+ we+binned+ the+ spectra+ into+ 1+ mas2+ pseudo7spaxels+ to+ produce+ a+ UV7opHcal+ rest7frame+spectral+cube+of+the+galaxy,+with+spectral+sampling+at+1+Å.+Finally+the+cube+was+redshiUed+in+wavelength+and+flux+to+z+=+3.+

Fig.)2:+(T7L)+Radial+mass+profile+of+the+galaxy,+for+gas,+stars,+dark+maXer+and+total;+(T7R)+Radial+density+profile+of+the+input+galaxy,+for+stars,+gas,+dark+maXer+and+combined+baryonic+maXer.+The+total+mass+is+4+x+1010+M¯ over+a+10x10+kpc+region.+The+black+dashed+lines+indicate+the+approximate+half7mass+radius.+(B7L)+Metallicity+distribuHon+of+the+star+parHcles+in+the+galaxy;+the+solar+value+is+indicated+with+the+black+dashed+line.+(B7R)+The+galaxy’s+star+formaHon+history+ploXed+as+stellar+mass+vs.+formaHon+Hme;+the+red+line+shows+the+age+of+the+Universe+at+z=3.++

OBSERVATIONS)WITH)E6ELT)HARMONI)A+ typical+ HARMONI+ observaHon+ of+ our+ z+ =+ 3+ galaxy+ was+ simulated+ using+ a+dedicated+ soUware+ tool+ that+ incorporates+ realisHc+ observing+ parameters+ and+modelled+ adapHve+ opHcs+ PSFs+ [2].+ In+ this+ case,+we+ assumed+ a+ seeing+ of+ 0.67”+and+ observaHons+ assisted+ by+ laser+ tomographic+ AO+ (LTAO).+ The+ spectral+resolving+power+was+ +R+=+3500,+spaxel+scale+10+x+10+mas,+and+we+simulated+a+2+hour+exposure+(DIT=600s).+The+wavelength7integrated+output+is+shown+in+Fig.+3+for+K7band+(λ=1.9572.2+µm),+corresponding+to+the+rest7frame+V7band+at+z+=+3.++Using+the+simulated+observaHonal+data+we+will+invesHgate+how+HARMONI+will+be+able+to+extend+dynamical+and+kinemaHc+galaxy+studies+to+the+early+Universe.+This+analysis+is+currently+ongoing.+

Fig.)3:+(L)+Slice+from+the+input++spectral+cube+of+the+z+=+3+galaxy,+with+the+flux+in+each+pixel+corresponding+to+the+light+from+star+parHcles+in+the+corresponding+1x1+mas+on+sky.+(R)+K7band+integrated+stellar+light+image+of+the+galaxy+sampled+at+R=3500+with+10x10+mas+spaxels.+

[1]+ThaXe+et+al,+Proc.+SPIE+vol.+8446,+id.+84461L+(2012);++[2]+Zieleniewski+et+al,+Proc.+AO4ELT3,+Florence+(2013);+[3]+Zieleniewski+et+al,+this+conference+(2014)+;+[4]+Pontzen+&+Governato,+Nature+vol.+506,+1717178+(2014);+[5]+Teyssier,+A&A+385,+3377364+(2002);+[6]+Pontzen,+Roskar,+SHnson+&+Woods,+ASCL+1305.002+(2013);++[7]+Bruzual+&+Charlot,+MNRAS+vol.+344+(4),+100071028+(2003)+

References)