HOP 0498

contact person in HINODE team

name :

General: Kobelski, Duncan (NASA/MSFC) / Watanabe (NAOJ) / Pontieu (LMSAL), XRT -- Reeves/ Testa (SAO), EIS -- Matthews/Culhane (UCL/MSSL)

e-mail :

adam.kobelski[at]nasa.gov, jessie.m.duncan[at]nasa.gov, tet_watanabe[at]jcom.zaq.ne.jp, bdp[at]lmsal.com, kreeves[at]cfa.harvard.edu, ptesta[at]cfa.harvard.edu, sarah.matthews[at]ucl.ac.uk, j.culhane[at]ucl.ac.uk

abstract of observational proposal

Main Objective: Plasma flows study inside an Active Region Dark Halo by using EIS and IRIS joint observations, with Solar Orbiter and DKIST supporting observations

Scientific Justification: Solar Active Regions (ARs) are often surrounded by areas appearing less bright in the EUV than the Quiet Sun (QS), which are called Dark Halos (DHs, Andretta et al. 2014). DHs are very common solar features, yet a consensus about their properties, origin and relationship with the nearby AR has not emerged yet. Some progress have been made with recent studies (Lezzi et al. 2023, Lezzi et al. 2024), but those works also pointed to the need for a comprehensive view of the atmospheric structure and dynamics of DHs from the chromosphere to the corona, up to about log T = 6.3. This study will investigate the relationship of DHs with AR upflows/downflows as a follow up of a previous HOP (0446) and the results of Lezzi et al. 2024, thus adding also Solar Orbiter and DKIST support. For the Hinode part, in particular, we propose to obtain Doppler shift maps of a DH in order to examine the plasma velocities inside it, by combining Hinode/EIS and IRIS simultaneous observations, that together allow a view of the solar atmosphere from the chromosphere to the corona.

request to EIS

EIS observation would be the same as in HOP0446. Details below: EIS observing sequence would consist of one run of Full Sun Spectral Sun (study ID #544) followed by one run of dhb_Spectral_atlas_covering_30x160_with_2"_slit_120s_exposures (study ID #468) on the same target. This sequence should be repeated during the planned Solar Orbiter observations.
The specific targeting of study #468 observations should be arranged with the proposers each time, following the Solar Orbiter Pointing Decision Meetings (PDM). ========================================================
EIS Study 1 Detail:
Full Sun Spectral Sun DHB_007 (study ID #544)
TARGET: Outskirts of Active Region
EXPOSURE TIME: 30s
RASTER: Scanning
NO. OF POINTING POSITIONS: 123
SLIT: 2"
STEP SIZE: 4"
WINDOW HEIGHT: 512 pixels
RASTER DURATION: 3690s
LINE LIST (ID #544)
Ion species Wavelength Default widths (A) (pixel)
FeXI 180.40 32
CaXV 182.10 32
FeX 184.33 32
FeVIII 185.21 24
FeXII 186.75 32
FeXI 188.40 48
CaXVII 192.47 56
CaXIV 194.10 40
FeXII 195.12 24
FeIX 197.86 24
CaXV 201.05 24
FeXIII. 202.04 24
FeXIII 203.83 24
CaXVI 208.50 32
SXIII 256.48 32
SiX 258.37 24
SiX 261.04 24
FeXVI 262.98 24
SX 264.30 72
FeXIV 270.52 24
SiVII 275.40 24
MgV 276.30 40
MgVII 278.40 24
MgVII 280.39 56
FeXV 284.16 24
========================================================
EIS Study 2 Detail: dhb_Spectral_atlas_covering_30x160_with_2"_slit_120s_exposures (study ID #468) on the same target
EXPOSURE TIME: 120s
RASTER: Scanning
NO. OF POINTING POSITIONS: 30
SLIT: 2"
STEP SIZE: 2"
WINDOW HEIGHT: 160 pixels
RASTER DURATION: 3600s
LINE LIST (ID #544)
Line Wavelength Default widths (A) (pixel)
CCDBSHRT0 177.54 1024
CCDBLONG0 200.37 1024
CCDASHRT0 257.02 1024
CCDALONG0 279.81 1024

remarks

Dates: The Solar Orbiter SOOP will run in 1+3 blocks, the first one aimed at an AR and the associated DH transiting the central meridian as seen by Solar Orbiter, the other three blocks will observe the same AR+DH complex as it crosses the limb. Planned times and dates for the Solar Orbiter joint observations:
- Block 1 (RB5_114): 2025-03-12T13:35:00Z - 2025-03-13T02:54:49Z
- Block 2.1 (RB5_111): 2025-03-17T20:35:00Z - 2025-03-17T21:37:00Z
- Block 2.2 (RB5_112): 2025-03-19T21:30:00Z - 2025-03-20T22:46:50Z
- Block 2.3 (RB5_113): 2025-03-23T18:00:00Z - 2025-03-24T18:36:46Z
Block 1 should be given higher priority over blocks 2.x.

Time window: Ideally, observation should be run close in time to DKIST observations (to be checked with proposers and DKIST contact points).

Target(s) of interest: AR+DH system selected during the Solar Orbiter Pointing Decision Meetings (PDM). Kick-off meeting: 5-Mar-2025 15:00 CET, target selection: 9-Mar-2025 15:00 CET.

Previous HOPs:
HOP 0466. Analysis of EIS observation in progress. First results described in Lezzi's PhD thesis (to be defended on Feb. 24th)