We present examples of accessing the KASI Virtual Observatory (VO) Simple Image Access (SIA) services. Currently, SIA is available for the MIRIS (Multipurpose IR Imaging System; http://miris.kasi.re.kr/miris/) dataset.
| Dataset | Access URL |
|---|---|
| MIRIS | https://data.kasi.re.kr/vo/api/miris/sia_v1 |
Python VO clients
As an example, the following shows how to access the MIRIS SIA service by using Python package PyVO (https://github.com/astropy/pyvo). See how to use its SIA modules in https://pyvo.readthedocs.io/en/latest/dal/index.html#simple-image-access .
| Code Block | ||||
|---|---|---|---|---|
| ||||
>>> import pyvo as vo
>>> import astropy
>>>
>>> pos = astropy.coordinates.SkyCoord(84.0, -70.0, unit='deg') # search position
>>> size = astropy.coordinates.Angle(1.0, unit='deg') # search radius
>>>
>>> sia_service = vo.dal.SIAService('https://data.kasi.re.kr/vo/api/miris/sia_v1') # SIA API
>>> sia_results = sia_service.search(pos=pos, size=size) # search results in the format of https://pyvo.readthedocs.io/en/latest/api/pyvo.dal.SIAResults.html#pyvo.dal.SIAResults
>>>
>>> sia_results
<Table length=11>
dataproduct_type obs_collection target_name s_ra s_dec Dim Bandpass Format Url
deg deg
object object object float64 float64 int32 object object object
---------------- -------------- ----------- --------- ---------- ----- -------- ---------- ---------------------------------------------------------
image MIRIS LMC a 84.083792 -70.450578 2 PAAL image/fits https://archive.kasi.re.kr/miris/201410/MS1412446136.fits
image MIRIS LMC a 84.086609 -70.454108 2 PAAL image/fits https://archive.kasi.re.kr/miris/201410/MS1413312122.fits
image MIRIS LMC a 84.069085 -70.455493 2 PAAC image/fits https://archive.kasi.re.kr/miris/201410/MS1413358623.fits
image MIRIS LMC a 84.08105 -70.460115 2 PAAL image/fits https://archive.kasi.re.kr/miris/201410/MS1413317934.fits
image MIRIS LMC a 84.095598 -70.460426 2 PAAC image/fits https://archive.kasi.re.kr/miris/201410/MS1412451951.fits
image MIRIS LMC a 84.049578 -70.461393 2 PAAL image/fits https://archive.kasi.re.kr/miris/201410/MS1412440324.fits
image MIRIS LMC a 84.107628 -70.461639 2 PAAL image/fits https://archive.kasi.re.kr/miris/201410/MS1412434511.fits
image MIRIS LMC a 84.095563 -70.462757 2 PAAC image/fits https://archive.kasi.re.kr/miris/201410/MS1412498451.fits
image MIRIS LMC a 84.091313 -70.463528 2 PAAC image/fits https://archive.kasi.re.kr/miris/201410/MS1413364435.fits
image MIRIS LMC a 84.103507 -70.463404 2 I image/fits https://archive.kasi.re.kr/miris/201410/MS1412504257.fits
image MIRIS LMC a 84.117384 -70.46529 2 PAAC image/fits https://archive.kasi.re.kr/miris/201410/MS1412492638.fits
>>> sia_results[0]
('image', 'MIRIS', 'LMC a', 84.083792, -70.450578, 2, 'PAAL', 'image/fits', 'https://archive.kasi.re.kr/miris/201410/MS1412446136.fits')
>>> sia_results[0]['Url']
'https://archive.kasi.re.kr/miris/201410/MS1412446136.fits'
>>>
>>> img_file = astropy.utils.data.download_file(sia_results[0]['Url'], cache=True)
Downloading https://archive.kasi.re.kr/miris/201410/MS1412446136.fits
|===================================================================================================================| 1.2M/1.2M (100.00%) 0s
>>> img_data = astropy.io.fits.getdata(img_file) |
Aladin as VO client
The KASI SIA service is not included as one of default services in the Aladin (https://aladin.cds.unistra.fr/). However, you can use Aladin's generic service menu. Click File → Open Server Selector → VO → Generic Simple Image Access v1 query. As shown in the following example, type the SIA service url and search parameters such as target position and radius.
The returned urls of images can be used to make Aladin load the images in the menu of File → Load direct URL.
Topcat as VO client
Topcat (https://www.star.bris.ac.uk/~mbt/topcat/) can be used as a VO client, which can access the KASI SIA services. Click VO → Simple Image Access (SIA) Query.
As shown above, type the SIA URL and search with a center position and a search radius. The Topcat generate a new table as the query results.