Review of Prominences in 304

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Review of Prominences in 304Å

• Lewis Fox
• 9/29/03

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Outline

• Motivation for this talk MOSES.
• What am I doing here?
• Pretty Pictures and Movies.
• Overview of some recent results.
• Some Open Questions
• Motivation MOSES - reprised

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Motivation

• MOSES Multi-Order Solar EUV Spectrograph
• A sounding rocket flight for June 04
• Primary Science Mission the He II Problem.
• Proof of Concept mission for Multi-Order Slitless
  Spectroscopy.
• Narrow band operation near 304Å

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What Am I Doing Here?

• AAS 2002 Meeting Sara Martin Speaks
• Charles talks to her about MOSES afterward, then
  tells me about the conversation.
• Charles Sara Martin says we could use MOSES to
  study prominences and filaments.
• My response Whats a filament?

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What Am I Doing Here?

• Early September 2003 Sara Martin invites MSU
  faculty and students to the PROM meeting.
• I mention the MOSES prominence/filament
  connection to Loren Acton.
• A conversation ensues. Several emails are
  exchanged.
• Result Im standing up here instead of sitting
  down there.

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Pretty Pictures
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Pretty Pictures
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Pretty Pictures
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Pretty Movies
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Overview of Recent Results

• Early indications were prominences in He II 304
  are essentially the same as in H?
• Led to multi-threaded isothermal strand model
• Formation temperature? 80 kK vs. 30 kK.
• Recent results show some differences between the
  two
• He II from upper portion, H? from lower (Wang et.
  al.)
• Can have He II prominence without H? emission
  (ibid.)

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Overview of Recent Results

• Other general properties also differentiate them
• He II prominences frequently taller 3-4
  thousand km. (Martin, 2002)
• Frequently tens of thousands of km longer (ibid.)
• Mass flows 30 km/s ranging from 10 70 km/s
  (Wang, 1999) as compared to 5 20 km/s in H?
  (Zirker et. al., 1998).
• Barbs do not usually coincide, but they obey the
  same chirality rules. (Wang, 2001).
• He II shows the outer part, H? the inner part.

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Some Open Questions

• It has been suggested that barbs terminate in
  regions of minority polarity (Wang, 2001, Martin
  and Echols, 1994).
• This has been observed in H?.
• But not yet shown in He II due to resolution of
  EIT.
• Counterstreaming barb flows
• Have they been observed in He II?

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Some Open Questions

• Activated Intervals
• Are they observed in He II?
• What is their connection to eruption?
• EIT data has correlated prominence eruption to
  CMEs in some cases (c.f. Delannée et. al. 2000)
• How strong is the correlation?
• What other factors play a role?
• What are the dynamics of prominence lift-off in
  He II?

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Motivation MOSES (reprised)

• Instrument Parameters
• 0.6/pixel
• 8.5x17 FOV
• 20 mÅ spectral resolution
• Narrow 304 band excludes all lines except Si XI
  303.3 Å and He II 303.8 Å
• MOSES will be capable of fast (10 s cadence),
  simultaneous, imaging spectroscopy.

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How?
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How?

• Ill-posed inversion
• Will we be able to extract meaningful information
  in this way?
• Current trial inversions can compute doppler
  shifts to 7 mÅ.
• Forward modeling is a viable option.
• Robust code exists.

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This has Promise

• Should have the spatial, spectral, and temporal
  resolution to address many of the questions
  raised.
• All I want for Christmas is an Orbiter.
• 5 minutes is not a lot of temporal coverage.
• Coordination with other observatories a must
• Large FOV helps.
• Lets hope for something exciting

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Thanks To

• Dr. Sara Martin for allowing me to take up this
  time at her meeting.
• Dr. Loren Acton for arranging it (and encouraging
  it).
• Dr. Charles Kankelborg for MOSES, without which
  Id be doing High-energy cosmic rays or General
  Relativity.
• Dr. Piet Martens for advice and encouragement.