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1 vote
0 answers
23 views

Using EAZY as photometric redshift estimation tool

I am new to JWST data analysis and currently trying to extract redshift of high redshift sources from the catalogue I created from SExtractor. I'm using EAZY (Brammer et al. 2008) for this purpose. I ...
Walker's user avatar
  • 79
4 votes
0 answers
54 views

How does SDSS estimate photometric redshift of sources?

I'm looking through the data in SDSS DR 12: ...
Jim421616's user avatar
  • 2,630
1 vote
0 answers
64 views

Angle to the line of sight

I don't understand this angle used in galaxy clustering. There is the line of sight and this angle to the line of sight which is not clear to me. Here is a transcript of a description from 1705.05442: ...
P. Ferreira's user avatar
2 votes
1 answer
115 views

Photometry templates -- what are the templates of?

Redshift measurements from photometric data can be determined using template-fitting (Cosmos website, SDSS photo-z). What does it mean to fit a template to determine redshift? What is the template of?
Jim421616's user avatar
  • 2,630
3 votes
0 answers
58 views

Kaggle dataset for Photo-Z estimation?

I would like to use the dataset for this kaggle but the competition was private, is closed and I have been unable to contact anyone directly. The challenge is machine learning for photo-z estimation ...
Julian Moore's user avatar
4 votes
0 answers
78 views

K-correction vs resizing photometric bands

Is there a difference between a K-correction (see Wiki https://en.wikipedia.org/wiki/K_correction) and simply "resizing" the bands, e.g. the 2-10 keV x-ray band, with the redshift? I've read ...
theWrongAlice's user avatar
5 votes
1 answer
166 views

Interpretation and understanding of the relation for the photometric redshift in a given bin

In the context of photometric probe of surveys (like LSST), I need to understand the relation I have to use for photometric bins. Considering $p_{ph}(z_p|z)$ the probability to measure a photometric ...
user avatar
4 votes
2 answers
124 views

Photometric redshift - empirical methods (machine learning)

I am currently learning about estimation of photometric redshifts with machine learning methods (or empirical methods in general). These methods use the knowledge about the photometry and the ...
user120112's user avatar
1 vote
0 answers
56 views

Relationship between photometric colour and redshift, part two

In the graphs in my previous question here, there are negative-sloped regions as the colour-z relationship oscillates. So if I look at how the I-W2 and W3-U colours change with redshift, as I've done ...
Jim421616's user avatar
  • 2,630
1 vote
1 answer
197 views

Relationship between photometric colour and redshift

In this paper, the authors describe the theoretical relationship between photometric colours, particularly in Figures 1 and 6: Since the colour is the difference between two magnitudes, and the ...
Jim421616's user avatar
  • 2,630
4 votes
1 answer
381 views

Estimating galactic dust extinction for medium band filters

I have a set of medium-band filters and I would like to compute $A_{\lambda}/E(B-V)$ for each filter which are not reported in the literatures. The magnitudes of the objects in the photometry ...
Dalek's user avatar
  • 261