Mapping the Diffuse Ultraviolet Sky with GALEX - arXiv

!"##$%&'()*'+$,,-.*'/0(1"2$30*('456'7$()'89:;< !"#"$%&'()%*#+,-&./&0/&12$)#3&4&5/&6/&7(8"%*"+ !

"#$%&#'"#()%)*)+',-'.()/,012(%3(4'5+#6&7,,/*'89:':;+0)?',-'@12(%3('&#$'

.()/,#,A24'B1+'C,1#('D,0E%#('F#%G+/(%)24'5&7)%A,/+4'H>?'=!=!I4'FJ. KL,//+(0,#$+#3+'&$$/+((M'NA*/)12O2&1,,?3,A

!"#$%&'$ P+'0/+(+#)'&'A&0',-')1+'$%--*(+'*7)/&G%,7+)'3,(A%3'Q&3E6/,*#$'%#')R,'R&G+7+#6)1'Q&#$(' STFUM'!8;:'VW'XFUM'=;!:'VY',G+/'&7A,()'Z8[',-')1+'(E2'*(%#6'&/31%G&7'$&)&'-/,A')1+' \.]^_'A%((%,#?'H,()',-')1+'$%--*(+'-7*`'%('$*+'),'$*()a(3&))+/+$'()&/7%61)'&#$'-,77,R('&' 3,(+3&#)'7&R'R%)1'(7,0+(',-''82#&A%3('^`07,/+/'S>^a!Y'(&)+77%)+'ST%`4' L/&G+#4'h'T/&#E'!gIgW'J1&7%A&4'H*/)124'h'T%`'=:!:Y?'D,R+G+/4'#,#+',-')1+(+'%#()/*A+#)(' R+/+',0)%A%i+$'-,/'A+&(*/+A+#)(',-')1+'$%--*(+'Q&3E6/,*#$'&#$')1+'-%/()'%#()/*A+#)' (0+3%-%3&772'$+(%6#+$'),'A+&(*/+')1+'$%--*(+'Q&3E6/,*#$'R&(')1+'X&//,RQ&#$'F7)/&G%,7+)' "A&6%#6'^`0+/%A+#)'-,/'P%$+aT%+7$'J*/G+2('SXFU"^PJY'R1%31',Q(+/G+$'&Q,*)'=8[',-' )1+'(E2'SJ31%A%#,G%31'+)'&7?'=::!Y'-,77,R+$'Q2'J@^.cdT"HJ'S^$+7()+%#'+)'&7?'=::9Y'R%)1' 3,G+/&6+',-'I:[',-')1+'(E2?

=

B1+'7&*#31',-')1+'\&7&`2'^G,7*)%,#'^`07,/+/'S!"#$%Y'%#'=::;'0/,G%$+$'&'#+R'07&)-,/A' -,/'$%--*(+'FU',Q(+/G&)%,#(?'"#')1+'Z'2+&/('(%#3+'%)('7&*#314'!"#$%'1&(',Q)&%#+$',G+/' ;:4:::',Q(+/G&)%,#('3,G+/%#6'Z8[',-')1+'(E2'%#')R,'*7)/&G%,7+)'Q&#$('S-&/a*7)/&G%,7+)4'TFUM' !;8:'j'!Z8:'V'&#$'#+&/a*7)/&G%,7+)4'XFUM'!Z8:'j'=I8:'VY?'.7)1,*61'&'-+R',-')1+' ,Q(+/G&)%,#('R+/+'&('7,#6'&('(+G+/&7')+#(',-')1,*(&#$(',-'(+3,#$(4'&77,R%#6'&'()*$2',-' (A&77'(3&7+'G&/%&)%,#('%#')1+'$%--*(+'FU'Q&3E6/,*#$'SJ*N&)1&'+)'&7?'=::gY4'A,()'R+/+',#72'&' -+R'1*#$/+$'(+3,#$('%#'7+#6)1'#+3+((%)&)%#6'Q%##%#6',G+/')1+'+#)%/+'-%+7$?'B1+'0/%A&/2' %#)+#)',-')1%('R,/E'%('),'0/+(+#)')1+'$%--*(+'Q&3E6/,*#$'&(',Q(+/G+$'-/,A'!"#$%4')1+'A,()' 3,A07+)+'&#$'(+#(%)%G+'(*/G+2',-')1+''$%--*(+'Q&3E6/,*#$'),'$&)+?'

."#/%0&$-*)# B1+'!"#$%'%#()/*A+#)'3,#(%()(',-'&'c%)31+2aL1/k)%+#')+7+(3,0+'R%)1'&'$%&A+)+/',-'8:' 3A'-,/')1+'0/%A&/2'A%//,/?']%61)'-/,A')1+'(E2'%('(+0&/&)+$'Q2'&'$%31/,%3',#),')R,'$+)+3),/(' STFU'&#$'XFUY'R%)1'&'(0&)%&7'/+(,7*)%,#',-';ll'j'8ll',G+/'&'!?=8m'-%+7$',-'G%+R?'B1+' %#()/*A+#)'&#$'%)('0/%A&/2'A%((%,#'1&('Q++#'$+(3/%Q+$'Q2'H&/)%#'+)'&7?'S=::8Y?'B1+'0/%A&/2' $&)&'0/,$*3)('SH,//%((+2'+)'&7?'=::ZY'-/,A'&'6%G+#',Q(+/G&)%,#'&/+'%A&6+(',-')1+'6%G+#'-%+7$' %#'+&31',-')1+')R,'Q&#$('&#$'&'A+/6+$'0,%#)'(,*/3+'3&)&7,6?'.'Q&3E6/,*#$'-%7+'%('&7(,' 3/+&)+$'-,/'+&31'Q&#$'Q2'i+/,%#6',*)')1+'()&/('%#')1+'-*77'%A&6+4'Q%##%#6',G+/'!g=ll'(f*&/+(' &#$')1+#'%#)+/0,7&)%#6'Q&3E'),')1+'-*77'!"#$%'/+(,7*)%,#'S(++'H,//%((+2'+)'&7?'=::Z'-,/'&' -*77'$+(3/%0)%,#Y?' B1+'A+$%&#',-')1+'%#$%G%$*&7'Q&3E6/,*#$('S-/,A')1+'Q&3E6/,*#$'-%7+Y'&)')1+'0,(%)%,#',-'

;

+&31',-')1+'()&/('%#')1+'!"#$%'A+/6+$'3&)&7,6'-,/'&'6%G+#',Q(+/G&)%,#'%('&/31%G+$'%#'&' 0*Q7%372'&33+((%Q7+'$&)&Q&(+'&)')1+'H*7)%A%((%,#'./31%G+'&)')1+'J0&3+'B+7+(3,0+'J3%+#3+' "#()%)*)+'SH.JBY'-/,A'R1+#3+'R+'1&G+'/+)/%+G+$')1+A?'P+'1&G+')+()+$')1+(+'G&7*+('&6&%#()' ,*/'%#$+0+#$+#)72'$+/%G+$'(E2'Q&3E6/,*#$('%#')R,'(+)(',-'$++0',Q(+/G&)%,#('SJ*N&)1&'+)'&7?' =::g4'=:!:Y'&#$'-%#$'6,,$'&6/++A+#)?'D,R+G+/4'R+'1&G+'&7(,'-,*#$'')1&)')1+'Q&3E6/,*#$' G&/%+(',G+/')1+'!"#$%'-%+7$'&)'(3&7+(',-'&'-+R'&/3A%#*)+(',/'7+(('R%)1'&'()&#$&/$'$+G%&)%,#' ,-'8:'j'=::'01'3Aa='(a!'(/a!'Va!4'$+0+#$%#6',#')1+'()/*3)*/+'%#')1+'-%+7$?'B1%('(1,*7$'Q+' 3,#(%$+/+$'&(')1+'*#3+/)&%#)2'%#',*/'G&7*+('R%)1')1+'0,((%Q%7%)2',-'6/+&)+/'$+G%&)%,#('%#' /+6%,#('R%)1'A,/+'()/*3)*/+? B1+'!"#$%'$&)&'%#37*$+'#,)'N*()')1+'&()/,012(%3&7'Q&3E6/,*#$'Q*)'&7(,'&%/67,R'&#$' i,$%&3&7'7%61)?'5,)1'$+0+#$',#')1+'$&)+'&#$')%A+',-')1+',Q(+/G&)%,#'&#$'R%77'G&/2',G+/')1+' 3&(+',-'&'7,#6',Q(+/G&)%,#'R1%31'A&2'3,#(%()',-'(+G+/&7'+`0,(*/+('(0/+&$',G+/'A,#)1(',/' +G+#'2+&/(?'B1+'&%/67,R'%#'+%)1+/'Q&#$'%('Q+)R++#'&Q,*)'=::'a';::'01'3Aa='(a!'(/a!'Va!'S5,--%' +)'&7?'=::ZW'J*N&)1&'+)'&7?'=::gY?'P+'1&G+'+()%A&)+$')1+'*#3+/)&%#)2'%#')1+'&%/67,R'),'Q+' &Q,*)'8:'01'3Aa='(a!'(/a!'Va!?'B1+'&%/67,R'%('&'()/,#6'-*#3)%,#',-')1+'7,3&7')%A+',-')1+' ,Q(+/G&)%,#'SJ*N&)1&'+)'&7?'=::gY'R1%31'R&('#,)'+&(%72'/+3,G+/&Q7+'-,/',*/',Q(+/G&)%,#(?' n,$%&3&7'7%61)4'(*#7%61)'(3&))+/+$'Q2'%#)+/07&#+)&/2'$*()4'A&2'Q+'+()%A&)+$'*(%#6'%)(' ,Q(+/G+$'$%()/%Q*)%,#'%#')1+',0)%3&7'(3&7+$'Q2')1+'(,7&/'(0+3)/*A'S]+%#+/)'+)'&7?'!ggIY?' .7)1,*61',-)+#')&E+#'),'Q+'*#%)24')1+'3,7,/'%#$+`'S/+7&)%G+'),')1+'(,7&/'(0+3)/*AY'R&('-,*#$' ),'%#3/+&(+'R%)1'$%()+'-/,A')1+'+37%0)%3'07&#+'Q2'H*/)12'+)'&7?'S!gg:Y'%#)/,$*3%#6'&#' &$$%)%,#&7'*#3+/)&%#)2'%#')1+'$+/%G+$'Q&3E6/,*#$(?'B1+'7+G+7',-')1+'i,$%&3&7'7%61)'$+0+#$('


^a!Y'$&)&',-'T%`'+)'&7?'S!gIgY?'B1+'3,A0&/&Q7+'(7,0+'-,/')1+'!::'bA'+A%((%,#' -/,A')1+'"#-/&/+$'.()/,#,A2'J&)+77%)+'S"c.JY'%('=?9'HC2'(/a!''S5,*7+/'h'@k/&*7)'!gIZY4'

8

%A072%#6'&#'&G+/&6+'TFUd"c'/&)%,',-'=!:'01,),#('3Aa='(a!'(/a!'Va!'SHC2'(/a!Ya!'&#$'&#' XFUd"c'/&)%,',-'!9Z'01,),#('3Aa='(a!'(/a!'Va!'SHC2'(/a!Ya!?'e-'3,*/(+4'A'01+#,A+#&' ,/%6%#&)%#6'%#')1+'\&7&`2'R,*7$'/+(*7)'%#'&'3,(+3&#)'7&R'Q*)')1+',/%6%#',-')1+'A&N,/%)2',-')1+' FU'+A%((%,#'%#'$*()'(3&))+/+$'7%61)'%('(1,R#'Q2'%)('3,//+7&)%,#'R%)1')1+'!::'bA'"c.J' +A%((%,#'ST%6?';Y?'B1+'TFUd"c'/&)%,'1&('&'(7,0+',-'';:='01,),#('3Aa='(a!'(/a!'Va!'SHC2'(/a!Ya!4' &'2a%#)+/3+0)',-'!:9'01,),#('3Aa='(a!'(/a!'Va!'&#$'&'3,//+7&)%,#'3,+--%3%+#)',-':?I='R%)1')1+' XFUd"c'/&)%,'1&G%#6'&'(7,0+',-'==:'01,),#('3Aa='(a!'(/a!'Va!'SHC2'(/a!Ya!''R%)1'&#'%#)+/3+0)',-' !g;'01,),#('3Aa='(a!'(/a!'Va!'&#$'&'3,//+7&)%,#'3,+--%3%+#)',-':?Z=?'"#'Q,)1'3&(+('R+'1&G+' /+()/%3)+$')1+'-%)'),')1,(+'7,3&)%,#('R1+/+')1+',0)%3&7'$+0)1'%('7+((')1&#':?Z'R1+/+')1+''FU' &#$'"c'/&$%&)%,#'&/+'Q,)1'$*+'),'+A%((%,#'-/,A',0)%3&772')1%#'7&2+/(',-'$*()?'.(')1+'3,7*A#' $+#(%)2',-')1+'$*()'%#3/+&(+(4')1+',0)%3&7'$+0)1'%#3/+&(+('/&0%$72'%#')1+'FU'R1%7+')1+' A+$%*A'/+A&%#(',0)%3&772')1%#'%#')1+'"c?'D+#3+4')1+'FU'-7*`'(&)*/&)+('R1%7+')1+'!::'bA' -7*`'3,#)%#*+('),'%#3/+&(+'7%#+&/72?'"#'&$$%)%,#4'7,3&7''+--+3)('Q+3,A+'%A0,/)&#)'&('/+7&)%G+72' )1%#'37,*$('%#'-/,#)',-'A&((%G+'A,7+3*7&/'37,*$('$,A%#&)+')1+'FU'R1%7+')1+'"c'&/%(+(' 0/%A&/%72'%#')1+'Q&3E6/,*#$'37,*$'&(',Q(+/G+$'+6?'%#''e01%*31*('SJ*N&)1&'+)'&7?'=::8Y'&#$' )1+'L,&7(&3E'SJ*N&)1&'+)'&7?'=::ZY?'")'(1,*7$'Q+'#,)+$'1+/+')1&)')1+',--(+)('R+'-%#$'&/+' $+0+#$+#)',#')1+'i+/,'0,%#)(',-')1+'"c.J'$&)&'&('R+77'&(')1+'\.]^_'$&)&4'+%)1+/',-'R1%31' A&2'Q+'R/,#672'+()%A&)+$? eQ(+/G+$'FUd"c'/&)%,('%#')1+'7%)+/&)*/+'/+'-/,A'37*()+/'&/,*#$')1+'=::'j';::'01'3A a=' (a!'(/a!'Va!'SHC2'(/a!Ya!'A&/E'SJ&((++#'h'>+1&/G+#6'!gg9W'@+/&*7)'+)'&7?'!gg!W'P/%61)'!gg=Y' Q*)'R%)1'(A&77+/'G&7*+('So''=::'01,),#('3Aa='(a!'(/a!'Va!'SHC2'(/a!Ya!Y'-,*#$'%#'T.FJB'

9

,Q(+/G&)%,#(',-'%#$%G%$*&7'/+6%,#('SJ&((+#'h'>+1&/G+#6'!gg9W'D&%E&7&'+)'&7?'!gg8Y'&#$'Q2' J31%A%#,G%31'+)'&7?'S=::!Y'R1,'-,*#$'/&)%,(',-'Q+)R++#'8:'&#$'!::'01,),#('3A a='(a!'(/a!'Va!' SHC2'(/a!Ya!'%#')1+%/'(*/G+2',-'=8[',-')1+'(E2?'P+'$,'-%#$'(%6#%-%3&#)'G&/%&)%,#'%#',*/' ,Q(+/G+$'TFUd"c'&#$'XFUd"c'/&)%,('ST%6?'+(0%)+')1%(',*)()&#$%#6'3,//+7&)%,#4')1+/+'%('()%77'3,#(%$+/&Q7+'()/*3)*/+'%#')1+' TFUdXFU'/&)%,'ST%6?'9Y?'B1%('A&2'/+-7+3)',)1+/'3,#)/%Q*)%,#('),')1+'TFU'Q&#$4'%#' 0&/)%3*7&/4'(*31'&('A,7+3*7&/'12$/,6+#'-7*,/+(3+#3+'SH&/)%#4'D*/R%)i4'h'5,R2+/'!gg:W' J*N&)1&'+)'&7?'=::gY',/'+A%((%,#'-/,A'+`3%)+$'7%#+('(*31'&('L"U'Sp,/0+7&'+)'&7?'=::9W'@&/E' +)'&7?'=::gY?'B1+(+'3,#)/%Q*),/('A&2'Q+'&('1%61'&('=:[',/'A,/+',-')1+'),)&7',Q(+/G+$'(%6#&7? J+G+/&7'%#$%G%$*&7'-+&)*/+('&/+'&00&/+#)'%#'T%6?'!'&#$')1+',)1+/'A&0(',-')1+'(E24'&A,#6()' )1+'A,()'0/,A%#+#)',-'R1%31'&/+')1+'+`)+#$+$'$*()'1&7,('&/,*#$')1+'Q/%61)'+&/72a)20+'()&/(' J0%3&'S74'Q'q';!9?=m4'8:?ImY'&#$'.31+/#&/'S74'Q'q'=g:?Im4'a8I?ImY?'B1+'1&7,'&/,*#$'J0%3&' A%61)'Q+'+`0+3)+$'&(')1+/A&7'+A%((%,#'-/,A'&'#+&/Q2'37,*$'%('(++#'%#')1+'%#-/&/+$'Sn&6*/24' C,#+('h'5,*7+/'!ggIY'R1%7+'&#'%AA+#(+'-&%#)'Dr'+A%((%,#'#+Q*7&'+`)+#$('&('-&/'&('!Im'

Z

-/,A')1+'()&/'Sc+2#,7$('!gI8Y?'X,'(%A%7&/'+`)+#$+$'#+Q*7&'1&('Q++#'&((,3%&)+$'R%)1' .31+/#&/'Q*)')1&)'()&/'%('&'-&()'/,)&),/'R%)1'3%/3*A()+77&/'+A%((%,#'+`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ggIYW')1+',#*('%('#,R'),'3/+&)+'*#%-%+$'A,$+7('-,/'$*()'(3&))+/%#6' &#$')1+'(*Q(+f*+#)')1+/A&7'+A%((%,#'R1%31'%#37*$+'A*7)%07+'(3&))+/%#6'&#$'37*A0%#6?'J*31' A,$+7('1&G+'Q++#'&007%+$'),'T.FJB''$&)&''Q2'P%))'+)'&7?'S!ggZY'R1,'-,*#$'&#'&7Q+$,',-' :?