[Heig] HEIG Obscore Note - ready for final review

[Karl Kosack]

> On Aug 21, 2026, at 17:31, Evans, Janet <jdeponte at cfa.harvard.edu> wrote:
> 
> Hi Karl,
> It's depends on the content.  Is it something big (hope not) like a new section that is better discussed in email or a few tweaks or typos?  Why don't you describe it in email and then we'll provide feedback.

The draft looks quite good, I just have a few minor comments, listed below:

- P8: standard set of independent [IRF] components: I think mentioning different particle progenitor types here is confusing, as those are not sub-components of an IRF, but a different IRFs. Instead could mention effective collection area if you want a third example?

- P8: "... and make rationale and well-considered proposals..." is awkward, did you mean "rational"? or "rationales"? Maybe just omit rationale, as a well considered proposal should contain a rationale.

- P8: Omit "very" in sentence "Some attributes are [very] specific to our domain..."  (meaningless)

- P11: It might be good to define what a "draw" is mathematically, perhaps in a footnote, as this is jargon and would help understand why the "draws" dataset is defined. Also, when using the word to represent a data product, please either put it in \emph{draws} or say "draws data product", which will make the paragraph read better. E.g. "The \emph{draws} can be interpreted to provide..."  , since draws is an English word that is not usually used in that way. 

- P11: maybe mention that _region_ datasets are not specific to HEA, but are used also in optical and other wavebands?

- P13: "However, some hea-event-lists include _spatial_ and time axes that are
calibrated physical quantities..."  Is that true? I think there is always a PSF, which is the calibration or IRF for the spatial axis.  For time, this is fine.

- P15: the term "drift scans" is used without any context or definition.  This is jargon and should be defined. It's just an observation made at a fixed alt/az coordinate rather than ra/dec, so is specific to alt/az mounted ground-based telescopes. 

- P21: same for "Tracking mode" (and probably "Scan mode" and "pointing mode"), which are not really HEA specific, but ground-based instrument-specific.  Maybe a general comment is that we introduce some of these terms not for HEA specifically, but for ground based instruments that do not use e.g. equatorial mounts, which happens to be common for some  HEA instruments.  

- P21: Pointing mode is specific to telescope *arrays*, which maybe is not obvious in the text. It might even be better to call it `array_pointing_mode` to be clear that it doesn't apply to individual telecopes, as this is quite a generic term?

- P24: When discussion "messenger_name", it might be good to mention that even a single HEA observatory may produce data for different messengers, e.g. HESS (and IACT) is nominally a gamma-ray instrument, but also has published papers on electron, iron, and proton spectra. Therefore the instrument name alone is not sufficient to distinguish the messenger, hence why this is proposed. 

- the definition of effective area is maybe a bit simplistic described  as the geometric area * efficiency (even if technically that is what it is): it is the true collection area (usually computed by Monte-carlo integration), of a system where the geometric collection area is difficult to define or is affected by spatial and/or energy-dependent instrumental effects such as vignetting, mirror reflectivity, detector quantum efficiency, etc.   E.g. for IACTs, the "geometric collection area" is not something we can compute.  


Cheers,
Karl



> 
> Thanks,
> -janet
> 
> On Fri, Aug 21, 2026 at 11:07 AM Karl Kosack <karl.kosack at cta-observatory.org> wrote:
> Hi Janet, 
> 
> For the final HEIG review, would you prefer our comments via email, or as an issue in the github repo?
> 
> Regards,
> Karl
> 
> > On Aug 12, 2026, at 23:08, Janet Evans via heig <heig at ivoa.net> wrote:
> > 
> > Dear HEIG, 
> > Apologies for the long gap in communication.  Here is a summary of some of the things that have happened since our last HEIG meeting.
> > 
> > o IVOA Interop in Strasbourg 
> > Great meeting for HEIG with interest in the Obscore extension, a plenary to present the HE Obscore extension doc details and the demos prepared by this group.
> > o Semantics meeting at Interop 
> > Several of us met with the Semantics WG to settle several vocabulary keywords - it was a good meeting
> > o Further Obscore Note input and final review/scrub
> > There is a new section 6 along with a vocabulary update and scrub for typos/etc.
> > 
> > It’s now your turn to review the document as we prepare to turn it over to the TCG/Exec for Endorsed Note status.  
> > Here’s the schedule we’re working to:
> > Wed, Aug 12 — Janet sends notice of final doc to HEIG for review (typos/minor edits, no new content)
> > Tue, Aug 25 — End of HEIG review/feedback
> > Thu, Aug 27 — Janet sends note to TCG with request for review/endorsed status 
> > 
> > The document is available in GitHub (https://github.com/ivoa/HighEnergyObsCoreExt?tab=readme-ov-file); I’ve also appended the PDF below.
> > 
> > Best regards,
> > -janet
> > 
> > Janet Evans | Software Development Manager | Chandra X-ray Center
> > Center for Astrophysics | Harvard & Smithsonian
> > Office: (617) 495-7160 
> > 60 Garden Street | MS 81 | Cambridge, MA 02138
> > 
> > 
> > 
> > <HighEnergyObsCoreExt-draft.pdf>
>