Coordinated Observations

CoObs Working Group session  -  Wednesday April 26^th at 4:20pm CEST

 Zoom meeting link:   https://caltech.zoom.us/j/84321299787

Agenda

• IACHEC support for XRISM flight calibration
  • Launch delayed, now no earlier than August 26^th
    • Pushes start of calibration observations to 2023-December
    • 2023 IACHEC multi-mission calibration campaign of 3C 273
      • move from June to December (or 2024 January)?
    • Many targets will be observed by NuSTAR and XMM (and others?) during PV-Phase
      • 2024 January to June
        
        
        
• IACHEC support for in-flight calibration of the Einstein Probe mission
  • FXT telescopes (but also WXT?)
  • Launch expected in November 2023

• Continued coordinated calibration support for high energy missions
  • IXPE, HXMT, Astrosat, others?

• Coordinated observation planning and communications

• XRISM calibration plans - Eric Miller
  • coordinating observatory data availability / processing (PDF slides)
• XRISM scheduling - Chris Baluta
  • communication paths between scheduling teams
• 2023 multi-mission coordinated calibration campaign (3C 273) - All

Documents for the meeting:

Eric's slides  PDF

Draft XRISM in-flight calibration target schedule (case study assuming mid-May 2023 launch)  Text File

Draft XRISM in-flight calibration target information. PDF

Notes from the meeting:

Attending (in alphabetical order):  Lucia Ballo, Chris Baluta, Jacobo Ebrero, Karl Forster, Katsuhiro Hayashi, Elisabeth Jourdain, Michael Loewenstein, Renee Ludlam, Herman Marshall, Eric Miller, Lorenzo Natalucci, Jan-Uwe Ness, Katja Pottschmidt, Celia Sanchez, Michael Smith, Yukikatsu Terada, Stefan Wagner, Josh Wing,

XRISM calibration plans – Eric Miller  (PDF slides)

• Presented plans requiring coordinated observations with other observatories
  • see "Planning in-flight calibration of XRISM" E.D. Miller et al (2020) SPIE online paper
• Calibration targets are interesting science targets as well
  • inclusion of the science team provides understanding of target idiosyncrasies

Timeline:

• First 3 months after launch is a commissioning phase, then:
  • 1 month of in-flight calibration
  • 6-months PV-phase with calibration observations scattered throughout

On-axis Absolute/Relative effective area calibration - requirement is 10% / 5%  for both instruments on-axis

• Generally done with blazars (time variable), in particular 3C 273
  • Mrk 421 is too bright for Resolve and 1ES 0229+200 is generally too faint, so although listed, they are not ideal targets
  • Fainter targets are good for Xtend (stricter bright source limit compared to Resolve) e.g. 1ES 0033+595
• Simultaneous observations requested: E.g. annual 3C 273 IACHEC campaign (see below)

Timing requirement - 1ms at 1-sigma for highest spectral resolution events (for Resolve)

• Pulsar observation: Crab (primary), three secondary targets
  • observations can wait for visibility (not required for PV-phase)

PSF calibration – observe bright sources off-axis and outside field of view

• Using PKS 2155-304 then Cyg X-2 for further outside FOV
  • These are variable so request simultaneous coordinated observation 

Energy scale and spectral response for each pixel - using raster scan observations of Capella

• Orbital variations (binary velocity) require coordinated observations with Chandra HETG during long XRISM observation
  • No need for strict GTI overlap

Coordinated observations mission Points of Contact (PoC) for Calibration Scientists and Operations (scheduling) teams

krl _at _ srl.caltech.edu

jwing _at_ cfs.harvard.edu

cxc_coord _at _ cfa.harvard.edu

nicer-sciplan _at _ bigbang.gsfc.nasa.gov

krl _at_ srl.caltech.edu

swiftods _at _ swift.psu.edu

xmmpi _at _ sciops.esa.int

cbaluta20 _at _ gmail.com

• Add possible coordinated observations with INTEGRAL  - Eric M. will discuss with Erik Kuulkers and Celia Sanchez - ACTION

• Will need authorization from each coordinated observatory for each observation – ACTION
  • Start the process before launch
• Also identify the team members that will analyze the data from the coordinating observatories – should be in place soon.

XRISM Calibration targets

• Some targets may be could be useful to observe during first month after launch when the Be gate valve is closed (absorbs all E < 2 keV and 50% E>2 keV)

Calibration targets with requested coordinated observations

Charts of target list and visibility plots (blue primary, orange secondary)

• Some targets could be useful for both Resolve and Xtend calibration (e.g. similar PSF’s)
• Calibration proposal documents will be made available (e.g. ½ page of details for each target)

ACTION - Plan to organize (multiple?) WG meetings during calibration campaign to discuss progress and any adjustments.

• Also to organize regular scheduling discussions - particularly during PV-phase where there may be many coordinated science observations

After PV-phase

• A plan is being developed by the XRISM instrument teams to determine routine calibration observations during the mission
  • Likely to join annual IACHEC multi-mission campaign on 3C 273
• E.g. E0102 / Perseus cluster routinely observed for low / high energy calibration and contamination monitoring

XRISM scheduling process – Chris Baluta

• Determine contact information of schedulers – communication paths
• No planned observations yet for Chandra (need cycle-25 proposal or DDT request) - ACTION

• Weekly schedule upload to spacecraft 
  • Posted online ~3 weeks in advance
• Response time for ToO’s - minimum of 2 days (3 days for weekend)

Suggest delay of annual IACHEC multi-mission calibration from June 2023 to January 2024 - ACTION

• Chandra, XMM-Newton visibility is good up to 2023-01-14
• Will be discussed at April IACHEC meeting
  
  

Review status of working group

Additional cross-calibration opportunities

• NuSTAR / XMM-Newton observations of the Crab in 2020/22
  • Leading to revised calibration expected in 2021
• Insight-HXMT will join in future observations - Lian T.

IACHEC Support for in-flight calibration of upcoming missions

• Launch planned for 2021 November 17th
  • Science observations begin around mid-December
• Target Visibility will be 90 deg from the Sun +/- 25 deg
• For observatory verification plan to observe:
  • Crab: Two half-day observations separated by about a week (due to telemetry limit)
  • 1ES 1959+650: used to check alignments - good target for IXPE as it is close to NEP and not too bright or faint

A/I   Begin scheduling discussions a few months before launch (discuss details at September IACHEC meeting?)

• From Herman M. 
  • May also use Cyg X-1 in observatory verification
  • Must be careful not to perform observations that potentially step on goals of science investigations
• Other coordinations?
  • Astrosat-CZTI - Dipankar B.
    • Polarization seen in Crab data and possibly Cyg X-1
  • However - energy range (>100 keV) not close to IXPE (< 10 keV) so cross-calibration is likely to be a science investigation
• Other polarization missions?
  • POLSTAR - not launched
  • polarlight - GPD