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This working group also supports additional opportunities for coordinated cross-calibration observations between observatories.
Activity
2021-10-22 - WG meeting on zoom
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3C 273 coordinated observation
Within this working yearly coordinated calibration observations of the quasar 3C273 are organized. On this dedicated page we collect all information and data about those observations.
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Activity
2023-05-14 - WG meeting at IACHEC meeting
2023-04-26 - WG meeting at IACHEC meeting
2023-02-10 - WG meeting on zoom
2021-10-22 - WG meeting on zoom
2021-05-18 - Chairs report at 2021 IACHEC Spring WG meeting 2021-05-18 - Chairs report at 2021 IACHEC Spring WG meeting is available here
2021-05-13 - WG meeting on zoom
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2024 May 14th - Working group session at IACHEC meeting
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Observatory | Exposure time (ks) | ...and at other wavelengths | ||
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Astrosat | 160 LAXPC (40 ks UVIT) | ATOM | BVRI | |
NICER | 45.9 | Effelsberg 100m | 2cm and 14mm bands | |
NuSTAR | 107+65+63 | H.E.S.S | TeV 10 ks/day | |
Swift | 20 | MAGIC | 30 GeV - 100 TeV | |
XMM-Newton | 122.6 |
Crab
- Parador de la Granja
1800 to 1930 CEST (= 1600 to 1730 UTC)
in room 1 and on zoom (see email and slack channel for connection URL)
Presentations:
A NICER look at X-ray cross-calibration using 3C 273 - Jeremy Hare
First results on XRISM effective area cross-calibration - Eric Miller/Takayuki Hayashi
NASA’s Astrophysics Cross-Observatory Science Support (ACROSS) Pilot Project - Jamie Kennea
followed by discussions.
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2023 April 26th - Working group session at IACHEC meeting
CoObs Working Group session - Wednesday April 26th at 4:20pm CEST
Zoom meeting link: https://caltech.zoom.us/j/84321299787
Meeting Time: 1420 UT | ||
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4:20pm CEST (Germany, Local) | ||
7:20am PDT (Los Angeles) | 10:20am EDT (Philadelphia) | 3:20pm BST (Leicester) |
7:50pm IST (Mumbai) | 10:20pm CST (Beijing) | 11:20pm JST (Tokyo) |
Agenda
- IACHEC support for XRISM flight calibration
- Launch delayed, now no earlier than August 26th
- 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
- 2024 January to June
- Launch delayed, now no earlier than August 26th
- 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
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2023 February 10th - Working group meeting
Meeting Time: 1300 UT | ||
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5am PST (Los Angeles) | 8am EST (New York) | 1pm GMT (Leicester) |
2pm CET (Madrid) | 6:30pm IST (Mumbai) | 10pm JST (Tokyo) |
Agenda
- 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
Mission | Calibration PoC | Operations PoC |
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IACHEC | Eric Miller | (Karl Forster) krl _at _ srl.caltech.edu |
Chandra | Paul Plucinsky | Josh Wing jwing _at_ cfs.harvard.edu cxc_coord _at _ cfa.harvard.edu |
NICER | Teruaki Enoto | NICER team nicer-sciplan _at _ bigbang.gsfc.nasa.gov |
NuSTAR | Katja Pottschmidt | Karl Forster krl _at_ srl.caltech.edu |
Swift | TBD | Jamie Kennea and Swift ops team swiftods _at _ swift.psu.edu |
XMM-Newton | Matteo Guainazzi | Lucia Ballo xmmpi _at _ sciops.esa.int |
XRISM | Eric Miller | Chris Baluta 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
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2021 October 22nd - Working group meeting
Observatory | Exposure time (ks) | ...and at other wavelengths | ||
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Astrosat | 160 LAXPC (40 ks UVIT) | ATOM | BVRI | |
NICER | 45.9 | Effelsberg 100m | 2cm and 14mm bands | |
NuSTAR | 107+65+63 | H.E.S.S | TeV 10 ks/day | |
Swift | 20 | MAGIC | 30 GeV - 100 TeV | |
XMM-Newton | 122.6 |
Crab
Coordinated observations by INTEGRAL, XMM-Newton, and NuSTAR continue with the goal of refining the NuSTAR and XMM-pn calibration. Observations coordinated with the IXPE schedule (currently 2022-02-21) are also planned.
- Kristin Madsen presented the analysis by Corin Marasco of the XMM-Newton, Chandra, NuSTAR, and Swift observations of 3C 273 that have been performed annually since 2015.
- This is an extension of the work presented in Madsen et al. (2017) AJ 153, 2 https://iopscience.iop.org/article/10.3847/1538-3881/153/1/2
- Joint fitting of the spectra from pairs of observations with matching Good Time Intervals were examined in bands:
- 3-7 keV for NuSTAR + Chandra/Swift/XMM-Newton pairs
- 1-5 keV for Chandra/Swift/XMM-Newton pairs
- Absorbed power-law model (zpow*cflux*tbabs) used to examine the measured flux relative to the model flux
- Example for 2017 observations:
Model parameters from the 2017 observations | |
Cross normalization constants from the pairs of observations are shown on the left. Note:
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- Communication with the Chandra team is underway to check the Chandra analysis
- The NuSTAR analysis will be redone with the updated calibration released this month (2021 October)
- NICER observations will also be folded into the analysis (Renee Ludlam)
- Analysis will be extended to evaluate within the concordance framework (arXiv)
- Flux ratio examined in narrow energy bands - model independent
- There is some complexity to the XMM spectrum - Felix Fuerst
- with correlated residuals between instruments
- Work is continuing and will include the 2021 XMM-Newton observations as well as the NICER observations.
NuSTAR observations of 1ES 0229+200 - Hannah Earnshaw (pdf)
- Three exposures obtained in August, 2021 (200 ks total)
- Compared to three short (~20 ks each) exposures obtained in 2013
- Spectrum can be modeled as an absorbed power law or a log-parabola continuum
- The source appears softer (gamma 2.03 -> 2.25) and fainter (about 25%) in the 2021 observations compared to 2013
- Even at historically low flux state the source is still sufficient for cross-calibration purposes
Swift-XRT monitoring of 1ES 0229+200
1ES 0229 with XMM-Newton and its impact on calibration - Felix Fuerst (pdf)
- 1ES 0229+200 observed on Oct 8-10, 2021
- 18.8 ks full frame exposure lost due to very bad background flaring
- Analysis of 60 ks small window EPIC-pn exposure presented
- can be modeled as an absorbed power law or cutoff power law
- Combined analysis with simultaneous 95 ks NuSTAR observation
- Fit improved with cutoff power law above 20 keV
- New NUSTAR calibration (CALDB20211020) improves agreement between NuSTAR FPM modules
- Analysis of joint XMM / NuSTAR observing campaign on the Crab was presented
- Observations performed every ~6 months
- Observations are used to create a correction functionfor EPIC-pn ARF
- Correction function will be vetted with more observations (calculated using MCMC)
- Analysis of joint observations of 3C 273 and 1ES 0229+200 indicate that EPIC-pn normalization is ~83% of (updated) NuSTAR FPMA
- Calibration update for EPIC-pn is being developed
- Power-law slope of 1ES 0229+200 will be evaluated with XMM-MOS+OM and Swift-XRT+UVOT data
Discussion
- It was noted that the new NuSTAR calibration appears to push the relative normalizations of XMM-pn and NuSTAR-FPM further apart
- Need to be careful to use similar extraction regions in analysis of Crab observations for cross-calibration purposes
- (extended source so observations at different epochs = different roll can sample different areas of the remnant)
- Chandra observations show spectral curvature
- however no improvement is seen when more complex models are used
Observation of 1ES 0229+200 with Astrosat - Sunil Chandra
- 1ES 0229+200 is a faint source for Astrosat-SXT, 74 ks exposure obtained in 2021 August
- Modeled as an absorbed power law
- Excess above 5 keV may be due to background and features below 0.5 keV may be residual calibration artifacts
- Astrosat-UVIT data is yet to be released
- There is also a previous observation by Astrosat (that may not be available yet)
Action Items:
- Jamie Kennea - will contact Andy B. to see if Swift-XRT 2021 data for 1ES 0229+200 will be analyzed - DONE
- Renee Ludlam - Will work with Felix F. on joint analysis of NICER observations of 1ES 0229+200 - DONE
The meeting concluded after a discussion about supporting IXPE in-flight calibration
- Launch scheduled for Dec 9th, 2021
- A preliminary long term plan is available at https://ixpe.msfc.nasa.gov/for_scientists/ltp.html
- There are many coordinated observations approved for scientific programs with INTEGRAL, XMM-Newton, NuSTAR, etc.
- Some may be useful for cross-calibration
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2021 May 13th - Working group meeting
- Kristin Madsen presented the analysis by Corin Marasco of the XMM-Newton, Chandra, NuSTAR, and Swift observations of 3C 273 that have been performed annually since 2015.
- This is an extension of the work presented in Madsen et al. (2017) AJ 153, 2 https://iopscience.iop.org/article/10.3847/1538-3881/153/1/2
- Joint fitting of the spectra from pairs of observations with matching Good Time Intervals were examined in bands:
- 3-7 keV for NuSTAR + Chandra/Swift/XMM-Newton pairs
- 1-5 keV for Chandra/Swift/XMM-Newton pairs
- Absorbed power-law model (zpow*cflux*tbabs) used to examine the measured flux relative to the model flux
- Example for 2017 observations:
Model parameters from the 2017 observations | |
Cross normalization constants from the pairs of observations are shown on the left. Note:
| |
- Communication with the Chandra team is underway to check the Chandra analysis
- The NuSTAR analysis will be redone with the updated calibration released this month (2021 October)
- NICER observations will also be folded into the analysis (Renee Ludlam)
- Analysis will be extended to evaluate within the concordance framework (arXiv)
- Flux ratio examined in narrow energy bands - model independent
- There is some complexity to the XMM spectrum - Felix Fuerst
- with correlated residuals between instruments
- Work is continuing and will include the 2021 XMM-Newton observations as well as the NICER observations.
NuSTAR observations of 1ES 0229+200 - Hannah Earnshaw (pdf)
- Three exposures obtained in August, 2021 (200 ks total)
- Compared to three short (~20 ks each) exposures obtained in 2013
- Spectrum can be modeled as an absorbed power law or a log-parabola continuum
- The source appears softer (gamma 2.03 -> 2.25) and fainter (about 25%) in the 2021 observations compared to 2013
- Even at historically low flux state the source is still sufficient for cross-calibration purposes
Swift-XRT monitoring of 1ES 0229+200
2021 May 13th Working group meeting
Review status of working group
- The chair has been very quiet since the last IACHEC meeting in May 2019 (apologies).
- Membership is open to all and has 60 colleagues subscribed to the WG slack channel (#coordinated-obs)
- Cross-calibration observations on 3C 273 were coordinated (thanks to Josh W. for starting the ball rolling with Chandra constraints each year)
- 2019-07-02 to 03 - Chandra, INTEGRAL, NICER, NuSTAR, Swift, XMM
- 2020-07-06 to 07 - Chandra, INTEGRAL, NICER, NuSTAR, Swift, XMM
- Communications
- There were no strong opinions about how best to communicate between WG members. Currently:
- email chair (Karl F.) krl _at_ srl.caltech.edu
- Slack channel: iachec.slack.com
- an email list server (hosted by Caltech) may be set up by Karl F. depending on what the other WG’s think (particularly the communications WG).
- DONE - iachec-co-obs@lists.srl.caltech.edu is active
- There were no strong opinions about how best to communicate between WG members. Currently:
- Dissemination of observation scheduling information
- International standards for target visibility and observation schedules have been developed by a team at ESAC, see https://www.cosmos.esa.int/web/vovisobs_protocols/home
- A client using these standards (ObjVisSAP, ObsLocTAP) implemented for INTEGRAL, XMM-Newton, Chandra, and NuSTAR is active (TOBY), see http://integral.esa.int/toby/
- (just click on the Calculate button to get latest schedules)
- Observatories are joining the callobaration (GAIA, NOT, MAGIC, XRISM)
- All IACHEC observatories are encouraged to join
- See also SmartNet http://www.isdc.unige.ch/smartnet/index.php
- Information about calibration targets and upcoming observations collected in google sheets
A/I Request that WG chairs look at lists on the google sheets and make/suggest additions/corrections
2021 3C 273 Cross-calibration campaign
- Confirmed observations scheduled for 2021 June 9th to 11th with Chandra, INTEGRAL, NuSTAR, XMM
- Kristin M. is advising two SURF students this (2021) summer in analysis of 3C 273 data taken since 2015
Mission | 2015 | (ks) | 2016 | (ks) | 2017 | (ks) | 2018 | (ks) | 2019 | (ks) | 2020 | (ks) | 2021 |
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Chandra | 2015-07-14 | 30 | 2016-06-27 | 30 | 2017-06-26 | 27 | 2018-07-04 | 30 | 2019-07-03 | 30 | 2020-07-06 | 29 | Y |
INTEGRAL | 2015-07-13 | 150 | 2016-06-26 | 100 | 2017-06-26 | 175 | 2018-07-04 | 100 | 2019-07-02 | 100 | 2020-07-04 | 120 | Y |
NICER |
2018-07-09 | 1.5 | 2019-06-30 | 38 | 2020-07-08 | 25 | ? | |||||||
NuSTAR | 2015-07-13 | 49 | 2016-06-26 | 35 | 2017-06-26 | 35 | 2018-07-04 | 40 | 2019-07-02 | 49 | 2020-07-06 | 44 | Y |
Swift | 2015-07-12 | 18 | 2016-06-26 | 40 | 2017-06-23 | 22 | 2018-07-14 | 17 | 2019-07-12 | 16 | 2020-07-16 | 18 | ? |
XMM | 2015-07-13 | 72 | 2016-06-26 | 67 | 2017-06-26 | 67 | 2018-07-04 | 78 | 2019-07-02 | 69 | 2020-07-06 | 70 | Y |
- This will be an update to Madsen et al. (2017) AJ 153, 2 https://iopscience.iop.org/article/10.3847/1538-3881/153/1/2
- It has always been difficult for Astrosat to join because 3C 273 is at low declination
- 3C 273 is a good target for XMM-RGS but there is pileup for EPIC instruments
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
- Astrosat-CZTI - Dipankar B.
- Other polarization missions?
- POLSTAR - not launched
- polarlight - GPD
- Launch likely to be between Sep 2022 - Aug 2023
- Effective area calibration observations will need ~30 ks (or at least 20 ks of overlap with coordinating observatories)
- NuSTAR will be useful to be able to calibrate XRISM instruments up to (possibly) 25 keV
- GTI based simultaneous periods would only be possible for a short time (< 1 day) due to relative orbit precession
- so aim for overlapping start/stop coordinated scheduling of calibration targets
- Crab will be used to calibrate effective area of RESOLVE
The potential of 1ES 0229+200 for calibration - Norbert Schartel & Felix Fuerst
- Motivation - Calibration model differences between NuSTAR and XMM-pn - soft excess?
- Is this caused by dust on mirror (or loss of mirror shells)?
- Blazars are good calibration sources - flat spectra between 200 eV and 15 keV
- Hence 3C 273 - (Swift monitoring) but this is bright of some missions and may some complexities to spectrum in this energy range
- Mkn 421 is difficult to model SED
- 1ES 0229+200
- XMM-MOS1 and PN can be fit with very simple power law + absorption
- Good fit of Power-law extrapolated to UV-Optical (XMM-OM)
- Flux is ~ 20% of 3C 273 so exposure time allocation will be larger but this may avoid pileup in sensitive missions
- Conclusion - Unique chance to calibrate from UV to X-ray
- Caveat - Source is variable - blazer! see Swift monitoring - so would require ~simultaneous observations (within ~few days)
- Past XMM and NuSTAR observations (separated by years) does not show evidence for significant spectral change (but observed at different flux levels)
- Target is not bright enough for INTEGRAL calibration observation
- For Swift the target may be too bright for PC-mode (pileup) but too faint for WT-mode - Jamie K.
- XMM + NuSTAR observations planned for 2021 July-August
- Swift observations will be requested - maybe multiple to examine variability
- Will ask for Swift-UVOT UV filters for cross-check calibration of XMM-OM
- TeV observatories HESS, MAGIC, and VERITAS have indicated they may join the campaign (likely with radio coverage)
- We encourage all missions to join cross-calibration campaign
- Swift observations will be requested - maybe multiple to examine variability
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Attachments:
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