Observational evidences of the propagating waves in/above chromospheric network

1
Observational evidences of the propagating waves
in/above chromospheric network

• Peter Gömöry
• Astronomical Institue of the Slovak Academy of
  Sciences

Institut dAstrophysique Spatiale, Orsay, France
2
Motivation (I)

• previous work based on analysis of the SOHO/CDS
  measurements (Gömöry et al. 2006, AA 448, 1169)
• target chromospheric network near the center of
  the solar disk
• spectral lines He I 584.33 Å (log T 4.5) ?
  chromosphere
• O V
  629.73 Å (log T 5.3) ? transition region
• Mg IX
  368.07 Å (log T 6.0) ? corona
• analyzed parameters temporal variations of the I
  and vD
• techniques cross-correlations, wavelet and phase
  difference analysis
• determined results
• significant negative time shift of 27 s between
  temporal variations of the He I and O V
  intensities
• determined time shift dominated by oscillations
  with 300 s periodicity
• no relevant time shift between temporal
  variations of the He I and O V Doppler shifts
• only very ambiguous results based on the analysis
  of the temporal variations of the Mg IX
  intensities and Doppler shifts

Institut dAstrophysique Spatiale, Orsay, France
3
Motivation (II)

• interpretation of the results
• negative time shift between the He I and O V
  intensities and no time shift between their
  Doppler shifts ? non-radiative energy had to be
  transferred from transition region to
  chromosphere without any significant bulk mass
  motion ? downward propagating magneto-acoustic
  waves in network
• ambiguous interpretation of the results based on
  the Mg IX intensities and Doppler shifts ?
  problems with the wave source localization
  (transition region or corona?)
• possible explanations
• observed parts of the transition region and
• corona not magnetically coupled
• presence of waves only in the low-lying loops
• verification of our results
• longer dataset
• better coverage of the solar atmosphere
• ? more spectral lines
• better signal in spectral lines with the
  formation
• temperature higher than 106 K
• ? HINODE instruments

Institut dAstrophysique Spatiale, Orsay, France
4
Motivation (II)

• interpretation of the results
• negative time shift between the He I and O V
  intensities and no time shift between their
  Doppler shifts ? non-radiative energy had to be
  transferred from transition region to
  chromosphere without any significant bulk mass
  motion ? downward propagating magneto-acoustic
  waves in network
• ambiguous interpretation of the results based on
  the Mg IX intensities and Doppler shifts ?
  problems with the wave source localization
  (transition region or corona?)
• possible explanations
• observed parts of the transition region and
• corona not magnetically coupled
• presence of waves only in the low-lying loops
• verification of our results
• longer dataset
• better coverage of the solar atmosphere
• ? more spectral lines
• better signal in spectral lines with the
  formation
• temperature higher than 106 K
• ? HINODE instruments

Institut dAstrophysique Spatiale, Orsay, France
5
Motivation (II)

• interpretation of the results
• negative time shift between the He I and O V
  intensities and no time shift between their
  Doppler shifts ? non-radiative energy had to be
  transferred from transition region to
  chromosphere without any significant bulk mass
  motion ? downward propagating magneto-acoustic
  waves in network
• ambiguous interpretation of the results based on
  the Mg IX intensities and Doppler shifts ?
  problems with the wave source localization
  (transition region or corona?)
• possible explanations
• observed parts of the transition region and
• corona not magnetically coupled
• presence of waves only in the low-lying loops
• verification of our results
• longer dataset
• better coverage of the solar atmosphere
• ? more spectral lines
• better signal in spectral lines with the
  formation
• temperature higher than 106 K
• ? HINODE instruments

Institut dAstrophysique Spatiale, Orsay, France
6
HINODE data (I)

• HINODE/EIS ? spectroscopic measurements of the TR
  and corona
• target chromospheric network near the center of
  the solar disk
• date/time August 18, 2007 1049 UT 1320 UT
• 11 spectral lines
• He II 256 Å (log T 4.9) Fe VIII 185 Å (log T
  5.6) Si VII 275 Å (log T 4.9) ? transition
  region
• Fe X 184 Å (log T 6.0) Fe XII 195 Å (log T
  6.1) Fe XIII 196 Å (log T 6.2) Fe XIII 202 Å
  (log T 6.2) Fe XIII 203 Å (log T 6.2) Fe XV
  284 Å (log T 6.3) Ca XVII 192 Å (log T 6.7)
  Fe XXIV 192 Å (log T 7.2) ? corona
• observing modes
• 2D rasters ? spatial coalignment with other data
  (DOT,TRACE, SoHO/EIT,CDS)
• number of repetitions 6 (3 before and 3 after
  sit-and_stare mode)
• slit 2 304
• step in X direction 2 number of steps 41 ?
  FOV 82 304
• 1D sit-and-stare ? temporal evolutions of the I
  and vD in/above network
• number of repetitions 5
• exposure time 10 s readout number of
  exposures per one run 135
• duration of one run 25 min. ? total duration
  125 min. (2 hours)
• slit 2 304

Institut dAstrophysique Spatiale, Orsay, France
7
HINODE data (II)
He II 256 Å (log T 4.9)
Y 304
Fe XII 195 Å (log T 6.1)
Y 304
Ca XVII 192 Å (log T 6.7)
Y 304
Fe XXIV 192 Å (log T 7.2)
Y 304
X 82
t 25 min
t 125 min
Institut dAstrophysique Spatiale, Orsay, France
8
HINODE data (III)

• HINODE/SOT ? context images of the photosphere
  and chromosphere
• instrument broad-band filter imager
• date August 18, 2007
• time 1032 UT 1329 UT
• pointing FOV centered around the EIS
• slit position
• spectral channels G-band and Ca II H
• cadence of images 10 s per filtergram
• number of exposures per channel 304
• FOV 109 109

Y 109
G-band
Y 109
Ca II H
X 109
Institut dAstrophysique Spatiale, Orsay, France
9
Planned analysis

• similar to our previous work (i.e.
  cross-correlations, wavelet analysis, phase
  difference analysis) but applied on much more
  complex dataset taken on August 18, 2007
• dataset
• HINODE/EIS spectroscopy ? searching for the
  evidences of propagating waves in the transition
  region and corona
• HINODE/SOT imaging ? photospheric and
  chromospheric response to propagating waves
  dynamics of bright points ? possible source of
  waves
• SoHO/CDS spectroscopy ? presence of possible
  waves in the upper chromosphere and transition
  region
• SoHO/MDI magnetometry ? changes in the
  photospheric magnetic field ? physical mechanism
  responsible for the excitation of waves
• SoHO/EIT imaging ? context images of the
  chromosphere and corona
• TRACE imaging ? context images of the corona
• DOT imaging ? photospheric and chromospheric
  response to propagating waves Ha channel with
  high spatial resolution

Institut dAstrophysique Spatiale, Orsay, France