[Heig] Start up of our HEIG
Dr. Ian N. Evans
ievans at cfa.harvard.edu
Fri Jan 24 20:53:07 CET 2025
Dear François,
Good to hear your feedback! This document was literally written as a level 0 starting point, with the hope that it would prompt others to chime in so we can refine what is needed to support the HE regime. And, like all my inputs, it was written from the perspective of somebody who wants to be able to use the IVOA to do science rather than from the perspective of somebody who has to do the implementation - i.e., it’s results oriented and not task oriented.
I do have some responses to your comments - again mostly from the perspective of what the issue is that I see rather than how to solve it.
— For o_ucd, o_unit etc.: I want to know as part of data discovery that a particular event list includes certain observables. Ideally, I would like to do this as part of the query - for example, I might only interested in event lists that include X-ray polarization observables. Adding new axes characterization may be the best way to move forward simply given what we already have, but it just seems to me that assuming that a dataset includes only a single observable is very limiting (especially when we start talking about advanced data products).
— s_fov, s_resolution etc.: I think the CADC proposal is helpful here. But it doesn’t really let me perform a query like “find me all Chandra datasets for which the spatial resolution at the location of Sgr A* in the field of view is < 2 arcsec”. I don’t know how to do this and it might indeed be non-trivial. Is this functionality needed in the UVOIR? Perhaps. I know from experience analyzing UV/optical objective prism data that spectral resolution across a single dataset can easily vary by a factor of 20 or more, so that is in a similar regime. Having worked with instrumentation in pretty much every waveband from radio to X-ray during my career, my view is that you are better off providing a capability generally in case somebody needs it in the future, since new instrumentation and techniques are being developed all the time.
— dataproduct_type: I agree with you that the vocabulary appears to be the right path forward. I noted in my Malta presentation that “spectrum” as currently defined in the data product vocabulary appears to be more restrictive than the ObsCore definition (and “light curve” is similar), so we should start there. Perhaps the issue in the vocabulary is simply due to a lack of precise definitions for the terms used IN the vocabulary!
— energy_min/max: In this particular case I believe that there is a technical issue that means that 32 bit em_min/max actually don’t work at VHE. IIRC, Bruno pointed this out.
— t_min/max, t_gti: I really think this should be addressed in core rather than just a HE extension for GTIs/STIs. Advanced data products - irrespective of waveband - may be comprised from data from many observations may span decades or more, albeit very sparsely, and that makes queries based on data overlap with a specified time interval undoable.
— irf_type/assocproduct_type etc.: Datalink may be the way to do this as you suggest. I don’t know that instrument responses necessarily have to be in ObsCore independently, although someone may want to access them independently from the event list (for example, if they are directly using a source spectrum data product). For advanced data products, we would definitely want to include some associated data products in ObsCore as they will be of interest in their own right.
Hope you are enjoying retirement!
Cheers,
—Ian
> On Jan 24, 2025, at 09:36, BONNAREL FRANCOIS gmail via heig <heig at ivoa.net> wrote:
>
> Dear all,
> I will not attend the meeting today.
> I had a quick look on this interesting document : https://wiki.ivoa.net/internal/IVOA/HEIG_Winter25/HEIG_obscore_summary.pdf <https://www.google.com/url?q=https://wiki.ivoa.net/internal/IVOA/HEIG_Winter25/HEIG_obscore_summary.pdf&source=gmail-imap&ust=1738334209000000&usg=AOvVaw11DEtOy1Wo1DxA3MzkYAAV>
> These are my retired person with radio domain eye 2 cents on this :
> + o_ucd, o_unit, etc... multiplicity :
> In the case of event lists with specific axes ("new" measured quantities) I wonder if o_ucd is the right place to tackle that. o_ucd was designed for the "dependant axis". Maybe adding new axes characterization should be a better choice. Look at the description of visibilities in the radio extension.
> + s_fov,s_resolution, etc.. min/max with dependency from the spectral coordinate (photon energy).
> This is a common issue with radio domain as you know. CADC proposed recently to add this in the root Obscore.But
> I wonder if UV/optical/IR astronomers really need that. We should not add to much in the root ObsCore. maybe common definition with the the radio domain is a better solution.
> + dataproduct_type : the current ObsCore vocabulary is limited. I think the IVOA dataproduct_type effort is the right place to define . To my knowledge it's not yet an official vocabulary and adding new termis is easy to do following the
> VEP procedure of vocab 2.0. So that's the place to play in for Heog people.
> + t_min/t_max : see t_gti
> + proposal_id : OK for multiplicity
>
> New terms :
> + ev_number : OK. I think there is even an IVOA characterization DM utype for that.
> + energy_min / energy_max : OK. But I think you know the equivalent f_min/f_max for radio domain was rejected by the community fairing value conflicts in case of duplication with em_min/ em_max (despite Mireille's an mine personal opinion)
> + t_gti : OK. this is the concept of time support in characterization terms. ascii tmoc is a possible format for that. also look if DALI proposed an xtype for this kind of list of intervals.
> + irf_ype , irf_description. I wonder if these complementary data have to be in ObsCore or are better located in DataLink associated to the main product (event list). In that case content_qualifier is the place to describe the exact type.
> + access_format, UCDS : I 'm OK with what is written
> Cheers
>
> François
>
>
> Le 23/01/2025 à a$14:47, Bruno Khelifi via heig a écrit :
>> Dear all,
>>
>> For the meeting of tomorrow, I send you a Zoom link (that I have reported in our meeting page of the Wiki):
>>
>> Link: https://u-paris.zoom.us/j/86351476440?pwd=2YMHRRAvFvIgLbdftUt0d4GAa1USmL.1 <https://www.google.com/url?q=https://u-paris.zoom.us/j/86351476440?pwd%3D2YMHRRAvFvIgLbdftUt0d4GAa1USmL.1&source=gmail-imap&ust=1738334209000000&usg=AOvVaw3ELNRnwn8wZFBz0M2t3C_->
>> Meeting ID: 863 5147 6440
>> Secret code: 937310
>> The best,
>> Bruno
>> Le 20/01/2025 à 18:08, Bruno Khelifi via heig a écrit :
>>> Dear all,
>>>
>>> Based of the pool outcome, the best time slot is the ideal one because some of you could not attend unfortunately. However,
>>> the meeting is fixed to this Friday 24th, 15h30 CET / 9:30 am EST.
>>>
>>> The draft meeting page can be found here: https://wiki.ivoa.net/twiki/bin/view/IVOA/HEIG_Winter25 <https://www.google.com/url?q=https://wiki.ivoa.net/twiki/bin/view/IVOA/HEIG_Winter25&source=gmail-imap&ust=1738334209000000&usg=AOvVaw25Tgxs_wOOY5z-2bdBbf4Q>. A meeting link will be sent by email soon and written in this page.
>>>
>>> The best,
>>> Janet and Bruno
>>>
>>> Le 16/01/2025 à 12:21, Bruno Khelifi a écrit :
>>>> Dear all,
>>>>
>>>> First of all, I profit of my email for the season's greetings. Best wishes to you and your relatives for this new year. We finished up 2024 with the creation of the HEIG with its attached note, which is an important achievement for the HE community. Congratulations to all !
>>>>
>>>> As starting point for our activities, we propose to remotely meet via Zoom to exchange about our roadmap for 2025, built from your collective inputs. This roadmap will be a guideline for our future meetings. Here is a doodle to find out the most appropriate date:
>>>> https://doodle.com/meeting/participate/id/bD6Z5Oye <https://www.google.com/url?q=https://doodle.com/meeting/participate/id/bD6Z5Oye&source=gmail-imap&ust=1738334209000000&usg=AOvVaw0_eBDrbLTflCluSuM3-kl5>
>>>> The tentative agenda is:
>>>> - IVOA news (Janet)
>>>> - 2025 roadmap: collection of items and definition (all)
>>>> - Organisation of HEIG: monthly meetings? and next hybrid meeting
>>>> - Thematic remote meeting: Obscore extension proposal by Patrick Dowler (see Janet's email of the 01/06/25)
>>>> - AoB (based on your feedback)
>>>>
>>>> The best,
>>>> Janet and Bruno
>>>>
>>>>
>>>>
>>>> Material: HEIG wiki page https://wiki.ivoa.net/twiki/bin/view/IVOA/HEGroup <https://www.google.com/url?q=https://wiki.ivoa.net/twiki/bin/view/IVOA/HEGroup&source=gmail-imap&ust=1738334209000000&usg=AOvVaw3LKpRKe-7OnJAih_tYAUNP>
>>>>
>>>> --
>>>>
>>>> Bruno Khelifi
>>>> Physicist at CNRS (laboratory APC, Paris)
>>>> Phone: +33.1.57.27.61.58 - Fax: +33.1.57.27.60.71
>>>> APC, IN2P3/CNRS - Universite de Paris Cite
>>> --
>>>
>>> Bruno Khelifi
>>> Physicist at CNRS (laboratory APC, Paris)
>>> Phone: +33.1.57.27.61.58 - Fax: +33.1.57.27.60.71
>>> APC, IN2P3/CNRS - Universite de Paris Cite
>>>
>>>
>> --
>>
>> Bruno Khelifi
>> Physicist at CNRS (laboratory APC, Paris)
>> Phone: +33.1.57.27.61.58 - Fax: +33.1.57.27.60.71
>> APC, IN2P3/CNRS - Universite de Paris Cite
>>
>>
>
> --
> heig mailing list
> heig at ivoa.net
> https://www.google.com/url?q=http://mail.ivoa.net/mailman/listinfo/heig&source=gmail-imap&ust=1738334209000000&usg=AOvVaw1r64WsMg9G79BexrwpHtWh
—
Dr. Ian Evans
Astrophysicist
Chandra X-ray Center
Center for Astrophysics | Harvard & Smithsonian
Office: (617) 496 7846 | Cell: (617) 699 5152
60 Garden Street | MS 81 | Cambridge, MA 02138


<http://cfa.harvard.edu/>cfa.harvard.edu <http://cfa.harvard.edu/> | Facebook <http://cfa.harvard.edu/facebook> | Twitter <http://cfa.harvard.edu/twitter> | YouTube <http://cfa.harvard.edu/youtube> | Newsletter <http://cfa.harvard.edu/newsletter>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.ivoa.net/pipermail/heig/attachments/20250124/c74495ad/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: PastedGraphic-2.png
Type: image/png
Size: 581 bytes
Desc: not available
URL: <http://mail.ivoa.net/pipermail/heig/attachments/20250124/c74495ad/attachment-0002.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: PastedGraphic-3.png
Type: image/png
Size: 21717 bytes
Desc: not available
URL: <http://mail.ivoa.net/pipermail/heig/attachments/20250124/c74495ad/attachment-0003.png>
More information about the heig
mailing list