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HINODE Operation Plan (HOP)

accepted on


 HOP No.

 HOP title

HOP 0441

Understanding the Correlation between Solar Abundances and F10.7 Radio Emission using JVLA during Increasing Solar Activity

plan term


@ @


 name : To, Bastian, Long, Baker, van Driel-Gesztelyi, Brooks @  e-mail : Proposer email (Primary first): shu.to.18[at]ucl.ac.uk; tbastian[at]nrao.edu; david.long[at]ucl.ac.uk; deborah.baker[at]ucl.ac.uk; lidia.vandriel[at]obspm.fr; dhbrooks.work[at]gmail.com

contact person in HINODE team

 name : Matthews, Culhane @  e-mail : sarah.matthews[at]ucl.ac.uk, j.culhane[at]ucl.ac.uk

 abstract of observational proposal
Main Objective:
Understanding the spatial correlation between Solar Abundances and F10.7 Radio Emission using JVLA during Increasing Solar Activity

Scientific Justification: Element abundance signatures have long been used as tracers of physical processes throughout astrophysics. Understanding the spatial and temporal variations in the composition of the solar corona offers an insight into how matter and energy flow from the chromosphere, where the plasma is separated according to chemical populations (i.e., fractionated), out into the heliosphere.

In a recent Nature Communications paper (Brooks et al. 2017), we demonstrated that the FIP bias derived from full-Sun spectra is highly correlated (r = 0.88) with the F10.7 cm radio flux, a solar activity proxy, during the rising phase of the solar cycle from 2010-2014. However, the correlation appears to become nonlinear at times of increased magnetic activity on the Sun (Brooks et al. 2017). As a result, in 2020, we organised a joint JVLA-EIS-IRIS observation campaign to investigate the spatial correlation between FIP bias and the different emission mechanisms of the F10.7 flux using a small and simple bipolar active region, AR 12759. The data obtained in the joint observation has been written up to form the key part of To et al. (In prep). The results show that in a small active region, FIP bias correlates well with the F10.7 free-free emission, but not the gyroresonace emission. In this follow up campaign, we would like to observe a more complex AR during increasing solar activity, further verifying and understand this breakdown in correlation.

The JVLA observation will be supported by simultaneous observations with the Hinode/EUV Imaging Spectrometer (EIS) and the Interface Region Imaging Spectrograph (IRIS). The combination of these three telescopes will ensure coverage in radio (VLA), UV (IRIS) and EUV (Hinode/EIS) emission throughout the solar atmosphere from the chromosphere to the corona. Results of the study will

1. improve our understanding of the underlying causes of the non-linearity of the FIP bias - F10.7 solar index correlation found by Brooks et al. (2017) and To et al. (In prep).

2. Provide constraints on the amplitude of composition variability related to solar cycle amplitude. This in turn will inform stellar astronomers about the amplitude of variability in stellar coronal composition and its dependence on magnetic activity.

 request to SOT
At least a single SP map encompassing the active region, particularly covering both polarities and a little bit of the surrounding photosphere. Repeat as telemetry allows.

 request to XRT
Filter: thin-Be and Al-Poly, FOV: 384h x 384h, Cadence: 60 s

 request to EIS
The science objective we proposed requires the presence of strong sunspot, ideally one with multiple sunspots. In case this target is not available, the next best target would be active regions with pore(s) visible in the HMI continuum.
If a complex active region is presence, EIS should run the active region scan with a lower exposure time,study HPW021VEL360x512v1_b (Included here in full under Subsection 3.1). In case of a simple AR with only 1-2 pore(s), EIS should run the active region scan, study 608, fullccd_scan_m106 (included under subsection 3.2). Under both situations, EIS should takes repeated scans of an active region
throughout its period on disk, and raster the study to create a larger FOV.

3.1 Case of a complex active region (>2 pores)
Fe XI 180.40
Ca XV 182.10
Fe X 184.33
Fe VIII 185.21
Fe XII 186.75
Fe XI 188.40
Ca XVII 192.47
Ca XIV 194.10
Fe XII 195.12
Fe IX 197.86
Ca XV 201.05
Fe XIII 202.04
Fe XIII 203.83
Ca XVI 208.50
Fe XXIV 255.00
S XIII 256.48
Si X 258.37
Fe XVI 262.98
S X 264.30
Fe XIV 270.52
Si VII 275.40
Mg V 276.30
Mg VII 278.40
Mg VII 280.39
Fe XV 284.16

3.2 Case of a relatively simple active region (1-2 pores)
STUDY: fullccd_scan_m106
RASTER: limb_fullccd_scan_m106
CCDBSHRT0 177.54
CCDBLONG0 200.37
CCDASHRT0 257.02
CCDALONG0 279.81

POINTING: Contact Andy To (shu.to.18@ucl.ac.uk) in order to provide target position.

 other participating instruments
IRIS requests:
Proposal has not been submitted to the IRIS team
3600259171 | Medium dense 192-step raster 63.1x60 192s C II Si IV Mg II h/k De | 1808.77 |1166.38 |0.44 | 9.4+/-0.1 | 1809+/-0 | 28.3+/-0.0 | 28.3+/-0.0 | 28.3+/-0.0 | 0.0+/-0.0


Dates: ToO;
2022/08/14-2022/09/26 - This period corresponds to the JVLA observation period;
4-5 consecutive days to track an active region are desired, but not required

Time window: 14:00 - 22:30 UT

Target(s) of interest: Active region(s). ToO, Active region with pores visible in HMI continuum.
Proposers to provide Hinode, IRIS and VLA 3-5 days advance notice of when to run full disk scans.

Previous HOPs:
HOP 390. HOP 390 was a prequel to this HOP, in which we observed a small active region, AR 12759, on 2020 April 3 and 7. The data obtained from the HOP 390 campaign is being written up into To et al. (In prep), and hopefully be published in 2022.

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