Interesting object(void?)


Hi there @ceciliaflwrs
I’m not sure but it might be a traffic signal on the Vogon Intergalactic Highway :rofl:

I don’t have any idea what the issue is but the fix is simple

Just click the Legacy Surveys DR9 Images button over on the right
It will redraw and all will be well

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Welcome! What you are looking at is not the “normal” part of the viewer but the “residuals” tab. I have linked the different views of the object (a galaxy) in the blue words. There is also a “models” tab. The “models” part is what a computer model thinks that the galaxy will look like.
The “normal” viewer is what is actually seen by the telescope - it is what is actually there. The “residuals” viewer is then whatever is in the actual image but wasn’t in the model (not sure but don’t think its the other way around) - it is the “residue” from what is detected versus the model. Hope that helps :slight_smile:


So it sounds like the residuals are mostly of interest to the folks that want to improve their models?

In the Legacy Surveys catalogs, the photometry is based off the models, so if the models are good, then the photometry can be believed.



Thanks to all.
I’m new with understanding how to use the features.


I’m newer too, don’t really know what anyone is saying lol… looks like a galaxy collision

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:nerd_face:Im new here.
I don’t know how to distingush what I mistake. I ask if anyone çan teach me?

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It just comes with experience to be honest. One learns making mistakes so the more mistakes made, the better. Here the gist is basically that the residuals tab doesn’t really matter unless you are interested in the photometry.

The residuals are like half of one image while the models are the other. Merging them together will get your image. It is called “masking” as seen in these layers.

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The model layer is what the model interprets the most likely scenario from the data is. The residuals layer is simply what remains after subtracting the raw data from the model.

Since the model here is designed to improve detections of extremely faint galaxies, it tends to take correlated sparse, faint flux and group it in to denser brighter flux. This makes it terrible at nearby brighter galaxies as it tends to remove most of the fainter detail.

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Thank you for the additional information.