Questions tagged [chandra]

Questions about the Chandra X-ray Obseravatory, the NASA satellite for X-ray astronomy.

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Bad syntax for region SIMPLE -- dmextract CIAO 4.15

I am trying to perform a radial profile analysis using Chandra's CIAO 4.15 dmextract function but keep getting the following error: "bad syntax for region SIMPLE". I cannot find any relevant ...
1 vote
0 answers
45 views

Angular extent of this composite Chandra / JWST image of the Tarantula Nebula?

I thought I’d ask this question here, as I couldn’t readily find the answer looking through online resources. What is the angular extent of the composite Chandra / JWST image of the Tarantula Nebula ...
1 vote
0 answers
29 views

To set up parameters for the sherpa tool

How to set the parameters - photon index and metal abundance in the CIAO Sherpa tool for an x-ray source? I am trying to analyze a bright x-ray source using the data extracted from the Chandra archive....
10 votes
1 answer
739 views

What is this object visible in the Chandra image of the Cartwheel galaxy that isn't visible in JWST image?

In the below images I aligned an image from Chandra of the Cartwheel galaxy over the image from JWST. The first is the Chandra image pasted on top, fully opaque. The second is just the JWST image, and ...
4 votes
2 answers
227 views

How does a galaxy in Abell 2261 exist without a black hole in the center?

Here a source says that astronomers looked for a black hole in the brightest galaxy in the cluster Abell 2261, A2261-BCG, but found nothing: However, X-ray observations from NASA's Chandra X-ray ...
9 votes
0 answers
197 views

Why would a black hole have a disk, but not emit x-rays?

There's a recent paper in Nature about LB-1, a B-class star orbiting a massive black hole. I don't understand how these two parts of the paper can be reconciled. On page 2, the authors argue that the ...
4 votes
1 answer
743 views

Fits file re-alignment

I would like to re-align an image using a reference image (taken from GAIA). I am aware of the software Koords developed by the Karma team: https://www.atnf.csiro.au/computing/software/karma/ ...