Data Access issue

Helpdesk Data Access
22

As long as your questions are still about the subject in the title of this Topic (“Data Access Issue” in this case), that is fine. If you have questions about other things besides data access, please open a new topic. This will help later users who might search for answers on a given subject. Thank you!

23

Apologies. I updated the code above. I just tested it and it works.

1 Like
24

Is there a simple way to determine the path structure for downloading data through AWS from heasarc? It seems like each mission is somewhat different in how the date is formatted. One thing that would be super useful is if heasarc provided the FTP (or aws) path as a column in these master tables. Then it would be easy to just pull the data based on obsID directly from the table. Or they could make new tables that are simply obsid and download path if they don’t want to add it to the master tables.

25

Ah sorry I just found the data find example notebook which addresses this issue. However after looking at the steps I still think this could be simplified further.

26

Each mission does its path differently. Hard-coding it like the above example may not be the easiest way as it assumes you know the structure.

For general use we recommend using tools like astroquery or pyvo.

For example, astroquery.heasarc
has functions that allows you to search for data, locate it on the HEASARC server (or aws) and then download it.

So for example, to download say obsid=4020180460 for NICER, you can do something like:

from astroquery.heasarc import Heasarc
# catalog name. Get/search the list by: Heasarc.list_catalogs
catalog = 'nicermastr'

# Get the relevant catalog enetry
query = f"SELECT * from {catalog} WHERE obsid = '4020180460'"
table = Heasarc.query_tap(query).to_table()

# Locate the data
links = Heasarc.locate_data(table, catalog_name=catalog)

# Download it from aws
Heasarc.download_data(links, host='aws')
1 Like
27

Is SAS available on Fornax currently? It doesn’t seem to be under the heasarc environment and I don’t see any option for it.

28

We are actively working on adding XMM SAS software. We plan to have it ready in the development image (Dev High Energy Astrophysics) soon.

1 Like
29

Note that you can also use the Xamin GUI interface to do your searching and then get it to give you a list of AWS URIs. That is mentioned somewhere probably but not prominently and thoroughly described. LMK if you want more info.

2 Likes