What can we learn about solar coronal mass ejections, coronal dimmings, and Extreme-Ultraviolet jets through spectroscopic observations?

3.4 MB·English

by  Hui Tian

What can we learn about solar coronal mass ejections, coronal dimmings,
and Extreme-Ultraviolet jets through spectroscopic observations?
HuiTian1, ScottW. McIntosh1, LidongXia2, JiansenHe3, XinWang1,3
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ABSTRACT
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Solareruptions,particularlycoronalmassejections(CMEs)andextreme-ultraviolet(EUV)jets,have
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rarely been investigatedwith spectroscopic observations. We analyze several data sets obtained by the
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EUVImagingSpectrometeronboardHinodeandfindvarioustypesofflowsduringCMEsandjeterup-

] tions.CME-induceddimmingregionsarefoundtobecharacterizedbysignificantblueshiftandenhanced
R
line width by using a single Gaussian fit. While a red-blue(RB) asymmetry analysis and a RB-guided
S doubleGaussianfitofthecoronallineprofilesindicatethatthesearelikelycausedbythesuperpositionof
h. astrongbackgroundemissioncomponentandarelativelyweak( 10%)high-speed( 100kms−1)up-
∼ ∼
p flowcomponent.Thisfindingsuggeststhattheoutflowvelocityinthedimmingregionisprobablyofthe
- orderof100kms−1,not 20kms−1asreportedpreviously.Densityandtemperaturediagnosticsofthe
o ∼
r dimmingregionsuggestthatdimmingisprimarilyaneffectofdensitydecreaseratherthantemperature
st change. Themasslossesindimmingregionsasestimatedfromdifferentmethodsareroughlyconsistent
a with each other and they are 20%-60% of the masses of the associated CMEs. With the guide of RB
[
asymmetryanalysis,wealsofindseveraltemperature-dependentoutflows(speedincreaseswithtempera-

1 ture)immediatelyoutsidethe(deepest)dimmingregion.Theseoutflowsmaybeevaporationflowswhich
v are caused by the enhancedthermal conductionor nonthermalelectron beams along reconnectingfield
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lines,orinducedbytheinteractionbetweentheopenedfieldlinesinthedimmingregionandtheclosed
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loops in the surrounding plage region. In an erupted CME loop and an EUV jet, profiles of emission
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2 linesformedatcoronalandtransitionregiontemperaturesarefoundtoexhibittwowell-separatedcompo-
. nents,analmoststationarycomponentaccountingforthebackgroundemissionandahighlyblueshifted
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( 200kms−1)componentrepresentingemissionfromtheeruptingmaterial. Thetwo componentscan
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∼
2 easilybedecomposedthroughadoubleGaussianfitandwecandiagnosetheelectrondensity,tempera-
1 tureandmassoftheejecta. Combiningthespeedoftheblueshiftedcomponentandtheprojectedspeed
: oftheeruptingmaterialderivedfromsimultaneousimagingobservations,wecancalculatetherealspeed
v
i oftheejecta.
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r Subjectheadings: Sun:coronalmassejections(CMEs)—Sun:flares—Sun:corona—line:profiles—solarwind
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1. Introduction Fengetal. 2009; Liuetal. 2010). Recent statistical
studiesofReinard&Biesecker(2008)andBewsheretal.
Coronal mass ejections (CMEs) are large-scale
(2008)haveshownthatmorethan50%ofthefrontside
solar eruptions and earth-directed CMEs are often
CMEs are associated with coronal dimmings (or
sourcesofstronggeomagneticstorms(e.g.,Goslingetal.
transient coronal holes), which are characterized
1991; Wangetal. 2002, 2006; Zhang&Low 2005;
by abruptly reduced emission in extreme-ultraviolet
(EUV) and soft X-rays (e.g., Rust&Hildner 1976;
1High Altitude Observatory, National Center for Atmospheric Gopalswamy&Hanaoka1998;Thompsonetal.1998;
Research,P.O.Box3000,Boulder,CO80307;[email protected]
Zarroetal. 1999; Zhouetal. 2003; DeTomaetal.
2Shandong Provincial Key Laboratory of Optical Astronomy
2005; McIntoshetal. 2007; Miklenicetal. 2011).
and Solar-Terrestrial Environment, School of Space Science and
Physics,ShandongUniversityatWeihai,Weihai264209,China Dimmings may mark locations of the footpoints of
3SchoolofEarthandSpaceSciences,PekingUniversity,China ejected flux ropes (e.g., Webbetal. 2000) or formed
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by reconnection between the erupting field and the toestimatethemassoftheeruptedmaterialandmass
surrounding magnetic structures (e.g., Attrilletal. lossinthedimmingregion.
2007; Mandrinietal. 2007). There are basically two So far there are only a few spectroscopic investi-
types of dimmings: small-scale dimmings associated gationsof CMEs, dimmings, and EUV jets in the lit-
with the two ends of a pre-CME sigmoid structure erature. Using observationsby the CoronalDiagnos-
(e.g., Sterling&Hudson 1997; Hudsonetal. 1998; tic Spectrometer(CDS, Harrisonetal. 1995) onboard
Zarroetal. 1999; Webbetal. 2000; Jiangetal. 2003; the Solar and Heliospheric Observatory (SOHO),
Chengetal. 2010) and global-scale dimmings which Harra&Sterling(2001)reportedsignificantblueshift
are often immediately proceeded by global ”EUV of emission lines formed at coronal and TR tem-
waves”(e.g.,Thompsonetal.2000;Attrilletal.2007). peratures in dimming regions. This result has been
Jet-like phenomena are small-scale solar erup- confirmed by recent high-resolution observations of
tionsand theyare oftenobservedin X-ray, EUV, and the EUV Imaging Spectrometer (EIS, Culhaneetal.
whitelight. Mostjetsareassociatedwithsmallflares 2007) onboard Hinode (Harraetal. 2007; Jinetal.
(Madjarskaetal. 2007). EUV jets are characterized 2009;Attrilletal.2010;Chenetal.2010a;Harraetal.
bynearlycollimatedhigh-speedmotionsofplasmaat 2011a). Blueshiftwasalsofoundinfootpointregions
coronalandtransitionregion(TR)temperatures(e.g., of small-scale eruptedloops (Heetal. 2010b). How-
Alexanderetal.1999;Linetal.2006;Liuetal.2011; ever, a preliminary study of McIntoshetal. (2010)
Shenetal.2011,2012;Srivastava&Murawski2011). suggests that some line profiles in the dimming re-
Studies have shown that EUV jets and X-ray jets are gionsareasymmetric,withaweakenhancementinthe
closely associated with each other (Kimetal. 2007; blue wings. EIS observations have also revealed an
Chiforetal.2008b;Heetal.2010b;Yangetal.2011). obvious increase of the line broadening in dimming
RecentobservationsbytheAtmosphericImagingAs- regions, whichwas interpretedasa growthofAlfve´n
sembly (AIA, Lemenetal. 2011) onboard the Solar waveamplitudeorinhomogeneitiesofflowvelocities
DynamicsObservatory(SDO)haverevealedthatfine- along the LOS (McIntosh 2009; Chenetal. 2010a;
scale EUV jets (high-speed outflows) are ubiquitous Dolla&Zhukov 2011). The presence of asymmet-
on the Sun (DePontieuetal. 2011;Tianetal. 2011b; ric line profiles suggests that there are probably two
Yangetal.2011). emission components and that a single Gaussian fit
KinematicsassociatedwithCMEsandEUVjetsare may not reveal the real physics in dimming regions
usually studied through coronagraph and broadband (McIntoshetal.2010;Dolla&Zhukov2011).
observations.Thehighcadenceandlargefieldofview The outflow speed derivedfrom a single Gaussian
(FOV)oftheseimagingobservationshavegreatlyen- fitisroughlyintherangeof10-40kms−1andusually
hanced our understanding of these solar eruptions. it does not change significantly for coronal emission
However,imagingobservationsonlyallowustostudy lines formed at different temperatures (Harraetal.
the plane of sky (POS) componentof the kinematics, 2007; Jinetal. 2009; Attrilletal. 2010; Chenetal.
whichisusuallyagoodapproximationofthefullkine- 2010a). However, Imadaetal. (2007) reported a
matics only for limb events. For earth-directederup- temperature-dependentoutflowinthedimmingregion
tions, especially halo-CMEs which are the cause of following a CME. The speed of the flow increases
moststronggeomagneticstorms,imaginginstruments from 10kms−1atlog(T/K)=4.9to 150kms−1at
∼ ∼
placedclosetotheSun-Earthlineoftenfailtoobserve log (T/K)=6.3. One-dimensionalmodeling effort has
their initial or completeevolution. Spectroscopicob- been taken to reconstruct this temperature-dependent
servations,ontheotherhand,canprovideinformation outflow(Imadaetal.2011).
on the plasma motions in the line of sight (LOS) di- Linesplittingisusuallyassociatedwithaveryhigh-
rection and thus are critical for us to understand the speed( 200kms−1 orlarger)plasmamotion. Using
kinematics of earth-directederuptions. For both disk CDS an∼d EIS observations, Harra&Sterling (2003),
andlimberuptions,theirthree-dimensional(3-D)evo- Asaietal. (2008) and Li&Ding (2012) found sig-
lutioncaninprincipleberevealedthroughsimultane- natures of line splitting indicative of plasma ejection
ousimagingandspectroscopicobservations. Inaddi- at a speed of 250 km s−1 during CMEs or fila-
tion, spectra of different emission lines can be used ment eruptions∼. Spectra obtained by the Solar Ul-
todiagnoseplasmapropertiessuchaselectrondensity traviolet Measurements of Emitted Radiation Spec-
andtemperature. Spectroscopicdatacanalsobeused trograph(SUMER,Wilhelmetal.1995;Lemaireetal.
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1997)onboardSOHOhaverevealedsignaturesofline emissionoftenconsistsofatleasttwocomponentsso
splitting associated with the expandingX-ray plasma thatpreviousresultsbasedonasingleGaussianfitmay
in a flare/CME event (Innesetal. 2001). Line split- need to be reconsidered. We apply the recently im-
ting or obviously blueshifted components have also proved techniques of red-blue (RB) asymmetry anal-
been found in spectra of EUV jets in coronal holes ysis and RB-guided double Gaussian fit (Tianetal.
andARs(Wilhelmetal.2002;Madjarskaetal. 2007; 2011c), whichweusedpreviouslytostudyproperties
Kamioetal.2007,2009;Chiforetal.2008a). of the high-speed outflows in non-eruptive active re-
Therehavebeenafewinvestigationsoftheplasma gions(ARs),tothespectraacquiredduringsolarerup-
propertiesofdimmingsandEUVjets.Harrison&Lyons tions. Wefindvarioustypesofflowsanddiscusspos-
(2000)andHarrisonetal.(2003)usedtheSiX347.40A˚ &356.0s4iAb˚lemechanismstoproducetheseflows. Wealsodi-
line pairs to diagnose the electron density and found agnosethe density, temperatureandmass loss (mass)
thatitdecreasedasdimmingoccurred.Usingsomeas- ofthedimmingregionaswellastheejectedmaterial.
sumptionsoftheemittingvolumeandthedistribution OuranalysesdemonstratethatEUVspectroscopicob-
of the amount of material at different temperatures, servationscanprovidealotofvaluableinformationon
they also made an effort to estimate the mass loss in solareruptions.
the dimming region and found that it is of the same
order as the mass of the associated CMEs. Taking 2. Observations, Single Gaussian fit, and RB
values of the formation heights of different emission asymmetryanalysis
lines and the densities from static solar atmosphere
Table1lists someofthe observationdetailsof the
models, Jinetal. (2009) also developed a method to
sixeventsweanalyzed.Theclassandpeaktimeofthe
estimate the mass losses in dimming regions associ-
associated flare are also listed for each event. There
ated with two events during 2006 Dec 13-15. Using
weremanyfastrepetitiverasters(witha scanningca-
theFe XII 186.88A˚ &195.12A˚ line pair,Chiforetal.
dence of 6 minutes) for Events 4&5 and we only
(2008a) measured electron densities higher than log ∼
(N /cm−3)=11 for an EUV jet. However, they only presentresultsforseveraloftheminthispaper.
e
simplysummedupthespectralintensitiesinthewave- The SSW routine eis prep.pro was applied to cor-
lengthwindowsofthelinesandcouldnotseparatethe rect and calibrate the EIS data. This includes CCD
blueshiftedcomponentfromthebackgroundemission pedestal and dark current subtraction, cosmic ray re-
component. moval, warm and hot pixels identification, absolute
calibration, error estimation, and so on. The effects
BesidesdimmingsandejectaassociatedwithCMEs
ofslittiltandorbitalvariation(thermaldrift)werees-
and EUV jets, other solar eruption related phe-
timated by using the SSW routine eis wave corr.pro
nomena such as flare induced chromospheric evap-
and removedfromthe data. After that, a runningav-
oration (Teriacaetal. 2003; Milliganetal. 2006a,b;
erage over 3 pixels along the slit was applied to the
Milligan&Dennis 2009; Milligan 2011; Chenetal.
spectratoimprovethesignaltonoiseratio. Notethat
2010b;Watanabeetal.2010;Li&Ding2011;Grahametal.
Tianetal.(2011c)usedthemedianvaluesofthemea-
2011; Liuetal. 2011), flare-related magnetic recon-
surement errors when averaging profiles over several
nection (Wangetal. 2007; Haraetal. 2011), filament
pixels.Inthispaperweregardtheselineprofilesasin-
oscillations(Chenetal.2008;Bocchialinietal.2011)
dependentmeasurementsoftheprofileatasinglepixel
and coronal waves (Harraetal. 2011b; Chenetal.
andusetheuncertaintypropagationtheorytocalculate
2011;Veronigetal.2011)havealsobeeninvestigated
themeasurementerrorsfortheaveragedprofile. This
throughEUV spectroscopic observations. As the ap-
usuallyleadstosmaller valuesofthe errors, whichis
proachingofthenewsolarmaximum,thereisnodoubt
reasonablesincethespatialaverageimprovesthesig-
thatmorespectroscopicobservationswillbeemployed
naltonoiseratio.
to study solar eruptionssince the high-resolutionEIS
instrumentis still in goodconditionand the Interface As a common practice, a single Gaussian fit was
RegionImagingSpectrograph(IRIS)isexpectedtobe applied to each spectrum. The line peak intensity,
launchedin2012. Dopplershiftandline widthcanthusbederived. We
assumezeroshiftoftheprofileaveragedovereachob-
Inthispaperweanalyzeseveraldatasetsobtained
servation region. We have to mention that the line
by EIS during CME eruptions and EUV jets. The
width can be expressed in different formats and dif-
shapesoftheEISspectrallineprofilessuggestthatthe
3
Peak Intensity (arbitrary unit) Velocity (km/s) Width (km/s) RB Asymmetry [70-130 km/s]
2.48 3.01 3.55 4.09 4.63 5.16 5.70 -42 -28 -14 0 14 28 42 44 50 56 62 68 74 80 -0.21-0.14-0.07 0.00 0.07 0.14 0.21
19:20-21:35
-50 -50 -50 --5500
c) -100 -100 -100 --110000
e
s
c
Y (ar -150 -150 -150 --115500
-200 -200 -200 --220000
-250 -250 -250 --225500
450 500 550 600 650 450 500 550 600 650 450 500 550 600 650 445500 550000 555500 660000 665500
01:15-03:30
-50 -50 -50 ---555000
c) -100 -100 -100 ---111000000
e
s
c
Y (ar -150 -150 -150 ---111555000
-200 -200 -200 ---222000000
-250 -250 -250 ---222555000
500 550 600 650 700 500 550 600 650 700 500 550 600 650 700 555000000 555555000 666000000 666555000 777000000
04:10-06:25
-50 -50 -50 --5500
c) -100 -100 -100 --110000
e
s
c
Y (ar -150 -150 -150 --115500
-200 -200 -200 --220000
-250 -250 -250 --225500
550 600 650 700 550 600 650 700 550 600 650 700 555500 660000 665500 770000
10:29-11:19
-50 -50 -50 --5500
c) -100 -100 -100 --110000
e
s
c
Y (ar -150 -150 -150 --115500
-200 -200 -200 --220000
-250 -250 -250 --225500
550 600 650 700 750 550 600 650 700 750 550 600 650 700 750 555500 660000 665500 770000 775500
X (arcsec) X (arcsec) X (arcsec) XX ((aarrccsseecc))
Fig. 1.—Spatialdistributionsofthepeakintensity,Dopplervelocityandexponentialwidthderivedfromthe single
Gaussianfit,andtheaverageRBP asymmetryinthevelocityintervalof70-130kms−1forFeXIII202.04A˚ inthe2006
Dec14-15observations.Thebeginningandendingtime(hour:minute)ofeachscanisindicatedintheintensityimage.
Thepre-eruptionconditionsare shownin thefirstrow. Thesquareineach panelofthe secondrowmarkslocations
whereprofilesareaveragedandpresentedinFigure7. TheredcontoursshowninthemapofRB asymmetryforthe
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01:15-03:30scanoutlinelocationswheretheRB asymmetry(70-130kms−1)issmallerthan-0.03andthesignalto
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noiseratiooftheprofileislargerthan8.
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Table1:EISObservationsUsedinThisStudy
Obs. ScanningPeriod Exposure Slit FlareClass&PeakTime Comment
ID time(s)
1 2006Dec1415:11-16:01 10 1′′ X1.5,Dec1422:15 CME&Dimming
2006Dec1419:20-21:35 30
2006Dec1501:15-03:30 30
2006Dec1504:10-06:25 30
2006Dec1510:29-11:19 10
2 2007May1909:42-10:30 10 1′′ B9.5,May1913:02 CME&Dimming
2007May1911:41-15:23 40
3 2006Dec1219:07-23:46 30 1′′ X3.4,Dec1302:40 CME&Dimming
2006Dec1301:12-05:41 30
4 2011Jun2102:11-05:18 9 2′′ C7.7,Jun2103:25 CME&Dimming
5 2011Feb1419:13-20:06 8 2′′ C6.6,Feb1419:30 CME
6 2007Jun501:51-02:04 5 2′′ C1.2,Jun504:23 EUVjet
2007Jun504:16-04:29 5
Peak Intensity (arbitrary unit) Velocity (km/s) Width (km/s) RB Asymmetry [70-130 km/s]
2.48 3.01 3.55 4.09 4.63 5.16 5.70 -42 -28 -14 0 14 28 42 44 50 56 62 68 74 80 -0.21-0.14-0.07 0.00 0.07 0.14 0.21
150 150 150 150
09:42-10:30
100 100 100 100
ec) 50 50 50 50
s
c
ar
Y ( 0 0 0 0
-50 -50 -50 -50
-50 0 50 100 -50 0 50 100 -50 0 50 100 -50 0 50 100
200 2 200 2 200 2 200 2
11:41-15:23
150 150 150 150
c) 100 100 100 100
e
s
arc 50 1 50 1 50 1 50 1
Y (
0 0 0 0
-50 -50 -50 -50
-50 0 50 100 150 -50 0 50 100 150 -50 0 50 100 150 -50 0 50 100 150
X (arcsec) X (arcsec) X (arcsec) X (arcsec)
Fig. 2.—SameasFigure1butforthe2007May19observations. Therectangularregions1&2markthelocations
wheretheFeXIII202.04A˚ profilesareaveragedandpresentedinFigure8.
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Peak Intensity (arbitrary unit) Velocity (km/s) Width (km/s) RB Asymmetry [70-130 km/s]
2.48 3.01 3.55 4.09 4.63 5.16 5.70 -42 -28 -14 0 14 28 42 44 50 56 62 68 74 80 -0.21 -0.14 -0.07 0.00 0.07 0.14 0.21
19:07-23:46
-50 -50 -50 -50
ec) -100 -100 -100 -100
arcs -150 -150 -150 -150
Y (
-200 -200 -200 -200
-250 -250 -250 -250
0 100 200 300 400 0 100 200 300 400 0 100 200 300 400 0 100 200 300 400
01:12-05:41
-50 3 4 -50 3 4 -50 3 4 -50 3 4
ec) -100 1 -100 1 -100 1 -100 1
arcs -150 -150 -150 -150
Y ( -200 2 -200 2 -200 2 -200 2
-250 -250 -250 -250
100 200 300 400 100 200 300 400 100 200 300 400 100 200 300 400
X (arcsec) X (arcsec) X (arcsec) X (arcsec)
Fig. 3.—SameasFigure1butforthe2006Dec12-13observations. Therectangularregions1-4markthelocations
wherelineprofilesareaveragedandpresentedinFigures10&14.
ferent names are assigned to different formats (e.g., (2011c)namedthismethodRB andtheyfurtherde-
S
Chaeetal.1998;Peter2010). AGaussianlineprofile velopedtwoothermethodsRB andRB ,whichare
P D
canbeexpressedas: basically the same as RB except the determination
S
of the line centroid. For RB , the spectral position
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I(v)=I exp( 1(v−v0)2), (1) correspondingtothepeakintensityisusedastheline
p −2 σ2 centroidandtheresultingRB profileisnormalizedto
wherev,Ip andv0 arethewavelengthvector(con- the peak intensity. For RBD, the line center of the
vertedinto velocitythroughDopplereffect), peak in- primarycomponent, which is derivedfrom the RB -
P
tensity and line center. Chaeetal. (1998) defined σ guideddoubleGaussianfit,isusedasthelinecentroid
as Gaussian width. While the Gaussian width men- andtheresultingRBprofileisnormalizedtothepeak
tionedby Peter (2010) is √2σ. In Tianetal. (2011c) intensity of the primary component. As pointed out
wefollowedPeter(2010)andusedboththenamesof byTianetal.(2011c),theRB techniquecanresolve
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Gaussianwidthand1/ewidthfor√2σ. Toavoidcon- theblueshiftedsecondarycomponentmoreaccurately
fusion, in the followingwe use the name exponential ascomparedtotheoriginallydefinedRB technique.
S
width(or1/ewidth,alsousedbyPeter(2010))instead Thus, here we apply the newly developed RB and
P
ofGaussianwidthfor√2σ. RB techniques, as well as the RB -guided double
D P
Thetechniqueof RBasymmetryanalysiswasfirst Gaussian fit (for details see Tianetal. 2011c), to the
introducedby DePontieuetal. (2009) anditis based datainthispaper.
on a comparison of the two wings of the line profile Figures 1-6 show the spatial distributions of the
at same velocityranges. Theline profilewas first in- peakintensity,velocityandexponentialwidthderived
terpolated to a spectral resolution ten times greater from the single Gaussian fit, and the average RB
P
thantheoriginalone,thenthebluewingemissionin- asymmetry in the velocity intervalof 70-130 km s−1
tegrated over a narrow spectral range was subtracted forFeXIII202.04A˚ orFeXII195.12A˚ intheobserva-
from that over the same range in the red wing. The tions of six events. For the RB asymmetry a neg-
P
range of integration was then sequentially stepped ative/positive value indicates an enhancement of the
outward from the line centroid to build an RB asym- blue/red wing. We preferto use the Fe XIII 202.04A˚
metry profile (simply RB profile). In our previous line to detect asymmetry since there is no identified
work(DePontieuetal.2009;DePontieu&McIntosh blendsinthisstrongline,althoughthepervasivepres-
2010;DePontieuetal.2011;McIntosh&DePontieu ence of very weak redward asymmetries outside the
2009a,b;McIntoshetal.2011;Tianetal.2011a;Mart´ınez-Sykodriamemtailn.g regions (in Figures 1-3) might suggest an
2011),weusedthesingleGaussianfittodeterminethe unidentifiedweakblendattheredwingofthelinepro-
line centroid and applied this technique to spectra in file. However,inFigures4-6wepresentresultsforthe
coronal holes, quiet Sun, and quiet ARs. Tianetal.
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Fig.4.—EvolutionofAIA193A˚ intensityandEISFeXII195.12A˚ lineparameters(peakintensity,velocityandwidth
derivedfromthesingleGaussianfit,andtheaverageRB asymmetryinthevelocityintervalof70-130kms−1)inthe
P
2011Jun21observations. ThetimeoftheAIAobservationandthebeginningtimeofeachEISscanareindicatedin
thecorrespondingintensityimages. Therectangularregionmarksthelocationswherelineprofilesareaveragedand
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presentedinFigure11. ThesizeoftheFOVisabout175′′ 152′′. Amovie(m4.mpeg)showingtheevolutionofAIA
171A˚ isavailableonline. ×
Fig. 5.—SameasFigure4butforthe2011Feb14observations. Theasteriskmarksthecenteroffivepixelsalong
theslitwherelineprofilesareaveragedandpresentedinFigure12. ThesizeoftheFOVisabout175′′ 160′′. For
×
illustrationsomebaddatafromsingleexposuresarereplacedbythedataofadjacentexposures. Amovie(m5.mpeg)
showingtheevolutionofAIA193A˚ isavailableonline.
8
Peak Intensity (arbitrary unit) Velocity (km/s) Width (km/s) RB Asymmetry [70-130 km/s]
2.48 3.01 3.55 4.09 4.63 5.16 5.70 -42 -28 -14 0 14 28 42 56 62 68 74 80 86 92 -0.21-0.14-0.07 0.00 0.07 0.14 0.21
-50 01:51-02:04 -50 -50 -50
-100 -100 -100 -100
c)
e
s
arc -150 -150 -150 -150
Y (
-200 -200 -200 -200
-250 -250 -250 -250
-600 -550 -500 -450 -600 -550 -500 -450 -600 -550 -500 -450 -600 -550 -500 -450
-50 04:16-04:29 -50 -50 -50
-100 -100 -100 -100
c)
e
s
arc -150 -150 -150 -150
Y (
-200 -200 -200 -200
-250 -250 -250 -250
-600 -550 -500 -450 -400 -600 -550 -500 -450 -400 -600 -550 -500 -450 -400 -600 -550 -500 -450 -400
X (arcsec) X (arcsec) X (arcsec) X (arcsec)
Fig. 6.—SameasFigure1butforFe XII195.12A˚ inthe2007Jun5observations. Therectangularregionmarksthe
locationswherelineprofilesareaveragedandpresentedinFigure13.
Fe XII 195.12A˚ line since the exposure time used in ming regions are characterized by a blueshift of 10-
theassociatedobservationsistooshortsothatonlythe 40 km s−1, a notable phenomenonin the Hinode era
strongFeXII195.12A˚ linehasenoughS/Ntoallowa (Harraetal. 2007; Jinetal. 2009; Attrilletal. 2010;
reliable RB asymmetry analysis to individualprofile. Chenetal. 2010a; Harraetal. 2011a). Enhancement
Since the blend Fe XII 195.18A˚ sits at the red wing of the line width in dimming regions has also been
of Fe XII 195.12A˚ (Youngetal. 2009), any blueward reportedbyMcIntosh(2009), Chenetal.(2010a)and
asymmetries detected by our RB technique are not Dolla&Zhukov(2011) andit isveryclear fromFig-
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causedbythisidentifiedblend. ures 1-4. The significant blueshift and enhancedline
The pre-eruption parameters are presented in the widtharesimilartothosefoundattheweak-emission
first row of each figure. The scanned regions for all boundaries of ARs (e.g., Marschetal. 2004, 2008;
rastersarealmostthesameforalmosteveryevent.The Harraetal. 2008; DelZanna 2008; DelZannaetal.
onlyexceptionisthe2007May19eventshowninFig- 2011;Doscheketal. 2007, 2008; Tripathietal. 2009;
ure 2, where we can clearly see that the observedre- Heetal.2010a;Murrayetal.2010;Brooks&Warren
gioninthepre-eruptionphaseisabout50′′ smallerin 2011;Warrenetal.2011;Bradshawetal.2011;Scott&Martens
solarY,comparedtothatintheeruptionphase. 2011;Youngetal.2012;Bakeretal.2012;Haraetal.
2008;DePontieuetal.2009;DePontieu&McIntosh
3. Flows 2010;McIntosh&DePontieu2009a,b;McIntoshetal.
2011;Peter2010;Bryansetal.2010;Ugarte-Urra&Warren
We found various types of flows in our observa- 2011;Mart´ınez-Sykoraetal.2011;Tianetal.2011a,c).
tions. In the followingwe mainly investigateproper- Figures1-4alsorevealasignificantbluewardasym-
tiesofthreetypesofoutflowsassociatedwithcoronal metry in dimming regions. We note that the blue-
dimmingsandCMEorEUVjeteruptions. ward asymmetries on maps of RB asymmetry for
S
the 2006 Dec 14-15 observations, which were pre-
3.1. High-speedoutflowsindimmingregions
sented by McIntoshetal. (2010), are not so promi-
nent as those in the RB asymmetry maps in our
Coronal dimmings are clearly seen from the in- P
Figure 1. This is because of the underestimation
tensity images presented in Figures 1-4. The dim-
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Fig.7.— RBasymmetryprofiles(bottom)oftheFeX184.54A˚,FeXII195.12A˚,FeXIII202.04A˚ andFeXIV274.20A˚
lineprofiles(top)averagedoverthesquaremarkedinFigure1. Top:Theobservedspectraandmeasurementerrorsare
shownasthediamondsanderrorbars,respectively.ThegreenlinesaresingleGaussianfits. Thetwodashedredlines
in eachpanelrepresentthetwo Gaussian componentsandthesolid redlineis thesum ofthe twocomponents. The
velocity(v) and exponentialwidth (w) derivedfromthe single (SGF) and double(1st/2nd for the two components)
Gaussianfits areshownin eachpanel. Also shownisthe intensityratioofthesecondarycomponentto theprimary
one(i2/i1).Bottom:theblackandbluelinesrepresentRBprofilesforRB andRB ,respectively.Errorbarsindicate
P D
theerrorspropagatedfromthemeasurementerrors. Thepeakrelativeintensity(i),velocity(v),and1/ewidth(w)are
shownineachpanel.
Fig. 8.— First&secondcolumns: RBasymmetryprofiles(bottom)ofFe XIII 202.04A˚ lineprofiles(top)averaged
overregions1 & 2 marked in Figure 2. Third & fourthcolumns: RB asymmetryprofiles (bottom)of the averaged
Fe XII 195.12A˚ lineprofiles(top)in dimmingregionsat02:51and03:18asshowninFigure4. Thelinestylesand
denotationsofparametersarethesameasinFigure7.
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