_version_ 1866917361236312064
author Uzsoy, Ana Sofía M.
Saydjari, Andrew K.
Dey, Arjun
Raichoor, Anand
Finkbeiner, Douglas P.
Gawiser, Eric
Lee, Kyoung-Soo
Ahlen, Steven
Bianchi, Davide
Brooks, David
Claybaugh, Todd
Cuceu, Andrei
de la Macorra, Axel
Doel, Peter
Font-Ribera, Andreu
Forero-Romero, Jaime E.
Gaztañaga, Enrique
Gontcho, Satya Gontcho A
Gutierrez, Gaston
Ishak, Mustapha
Kehoe, Robert
Kirkby, David
Kremin, Anthony
Landriau, Martin
Guillou, Laurent Le
Meisner, Aaron
Miquel, Ramon
Moustakas, John
Palanque-Delabrouille, Nathalie
Prada, Francisco
Pérez-Ràfols, Ignasi
Rossi, Graziano
Sanchez, Eusebio
Schlegel, David
Schubnell, Michael
Seo, Hee-Jong
Sprayberry, David
Tarlé, Gregory
Weaver, Benjamin Alan
Zou, Hu
author_facet Uzsoy, Ana Sofía M.
Saydjari, Andrew K.
Dey, Arjun
Raichoor, Anand
Finkbeiner, Douglas P.
Gawiser, Eric
Lee, Kyoung-Soo
Ahlen, Steven
Bianchi, Davide
Brooks, David
Claybaugh, Todd
Cuceu, Andrei
de la Macorra, Axel
Doel, Peter
Font-Ribera, Andreu
Forero-Romero, Jaime E.
Gaztañaga, Enrique
Gontcho, Satya Gontcho A
Gutierrez, Gaston
Ishak, Mustapha
Kehoe, Robert
Kirkby, David
Kremin, Anthony
Landriau, Martin
Guillou, Laurent Le
Meisner, Aaron
Miquel, Ramon
Moustakas, John
Palanque-Delabrouille, Nathalie
Prada, Francisco
Pérez-Ràfols, Ignasi
Rossi, Graziano
Sanchez, Eusebio
Schlegel, David
Schubnell, Michael
Seo, Hee-Jong
Sprayberry, David
Tarlé, Gregory
Weaver, Benjamin Alan
Zou, Hu
contents Lyman Alpha Emitters (LAEs) are valuable high-redshift cosmological probes traditionally identified using specialized narrow-band photometric surveys. In ground-based spectroscopy, it can be difficult to distinguish the sharp LAE peak from residual sky emission lines using automated methods, leading to misclassified redshifts. We present a Bayesian spectral component separation technique to automatically determine spectroscopic redshifts for LAEs while marginalizing over sky residuals. We use visually inspected spectra of LAEs obtained using the Dark Energy Spectroscopic Instrument (DESI) to create a data-driven prior and can determine redshift by jointly inferring sky residual, LAE, and residual components for each individual spectrum. We demonstrate this method on 881 spectroscopically observed $z = 2-4$ DESI LAE candidate spectra and determine their redshifts with $>$90% accuracy when validated against visually inspected redshifts. Using the $Δχ^2$ value from our pipeline as a proxy for detection confidence, we then explore potential survey design choices and implications for targeting LAEs with medium-band photometry. This method allows for scalability and accuracy in determining redshifts from DESI spectra, and the results provide recommendations for LAE targeting in anticipation of future high-redshift spectroscopic surveys.
format Preprint
id arxiv_https___arxiv_org_abs_2504_06870
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Bayesian Component Separation for DESI LAE Automated Spectroscopic Redshifts and Photometric Targeting
Uzsoy, Ana Sofía M.
Saydjari, Andrew K.
Dey, Arjun
Raichoor, Anand
Finkbeiner, Douglas P.
Gawiser, Eric
Lee, Kyoung-Soo
Ahlen, Steven
Bianchi, Davide
Brooks, David
Claybaugh, Todd
Cuceu, Andrei
de la Macorra, Axel
Doel, Peter
Font-Ribera, Andreu
Forero-Romero, Jaime E.
Gaztañaga, Enrique
Gontcho, Satya Gontcho A
Gutierrez, Gaston
Ishak, Mustapha
Kehoe, Robert
Kirkby, David
Kremin, Anthony
Landriau, Martin
Guillou, Laurent Le
Meisner, Aaron
Miquel, Ramon
Moustakas, John
Palanque-Delabrouille, Nathalie
Prada, Francisco
Pérez-Ràfols, Ignasi
Rossi, Graziano
Sanchez, Eusebio
Schlegel, David
Schubnell, Michael
Seo, Hee-Jong
Sprayberry, David
Tarlé, Gregory
Weaver, Benjamin Alan
Zou, Hu
Instrumentation and Methods for Astrophysics
Cosmology and Nongalactic Astrophysics
Applications
Lyman Alpha Emitters (LAEs) are valuable high-redshift cosmological probes traditionally identified using specialized narrow-band photometric surveys. In ground-based spectroscopy, it can be difficult to distinguish the sharp LAE peak from residual sky emission lines using automated methods, leading to misclassified redshifts. We present a Bayesian spectral component separation technique to automatically determine spectroscopic redshifts for LAEs while marginalizing over sky residuals. We use visually inspected spectra of LAEs obtained using the Dark Energy Spectroscopic Instrument (DESI) to create a data-driven prior and can determine redshift by jointly inferring sky residual, LAE, and residual components for each individual spectrum. We demonstrate this method on 881 spectroscopically observed $z = 2-4$ DESI LAE candidate spectra and determine their redshifts with $>$90% accuracy when validated against visually inspected redshifts. Using the $Δχ^2$ value from our pipeline as a proxy for detection confidence, we then explore potential survey design choices and implications for targeting LAEs with medium-band photometry. This method allows for scalability and accuracy in determining redshifts from DESI spectra, and the results provide recommendations for LAE targeting in anticipation of future high-redshift spectroscopic surveys.
title Bayesian Component Separation for DESI LAE Automated Spectroscopic Redshifts and Photometric Targeting
topic Instrumentation and Methods for Astrophysics
Cosmology and Nongalactic Astrophysics
Applications
url https://arxiv.org/abs/2504.06870