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HINODE Operation Plan (HOP)

accepted on


 HOP No.

 HOP title

HOP 0353

Study of the heating of the quiet chromosphere with ALMA

plan term


@ @


 name : Nindos @  e-mail : anindos[at]cc.uoi.gr

contact person in HINODE team

 name : Savage, Watanabe, De Pontieu
@  e-mail : sabrina.savage[at]nasa.gov, watanabe[at]uvlab.mtk.nao.ac.jp, bdp[at]lmsal.com

 abstract of observational proposal
Main Objective:
ALMA-Hinode-IRIS coordinated observations of a quiet Sun region to study chromospheric heating.

Scientific Justification:
We intend to carry out a comprehensive study of the heating of the quiet Sun chromosphere using ALMA observations at 1 and 3 mm in coordination with IRIS, Hinode, and BBSO observations. Several spectral lines observed by IRIS are formed at about the same height as the mm continua observed with ALMA, but probe different plasma properties. Hinode SOT data will provide information about the photosphere while context information about the corona will be obtained by Hinode XRT. Our aim is to detect, for the first time in the same observations, both transient bright features indicative of shocks that form as magneto acoustic waves propagate in the chromosphere, and small-scale flare-like brightenings indicative of magnetic reconnection.

The primary diagnostic to distinguish them will be their different temporal characteristics. We will compare the occurrence rates of the two types of heating events, and we will also compare their properties with those of similar events that will be detected by the instruments that will be co-observing with ALMA.

 request to SOT
Regular fast maps: 3.8 s for one position (2 cycles, 1.6 s). The maps should be 45''-wide, therefore for 150 positions (0.3'' x 150 = 45'') 9.5 minutes will be required.

 request to XRT
A few full-sun images just before and just after the ALMA observations. We request the Al-poly and Al-mesh to be used with a 2x2 binning, giving a spatial resolution of ~2"/pixel.

 request to EIS

 other participating instruments
ALMA: #653
After discussions with Bart De Pontieu we request a 2 step raster with 1" between the two steps, 120" long slit, 8 s exposure times, FUV spectrally summed by factor of 2, 18 s cadence of raster,
36 s cadence for all SJI:
3640258010 | Large sparse 2-step raster 1x120 2s Deep x 8 FUV spectrally rebinned | 36.70 | 31.10 | 0.6 | 9.2+/-0.1 | 18.4+/-0.0 | 36.7+/-0.0 | 36.7+/-0.0 | 36.7+/-0.0 | 36.7+/-0.0

Dates: The ALMA observations will probably take place sometime in April 2018.

Time window: We have asked for one 4-hour session of ALMA observations. We will notify the Hinode/IRIS planners about the exact date/time of the ALMA observations as soon as we hear from ALMA. We request synoptics to be shifted before or after our observations. We also request IRIS not to be in eclipse during our observations.

Target(s) of interest: At both ALMA frequencies, we will observe a quiet Sun region close to disk center.

Previous HOP information:
HOP-333 (March 2017)

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