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1. Characterization of DESI fiber assignment incompleteness effect on 2-point clustering and mitigation methods for DR1 analysis

Author

Bianchi, D., Hanif, M. M. S, Rosell, A. Carnero, Lasker, J., Ross, A. J., Pinon, M., de Mattia, A., White, M., Ahlen, S., Bailey, S., Brooks, D., Burtin, E., Chaussidon, E., Claybaugh, T., Cole, S., de la Macorra, A., Ferraro, S., Font-Ribera, A., Forero-Romero, J. E., Gaztañaga, E., Gontcho, S. Gontcho A, Gutierrez, G., Guy, J., Hahn, C., Honscheid, K., Howlett, C., Juneau, S., Kirkby, D., Kisner, T., Kremin, A., Landriau, M., Guillou, L. Le, Levi, M. E., McDonald, P., Meisner, A., Miquel, R., Moustakas, J., Palanque-Delabrouille, N., Percival, W. J., Prada, F., Pérez-Ràfols, I., Raichoor, A., Rossi, G., Sanchez, E., Schlegel, D., Schubnell, M., Sharples, R., Silber, J., Sprayberry, D., Tarlé, G., Vargas-Magaña, M., Weaver, B. A., Zarrouk, P., Zhou, R., and Zou, H.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present an in-depth analysis of the fiber assignment incompleteness in the Dark Energy Spectroscopic Instrument (DESI) Data Release 1 (DR1). This incompleteness is caused by the restricted mobility of the robotic fiber positioner in the DESI focal plane, which limits the number of galaxies that can be observed at the same time, especially at small angular separations. As a result, the observed clustering amplitude is suppressed in a scale-dependent manner, which, if not addressed, can severely impact the inference of cosmological parameters. We discuss the methods adopted for simulating fiber assignment on mocks and data. In particular, we introduce the fast fiber assignment (FFA) emulator, which was employed to obtain the power spectrum covariance adopted for the DR1 full-shape analysis. We present the mitigation techniques, organised in two classes: measurement stage and model stage. We then use high fidelity mocks as a reference to quantify both the accuracy of the FFA emulator and the effectiveness of the different measurement-stage mitigation techniques. This complements the studies conducted in a parallel paper for the model-stage techniques, namely the $\theta$-cut approach. We find that pairwise inverse probability (PIP) weights with angular upweighting recover the "true" clustering in all the cases considered, in both Fourier and configuration space. Notably, we present the first ever power spectrum measurement with PIP weights from real data., Comment: 42 pages, 19 figures

Published
2024

2. Mitigating Imaging Systematics for DESI 2024 Emission Line Galaxies and Beyond

Author

Rosado-Marín, A. J., Ross, A. J., Seo, H., Rezaie, M., Kong, H., de Mattia, A., Zhou, R., Ahlen, S., Bianchi, D., Brooks, D., Claybaugh, T., de la Macorra, A., Doel, P., Fanning, K., Ferraro, S., Gontcho, S. Gontcho A, Gutierrez, G., Hahn, C., Juneau, S., Kehoe, R., Kremin, A., Meisner, A., Miquel, R., Moustakas, J., Newman, J. A., Palanque-Delabrouille, N., Percival, W. J., Prada, F., Pérez-Ràfols, I., Rossi, G., Sanchez, E., Schlegel, D., Schubnell, M., Sprayberry, D., Vargas-Magaña, M., Weaver, B. A., Zou, H., Ruggeri, R., Krolewski, A., Yu, J., Raichoor, A., and Hanif, M. M. S

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

Emission Line Galaxies (ELGs) are one of the main tracers that the Dark Energy Spectroscopic Instrument (DESI) uses to probe the universe. However, they are afflicted by strong spurious correlations between target density and observing conditions known as imaging systematics. We present the imaging systematics mitigation applied to the DESI Data Release 1 (DR1) large-scale structure catalogs used in the DESI 2024 cosmological analyses. We also explore extensions of the fiducial treatment. This includes a combined approach, through forward image simulations in conjunction with neural network-based regression, to obtain an angular selection function that mitigates the imaging systematics observed in the DESI DR1 ELGs target density. We further derive a line-of-sight selection function from the forward model that removes the strong redshift dependence between imaging systematics and low redshift ELGs. Combining both angular and redshift-dependent systematics, we construct a 3D selection function and assess the impact of all selection functions on clustering statistics. We quantify differences between these extended treatments and the fiducial treatment in terms of the measured 2-point statistics. We find that the results are generally consistent with the fiducial treatment and conclude that the differences are far less than the imaging systematics uncertainty included in DESI 2024 full-shape measurements. We extend our investigation to the ELGs at $0.6

Published
2024

3. DESI 2024 VII: Cosmological Constraints from the Full-Shape Modeling of Clustering Measurements

Author

DESI Collaboration, Adame, A. G., Aguilar, J., Ahlen, S., Alam, S., Alexander, D. M., Prieto, C. Allende, Alvarez, M., Alves, O., Anand, A., Andrade, U., Armengaud, E., Avila, S., Aviles, A., Awan, H., Bahr-Kalus, B., Bailey, S., Baltay, C., Bault, A., Behera, J., BenZvi, S., Beutler, F., Bianchi, D., Blake, C., Blum, R., Bonici, M., Brieden, S., Brodzeller, A., Brooks, D., Buckley-Geer, E., Burtin, E., Calderon, R., Canning, R., Rosell, A. Carnero, Cereskaite, R., Cervantes-Cota, J. L., Chabanier, S., Chaussidon, E., Chaves-Montero, J., Chebat, D., Chen, S., Chen, X., Claybaugh, T., Cole, S., Cuceu, A., Davis, T. M., Dawson, K., de la Macorra, A., de Mattia, A., Deiosso, N., Dey, A., Dey, B., Ding, Z., Doel, P., Edelstein, J., Eftekharzadeh, S., Eisenstein, D. J., Elbers, W., Elliott, A., Fagrelius, P., Fanning, K., Ferraro, S., Ereza, J., Findlay, N., Flaugher, B., Font-Ribera, A., Forero-Sánchez, D., Forero-Romero, J. E., Frenk, C. S., Garcia-Quintero, C., Garrison, L. H., Gaztañaga, E., Gil-Marín, H., Gontcho, S. Gontcho A, Gonzalez-Morales, A. X., Gonzalez-Perez, V., Gordon, C., Green, D., Gruen, D., Gsponer, R., Gutierrez, G., Guy, J., Hadzhiyska, B., Hahn, C., Hanif, M. M. S, Herrera-Alcantar, H. K., Honscheid, K., Howlett, C., Huterer, D., Iršič, V., Ishak, M., Joyce, R., Juneau, S., Karaçaylı, N. G., Kehoe, R., Kent, S., Kirkby, D., Kong, H., Koposov, S. E., Kremin, A., Krolewski, A., Lahav, O., Lai, Y., Lan, T. -W., Landriau, M., Lang, D., Lasker, J., Goff, J. M. Le, Guillou, L. Le, Leauthaud, A., Levi, M. E., Li, T. S., Lodha, K., Magneville, C., Manera, M., Margala, D., Martini, P., Matthewson, W., Maus, M., McDonald, P., Medina-Varela, L., Meisner, A., Mena-Fernández, J., Miquel, R., Moon, J., Moore, S., Moustakas, J., Mudur, N., Mueller, E., Muñoz-Gutiérrez, A., Myers, A. D., Nadathur, S., Napolitano, L., Neveux, R., Newman, J. A., Nguyen, N. M., Nie, J., Niz, G., Noriega, H. E., Padmanabhan, N., Paillas, E., Palanque-Delabrouille, N., Pan, J., Penmetsa, S., Percival, W. J., Pieri, M. M., Pinon, M., Poppett, C., Porredon, A., Prada, F., Pérez-Fernández, A., Pérez-Ràfols, I., Rabinowitz, D., Raichoor, A., Ramírez-Pérez, C., Ramirez-Solano, S., Rashkovetskyi, M., Ravoux, C., Rezaie, M., Rich, J., Rocher, A., Rockosi, C., Roe, N. A., Rosado-Marin, A., Ross, A. J., Rossi, G., Ruggeri, R., Ruhlmann-Kleider, V., Samushia, L., Sanchez, E., Saulder, C., Schlafly, E. F., Schlegel, D., Schubnell, M., Seo, H., Shafieloo, A., Sharples, R., Silber, J., Slosar, A., Smith, A., Sprayberry, D., Tan, T., Tarlé, G., Taylor, P., Trusov, S., Vaisakh, R., Valcin, D., Valdes, F., Valogiannis, G., Vargas-Magaña, M., Verde, L., Walther, M., Wang, B., Wang, M. S., Weaver, B. A., Weaverdyck, N., Wechsler, R. H., Weinberg, D. H., White, M., Wilson, M. J., Yi, L., Yu, J., Yu, Y., Yuan, S., Yèche, C., Zaborowski, E. A., Zarrouk, P., Zhang, H., Zhao, C., Zhao, R., Zhou, R., Zhuang, T., and Zou, H.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present cosmological results from the measurement of clustering of galaxy, quasar and Lyman-$\alpha$ forest tracers from the first year of observations with the Dark Energy Spectroscopic Instrument (DESI Data Release 1). We adopt the full-shape (FS) modeling of the power spectrum, including the effects of redshift-space distortions, in an analysis which has been validated in a series of supporting papers. In the flat $\Lambda$CDM cosmological model, DESI (FS+BAO), combined with a baryon density prior from Big Bang Nucleosynthesis and a weak prior on the scalar spectral index, determines matter density to $\Omega_\mathrm{m}=0.2962\pm 0.0095$, and the amplitude of mass fluctuations to $\sigma_8=0.842\pm 0.034$. The addition of the cosmic microwave background (CMB) data tightens these constraints to $\Omega_\mathrm{m}=0.3056\pm 0.0049$ and $\sigma_8=0.8121\pm 0.0053$, while further addition of the the joint clustering and lensing analysis from the Dark Energy Survey Year-3 (DESY3) data leads to a 0.4% determination of the Hubble constant, $H_0 = (68.40\pm 0.27)\,{\rm km\,s^{-1}\,Mpc^{-1}}$. In models with a time-varying dark energy equation of state, combinations of DESI (FS+BAO) with CMB and type Ia supernovae continue to show the preference, previously found in the DESI DR1 BAO analysis, for $w_0>-1$ and $w_a<0$ with similar levels of significance. DESI data, in combination with the CMB, impose the upper limits on the sum of the neutrino masses of $\sum m_\nu < 0.071\,{\rm eV}$ at 95% confidence. DESI data alone measure the modified-gravity parameter that controls the clustering of massive particles, $\mu_0=0.11^{+0.45}_{-0.54}$, while the combination of DESI with the CMB and the clustering and lensing analysis from DESY3 constrains both modified-gravity parameters, giving $\mu_0 = 0.04\pm 0.22$ and $\Sigma_0 = 0.044\pm 0.047$, in agreement with general relativity. [Abridged.], Comment: This DESI Collaboration Key Publication is part of the 2024 publication series using the first year of observations (see https://data.desi.lbl.gov/doc/papers/). 55 pages, 10 figures

Published
2024

4. DESI 2024 II: Sample Definitions, Characteristics, and Two-point Clustering Statistics

Author

DESI Collaboration, Adame, A. G., Aguilar, J., Ahlen, S., Alam, S., Alexander, D. M., Alvarez, M., Alves, O., Anand, A., Andrade, U., Armengaud, E., Avila, S., Aviles, A., Awan, H., Bailey, S., Baltay, C., Bault, A., Behera, J., BenZvi, S., Beutler, F., Bianchi, D., Blake, C., Blum, R., Brieden, S., Brodzeller, A., Brooks, D., Brown, Z., Buckley-Geer, E., Burtin, E., Calderon, R., Canning, R., Rosell, A. Carnero, Cereskaite, R., Cervantes-Cota, J. L., Chabanier, S., Chaussidon, E., Chaves-Montero, J., Chen, S., Chen, X., Claybaugh, T., Cole, S., Cuceu, A., Davis, T. M., Dawson, K., de la Macorra, A., de Mattia, A., Deiosso, N., Demina, R., Dey, A., Dey, B., Ding, Z., Doel, P., Edelstein, J., Eftekharzadeh, S., Eisenstein, D. J., Elliott, A., Fagrelius, P., Fanning, K., Ferraro, S., Ereza, J., Findlay, N., Flaugher, B., Font-Ribera, A., Forero-Sánchez, D., Forero-Romero, J. E., Frenk, C. S., Garcia-Quintero, C., Gaztañaga, E., Gil-Marín, H., Gontcho, S. Gontcho A, Gonzalez-Morales, A. X., Gonzalez-Perez, V., Gordon, C., Green, D., Gruen, D., Gsponer, R., Gutierrez, G., Guy, J., Hadzhiyska, B., Hahn, C., Hanif, M. M. S, Herrera-Alcantar, H. K., Honscheid, K., Hou, J., Howlett, C., Huterer, D., Iršič, V., Ishak, M., Juneau, S., Karaçaylı, N. G., Kehoe, R., Kent, S., Kirkby, D., Kitaura, F. -S., Kong, H., Kremin, A., Krolewski, A., Lai, Y., Lan, T. -W., Landriau, M., Lang, D., Lasker, J., Goff, J. M. Le, Guillou, L. Le, Leauthaud, A., Levi, M. E., Li, T. S., Lodha, K., Magneville, C., Manera, M., Margala, D., Martini, P., Maus, M., McDonald, P., Medina-Varela, L., Meisner, A., Mena-Fernández, J., Miquel, R., Moon, J., Moore, S., Moustakas, J., Mudur, N., Mueller, E., Muñoz-Gutiérrez, A., Myers, A. D., Nadathur, S., Napolitano, L., Neveux, R., Newman, J. A., Nguyen, N. M., Nie, J., Niz, G., Noriega, H. E., Padmanabhan, N., Paillas, E., Palanque-Delabrouille, N., Pan, J., Penmetsa, S., Percival, W. J., Pieri, M. M., Pinon, M., Poppett, C., Porredon, A., Prada, F., Pérez-Fernández, A., Pérez-Ràfols, I., Rabinowitz, D., Raichoor, A., Ramírez-Pérez, C., Ramirez-Solano, S., Rashkovetskyi, M., Ravoux, C., Rezaie, M., Rich, J., Rocher, A., Rockosi, C., Roe, N. A., Rosado-Marin, A., Ross, A. J., Rossi, G., Ruggeri, R., Ruhlmann-Kleider, V., Samushia, L., Sanchez, E., Saulder, C., Schlafly, E. F., Schlegel, D., Scholte, D., Schubnell, M., Seo, H., Sharples, R., Silber, J., Slosar, A., Smith, A., Sprayberry, D., Tan, T., Tarlé, G., Trusov, S., Vaisakh, R., Valcin, D., Valdes, F., Vargas-Magaña, M., Verde, L., Walther, M., Wang, B., Wang, M. S., Weaver, B. A., Weaverdyck, N., Wechsler, R. H., Weinberg, D. H., White, M., Wilson, M. J., Yu, J., Yu, Y., Yuan, S., Yèche, C., Zaborowski, E. A., Zarrouk, P., Zhang, H., Zhao, C., Zhao, R., Zhou, R., and Zou, H.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present the samples of galaxies and quasars used for DESI 2024 cosmological analyses, drawn from the DESI Data Release 1 (DR1). We describe the construction of large-scale structure (LSS) catalogs from these samples, which include matched sets of synthetic reference `randoms' and weights that account for variations in the observed density of the samples due to experimental design and varying instrument performance. We detail how we correct for variations in observational completeness, the input `target' densities due to imaging systematics, and the ability to confidently measure redshifts from DESI spectra. We then summarize how remaining uncertainties in the corrections can be translated to systematic uncertainties for particular analyses. We describe the weights added to maximize the signal-to-noise of DESI DR1 2-point clustering measurements. We detail measurement pipelines applied to the LSS catalogs that obtain 2-point clustering measurements in configuration and Fourier space. The resulting 2-point measurements depend on window functions and normalization constraints particular to each sample, and we present the corrections required to match models to the data. We compare the configuration- and Fourier-space 2-point clustering of the data samples to that recovered from simulations of DESI DR1 and find they are, generally, in statistical agreement to within 2\% in the inferred real-space over-density field. The LSS catalogs, 2-point measurements, and their covariance matrices will be released publicly with DESI DR1., Comment: This DESI Collaboration Key Publication is part of the 2024 publication series using the first year of observations (see https://data.desi.lbl.gov/doc/papers/)

Published
2024

5. DESI 2024 V: Full-Shape Galaxy Clustering from Galaxies and Quasars

Author

DESI Collaboration, Adame, A. G., Aguilar, J., Ahlen, S., Alam, S., Alexander, D. M., Alvarez, M., Alves, O., Anand, A., Andrade, U., Armengaud, E., Avila, S., Aviles, A., Awan, H., Bailey, S., Baltay, C., Bault, A., Behera, J., BenZvi, S., Beutler, F., Bianchi, D., Blake, C., Blum, R., Brieden, S., Brodzeller, A., Brooks, D., Buckley-Geer, E., Burtin, E., Calderon, R., Canning, R., Rosell, A. Carnero, Cereskaite, R., Cervantes-Cota, J. L., Chabanier, S., Chaussidon, E., Chaves-Montero, J., Chen, S., Chen, X., Claybaugh, T., Cole, S., Cuceu, A., Davis, T. M., Dawson, K., de la Macorra, A., de Mattia, A., Deiosso, N., Dey, A., Dey, B., Ding, Z., Doel, P., Edelstein, J., Eftekharzadeh, S., Eisenstein, D. J., Elliott, A., Fagrelius, P., Fanning, K., Ferraro, S., Ereza, J., Findlay, N., Flaugher, B., Font-Ribera, A., Forero-Sánchez, D., Forero-Romero, J. E., Garcia-Quintero, C., Garrison, L. H., Gaztañaga, E., Gil-Marín, H., Gontcho, S. Gontcho A, Gonzalez-Morales, A. X., Gonzalez-Perez, V., Gordon, C., Green, D., Gruen, D., Gsponer, R., Gutierrez, G., Guy, J., Hadzhiyska, B., Hahn, C., Hanif, M. M. S, Herrera-Alcantar, H. K., Honscheid, K., Howlett, C., Huterer, D., Iršič, V., Ishak, M., Juneau, S., Karaçaylı, N. G., Kehoe, R., Kent, S., Kirkby, D., Kong, H., Koposov, S. E., Kremin, A., Krolewski, A., Lai, Y., Lan, T. -W., Landriau, M., Lang, D., Lasker, J., Goff, J. M. Le, Guillou, L. Le, Leauthaud, A., Levi, M. E., Li, T. S., Lodha, K., Magneville, C., Manera, M., Margala, D., Martini, P., Maus, M., McDonald, P., Medina-Varela, L., Meisner, A., Mena-Fernández, J., Miquel, R., Moon, J., Moore, S., Moustakas, J., Mueller, E., Muñoz-Gutiérrez, A., Myers, A. D., Nadathur, S., Napolitano, L., Neveux, R., Newman, J. A., Nguyen, N. M., Nie, J., Niz, G., Noriega, H. E., Padmanabhan, N., Paillas, E., Palanque-Delabrouille, N., Pan, J., Penmetsa, S., Percival, W. J., Pieri, M. M., Pinon, M., Poppett, C., Porredon, A., Prada, F., Pérez-Fernández, A., Pérez-Ràfols, I., Rabinowitz, D., Raichoor, A., Ramírez-Pérez, C., Ramirez-Solano, S., Rashkovetskyi, M., Ravoux, C., Rezaie, M., Rich, J., Rocher, A., Rockosi, C., Rodríguez-Martínez, F., Roe, N. A., Rosado-Marin, A., Ross, A. J., Rossi, G., Ruggeri, R., Ruhlmann-Kleider, V., Samushia, L., Sanchez, E., Saulder, C., Schlafly, E. F., Schlegel, D., Schubnell, M., Seo, H., Sharples, R., Silber, J., Slosar, A., Smith, A., Sprayberry, D., Tan, T., Tarlé, G., Trusov, S., Vaisakh, R., Valcin, D., Valdes, F., Vargas-Magaña, M., Verde, L., Walther, M., Wang, B., Wang, M. S., Weaver, B. A., Weaverdyck, N., Wechsler, R. H., Weinberg, D. H., White, M., Wilson, M. J., Yu, J., Yu, Y., Yuan, S., Yèche, C., Zaborowski, E. A., Zarrouk, P., Zhang, H., Zhao, C., Zhao, R., Zhou, R., and Zou, H.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present the measurements and cosmological implications of the galaxy two-point clustering using over 4.7 million unique galaxy and quasar redshifts in the range $0.1

Published
2024

6. High-redshift LBG selection from broadband and wide photometric surveys using a Random Forest algorithm

Author

Payerne, C., Doumerg, W. d'Assignies, Yèche, C., Ruhlmann-Kleider, V., Raichoor, A., Lang, D., Aguilar, J. N., Ahlen, S., Bianchi, D., Brooks, D., Claybaugh, T., Cole, S., de la Macorra, A., Dey, B., Doel, P., Font-Ribera, A., Forero-Romero, J. E., Gontcho, S. Gontcho A, Gutierrez, G., Honscheid, K., Juneau, S., Lambert, A., Landriau, M., Guillou, L. Le, Levi, M. E., Magneville, C., Manera, M., Meisner, A., Miquel, R., Moustakas, J., Newman, J. A., Palanque-Delabrouille, N., Percival, W., Prada, F., Pérez-Ràfols, I., Rossi, G., Sanchez, E., Schlegel, D., Schubnell, M., Sprayberry, D., Tarlé, G., Weaver, B. A., and Zou, H.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

In this paper, we investigate the possibility of selecting high-redshift Lyman-Break Galaxies (LBG) using current and future broadband wide photometric surveys, such as UNIONS or the Vera C. Rubin LSST, using a Random Forest algorithm. This work is conducted in the context of future large-scale structure spectroscopic surveys like DESI-II, the next phase of the Dark Energy Spectroscopic Instrument (DESI), which will start around 2029. We use deep imaging data from HSC and CLAUDS on the COSMOS and XMM-LSS fields. To predict the selection performance of LBGs with image quality similar to UNIONS, we degrade the $u, g, r, i$ and $z$ bands to UNIONS depth. The Random Forest algorithm is trained with the $u,g,r,i$ and $z$ bands to classify LBGs in the $2.5 < z < 3.5$ range. We find that fixing a target density budget of $1,100$ deg$^{-2}$, the Random Forest approach gives a density of $z>2$ targets of $873$ deg$^{-2}$, and a density of $493$ deg$^{-2}$ of confirmed LBGs after spectroscopic confirmation with DESI. This UNIONS-like selection was tested in a dedicated spectroscopic observation campaign of 1,000 targets with DESI on the COSMOS field, providing a safe spectroscopic sample with a mean redshift of 3. This sample is used to derive forecasts for DESI-II, assuming a sky coverage of 5,000 deg$^2$. We predict uncertainties on Alcock-Paczynski parameters $\alpha_\perp$ and $\alpha_{\parallel}$ to be 0.7$\%$ and 1$\%$ for $2.6

Published
2024

7. Stellar reddening map from DESI imaging and spectroscopy

Author

Zhou, Rongpu, Guy, Julien, Koposov, Sergey E., Schlafly, Edward F., Schlegel, David, Aguilar, Jessica, Ahlen, Steven, Bailey, Stephen, Bianchi, David, Brooks, David, Chaussidon, Edmond, Claybaugh, Todd, Dawson, Kyle, de la Macorra, Axel, Dey, Biprateep, Eisenstein, Daniel J., Ferraro, Simone, Font-Ribera, Andreu, Forero-Romero, Jaime E., Gaztañaga, Enrique, Gontcho, Satya Gontcho A, Gutierrez, Gaston, Honscheid, Klaus, Juneau, Stephanie, Kehoe, Robert, Kirkby, David, Kisner, Theodore, Kremin, Anthony, Lambert, Andrew, Landriau, Martin, Guillou, Laurent Le, Levi, Michael E., Li, Ting S., Manera, Marc, Martini, Paul, Meisner, Aaron, Miquel, Ramon, Moustakas, John, Myers, Adam D., Newman, Jeffrey A., Niz, Gustavo, Palanque-Delabrouille, Nathalie, Percival, Will J., Poppett, Claire, Prada, Francisco, Raichoor, Anand, Ross, Ashley J., Rossi, Graziano, Sanchez, Eusebio, Saydjari, Andrew K., Schubnell, Michael, Sprayberry, David, Tarl, Gregory, Weaver, Benjamin A., Zarrouk, Pauline, and Zou, Hu

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present new Galactic reddening maps of the high Galactic latitude sky using DESI imaging and spectroscopy. We directly measure the reddening of 2.6 million stars by comparing the observed stellar colors in $g-r$ and $r-z$ from DESI imaging with the synthetic colors derived from DESI spectra from the first two years of the survey. The reddening in the two colors is on average consistent with the \cite{fitzpatrick_correcting_1999} extinction curve with $R_\mathrm{V}=3.1$. We find that our reddening maps differ significantly from the commonly used \cite{schlegel_maps_1998} (SFD) reddening map (by up to 80 mmag in $E(B-V)$), and we attribute most of this difference to systematic errors in the SFD map. To validate the reddening map, we select a galaxy sample with extinction correction based on our reddening map, and this yields significantly better uniformity than the SFD extinction correction. Finally, we discuss the potential systematic errors in the DESI reddening measurements, including the photometric calibration errors that are the limiting factor on our accuracy. The $E(g-r)$ and $E(g-r)$ maps presented in this work, and for convenience their corresponding $E(B-V)$ maps with SFD calibration, are publicly available., Comment: Submitted to the Open Journal of Astrophysics. Associated data files: https://data.desi.lbl.gov/public/papers/mws/desi_dust/y2/v1/maps/

Published
2024

8. Archetype-based Redshift Estimation for the Dark Energy Spectroscopic Instrument Survey

Author

Anand, Abhijeet, Guy, Julien, Bailey, Stephen, Moustakas, John, Aguilar, J, Ahlen, S, Bolton, AS, Brodzeller, A, Brooks, D, Claybaugh, T, Cole, S, de la Macorra, A, Dey, Biprateep, Fanning, K, Forero-Romero, JE, Gaztañaga, E, Gontcho, S Gontcho A, Gutierrez, G, Honscheid, K, Howlett, C, Juneau, S, Kirkby, D, Kisner, T, Kremin, A, Lambert, A, Landriau, M, Le Guillou, L, Manera, M, Meisner, A, Miquel, R, Mueller, E, Niz, G, Palanque-Delabrouille, N, Percival, WJ, Poppett, C, Prada, F, Raichoor, A, Rezaie, M, Rossi, G, Sanchez, E, Schlafly, EF, Schlegel, D, Schubnell, M, Sprayberry, D, Tarlé, G, Warner, C, Weaver, BA, Zhou, R, and Zou, H

Subjects
Particle and High Energy Physics, Astronomical Sciences, Physical Sciences, Affordable and Clean Energy, Astronomical and Space Sciences, Astronomy & Astrophysics, Astronomical sciences, Particle and high energy physics
Abstract

We present a computationally efficient galaxy archetype-based redshift estimation and spectral classification method for the Dark Energy Survey Instrument (DESI) survey. The DESI survey currently relies on a redshift fitter and spectral classifier using a linear combination of principal component analysis-derived templates, which is very efficient in processing large volumes of DESI spectra within a short time frame. However, this method occasionally yields unphysical model fits for galaxies and fails to adequately absorb calibration errors that may still be occasionally visible in the reduced spectra. Our proposed approach improves upon this existing method by refitting the spectra with carefully generated physical galaxy archetypes combined with additional terms designed to absorb data reduction defects and provide more physical models to the DESI spectra. We test our method on an extensive data set derived from the survey validation (SV) and Year 1 (Y1) data of DESI. Our findings indicate that the new method delivers marginally better redshift success for SV tiles while reducing catastrophic redshift failure by 10%-30%. At the same time, results from millions of targets from the main survey show that our model has relatively higher redshift success and purity rates (0.5%-0.8% higher) for galaxy targets while having similar success for QSOs. These improvements also demonstrate that the main DESI redshift pipeline is generally robust. Additionally, it reduces the false-positive redshift estimation by 5%−40% for sky fibers. We also discuss the generic nature of our method and how it can be extended to other large spectroscopic surveys, along with possible future improvements.

Published
2024

9. The clustering of Lyman Alpha Emitting galaxies at

Author

White, Martin, Raichoor, A, Dey, Arjun, Garrison, Lehman H, Gawiser, Eric, Lang, D, Lee, Kyoung-soo, Myers, AD, Schlegel, D, Valdes, F, Aguilar, J, Ahlen, S, Brooks, D, Chaussidon, E, Claybaugh, T, Dawson, K, de la Macorra, A, Dey, Biprateep, Doel, P, Fanning, K, Font-Ribera, A, Forero-Romero, JE, Gontcho, S Gontcho A, Gutierrez, G, Guy, J, Honscheid, K, Kirkby, D, Kremin, A, Landriau, M, Le Guillou, L, Levi, ME, Magneville, C, Manera, M, Martini, P, Meisner, A, Miquel, R, Moon, B, Newman, JA, Niz, G, Palanque-Delabrouille, N, Park, C, Percival, WJ, Prada, F, Rossi, G, Ruhlmann-Kleider, V, Sanchez, E, Schlafly, EF, Schubnell, M, Seo, H, Sprayberry, D, Tarlé, G, Weaver, BA, Yang, Y, Yèche, C, and Zou, H

Subjects
Astronomical Sciences, Physical Sciences, galaxy clustering, galaxy surveys, high redshift galaxies, redshift surveys, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Astronomical sciences, Particle and high energy physics
Abstract

We measure the clustering of Lyman Alpha Emitting galaxies (LAEs) selected from the One-hundred-square-degree DECam Imaging in Narrowbands (ODIN) survey, with spectroscopic follow-up from Dark Energy Spectroscopic Instrument (DESI). We use DESI spectroscopy to optimize our selection and to constrain the interloper fraction and redshift distribution of our narrow-band selected sources. We select samples of 4000 LAEs at z = 2.45 and 3.1 in 9 sq.deg. centered on the COSMOS field with median Lyα fluxes of ≈ 10-16 erg s-1 cm-2. Covariances and cosmological inferences are obtained from a series of mock catalogs built upon high-resolution N-body simulations that match the footprint, number density, redshift distribution and observed clustering of the sample. We find that both samples have a correlation length of r 0 = 3.0 ± 0.2 h-1 Mpc. Within our fiducial cosmology these correspond to 3D number densities of ≈ 10-3 h3 Mpc-3 and, from our mock catalogs, biases of 1.7 and 2.0 at z = 2.45 and 3.1, respectively. We discuss the implications of these measurements for the use of LAEs as large-scale structure tracers for high-redshift cosmology.

Published
2024

10. High redshift LBGs from deep broadband imaging for future spectroscopic surveys

Author

Ruhlmann-Kleider, Vanina, Yèche, Christophe, Magneville, Christophe, Coquinot, Henri, Armengaud, Eric, Palanque-Delabrouille, Nathalie, Raichoor, Anand, Aguilar, Jessica Nicole, Ahlen, Steven, Arnouts, Stéphane, Brooks, David, Chaussidon, Edmond, Claybaugh, Todd, Dawson, Kyle, de la Macorra, Axel, Dey, Arjun, Dey, Biprateep, Doel, Peter, Fanning, Kevin, Ferraro, Simone, Forero-Romero, Jaime E, Gontcho, Satya Gontcho A, Gutierrez, Gaston, Gwyn, Stephen, Honscheid, Klaus, Juneau, Stephanie, Kehoe, Robert, Kisner, Theodore, Kremin, Anthony, Lambert, Andrew, Landriau, Martin, Le Guillou, Laurent, Levi, Michael E, Manera, Marc, Martini, Paul, Meisner, Aaron, Miquel, Ramon, Moustakas, John, Mueller, Eva-Maria, Muñoz-Gutiérrez, Andrea, Newman, Jeffrey A, Nie, Jundan, Niz, Gustavo, Payerne, Constantin, Picouet, Vincent, Ravoux, Corentin, Rezaie, Mehdi, Rossi, Graziano, Sanchez, Eusebio, Sawicki, Marcin, Schlafly, Edward F, Schlegel, David, Schubnell, Michael, Seo, Hee-Jong, Silber, Joseph, Sprayberry, David, Taran, Julien, Tarlé, Gregory, Weaver, Benjamin A, White, Martin, Wilson, Michael J, Zhou, Zhimin, and Zou, Hu

Subjects
Particle and High Energy Physics, Astronomical Sciences, Physical Sciences, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Astronomical sciences, Particle and high energy physics
Abstract

Abstract: Lyman break galaxies (LBGs) are promising probes for clustering measurements at high redshift, z > 2, a region only covered so far by Lyman-α forest measurements. In this paper, we investigate the feasibility of selecting LBGs by exploiting the existence of a strong deficit of flux shortward of the Lyman limit, due to various absorption processes along the line of sight. The target selection relies on deep imaging data from the HSC and CLAUDS surveys in the g, r, z and u bands, respectively, with median depths reaching 27 AB in all bands. The selections were validated by several dedicated spectroscopic observation campaigns with DESI. Visual inspection of spectra has enabled us to develop an automated spectroscopic typing and redshift estimation algorithm specific to LBGs. Based on these data and tools, we assess the efficiency and purity of target selections optimised for different purposes. Selections providing a wide redshift coverage retain 57% of the observed targets after spectroscopic confirmation with DESI, and provide an efficiency for LBGs of 83±3%, for a purity of the selected LBG sample of 90±2%. This would deliver a confirmed LBG density of ~ 620 deg-2 in the range 2.3 < z < 3.5 for a r-band limiting magnitude r < 24.2. Selections optimised for high redshift efficiency retain 73% of the observed targets after spectroscopic confirmation, with 89±4% efficiency for 97±2% purity. This would provide a confirmed LBG density of ~ 470 deg-2 in the range 2.8 < z < 3.5 for a r-band limiting magnitude r < 24.5. A preliminary study of the LBG sample 3d-clustering properties is also presented and used to estimate the LBG linear bias. A value of b LBG = 3.3 ± 0.2  (stat.) is obtained for a mean redshift of 2.9 and a limiting magnitude in r of 24.2, in agreement with results reported in the literature.

Published
2024

11. Measuring Fiber Positioning Accuracy and Throughput with Fiber Dithering for the Dark Energy Spectroscopic Instrument

Author

Schlafly, EF, Schlegel, D, BenZvi, S, Raichoor, A, Forero-Romero, JE, Aguilar, J, Ahlen, S, Bailey, S, Bault, A, Brooks, D, Claybaugh, T, Dawson, K, de la Macorra, A, Dey, Arjun, Doel, P, Gaztañaga, E, Gontcho, S Gontcho A, Guy, J, Hahn, C, Honscheid, K, Jimenez, J, Kent, S, Kirkby, D, Kisner, T, Kremin, A, Lambert, A, Landriau, M, Levi, ME, Manera, M, Martini, P, Meisner, A, Miquel, R, Moustakas, J, Myers, AD, Nie, J, Palanque-Delabrouille, N, Percival, WJ, Poppett, C, Prada, F, Rabinowitz, D, Rezaie, M, Rossi, G, Sanchez, E, Schubnell, M, Sharples, R, Silber, J, Tarlé, G, Weaver, BA, Zhou, Z, and Zou, H

Subjects
Particle and High Energy Physics, Astronomical Sciences, Physical Sciences, Astronomical and Space Sciences, Astronomy & Astrophysics, Astronomical sciences, Particle and high energy physics
Abstract

Highly multiplexed, fiber-fed spectroscopy is enabling surveys of millions of stars and galaxies. The performance of these surveys depends on accurately positioning fibers in the focal plane to capture target light. We describe a technique to measure the positioning accuracy of fibers by dithering fibers slightly around their ideal locations. This approach also enables measurement of the total system throughput and point-spread function delivered to the focal plane. We then apply this technique to observations from the Dark Energy Survey Instrument (DESI), and demonstrate that DESI positions fibers to within 0.″08 of their targets (5% of a fiber diameter) and achieves a system throughput within about 7% of expectations.

Published
2024

12. The clustering of Lyman Alpha Emitting galaxies at z=2-3

Author

White, M., Raichoor, A., Dey, Arjun, Garrison, Lehman H., Gawiser, Eric, Lang, D., Lee, Kyoung-soo, Myers, A. D., Schlegel, D., Valdes, F., Aguilar, J., Ahlen, S., Brooks, D., Chaussidon, E., Claybaugh, T., Dawson, K., de la Macorra, A., Dey, Biprateep, Doel, P., Fanning, K., Font-Ribera, A., Forero-Romero, J. E., Gontcho, S. Gontcho A, Gutierrez, G., Guy, J., Honscheid, K., Kirkby, D., Kremin, A., Landriau, M., Guillou, L. Le, Levi, M. E., Magneville, C., Manera, M., Martini, P., Meisner, A., Miquel, R., Moon, B., Newman, J. A., Niz, G., Palanque-Delabrouille, N., Park, C., Percival, W. J., Prada, F., Rossi, G., Ruhlmann-Kleider, V., Sanchez, E., Schlafly, E. F., Schubnell, M., Seo, H., Sprayberry, D., Tarlé, G., Weaver, B. A., Yang, Y., Yèche, C., and Zou, H.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We measure the clustering of Lyman Alpha Emitting galaxies (LAEs) selected from the One-hundred-square-degree DECam Imaging in Narrowbands (ODIN) survey, with spectroscopic follow-up from Dark Energy Spectroscopic Instrument (DESI). We use DESI spectroscopy to optimize our selection and to constrain the interloper fraction and redshift distribution of our narrow-band selected sources. We select samples of 4000 LAEs at z=2.45 and 3.1 in 9 sq.deg. centered on the COSMOS field with median LyA fluxes of 10^{-16}erg/s/cm2. Covariances and cosmological inferences are obtained from a series of mock catalogs built upon high-resolution N-body simulations that match the footprint, number density, redshift distribution and observed clustering of the sample. We find that both samples have a correlation length of r_0=(3.0\pm 0.2)Mpc/h. Within our fiducial cosmology these correspond to 3D number densities of 10^{-3} h^3/Mpc^3 and, from our mock catalogs, biases of 1.7 and 2.0 at z=2.45 and 3.1, respectively. We discuss the implications of these measurements for the use of LAEs as large-scale structure tracers for high-redshift cosmology., Comment: 26 pages, 13 figures; minor revisions to match version accepted by JCAP

Published
2024

13. The Construction of Large-scale Structure Catalogs for the Dark Energy Spectroscopic Instrument

Author

Ross, A. J., Aguilar, J., Ahlen, S., Alam, S., Anand, A., Bailey, S., Bianchi, D., Brieden, S., Brooks, D., Burtin, E., Rosell, A. Carnero, Chaussidon, E., Claybaugh, T., Cole, S., Dawson, K., de la Macorra, A., de Mattia, A., Dey, Arjun, Dey, Biprateep, Doel, P., Fanning, K., Ferraro, S., Ereza, J., Font-Ribera, A., Forero-Romero, J. E., Gaztañaga, E., Gil-Marín, H., Gontcho, S. Gontcho A, Gonzalez-Morales, A. X., Guy, J., Hahn, C., Heydenreich, S., Honscheid, K., Howlett, C., Ishak, M., Karim, T., Kirkby, D., Kisner, T., Kong, H., Kremin, A., Krolewski, A., Lambert, A., Landriau, M., Lasker, J., Guillou, L. Le, Levi, M. E., Manera, M., Martini, P., McDonald, P., Meisner, A., Miquel, R., Moon, J., Moustakas, J., Muñoz-Gutiérrez, A., Myers, A. D., Nadathur, S., Napolitano, L., Newman, J. A., Nie, J., Niz, G., Palanque-Delabrouille, N., Percival, W. J., Poppett, C., Prada, F., Raichoor, A., Ravoux, C., Rezaie, M., Rosado-Marin, A., Rossi, G., Samushia, L., Sanchez, E., Schlafly, E. F., Schlegel, D., Seo, H., Smith, A., Sprayberry, D., Tarlé, G., Valcin, D., Vargas-Magaña, M., Weaver, B. A., Wilson, M., Yu, J., Zarrouk, P., Zhao, C., Zhou, R., and Zou, H.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present the technical details on how large-scale structure (LSS) catalogs are constructed from redshifts measured from spectra observed by the Dark Energy Spectroscopic Instrument (DESI). The LSS catalogs provide the information needed to determine the relative number density of DESI tracers as a function of redshift and celestial coordinates and, e.g., determine clustering statistics. We produce catalogs that are weighted subsamples of the observed data, each matched to a weighted `random' catalog that forms an unclustered sampling of the probability density that DESI could have observed those data at each location. Precise knowledge of the DESI observing history and associated hardware performance allows for a determination of the DESI footprint and the number of times DESI has covered it at sub-arcsecond level precision. This enables the completeness of any DESI sample to be modeled at this same resolution. The pipeline developed to create LSS catalogs has been designed to easily allow robustness tests and enable future improvements. We describe how it allows ongoing work improving the match between galaxy and random catalogs, such as including further information when assigning redshifts to randoms, accounting for fluctuations in target density, accounting for variation in the redshift success rate, and accommodating blinding schemes., Comment: Accepted (by JCAP) version of supporting publication of DESI 2024II: Sample definitions, characteristics, and two-point clustering statistics

Published
2024

14. DESI 2024 VI: Cosmological Constraints from the Measurements of Baryon Acoustic Oscillations

Author

DESI Collaboration, Adame, A. G., Aguilar, J., Ahlen, S., Alam, S., Alexander, D. M., Alvarez, M., Alves, O., Anand, A., Andrade, U., Armengaud, E., Avila, S., Aviles, A., Awan, H., Bahr-Kalus, B., Bailey, S., Baltay, C., Bault, A., Behera, J., BenZvi, S., Bera, A., Beutler, F., Bianchi, D., Blake, C., Blum, R., Brieden, S., Brodzeller, A., Brooks, D., Buckley-Geer, E., Burtin, E., Calderon, R., Canning, R., Rosell, A. Carnero, Cereskaite, R., Cervantes-Cota, J. L., Chabanier, S., Chaussidon, E., Chaves-Montero, J., Chen, S., Chen, X., Claybaugh, T., Cole, S., Cuceu, A., Davis, T. M., Dawson, K., de la Macorra, A., de Mattia, A., Deiosso, N., Dey, A., Dey, B., Ding, Z., Doel, P., Edelstein, J., Eftekharzadeh, S., Eisenstein, D. J., Elliott, A., Fagrelius, P., Fanning, K., Ferraro, S., Ereza, J., Findlay, N., Flaugher, B., Font-Ribera, A., Forero-Sánchez, D., Forero-Romero, J. E., Frenk, C. S., Garcia-Quintero, C., Gaztañaga, E., Gil-Marín, H., Gontcho, S. Gontcho A, Gonzalez-Morales, A. X., Gonzalez-Perez, V., Gordon, C., Green, D., Gruen, D., Gsponer, R., Gutierrez, G., Guy, J., Hadzhiyska, B., Hahn, C., Hanif, M. M. S, Herrera-Alcantar, H. K., Honscheid, K., Howlett, C., Huterer, D., Iršič, V., Ishak, M., Juneau, S., Karaçaylı, N. G., Kehoe, R., Kent, S., Kirkby, D., Kremin, A., Krolewski, A., Lai, Y., Lan, T. -W., Landriau, M., Lang, D., Lasker, J., Goff, J. M. Le, Guillou, L. Le, Leauthaud, A., Levi, M. E., Li, T. S., Linder, E., Lodha, K., Magneville, C., Manera, M., Margala, D., Martini, P., Maus, M., McDonald, P., Medina-Varela, L., Meisner, A., Mena-Fernández, J., Miquel, R., Moon, J., Moore, S., Moustakas, J., Mudur, N., Mueller, E., Muñoz-Gutiérrez, A., Myers, A. D., Nadathur, S., Napolitano, L., Neveux, R., Newman, J. A., Nguyen, N. M., Nie, J., Niz, G., Noriega, H. E., Padmanabhan, N., Paillas, E., Palanque-Delabrouille, N., Pan, J., Penmetsa, S., Percival, W. J., Pieri, M. M., Pinon, M., Poppett, C., Porredon, A., Prada, F., Pérez-Fernández, A., Pérez-Ràfols, I., Rabinowitz, D., Raichoor, A., Ramírez-Pérez, C., Ramirez-Solano, S., Ravoux, C., Rashkovetskyi, M., Rezaie, M., Rich, J., Rocher, A., Rockosi, C., Roe, N. A., Rosado-Marin, A., Ross, A. J., Rossi, G., Ruggeri, R., Ruhlmann-Kleider, V., Samushia, L., Sanchez, E., Saulder, C., Schlafly, E. F., Schlegel, D., Schubnell, M., Seo, H., Shafieloo, A., Sharples, R., Silber, J., Slosar, A., Smith, A., Sprayberry, D., Tan, T., Tarlé, G., Taylor, P., Trusov, S., Ureña-López, L. A., Vaisakh, R., Valcin, D., Valdes, F., Vargas-Magaña, M., Verde, L., Walther, M., Wang, B., Wang, M. S., Weaver, B. A., Weaverdyck, N., Wechsler, R. H., Weinberg, D. H., White, M., Yu, J., Yu, Y., Yuan, S., Yèche, C., Zaborowski, E. A., Zarrouk, P., Zhang, H., Zhao, C., Zhao, R., Zhou, R., Zhuang, T., and Zou, H.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present cosmological results from the measurement of baryon acoustic oscillations (BAO) in galaxy, quasar and Lyman-$\alpha$ forest tracers from the first year of observations from the Dark Energy Spectroscopic Instrument (DESI), to be released in the DESI Data Release 1. DESI BAO provide robust measurements of the transverse comoving distance and Hubble rate, or their combination, relative to the sound horizon, in seven redshift bins from over 6 million extragalactic objects in the redshift range $0.1-1$ and $w_a<0$. This preference is 2.6$\sigma$ for the DESI+CMB combination, and persists or grows when SN~Ia are added in, giving results discrepant with the $\Lambda$CDM model at the $2.5\sigma$, $3.5\sigma$ or $3.9\sigma$ levels for the addition of Pantheon+, Union3, or DES-SN5YR datasets respectively. For the flat $\Lambda$CDM model with the sum of neutrino mass $\sum m_\nu$ free, combining the DESI and CMB data yields an upper limit $\sum m_\nu < 0.072$ $(0.113)$ eV at 95% confidence for a $\sum m_\nu>0$ $(\sum m_\nu>0.059)$ eV prior. These neutrino-mass constraints are substantially relaxed in models beyond $\Lambda$CDM. [Abridged.], Comment: This DESI Collaboration Key Publication is part of the 2024 publication series using the first year of observations (see https://data.desi.lbl.gov/doc/papers). 68 pages, 15 figures. Version accepted for publication in JCAP

Published
2024

15. DESI 2024 IV: Baryon Acoustic Oscillations from the Lyman Alpha Forest

Author

DESI Collaboration, Adame, A. G., Aguilar, J., Ahlen, S., Alam, S., Alexander, D. M., Alvarez, M., Alves, O., Anand, A., Andrade, U., Armengaud, E., Avila, S., Aviles, A., Awan, H., Bailey, S., Baltay, C., Bault, A., Bautista, J., Behera, J., BenZvi, S., Beutler, F., Bianchi, D., Blake, C., Blum, R., Brieden, S., Brodzeller, A., Brooks, D., Buckley-Geer, E., Burtin, E., Calderon, R., Canning, R., Rosell, A. Carnero, Cereskaite, R., Cervantes-Cota, J. L., Chabanier, S., Chaussidon, E., Chaves-Montero, J., Chen, S., Chen, X., Claybaugh, T., Cole, S., Cuceu, A., Davis, T. M., Dawson, K., de la Cruz, R., de la Macorra, A., de Mattia, A., Deiosso, N., Dey, A., Dey, B., Ding, J., Ding, Z., Doel, P., Edelstein, J., Eftekharzadeh, S., Eisenstein, D. J., Elliott, A., Fagrelius, P., Fanning, K., Ferraro, S., Ereza, J., Findlay, N., Flaugher, B., Font-Ribera, A., Forero-Sánchez, D., Forero-Romero, J. E., Garcia-Quintero, C., Gaztañaga, E., Gil-Marín, H., Gontcho, S. Gontcho A, Gonzalez-Morales, A. X., Gonzalez-Perez, V., Gordon, C., Green, D., Gruen, D., Gsponer, R., Gutierrez, G., Guy, J., Hadzhiyska, B., Hahn, C., Hanif, M. M. S, Herrera-Alcantar, H. K., Honscheid, K., Howlett, C., Huterer, D., Iršič, V., Ishak, M., Juneau, S., Karaçayli, N. G., Kehoe, R., Kent, S., Kirkby, D., Kremin, A., Krolewski, A., Lai, Y., Lan, T. -W., Landriau, M., Lang, D., Lasker, J., Goff, J. M. Le, Guillou, L. Le, Leauthaud, A., Levi, M. E., Li, T. S., Linder, E., Lodha, K., Magneville, C., Manera, M., Margala, D., Martini, P., Maus, M., McDonald, P., Medina-Varela, L., Meisner, A., Mena-Fernández, J., Miquel, R., Moon, J., Moore, S., Moustakas, J., Mueller, E., Muñoz-Gutiérrez, A., Myers, A. D., Nadathur, S., Napolitano, L., Neveux, R., Newman, J. A., Nguyen, N. M., Nie, J., Niz, G., Noriega, H. E., Padmanabhan, N., Paillas, E., Palanque-Delabrouille, N., Pan, J., Penmetsa, S., Percival, W. J., Pieri, M. M., Pinon, M., Poppett, C., Porredon, A., Prada, F., Pérez-Fernández, A., Pérez-Ràfols, I., Rabinowitz, D., Raichoor, A., Ramírez-Pérez, C., Ramirez-Solano, S., Rashkovetskyi, M., Ravoux, C., Rezaie, M., Rich, J., Rocher, A., Rockosi, C., Roe, N. A., Rosado-Marin, A., Ross, A. J., Rossi, G., Ruggeri, R., Ruhlmann-Kleider, V., Samushia, L., Sanchez, E., Saulder, C., Schlafly, E. F., Schlegel, D., Schubnell, M., Seo, H., Sharples, R., Silber, J., Sinigaglia, F., Slosar, A., Smith, A., Sprayberry, D., Tan, T., Tarlé, G., Trusov, S., Vaisakh, R., Valcin, D., Valdes, F., Vargas-Magaña, M., Verde, L., Walther, M., Wang, B., Wang, M. S., Weaver, B. A., Weaverdyck, N., Wechsler, R. H., Weinberg, D. H., White, M., Yu, J., Yu, Y., Yuan, S., Yèche, C., Zaborowski, E. A., Zarrouk, P., Zhang, H., Zhao, C., Zhao, R., Zhou, R., and Zou, H.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present the measurement of Baryon Acoustic Oscillations (BAO) from the Lyman-$\alpha$ (Ly$\alpha$) forest of high-redshift quasars with the first-year dataset of the Dark Energy Spectroscopic Instrument (DESI). Our analysis uses over $420\,000$ Ly$\alpha$ forest spectra and their correlation with the spatial distribution of more than $700\,000$ quasars. An essential facet of this work is the development of a new analysis methodology on a blinded dataset. We conducted rigorous tests using synthetic data to ensure the reliability of our methodology and findings before unblinding. Additionally, we conducted multiple data splits to assess the consistency of the results and scrutinized various analysis approaches to confirm their robustness. For a given value of the sound horizon ($r_d$), we measure the expansion at $z_{\rm eff}=2.33$ with 2\% precision, $H(z_{\rm eff}) = (239.2 \pm 4.8) (147.09~{\rm Mpc} /r_d)$ km/s/Mpc. Similarly, we present a 2.4\% measurement of the transverse comoving distance to the same redshift, $D_M(z_{\rm eff}) = (5.84 \pm 0.14) (r_d/147.09~{\rm Mpc})$ Gpc. Together with other DESI BAO measurements at lower redshifts, these results are used in a companion paper to constrain cosmological parameters., Comment: This DESI Collaboration Key Publication is part of the 2024 publication series using the first year of observations (see https://data.desi.lbl.gov/doc/papers). Minor changes in v4, version accepted for publication in JCAP

Published
2024

16. DESI 2024 III: Baryon Acoustic Oscillations from Galaxies and Quasars

Author

DESI Collaboration, Adame, A. G., Aguilar, J., Ahlen, S., Alam, S., Alexander, D. M., Alvarez, M., Alves, O., Anand, A., Andrade, U., Armengaud, E., Avila, S., Aviles, A., Awan, H., Bailey, S., Baltay, C., Bault, A., Behera, J., BenZvi, S., Beutler, F., Bianchi, D., Blake, C., Blum, R., Brieden, S., Brodzeller, A., Brooks, D., Buckley-Geer, E., Burtin, E., Calderon, R., Canning, R., Rosell, A. Carnero, Cereskaite, R., Cervantes-Cota, J. L., Chabanier, S., Chaussidon, E., Chaves-Montero, J., Chen, S., Chen, X., Claybaugh, T., Cole, S., Cuceu, A., Davis, T. M., Dawson, K., de la Macorra, A., de Mattia, A., Deiosso, N., Dey, A., Dey, B., Ding, Z., Doel, P., Edelstein, J., Eftekharzadeh, S., Eisenstein, D. J., Elliott, A., Fagrelius, P., Fanning, K., Ferraro, S., Ereza, J., Findlay, N., Flaugher, B., Font-Ribera, A., Forero-Sánchez, D., Forero-Romero, J. E., Garcia-Quintero, C., Gaztañaga, E., Gil-Marín, H., Gontcho, S. Gontcho A, Gonzalez-Morales, A. X., Gonzalez-Perez, V., Gordon, C., Green, D., Gruen, D., Gsponer, R., Gutierrez, G., Guy, J., Hadzhiyska, B., Hahn, C., Hanif, M. M. S, Herrera-Alcantar, H. K., Honscheid, K., Howlett, C., Huterer, D., Iršič, V., Ishak, M., Juneau, S., Karaçaylı, N. G., Kehoe, R., Kent, S., Kirkby, D., Kremin, A., Krolewski, A., Lai, Y., Lan, T. -W., Landriau, M., Lang, D., Lasker, J., Goff, J. M. Le, Guillou, L. Le, Leauthaud, A., Levi, M. E., Li, T. S., Linder, E., Lodha, K., Magneville, C., Manera, M., Margala, D., Martini, P., Maus, M., McDonald, P., Medina-Varela, L., Meisner, A., Mena-Fernández, J., Miquel, R., Moon, J., Moore, S., Moustakas, J., Mudur, N., Mueller, E., Muñoz-Gutiérrez, A., Myers, A. D., Nadathur, S., Napolitano, L., Neveux, R., Newman, J. A., Nguyen, N. M., Nie, J., Niz, G., Noriega, H. E., Padmanabhan, N., Paillas, E., Palanque-Delabrouille, N., Pan, J., Penmetsa, S., Percival, W. J., Pieri, M., Pinon, M., Poppett, C., Porredon, A., Prada, F., Pérez-Fernández, A., Pérez-Ràfols, I., Rabinowitz, D., Raichoor, A., Ramírez-Pérez, C., Ramirez-Solano, S., Rashkovetskyi, M., Rezaie, M., Rich, J., Rocher, A., Rockosi, C., Roe, N. A., Rosado-Marin, A., Ross, A. J., Rossi, G., Ruggeri, R., Ruhlmann-Kleider, V., Samushia, L., Sanchez, E., Saulder, C., Schlafly, E. F., Schlegel, D., Schubnell, M., Seo, H., Sharples, R., Silber, J., Slosar, A., Smith, A., Sprayberry, D., Swanson, J., Tan, T., Tarlé, G., Trusov, S., Vaisakh, R., Valcin, D., Valdes, F., Vargas-Magaña, M., Verde, L., Walther, M., Wang, B., Wang, M. S., Weaver, B. A., Weaverdyck, N., Wechsler, R. H., Weinberg, D. H., White, M., Yu, J., Yu, Y., Yuan, S., Yèche, C., Zaborowski, E. A., Zarrouk, P., Zhang, H., Zhao, C., Zhao, R., Zhou, R., and Zou, H.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present the DESI 2024 galaxy and quasar baryon acoustic oscillations (BAO) measurements using over 5.7 million unique galaxy and quasar redshifts in the range 0.1

Published
2024

17. Measuring Fiber Positioning Accuracy and Throughput with Fiber Dithering for the Dark Energy Spectroscopic Instrument

Author

Schlafly, E. F., Schlegel, D., BenZvi, S., Raichoor, A., Forero-Romero, J. E., Aguilar, J., Ahlen, S., Bailey, S., Bault, A., Brooks, D., Claybaugh, T., Dawson, K., de la Macorra, A., Dey, Arjun, Doel, P., Gaztañaga, E., Gontcho, S. Gontcho A, Guy, J., Hahn, C., Honscheid, K., Jimenez, J., Kent, S., Kirkby, D., Kisner, T., Kremin, A., Lambert, A., Landriau, M., Levi, M. E., Manera, M., Martini, P., Meisner, A., Miquel, R., Moustakas, J., Myers, A. D., Nie, J., Palanque-Delabrouille, N., Percival, W. J., Poppett, C., Prada, F., Rabinowitz, D., Rezaie, M., Rossi, G., Sanchez, E., Schubnell, M., Sharples, R., Silber, J., Tarlé, G., Weaver, B. A., Zhou, Z., and Zou, H.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

Highly multiplexed, fiber-fed spectroscopy is enabling surveys of millions of stars and galaxies. The performance of these surveys depends on accurately positioning fibers in the focal plane to capture target light. We describe a technique to measure the positioning accuracy of fibers by dithering fibers slightly around their ideal locations. This approach also enables measurement of the total system throughput and point spread function delivered to the focal plane. We then apply this technique to observations from the Dark Energy Survey Instrument (DESI), and demonstrate that DESI positions fibers to within 0.08" of their targets (5% of a fiber diameter) and achieves a system throughput within about 5% of expectations., Comment: 17 pages, 9 figures

Published
2024

18. DESI complete calibration of the colour–redshift relation (DC3R2): results from early DESI data

Author

McCullough, J, Gruen, D, Amon, A, Roodman, A, Masters, D, Raichoor, A, Schlegel, D, Canning, R, Castander, FJ, DeRose, J, Miquel, R, Myles, J, Newman, JA, Slosar, A, Speagle, J, Wilson, MJ, Aguilar, J, Ahlen, S, Bailey, S, Brooks, D, Claybaugh, T, Cole, S, Dawson, K, de la Macorra, A, Doel, P, Forero-Romero, JE, Gontcho, S Gontcho A, Guy, J, Kehoe, R, Kremin, A, Landriau, M, Le Guillou, L, Levi, M, Manera, M, Martini, P, Meisner, A, Moustakas, J, Nie, J, Percival, WJ, Poppett, C, Prada, F, Rezaie, M, Rossi, G, Sanchez, E, Seo, H, Tarlé, G, Weaver, BA, Zhou, Z, Zou, H, and Collaboration, DESI

Subjects
Space Sciences, Physical Sciences, gravitational lensing: weak, techniques: spectroscopic, surveys, galaxies: distances and redshifts, Astronomical and Space Sciences, Astronomy & Astrophysics, Astronomical sciences, Particle and high energy physics, Space sciences
Abstract

We present initial results from the Dark Energy Spectroscopic Instrument (DESI) complete calibration of the colour–redshift relation (DC3R2) secondary target survey. Our analysis uses 230 k galaxies that overlap with KiDS-VIKING ugriZYJHKs photometry to calibrate the colour–redshift relation and to inform photometric redshift (photo-z) inference methods of future weak lensing surveys. Together with emission line galaxies (ELGs), luminous red galaxies (LRGs), and the Bright Galaxy Survey (BGS) that provide samples of complementary colour, the DC3R2 targets help DESI to span 56 per cent of the colour space visible to Euclid and LSST with high confidence spectroscopic redshifts. The effects of spectroscopic completeness and quality are explored, as well as systematic uncertainties introduced with the use of common Self-Organizing Maps trained on different photometry than the analysis sample. We further examine the dependence of redshift on magnitude at fixed colour, important for the use of bright galaxy spectra to calibrate redshifts in a fainter photometric galaxy sample. We find that noise in the KiDS-VIKING photometry introduces a dominant, apparent magnitude dependence of redshift at fixed colour, which indicates a need for carefully chosen deep drilling fields, and survey simulation to model this effect for future weak lensing surveys.

Published
2024

19. Resolving the explosion of supernova 2023ixf in Messier 101 within its complex circumstellar environment

Author

Zimmerman, E. A., Irani, I., Chen, P., Gal-Yam, A., Schulze, S., Perley, D. A., Sollerman, J., Filippenko, A. V., Shenar, T., Yaron, O., Shahaf, S., Bruch, R. J., Ofek, E. O., De Cia, A., Brink, T. G., Yang, Y., Vasylyev, S. S., Ami, S. Ben, Aubert, M., Badash, A., Bloom, J. S., Brown, P. J., De, K., Dimitriadis, G., Fransson, C., Fremling, C., Hinds, K., Horesh, A., Johansson, J. P., Kasliwal, M. M., Kulkarni, S. R., Kushnir, D., Martin, C., Matuzewski, M., McGurk, R. C., Miller, A. A., Morag, J., Neil, J. D., Nugent, P. E., Post, R. S., Prusinski, N. Z., Qin, Y., Raichoor, A., Riddle, R., Rowe, M., Rusholme, B., Sfaradi, I., Sjoberg, K. M., Soumagnac, M., Stein, R. D., Strotjohann, N. L., Terwel, J. H., Wasserman, T., Wise, J., Wold, A., Yan, L., and Zhang, K.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics
Abstract

Observing a supernova explosion shortly after it occurs can reveal important information about the physics of stellar explosions and the nature of the progenitor stars of supernovae (SNe). When a star with a well-defined edge explodes in vacuum, the first photons to escape from its surface appear as a brief shock-breakout flare. The duration of this flare can extend to at most a few hours even for nonspherical breakouts from supergiant stars, after which the explosion ejecta should expand and cool. Alternatively, for stars exploding within a distribution of sufficiently dense optically thick circumstellar material, the first photons escape from the material beyond the stellar edge, and the duration of the initial flare can extend to several days, during which the escaping emission indicates photospheric heating. The difficulty in detecting SN explosions promptly after the event has so far limited data regarding supergiant stellar explosions mostly to serendipitous observations that, owing to the lack of ultraviolet (UV) data, were unable to determine whether the early emission is heating or cooling, and hence the nature of the early explosion event. Here, we report observations of SN 2023ixf in the nearby galaxy M101, covering the early days of the event. Using UV spectroscopy from the Hubble Space Telescope (HST) as well as a comprehensive set of additional multiwavelength observations, we trace the photometric and spectroscopic evolution of the event and are able to temporally resolve the emergence and evolution of the SN emission.

Published
2023
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20. The complex circumstellar environment of supernova 2023ixf

Author

Zimmerman, EA, Irani, I, Chen, P, Gal-Yam, A, Schulze, S, Perley, DA, Sollerman, J, Filippenko, AV, Shenar, T, Yaron, O, Shahaf, S, Bruch, RJ, Ofek, EO, De Cia, A, Brink, TG, Yang, Y, Vasylyev, SS, Ben Ami, S, Aubert, M, Badash, A, Bloom, JS, Brown, PJ, De, K, Dimitriadis, G, Fransson, C, Fremling, C, Hinds, K, Horesh, A, Johansson, JP, Kasliwal, MM, Kulkarni, SR, Kushnir, D, Martin, C, Matuzewski, M, McGurk, RC, Miller, AA, Morag, J, Neil, JD, Nugent, PE, Post, RS, Prusinski, NZ, Qin, Y, Raichoor, A, Riddle, R, Rowe, M, Rusholme, B, Sfaradi, I, Sjoberg, KM, Soumagnac, M, Stein, RD, Strotjohann, NL, Terwel, JH, Wasserman, T, Wise, J, Wold, A, Yan, L, and Zhang, K

Subjects
Astronomical Sciences, Physical Sciences, General Science & Technology
Abstract

The early evolution of a supernova (SN) can reveal information about the environment and the progenitor star. When a star explodes in vacuum, the first photons to escape from its surface appear as a brief, hours-long shock-breakout flare1,2, followed by a cooling phase of emission. However, for stars exploding within a distribution of dense, optically thick circumstellar material (CSM), the first photons escape from the material beyond the stellar edge and the duration of the initial flare can extend to several days, during which the escaping emission indicates photospheric heating3. Early serendipitous observations2,4 that lacked ultraviolet (UV) data were unable to determine whether the early emission is heating or cooling and hence the nature of the early explosion event. Here we report UV spectra of the nearby SN 2023ixf in the galaxy Messier 101 (M101). Using the UV data as well as a comprehensive set of further multiwavelength observations, we temporally resolve the emergence of the explosion shock from a thick medium heated by the SN emission. We derive a reliable bolometric light curve that indicates that the shock breaks out from a dense layer with a radius substantially larger than typical supergiants.

Published
2024

21. DESI Complete Calibration of the Color-Redshift Relation (DC3R2): Results from early DESI data

Author

McCullough, J., Gruen, D., Amon, A., Roodman, A., Masters, D., Raichoor, A., Schlegel, D., Canning, R., Castander, F. J., DeRose, J., Miquel, R., Myles, J., Newman, J. A., Slosar, A., Speagle, J., Wilson, M. J., Aguilar, J., Ahlen, S., Bailey, S., Brooks, D., Claybaugh, T., Cole, S., Dawson, K., de la Macorra, A., Doel, P., Forero-Romero, J. E., Gontcho, S. Gontcho A, Guy, J., Kehoe, R., Kremin, A., Landriau, M., Guillou, L. Le, Levi, M., Manera, M., Martini, P., Meisner, A., Moustakas, J., Nie, J., Percival, W. J., Poppett, C., Prada, F., Rezaie, M., Rossi, G., Sanchez, E., Seo, H., Tarlé, G., Weaver, B. A., Zhou, Z., and Zou, H.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present initial results from the Dark Energy Spectroscopic Instrument (DESI) Complete Calibration of the Color-Redshift Relation (DC3R2) secondary target survey. Our analysis uses 230k galaxies that overlap with KiDS-VIKING $ugriZYJHK_s$ photometry to calibrate the color-redshift relation and to inform photometric redshift (photo-z) inference methods of future weak lensing surveys. Together with Emission Line Galaxies (ELGs), Luminous Red Galaxies (LRGs), and the Bright Galaxy Survey (BGS) that provide samples of complementary color, the DC3R2 targets help DESI to span 56% of the color space visible to Euclid and LSST with high confidence spectroscopic redshifts. The effects of spectroscopic completeness and quality are explored, as well as systematic uncertainties introduced with the use of common Self Organizing Maps trained on different photometry than the analysis sample. We further examine the dependence of redshift on magnitude at fixed color, important for the use of bright galaxy spectra to calibrate redshifts in a fainter photometric galaxy sample. We find that noise in the KiDS-VIKING photometry introduces a dominant, apparent magnitude dependence of redshift at fixed color, which indicates a need for carefully chosen deep drilling fields, and survey simulation to model this effect for future weak lensing surveys., Comment: 19 pages, 16 figures, published in MNRAS, interactive visualizations at https://jmccull.github.io/DC3R2_Overview

Published
2023
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22. The DESI One-Percent Survey: exploring a generalized SHAM for multiple tracers with the UNIT simulation

Author

Yu, Jiaxi, Zhao, Cheng, Gonzalez-Perez, Violeta, Chuang, Chia-Hsun, Brodzeller, Allyson, de Mattia, Arnaud, Kneib, Jean-Paul, Krolewski, Alex, Rocher, Antoine, Ross, Ashley, Wang, Yunchong, Yuan, Sihan, Zhang, Hanyu, Zhou, Rongpu, Aguilar, Jessica Nicole, Ahlen, Steven, Brooks, David, Dawson, Kyle, de la Macorra, Alex, Doel, Peter, Fanning, Kevin, Font-Ribera, Andreu, Forero-Romero, Jaime, Gontcho, Satya Gontcho A, Honscheid, Klaus, Kehoe, Robert, Kisner, Theodore, Kremin, Anthony, Landriau, Martin, Manera, Marc, Martini, Paul, Meisner, Aaron, Miquel, Ramon, Moustakas, John, Nie, Jundan, Percival, Will, Poppett, Claire, Raichoor, Anand, Rossi, Graziano, Seo, Hee-Jong, Tarlé, Gregory, Zhou, Zhimin, and Zou, Hu

Subjects
Space Sciences, Physical Sciences, methods: observational, methods: statistical, Galaxy: halo, large-scale structure of Universe, Astronomical and Space Sciences, Astronomy & Astrophysics, Astronomical sciences, Particle and high energy physics, Space sciences
Abstract

We perform SubHalo Abundance Matching (SHAM) studies on UNIT simulations with {σ, Vceil, vsmear}-SHAM and {σ, Vceil, fsat}-SHAM. They are designed to reproduce the clustering on 5-30 of luminous red galaxies (LRGs), emission-line galaxies (ELGs), and quasi-stellar objects (QSOs) at 0.4 < z < 3.5 from DESI (Dark Energy Spectroscopic Instrument) One Percent Survey. Vceil is the incompleteness of the massive host (sub)haloes and is the key to the generalized SHAM. vsmear models the clustering effect of redshift uncertainties, providing measurements consistent with those from repeat observations. A free satellite fraction fsat is necessary to reproduce the clustering of ELGs. We find ELGs present a more complex galaxy-halo mass relation than LRGs reflected in their weak constraints on σ. LRGs, QSOs, and ELGs show increasing Vceil values, corresponding to the massive galaxy incompleteness of LRGs, the quenched star formation of ELGs and the quenched black hole accretion of QSOs. For LRGs, a Gaussian vsmear presents a better profile for subsamples at redshift bins than a Lorentzian profile used for other tracers. The impact of the statistical redshift uncertainty on ELG clustering is negligible. The best-fitting satellite fraction for DESI ELGs is around 4 per cent, lower than previous estimations for ELGs. The mean halo mass log10((Mvir)) in for LRGs, ELGs, and QSOs are 13.16 ± 0.01, 11.90 ± 0.06, and 12.66 ± 0.45, respectively. Our generalized SHAM algorithms facilitate the production of multitracer galaxy mocks for cosmological tests.

Published
2023

23. NANCY: Next-generation All-sky Near-infrared Community surveY

Author

Han, Jiwon Jesse, Dey, Arjun, Price-Whelan, Adrian M., Najita, Joan, Schlafly, Edward F., Saydjari, Andrew, Wechsler, Risa H., Bonaca, Ana, Schlegel, David J, Conroy, Charlie, Raichoor, Anand, Drlica-Wagner, Alex, Kollmeier, Juna A., Koposov, Sergey E., Besla, Gurtina, Rix, Hans-Walter, Goodman, Alyssa, Finkbeiner, Douglas, Anand, Abhijeet, Ashby, Matthew, Bahr-Kalus, Benedict, Beaton, Rachel, Behera, Jayashree, Bell, Eric F., Bellm, Eric C, BenZvi, Segev, Silva, Leandro Beraldo e, Birrer, Simon, Blanton, Michael R., Bock, Jamie, Broekgaarden, Floor, Brout, Dillon, Brown, Warren, Brown, Anthony G. A., Bulbul, Esra, Calderon, Rodrigo, Carlin, Jeffrey L, Carrillo, Andreia, Castander, Francisco Javier, Chakraborty, Priyanka, Chandra, Vedant, Chiang, Yi-Kuan, Choi, Yumi, Clark, Susan E., Clarkson, William I., Cooper, Andrew, Crill, Brendan, Cunha, Katia, Cunningham, Emily, Dalcanton, Julianne, Danieli, Shany, Daylan, Tansu, de Jong, Roelof S., DeRose, Joseph, Dey, Biprateep, Dickinson, Mark, Dominguez, Mariano, Dong, Dillon, Eifler, Tim, El-Badry, Kareem, Erkal, Denis, Escala, Ivanna, Fazio, Giovanni, Ferguson, Annette M. N., Ferraro, Simone, Filion, Carrie, Forero-Romero, Jaime E., Fu, Shenming, Galbany, Lluís, Garavito-Camargo, Nicolas, Gawiser, Eric, Geha, Marla, Gnedin, Oleg Y., Gomez, Sebastian, Greene, Jenny, Guy, Julien, Hadzhiyska, Boryana, Hawkins, Keith, Heinrich, Chen, Hernquist, Lars, Hirata, Christopher, Hora, Joseph, Horowitz, Benjamin, Horta, Danny, Huang, Caroline, Huang, Xiaosheng, Huanyuan, Shan, Hunt, Jason A. S., Ibata, Rodrigo, Jannuzi, Buell, Johnston, Kathryn V., Jones, Michael G., Juneau, Stephanie, Kado-Fong, Erin, Kalari, Venu, Kallivayalil, Nitya, Karim, Tanveer, Keeley, Ryan, Khoperskov, Sergey, Kim, Bokyoung, Kovács, András, Krause, Elisabeth, Kremer, Kyle, Kremin, Anthony, Krolewski, Alex, Kulkarni, S. R., Kuna, Marine, L'Huillier, Benjamin, Lacy, Mark, Lan, Ting-Wen, Lang, Dustin, Leahy, Denis, Li, Jiaxuan, Lim, Seunghwan, López-Morales, Mercedes, Macri, Lucas, Marc, Manera, Mau, Sidney, McCarthy, Patrick J, McDonald, Eithne, McQuinn, Kristen, Meisner, Aaron, Melnick, Gary, Merloni, Andrea, Millard, Cléa, Millon, Martin, Minchev, Ivan, Montero-Camacho, Paulo, Morales-Gutierrez, Catalina, Morrell, Nidia, Moustakas, John, Moustakas, Leonidas, Murray, Zachary, Mutlu-Pakdil, Burcin, Myeong, GyuChul, Myers, Adam D., Nadler, Ethan, Navarete, Felipe, Ness, Melissa, Nidever, David L., Nikutta, Robert, Nushkia, Chamba, Olsen, Knut, Pace, Andrew B., Pacucci, Fabio, Padmanabhan, Nikhil, Parkinson, David, Pearson, Sarah, Peng, Eric W., Petric, Andreea O., Petric, Andreea, Ratcliffe, Bridget, Razieh, Emami, Reiprich, Thomas, Rezaie, Mehdi, Ricci, Marina, Rich, R. Michael, Richstein, Hannah, Riley, Alexander H., Rockosi, Constance, Rossi, Graziano, Salvato, Mara, Samushia, Lado, Sanchez, Javier, Sand, David J, Sanderson, Robyn E, Šarčević, Nikolina, Sarkar, Arnab, Savino, Alessandro, Schweizer, Francois, Shafieloo, Arman, Shengqi, Yang, Shields, Joseph, Shipp, Nora, Simon, Josh, Siudek, Malgorzata, Siwei, Zou, Slepian, Zachary, Smith, Verne, Sobeck, Jennifer, Sohn, Sangmo Tony, Som, Debopam, Speagle, Joshua S., Spergel, David, Szabo, Robert, Tan, Ting, Theissen, Christopher, Tollerud, Erik, Tolls, Volker, Tran, Kim-Vy, Tsiane, Kabelo, Vacca, William D., Valluri, Monica, Verberi, TonyLouis, Warfield, Jack, Weaverdyck, Noah, Weiner, Benjamin, Weisz, Daniel, Wetzel, Andrew, White, Martin, Williams, Christina C., Wolk, Scott, Wu, John F., Wyse, Rosemary, Yang, Justina R., Zaritsky, Dennis, Zelko, Ioana A., Zhimin, Zhou, and Zucker, Catherine

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The Nancy Grace Roman Space Telescope is capable of delivering an unprecedented all-sky, high-spatial resolution, multi-epoch infrared map to the astronomical community. This opportunity arises in the midst of numerous ground- and space-based surveys that will provide extensive spectroscopy and imaging together covering the entire sky (such as Rubin/LSST, Euclid, UNIONS, SPHEREx, DESI, SDSS-V, GALAH, 4MOST, WEAVE, MOONS, PFS, UVEX, NEO Surveyor, etc.). Roman can uniquely provide uniform high-spatial-resolution (~0.1 arcsec) imaging over the entire sky, vastly expanding the science reach and precision of all of these near-term and future surveys. This imaging will not only enhance other surveys, but also facilitate completely new science. By imaging the full sky over two epochs, Roman can measure the proper motions for stars across the entire Milky Way, probing 100 times fainter than Gaia out to the very edge of the Galaxy. Here, we propose NANCY: a completely public, all-sky survey that will create a high-value legacy dataset benefiting innumerable ongoing and forthcoming studies of the universe. NANCY is a pure expression of Roman's potential: it images the entire sky, at high spatial resolution, in a broad infrared bandpass that collects as many photons as possible. The majority of all ongoing astronomical surveys would benefit from incorporating observations of NANCY into their analyses, whether these surveys focus on nearby stars, the Milky Way, near-field cosmology, or the broader universe., Comment: Submitted to the call for white papers for the Roman Core Community Survey (June 16th, 2023), and to the Bulletin of the AAS

Published
2023

24. The Early Data Release of the Dark Energy Spectroscopic Instrument

Author

DESI Collaboration, Adame, A. G., Aguilar, J., Ahlen, S., Alam, S., Aldering, G., Alexander, D. M., Alfarsy, R., Prieto, C. Allende, Alvarez, M., Alves, O., Anand, A., Andrade-Oliveira, F., Armengaud, E., Asorey, J., Avila, S., Aviles, A., Bailey, S., Balaguera-Antolínez, A., Ballester, O., Baltay, C., Bault, A., Bautista, J., Behera, J., Beltran, S. F., BenZvi, S., Silva, L. Beraldo e, Bermejo-Climent, J. R., Berti, A., Besuner, R., Beutler, F., Bianchi, D., Blake, C., Blum, R., Bolton, A. S., Brieden, S., Brodzeller, A., Brooks, D., Brown, Z., Buckley-Geer, E., Burtin, E., Cabayol-Garcia, L., Cai, Z., Canning, R., Cardiel-Sas, L., Rosell, A. Carnero, Castander, F. J., Cervantes-Cota, J. L., Chabanier, S., Chaussidon, E., Chaves-Montero, J., Chen, S., Chen, X., Chuang, C., Claybaugh, T., Cole, S., Cooper, A. P., Cuceu, A., Davis, T. M., Dawson, K., de Belsunce, R., de la Cruz, R., de la Macorra, A., Della Costa, J., de Mattia, A., Demina, R., Demirbozan, U., DeRose, J., Dey, A., Dey, B., Dhungana, G., Ding, J., Ding, Z., Doel, P., Doshi, R., Douglass, K., Edge, A., Eftekharzadeh, S., Eisenstein, D. J., Elliott, A., Escoffier, S., Fagrelius, P., Fan, X., Fanning, K., Fawcett, V. A., Ferraro, S., Ereza, J., Flaugher, B., Font-Ribera, A., Forero-Sánchez, D., Forero-Romero, J. E., Frenk, C. S., Gänsicke, B. T., García, L. Á., García-Bellido, J., Garcia-Quintero, C., Garrison, L. H., Gil-Marín, H., Golden-Marx, J., Gontcho, S. Gontcho A, Gonzalez-Morales, A. X., Gonzalez-Perez, V., Gordon, C., Graur, O., Green, D., Gruen, D., Guy, J., Hadzhiyska, B., Hahn, C., Han, J. J., Hanif, M. M. S, Herrera-Alcantar, H. K., Honscheid, K., Hou, J., Howlett, C., Huterer, D., Iršič, V., Ishak, M., Jacques, A., Jana, A., Jiang, L., Jimenez, J., Jing, Y. P., Joudaki, S., Jullo, E., Juneau, S., Kizhuprakkat, N., Karaçaylı, N. G., Karim, T., Kehoe, R., Kent, S., Khederlarian, A., Kim, S., Kirkby, D., Kisner, T., Kitaura, F., Kneib, J., Koposov, S. E., Kovács, A., Kremin, A., Krolewski, A., L'Huillier, B., Lahav, O., Lambert, A., Lamman, C., Lan, T. -W., Landriau, M., Lang, D., Lange, J. U., Lasker, J., Leauthaud, A., Guillou, L. Le, Levi, M. E., Li, T. S., Linder, E., Lyons, A., Magneville, C., Manera, M., Manser, C. J., Margala, D., Martini, P., McDonald, P., Medina, G. E., Medina-Varela, L., Meisner, A., Mena-Fernández, J., Meneses-Rizo, J., Mezcua, M., Miquel, R., Montero-Camacho, P., Moon, J., Moore, S., Moustakas, J., Mueller, E., Mundet, J., Muñoz-Gutiérrez, A., Myers, A. D., Nadathur, S., Napolitano, L., Neveux, R., Newman, J. A., Nie, J., Nikutta, R., Niz, G., Norberg, P., Noriega, H. E., Paillas, E., Palanque-Delabrouille, N., Palmese, A., Zhiwei, P., Parkinson, D., Penmetsa, S., Percival, W. J., Pérez-Fernández, A., Pérez-Ràfols, I., Pieri, M., Poppett, C., Porredon, A., Pothier, S., Prada, F., Pucha, R., Raichoor, A., Ramírez-Pérez, C., Ramirez-Solano, S., Rashkovetskyi, M., Ravoux, C., Rocher, A., Rockosi, C., Ross, A. J., Rossi, G., Ruggeri, R., Ruhlmann-Kleider, V., Sabiu, C. G., Said, K., Saintonge, A., Samushia, L., Sanchez, E., Saulder, C., Schaan, E., Schlafly, E. F., Schlegel, D., Scholte, D., Schubnell, M., Seo, H., Shafieloo, A., Sharples, R., Sheu, W., Silber, J., Sinigaglia, F., Siudek, M., Slepian, Z., Smith, A., Soumagnac, M. T., Sprayberry, D., Stephey, L., Suárez-Pérez, J., Sun, Z., Tan, T., Tarlé, G., Tojeiro, R., Ureña-López, L. A., Vaisakh, R., Valcin, D., Valdes, F., Valluri, M., Vargas-Magaña, M., Variu, A., Verde, L., Walther, M., Wang, B., Wang, M. S., Weaver, B. A., Weaverdyck, N., Wechsler, R. H., White, M., Xie, Y., Yang, J., Yèche, C., Yu, J., Yuan, S., Zhang, H., Zhang, Z., Zhao, C., Zheng, Z., Zhou, R., Zhou, Z., Zou, H., Zou, S., and Zu, Y.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The Dark Energy Spectroscopic Instrument (DESI) completed its five-month Survey Validation in May 2021. Spectra of stellar and extragalactic targets from Survey Validation constitute the first major data sample from the DESI survey. This paper describes the public release of those spectra, the catalogs of derived properties, and the intermediate data products. In total, the public release includes good-quality spectral information from 466,447 objects targeted as part of the Milky Way Survey, 428,758 as part of the Bright Galaxy Survey, 227,318 as part of the Luminous Red Galaxy sample, 437,664 as part of the Emission Line Galaxy sample, and 76,079 as part of the Quasar sample. In addition, the release includes spectral information from 137,148 objects that expand the scope beyond the primary samples as part of a series of secondary programs. Here, we describe the spectral data, data quality, data products, Large-Scale Structure science catalogs, access to the data, and references that provide relevant background to using these spectra., Comment: 43 pages, 7 figures, 17 tables, accepted for publication in the Astronomical Journal

Published
2023
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25. Survey Operations for the Dark Energy Spectroscopic Instrument

Author

Schlafly, E. F., Kirkby, D., Schlegel, D. J., Myers, A. D., Raichoor, A., Dawson, K., Aguilar, J., Prieto, C. Allende, Bailey, S., BenZvi, S., Bermejo-Climent, J., Brooks, D., de la Macorra, A., Dey, Arjun, Doel, P., Fanning, K., Font-Ribera, A., Forero-Romero, J. E., García-Bellido, J., Gontcho, S. Gontcho A, Guy, J., Hahn, C., Honscheid, K., Ishak, M., Juneau, S., Kehoe, R., Kisner, T., Kremin, A., Landriau, M., Lang, D. A., Lasker, J., Levi, M. E., Magneville, C., Manser, C. J., Martini, P., Meisner, A. M., Miquel, R., Moustakas, J., Newman, J. A., Nie, Jundan, Palanque-Delabrouille, N., Percival, W. J., Poppett, C., Rockosi, C., Ross, A. J., Rossi, G., Tarlé, G., Weaver, B. A., Yèche, C., and Zhou, R.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The Dark Energy Spectroscopic Instrument (DESI) survey is a spectroscopic survey of tens of millions of galaxies at $0 < z < 3.5$ covering 14,000 square degrees of the sky. In its first 1.1 years of survey operations, it has observed more than 14 million galaxies and 4 million stars. We describe the processes that govern DESI's observations of the 15,000 fields composing the survey. This includes the planning of each night's observations in the afternoon; automatic selection of fields to observe during the night; real-time assessment of field completeness on the basis of observing conditions during each exposure; reduction, redshifting, and quality assurance of each field of targets in the morning following observation; and updates to the list of future targets to observe on the basis of these results. We also compare the performance of the survey with historical expectations and find good agreement. Simulations of the weather and of DESI observations using the real field-selection algorithm show good agreement with the actual observations. After accounting for major unplanned shutdowns, the dark time survey is progressing about 7% faster than forecast, which is good agreement given approximations made in the simulations., Comment: 30 pages, 12 figures; updated following referee report

Published
2023

26. Validation of the Scientific Program for the Dark Energy Spectroscopic Instrument

Author

DESI Collaboration, Adame, A. G., Aguilar, J., Ahlen, S., Alam, S., Aldering, G., Alexander, D. M., Alfarsy, R., Prieto, C. Allende, Alvarez, M., Alves, O., Anand, A., Andrade-Oliveira, F., Armengaud, E., Asorey, J., Avila, S., Aviles, A., Bailey, S., Balaguera-Antolínez, A., Ballester, O., Baltay, C., Bault, A., Bautista, J., Behera, J., Beltran, S. F., BenZvi, S., Silva, L. Beraldo e, Bermejo-Climent, J. R., Berti, A., Besuner, R., Beutler, F., Bianchi, D., Blake, C., Blum, R., Bolton, A. S., Brieden, S., Brodzeller, A., Brooks, D., Brown, Z., Buckley-Geer, E., Burtin, E., Cabayol-Garcia, L., Cai, Z., Canning, R., Cardiel-Sas, L., Rosell, A. Carnero, Castander, F. J., Cervantes-Cota, J. L., Chabanier, S., Chaussidon, E., Chaves-Montero, J., Chen, S., Chuang, C., Claybaugh, T., Cole, S., Cooper, A. P., Cuceu, A., Davis, T. M., Dawson, K., de Belsunce, R., de la Cruz, R., de la Macorra, A., de Mattia, A., Demina, R., Demirbozan, U., DeRose, J., Dey, A., Dey, B., Dhungana, G., Ding, J., Ding, Z., Doel, P., Doshi, R., Douglass, K., Edge, A., Eftekharzadeh, S., Eisenstein, D. J., Elliott, A., Escoffier, S., Fagrelius, P., Fan, X., Fanning, K., Fawcett, V. A., Ferraro, S., Ereza, J., Flaugher, B., Font-Ribera, A., Forero-Sánchez, D., Forero-Romero, J. E., Frenk, C. S., Gänsicke, B. T., García, L. Á., García-Bellido, J., Garcia-Quintero, C., Garrison, L. H., Gil-Marín, H., Golden-Marx, J., Gontcho, S. Gontcho A, Gonzalez-Morales, A. X., Gonzalez-Perez, V., Gordon, C., Graur, O., Green, D., Gruen, D., Guy, J., Hadzhiyska, B., Hahn, C., Han, J. J., Hanif, M. M. S, Herrera-Alcantar, H. K., Honscheid, K., Hou, J., Howlett, C., Huterer, D., Iršič, V., Ishak, M., Jana, A., Jiang, L., Jimenez, J., Jing, Y. P., Joudaki, S., Joyce, R., Jullo, E., Juneau, S., Kizhuprakkat, N., Karaçaylı, N. G., Karim, T., Kehoe, R., Kent, S., Khederlarian, A., Kim, S., Kirkby, D., Kisner, T., Kitaura, F., Kneib, J., Koposov, S. E., Kovács, A., Kremin, A., Krolewski, A., L'Huillier, B., Lahav, O., Lambert, A., Lamman, C., Lan, T. -W., Landriau, M., Lang, D., Lange, J. U., Lasker, J., Guillou, L. Le, Leauthaud, A., Levi, M. E., Li, T. S., Linder, E., Lyons, A., Magneville, C., Manera, M., Manser, C. J., Margala, D., Martini, P., McDonald, P., Medina, G. E., Medina-Varela, L., Meisner, A., Mena-Fernández, J., Meneses-Rizo, J., Mezcua, M., Miquel, R., Montero-Camacho, P., Moon, J., Moore, S., Moustakas, J., Mueller, E., Mundet, J., Muñoz-Gutiérrez, A., Myers, A. D., Nadathur, S., Napolitano, L., Neveux, R., Newman, J. A., Nie, J., Niz, G., Norberg, P., Noriega, H. E., Paillas, E., Palanque-Delabrouille, N., Palmese, A., Zhiwei, P., Parkinson, D., Penmetsa, S., Percival, W. J., Pérez-Fernández, A., Pérez-Ràfols, I., Pieri, M., Poppett, C., Porredon, A., Prada, F., Pucha, R., Raichoor, A., Ramírez-Pérez, C., Ramirez-Solano, S., Rashkovetskyi, M., Ravoux, C., Rocher, A., Rockosi, C., Ross, A. J., Rossi, G., Ruggeri, R., Ruhlmann-Kleider, V., Sabiu, C. G., Said, K., Saintonge, A., Samushia, L., Sanchez, E., Saulder, C., Schaan, E., Schlafly, E. F., Schlegel, D., Scholte, D., Schubnell, M., Seo, H., Shafieloo, A., Sharples, R., Sheu, W., Silber, J., Sinigaglia, F., Siudek, M., Slepian, Z., Smith, A., Sprayberry, D., Stephey, L., Suárez-Pérez, J., Sun, Z., Tan, T., Tarlé, G., Tojeiro, R., Ureña-López, L. A., Vaisakh, R., Valcin, D., Valdes, F., Valluri, M., Vargas-Magaña, M., Variu, A., Verde, L., Walther, M., Wang, B., Wang, M. S., Weaver, B. A., Weaverdyck, N., Wechsler, R. H., White, M., Xie, Y., Yang, J., Yèche, C., Yu, J., Yuan, S., Zhang, H., Zhang, Z., Zhao, C., Zheng, Z., Zhou, R., Zhou, Z., Zou, H., Zou, S., and Zu, Y.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The Dark Energy Spectroscopic Instrument (DESI) was designed to conduct a survey covering 14,000 deg$^2$ over five years to constrain the cosmic expansion history through precise measurements of Baryon Acoustic Oscillations (BAO). The scientific program for DESI was evaluated during a five month Survey Validation (SV) campaign before beginning full operations. This program produced deep spectra of tens of thousands of objects from each of the stellar (MWS), bright galaxy (BGS), luminous red galaxy (LRG), emission line galaxy (ELG), and quasar target classes. These SV spectra were used to optimize redshift distributions, characterize exposure times, determine calibration procedures, and assess observational overheads for the five-year program. In this paper, we present the final target selection algorithms, redshift distributions, and projected cosmology constraints resulting from those studies. We also present a `One-Percent survey' conducted at the conclusion of Survey Validation covering 140 deg$^2$ using the final target selection algorithms with exposures of a depth typical of the main survey. The Survey Validation indicates that DESI will be able to complete the full 14,000 deg$^2$ program with spectroscopically-confirmed targets from the MWS, BGS, LRG, ELG, and quasar programs with total sample sizes of 7.2, 13.8, 7.46, 15.7, and 2.87 million, respectively. These samples will allow exploration of the Milky Way halo, clustering on all scales, and BAO measurements with a statistical precision of 0.28% over the redshift interval $z<1.1$, 0.39% over the redshift interval $1.1

Published
2023
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27. Witnessing the intracluster medium assembly at the cosmic noon in JKCS041

Author

Andreon, S., Romero, C., Aussel, H., Bhandarkar, T., Devlin, M., Dicker, S., Ladjelate, B., Lowe, I., Mason, B., Mroczkowski, T., Raichoor, A., Sarazin, C., and Trinchieri, G.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

In this work we study the intracluster medium of a galaxy cluster at the cosmic noon: JKCS041 at z=1.803. A 28h long Sunyaev-Zel'dovich (SZ) observation using MUSTANG-2 allows us to detect JKCS041, even if intrinsically extremely faint compared to other SZ-detected clusters. We found that the SZ peak is offset from the X-ray center by about 220 kpc in the direction of the brightest cluster galaxy, which we interpret as due to the cluster being observed just after first passage of a major merger. JKCS041 has a low central pressure and a low Compton Y compared to local clusters selected by their intracluster medium (ICM), likely because the cluster is still in the process of assembly but also in part because of a hard-to-quantify bias in current local ICM-selected samples. JKCS041 has a 0.5 dex fainter Y signal than another less massive z~1.8 cluster, exemplifying how much different weak-lensing mass and SZ mass can be at high redshift. The observations we present provide us with the measurement of the most distant resolved pressure profile of a galaxy cluster. Comparison with a library of plausibly descendants shows that JKCS041 pressure profile will likely increase by about 0.7 dex in the next 10 Gyr at all radii., Comment: MNRAS, in press

Published
2023
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28. First Detection of the BAO Signal from Early DESI Data

Author

Moon, Jeongin, Valcin, David, Rashkovetskyi, Michael, Saulder, Christoph, Aguilar, Jessica Nicole, Ahlen, Steven, Alam, Shadab, Bailey, Stephen, Baltay, Charles, Blum, Robert, Brooks, David, Burtin, Etienne, Chaussidon, Edmond, Dawson, Kyle, de la Macorra, Axel, de Mattia, Arnaud, Dhungana, Govinda, Eisenstein, Daniel, Flaugher, Brenna, Font-Ribera, Andreu, Forero-Romero, Jaime E., Garcia-Quintero, Cristhian, Gontcho, Satya Gontcho A, Guy, Julien, Hanif, Malik Muhammad Sikandar, Honscheid, Klaus, Ishak, Mustapha, Kehoe, Robert, Kim, Sumi, Kisner, Theodore, Kremin, Anthony, Landriau, Martin, Guillou, Laurent Le, Levi, Michael, Manera, Marc, Martini, Paul, McDonald, Patrick, Meisner, Aaron, Miquel, Ramon, Moustakas, John, Myers, Adam, Nadathur, Seshadri, Neveux, Richard, Newman, Jeffrey A., Nie, Jundan, Padmanabhan, Nikhil, Palanque-Delabrouille, Nathalie, Percival, Will, Fernández, Alejandro Pérez, Poppett, Claire, Prada, Francisco, Raichoor, Anand, Ross, Ashley J., Rossi, Graziano, Samushia, Lado, Schlegel, David, Seo, Hee-Jong, Tarlé, Gregory, Magana, Mariana Vargas, Variu, Andrei, Weaver, Benjamin Alan, White, Martin J., Yèche, Christophe, Yuan, Sihan, Zhao, Cheng, Zhou, Rongpu, Zhou, Zhimin, and Zou, Hu

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present the first detection of the baryon acoustic oscillations (BAO) signal obtained using unblinded data collected during the initial two months of operations of the Stage-IV ground-based Dark Energy Spectroscopic Instrument (DESI). From a selected sample of 261,291 Luminous Red Galaxies spanning the redshift interval 0.4 < z < 1.1 and covering 1651 square degrees with a 57.9% completeness level, we report a ~5 sigma level BAO detection and the measurement of the BAO location at a precision of 1.7%. Using a Bright Galaxy Sample of 109,523 galaxies in the redshift range 0.1 < z < 0.5, over 3677 square degrees with a 50.0% completeness, we also detect the BAO feature at ~3 sigma significance with a 2.6% precision. These first BAO measurements represent an important milestone, acting as a quality control on the optimal performance of the complex robotically-actuated, fiber-fed DESI spectrograph, as well as an early validation of the DESI spectroscopic pipeline and data management system. Based on these first promising results, we forecast that DESI is on target to achieve a high-significance BAO detection at sub-percent precision with the completed 5-year survey data, meeting the top-level science requirements on BAO measurements. This exquisite level of precision will set new standards in cosmology and confirm DESI as the most competitive BAO experiment for the remainder of this decade., Comment: 17 pages, 10 figures, 4 tables. MNRAS, 525, 5406. Author accepted manuscript matching the published version

Published
2023
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29. Abundance matching analysis of the emission line galaxy sample in the extended Baryon Oscillation Spectroscopic Survey

Author

Lin, Sicheng, Tinker, Jeremy L., Blanton, Michael R., Guo, Hong, Raichoor, Anand, Comparat, Johan, and Brownstein, Joel R.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present the measurements of the small-scale clustering for the emission line galaxy (ELG) sample from the extended Baryon Oscillation Spectroscopic Survey (eBOSS) in the Sloan Digital Sky Survey IV (SDSS-IV). We use conditional abundance matching method to interpret the clustering measurements from $0.34h^{-1}\textrm{Mpc}$ to $70h^{-1}\textrm{Mpc}$. In order to account for the correlation between properties of emission line galaxies and their environment, we add a secondary connection between star formation rate of ELGs and halo accretion rate. Three parameters are introduced to model the ELG [OII] luminosity and to mimic the target selection of eBOSS ELGs. The parameters in our models are optimized using Markov Chain Monte Carlo (MCMC) method. We find that by conditionally matching star formation rate of galaxies and the halo accretion rate, we are able to reproduce the eBOSS ELG small scale clustering within 1$\sigma$ error level. Our best fit model shows that the eBOSS ELG sample only consists of $\sim 12\%$ of all star-forming galaxies, and the satellite fraction of eBOSS ELG sample is 19.3\%. We show that the effect of assembly bias is $\sim20\%$ on the two-point correlation function and $\sim5\%$ on the void probability function at scale of $r\sim 20 h^{-1}\rm Mpc$., Comment: MNRAS, Volume 519, Issue 3

Published
2023

30. The Spectroscopic Data Processing Pipeline for the Dark Energy Spectroscopic Instrument

Author

Guy, J, Bailey, S, Kremin, A, Alam, Shadab, Alexander, DM, Prieto, C Allende, BenZvi, S, Bolton, AS, Brooks, D, Chaussidon, E, Cooper, AP, Dawson, K, de la Macorra, A, Dey, A, Dey, Biprateep, Dhungana, G, Eisenstein, DJ, Font-Ribera, A, Forero-Romero, JE, Gaztañaga, E, Gontcho, S Gontcho A, Green, D, Honscheid, K, Ishak, M, Kehoe, R, Kirkby, D, Kisner, T, Koposov, Sergey E, Lan, Ting-Wen, Landriau, M, Le Guillou, L, Levi, Michael E, Magneville, C, Manser, Christopher J, Martini, P, Meisner, Aaron M, Miquel, R, Moustakas, J, Myers, Adam D, Newman, Jeffrey A, Nie, Jundan, Palanque-Delabrouille, N, Percival, WJ, Poppett, C, Prada, F, Raichoor, A, Ravoux, C, Ross, AJ, Schlafly, EF, Schlegel, D, Schubnell, M, Sharples, Ray M, Tarlé, Gregory, Weaver, BA, Yéche, Christophe, Zhou, Rongpu, Zhou, Zhimin, and Zou, H

Subjects
Nuclear and Plasma Physics, Physical Sciences, Affordable and Clean Energy, Astronomical and Space Sciences, Astronomy & Astrophysics, Astronomical sciences, Particle and high energy physics
Abstract

We describe the spectroscopic data processing pipeline of the Dark Energy Spectroscopic Instrument (DESI), which is conducting a redshift survey of about 40 million galaxies and quasars using a purpose-built instrument on the 4 m Mayall Telescope at Kitt Peak National Observatory. The main goal of DESI is to measure with unprecedented precision the expansion history of the universe with the baryon acoustic oscillation technique and the growth rate of structure with redshift space distortions. Ten spectrographs with three cameras each disperse the light from 5000 fibers onto 30 CCDs, covering the near-UV to near-infrared (3600-9800 Å) with a spectral resolution ranging from 2000 to 5000. The DESI data pipeline generates wavelength- and flux-calibrated spectra of all the targets, along with spectroscopic classifications and redshift measurements. Fully processed data from each night are typically available to the DESI collaboration the following morning. We give details about the pipeline's algorithms, and provide performance results on the stability of the optics, the quality of the sky background subtraction, and the precision and accuracy of the instrumental calibration. This pipeline has been used to process the DESI Survey Validation data set, and has exceeded the project's requirements for redshift performance, with high efficiency and a purity greater than 99% for all target classes.

Published
2023

31. The Spectroscopic Data Processing Pipeline for the Dark Energy Spectroscopic Instrument

Author

Guy, J., Bailey, S., Kremin, A., Alam, Shadab, Alexander, D. M., Prieto, C. Allende, BenZvi, S., Bolton, A. S., Brooks, D., Chaussidon, E., Cooper, A. P., Dawson, K., de la Macorra, A., Dey, A., Dey, Biprateep, Dhungana, G., Eisenstein, D. J., Font-Ribera, A., Forero-Romero, J. E., Gaztañaga, E., Gontcho, S. Gontcho A, Green, D., Honscheid, K., Ishak, M., Kehoe, R., Kirkby, D., Kisner, T., Koposov, Sergey E., Lan, Ting-Wen, Landriau, M., Guillou, L. Le, Levi, Michael E., Magneville, C., Manser, Christopher J., Martini, P., Meisner, Aaron M., Miquel, R., Moustakas, J., Myers, Adam D., Newman, Jeffrey A., Nie, Jundan, Palanque-Delabrouille, N., Percival, W. J., Poppett, C., Prada, F., Raichoor, A., Ravoux, C., Ross, A. J., Schlafly, E. F., Schlegel, D., Schubnell, M., Sharples, Ray M., Tarlé, Gregory, Weaver, B. A., Yèche, Christophe, Zhou, Rongpu, Zhou, Zhimin, and Zou, H.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We describe the spectroscopic data processing pipeline of the Dark Energy Spectroscopic Instrument (DESI), which is conducting a redshift survey of about 40 million galaxies and quasars using a purpose-built instrument on the 4-m Mayall Telescope at Kitt Peak National Observatory. The main goal of DESI is to measure with unprecedented precision the expansion history of the Universe with the Baryon Acoustic Oscillation technique and the growth rate of structure with Redshift Space Distortions. Ten spectrographs with three cameras each disperse the light from 5000 fibers onto 30 CCDs, covering the near UV to near infrared (3600 to 9800 Angstrom) with a spectral resolution ranging from 2000 to 5000. The DESI data pipeline generates wavelength- and flux-calibrated spectra of all the targets, along with spectroscopic classifications and redshift measurements. Fully processed data from each night are typically available to the DESI collaboration the following morning. We give details about the pipeline's algorithms, and provide performance results on the stability of the optics, the quality of the sky background subtraction, and the precision and accuracy of the instrumental calibration. This pipeline has been used to process the DESI Survey Validation data set, and has exceeded the project's requirements for redshift performance, with high efficiency and a purity greater than 99 percent for all target classes., Comment: AJ, revised version, 55 pages, 55 figures, 4 tables

Published
2022
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32. The MegaMapper: A Stage-5 Spectroscopic Instrument Concept for the Study of Inflation and Dark Energy

Author

Schlegel, David J., Kollmeier, Juna A., Aldering, Greg, Bailey, Stephen, Baltay, Charles, Bebek, Christopher, BenZvi, Segev, Besuner, Robert, Blanc, Guillermo, Bolton, Adam S., Bonaca, Ana, Bouri, Mohamed, Brooks, David, Buckley-Geer, Elizabeth, Cai, Zheng, Crane, Jeffrey, Demina, Regina, DeRose, Joseph, Dey, Arjun, Doel, Peter, Fan, Xiaohui, Ferraro, Simone, Finkbeiner, Douglas, Font-Ribera, Andreu, Gontcho, Satya Gontcho A, Green, Daniel, Gutierrez, Gaston, Guy, Julien, Heetderks, Henry, Huterer, Dragan, Infante, Leopoldo, Jelinsky, Patrick, Karagiannis, Dionysios, Kent, Stephen M., Kim, Alex G., Kneib, Jean-Paul, Kremin, Anthony, Kronig, Luzius, Konidaris, Nick, Lahav, Ofer, Lampton, Michael L., Landriau, Martin, Lang, Dustin, Leauthaud, Alexie, Levi, Michael E., Liguori, Michele, Linder, Eric V., Magneville, Christophe, Martini, Paul, Mateo, Mario, McDonald, Patrick, Miller, Christopher J., Moustakas, John, Myers, Adam D., Mulchaey, John, Newman, Jeffrey A., Nugent, Peter E., Padmanabhan, Nikhil, Palanque-Delabrouille, Nathalie, Piro, Antonella Palmese Anthony L., Poppett, Claire, Prochaska, Jason X., Pullen, Anthony R., Rabinowitz, David, Raichoor, Anand, Ramirez, Solange, Rix, Hans-Walter, Ross, Ashley J., Samushia, Lado, Schaan, Emmanuel, Schubnell, Michael, Seljak, Uros, Seo, Hee-Jong, Shectman, Stephen A., Schlafly, Edward F., Silber, Joseph, Simon, Joshua D., Slepian, Zachary, Slosar, Anže, Soares-Santos, Marcelle, Tarlé, Greg, Thompson, Ian, Valluri, Monica, Wechsler, Risa H., White, Martin, Wilson, Michael J., Yèche, Christophe, Zaritsky, Dennis, and Zhou, Rongpu

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, High Energy Physics - Experiment
Abstract

In this white paper, we present the MegaMapper concept. The MegaMapper is a proposed ground-based experiment to measure Inflation parameters and Dark Energy from galaxy redshifts at $2

Published
2022

33. A Spectroscopic Road Map for Cosmic Frontier: DESI, DESI-II, Stage-5

Author

Schlegel, David J., Ferraro, Simone, Aldering, Greg, Baltay, Charles, BenZvi, Segev, Besuner, Robert, Blanc, Guillermo A., Bolton, Adam S., Bonaca, Ana, Brooks, David, Buckley-Geer, Elizabeth, Cai, Zheng, DeRose, Joseph, Dey, Arjun, Doel, Peter, Drlica-Wagner, Alex, Fan, Xiaohui, Gutierrez, Gaston, Green, Daniel, Guy, Julien, Huterer, Dragan, Infante, Leopoldo, Jelinsky, Patrick, Karagiannis, Dionysios, Kent, Stephen M., Kim, Alex G., Kneib, Jean-Paul, Kollmeier, Juna A., Kremin, Anthony, Lahav, Ofer, Landriau, Martin, Lang, Dustin, Leauthaud, Alexie, Levi, Michael E., Linder, Eric V., Magneville, Christophe, Martini, Paul, McDonald, Patrick, Miller, Christopher J., Myers, Adam D., Newman, Jeffrey A., Nugent, Peter E., Palanque-Delabrouille, Nathalie, Padmanabhan, Nikhil, Palmese, Antonella, Poppett, Claire, Prochaska, Jason X., Raichoor, Anand, Ramirez, Solange, Sailer, Noah, Schaan, Emmanuel, Schubnell, Michael, Seljak, Uros, Seo, Hee-Jong, Silber, Joseph, Simon, Joshua D., Slepian, Zachary, Soares-Santos, Marcelle, Tarle, Greg, Valluri, Monica, Weaverdyck, Noah J., Wechsler, Risa H., White, Martin, Yeche, Christophe, and Zhou, Rongpu

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, High Energy Physics - Experiment
Abstract

In this white paper, we present an experimental road map for spectroscopic experiments beyond DESI. DESI will be a transformative cosmological survey in the 2020s, mapping 40 million galaxies and quasars and capturing a significant fraction of the available linear modes up to z=1.2. DESI-II will pilot observations of galaxies both at much higher densities and extending to higher redshifts. A Stage-5 experiment would build out those high-density and high-redshift observations, mapping hundreds of millions of stars and galaxies in three dimensions, to address the problems of inflation, dark energy, light relativistic species, and dark matter. These spectroscopic data will also complement the next generation of weak lensing, line intensity mapping and CMB experiments and allow them to reach their full potential., Comment: Contribution to Snowmass 2021

Published
2022

34. DESI Observations of the Andromeda Galaxy: Revealing the Immigration History of our Nearest Neighbor

Author

Dey, Arjun, Najita, Joan R., Koposov, S. E., Josephy-Zack, J., Maxemin, Gabriel, Bell, Eric F., Poppett, C., Patel, E., Silva, L. Beraldo e, Raichoor, A., Schlegel, D., Lang, D., Meisner, A., Myers, Adam D., Aguilar, J., Ahlen, S., Prieto, C. Allende, Brooks, D., Cooper, A. P., Dawson, K. S., de la Macorra, A., Doel, P., Font-Ribera, A., Garcia-Bellido, Juan, Gontcho, S. Gontcho A, Guy, J., Honscheid, K., Kehoe, R., Kisner, T., Kremin, A., Landriau, M., Guillou, L. Le, Levi, Michael E., Li, T. S., Martini, Paul, Miquel, R., Moustakas, J., Nie, Jundan, Palanque-Delabrouille, N., Prada, F., Schlafly, E. F., Sharples, Ray M., Tarle, Gregory, Ting, Yuan-Sen, Tyas, L., Valluri, M., Wechsler, Risa H., and Zou, H.

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present DESI observations of the inner halo of M31, which reveal the kinematics of a recent merger - a galactic immigration event - in exquisite detail. Of the 11,416 sources studied in 3.75 hour of on-sky exposure time, 7,438 are M31 sources with well measured radial velocities. The observations reveal intricate coherent kinematic structure in the positions and velocities of individual stars: streams, wedges, and chevrons. While hints of coherent structures have been previously detected in M31, this is the first time they have been seen with such detail and clarity in a galaxy beyond the Milky Way. We find clear kinematic evidence for shell structures in the Giant Stellar Stream, the Northeast Shelf and Western Shelf regions. The kinematics are remarkably similar to the predictions of dynamical models constructed to explain the spatial morphology of the inner halo. The results are consistent with the interpretation that much of the substructure in the inner halo of M31 is produced by a single galactic immigration event 1 - 2 Gyr ago. Significant numbers of metal-rich stars ([Fe/H]$>-0.5$) are present in all of the detected substructures, suggesting that the immigrating galaxy had an extended star formation history. We also investigate the ability of the shells and Giant Stellar Stream to constrain the gravitational potential of M31, and estimate the mass within a projected radius of 125 kpc to be ${\rm log_{10}}\, M_{\rm NFW}(<125\,{\rm kpc})/M_\odot = 11.80_{-0.10}^{+0.12}$. The results herald a new era in our ability to study stars on a galactic scale and the immigration histories of galaxies., Comment: 45 pages, 22 figures, 8 tables; Astrophysical Journal in press; Data at https://zenodo.org/record/6977494

Published
2022
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35. The Target-selection Pipeline for the Dark Energy Spectroscopic Instrument

Author

Myers, Adam D., Moustakas, John, Bailey, Stephen, Weaver, Benjamin A., Cooper, Andrew P., Forero-Romero, Jaime E., Abolfathi, Bela, Alexander, David M., Brooks, David, Chaussidon, Edmond, Chuang, Chia-Hsun, Dawson, Kyle, Dey, Arjun, Dey, Biprateep, Dhungana, Govinda, Doel, Peter, Fanning, Kevin, Gaztañaga, Enrique, Gontcho, Satya Gontcho A, Gonzalez-Morales, Alma X., Hahn, ChangHoon, Herrera-Alcantar, Hiram K., Honscheid, Klaus, Ishak, Mustapha, Karim, Tanveer, Kirkby, David, Kisner, Theodore, Koposov, Sergey E., Kremin, Anthony, Lan, Ting-Wen, Landriau, Martin, Lang, Dustin, Levi, Michael E., Magneville, Christophe, Napolitano, Lucas, Martini, Paul, Meisner, Aaron, Newman, Jeffrey A., Palanque-Delabrouille, Nathalie, Percival, Will, Poppett, Claire, Prada, Francisco, Raichoor, Anand, Ross, Ashley J., Schlafly, Edward F., Schlegel, David, Schubnell, Michael, Tan, Ting, Tarle, Gregory, Wilson, Michael J., Yèche, Christophe, Zhou, Rongpu, Zhou, Zhimin, and Zou, Hu

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

In 2021 May, the Dark Energy Spectroscopic Instrument (DESI) began a 5 yr survey of approximately 50 million total extragalactic and Galactic targets. The primary DESI dark-time targets are emission line galaxies (ELGs), luminous red galaxies (LRGs) and quasars (QSOs). In bright time, DESI will focus on two surveys known as the Bright Galaxy Survey (BGS) and the Milky Way Survey (MWS). DESI also observes a selection of "secondary" targets for bespoke science goals. This paper gives an overview of the publicly available pipeline (desitarget) used to process targets for DESI observations. Highlights include details of the different DESI survey targeting phases, the targeting ID (TARGETID) used to define unique targets, the bitmasks used to indicate a particular type of target, the data model and structure of DESI targeting files, and examples of how to access and use the desitarget code base. This paper will also describe "supporting" DESI target classes, such as standard stars, sky locations, and random catalogs that mimic the angular selection function of DESI targets. The DESI target selection pipeline is complex and sizable; this paper attempts to summarize the most salient information required to understand and work with DESI targeting data., Comment: AJ, accepted, 27 pages, 4 figures, 10 tables, one of a suite of 8 papers detailing targeting for DESI. Minor textual updates to better match the final, accepted version. Also added two missing co-authors

Published
2022
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36. The DESI Survey Validation: Results from Visual Inspection of Bright Galaxies, Luminous Red Galaxies, and Emission Line Galaxies

Author

Lan, Ting-Wen, Tojeiro, R., Armengaud, E., Prochaska, J. Xavier, Davis, T. M., Alexander, David M., Raichoor, A., Zhou, Rongpu, Yeche, Christophe, Balland, C., BenZvi, S., Berti, A., Canning, R., Carr, A., Chittenden, H., Cole, S., Cousinou, M. -C., Dawson, K., Dey, Biprateep, Douglass, K., Edge, A., Escoffier, S., Glanville, A., Gontcho, S. Gontcho A, Guy, J., Hahn, C., Howlett, C., Hwang, Ho Seong, Jiang, L., Kovacs, A., Mezcua, M., Moore, S., Nadathur, S., Oh, M., Parkinson, D., Rocher, A., Ross, A. J., Ruhlmann-Kleider, V., Sabiu, C. G., Said, K., Saulder, C., Sierra-Porta, D., Weiner, B., Yu, J., Zarrouk, P., Zhang, Y., Zou, H., Ahlen, S., Bailey, S., Brooks, D., Cooper, A. P., de la Macorra, A., Dey, A., Dhungana, G., Doel, P., Eftekharzadeh, S., Fanning, K., Font-Ribera, A., Garrison, L., Gaztanaga, E., Kehoe, R., Kisner, T., Kremin, A., Landriau, M., Guillou, L. Le, Levi, Michael E., Magneville, C., Meisner, Aaron M., Miquel, R., Moustakas, J., Myers, Adam D., Newman, Jeffrey A., Nie, J. D., Palanque-Delabrouille, N., Percival, W. J., Poppett, C., Prada, F., Schubnell, M., Tarle, Gregory, Weaver, B. A., Zhang, K., and Zhou, Zhimin

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

The Dark Energy Spectroscopic Instrument (DESI) Survey has obtained a set of spectroscopic measurements of galaxies to validate the final survey design and target selections. To assist in these tasks, we visually inspect (VI) DESI spectra of approximately 2,500 bright galaxies, 3,500 luminous red galaxies (LRGs), and 10,000 emission line galaxies (ELGs), to obtain robust redshift identifications. We then utilize the VI redshift information to characterize the performance of the DESI operation. Based on the VI catalogs, our results show that the final survey design yields samples of bright galaxies, LRGs, and ELGs with purity greater than $99\%$. Moreover, we demonstrate that the precision of the redshift measurements is approximately 10 km/s for bright galaxies and ELGs and approximately 40 km/s for LRGs. The average redshift accuracy is within 10 km/s for the three types of galaxies. The VI process also helps improve the quality of the DESI data by identifying spurious spectral features introduced by the pipeline. Finally, we show examples of unexpected real astronomical objects, such as Ly$\alpha$ emitters and strong lensing candidates, identified by VI. These results demonstrate the importance and utility of visually inspecting data from incoming and upcoming surveys, especially during their early operation phases., Comment: 22 pages, 14 figures, 3 tables, one of a suite of 8 papers detailing targeting for DESI. ApJ accepted version with minor textual updates

Published
2022
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37. Target Selection and Validation of DESI Luminous Red Galaxies

Author

Zhou, Rongpu, Dey, Biprateep, Newman, Jeffrey A., Eisenstein, Daniel J., Dawson, K., Bailey, S., Berti, A., Guy, J., Lan, Ting-Wen, Zou, H., Aguilar, J., Ahlen, S., Alam, Shadab, Brooks, D., de la Macorra, A., Dey, A., Dhungana, G., Fanning, K., Font-Ribera, A., Gontcho, S. Gontcho A, Honscheid, K., Ishak, Mustapha, Kisner, T., Kovács, A., Kremin, A., Landriau, M., Levi, Michael E., Magneville, C., Manera, Marc, Martini, P., Meisner, Aaron M., Miquel, R., Moustakas, J., Myers, Adam D., Nie, Jundan, Palanque-Delabrouille, N., Percival, W. J., Poppett, C., Prada, F., Raichoor, A., Ross, A. J., Schlafly, E., Schlegel, D., Schubnell, M., Tarlé, Gregory, Weaver, B. A., Wechsler, R. H., Yèche, Christophe, and Zhou, Zhimin

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

The Dark Energy Spectroscopic Instrument (DESI) is carrying out a 5-year survey that aims to measure the redshifts of tens of millions of galaxies and quasars, including 8 million luminous red galaxies (LRGs) in the redshift range of $0.4

Published
2022
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38. Overview of the DESI Milky Way Survey

Author

Cooper, Andrew P., Koposov, Sergey E., Prieto, Carlos Allende, Manser, Christopher J., Kizhuprakkat, Namitha, Myers, Adam D., Dey, Arjun, Gaensicke, Boris T., Li, Ting S., Rockosi, Constance, Valluri, Monica, Najita, Joan, Deason, Alis, Raichoor, Anand, Wang, Mei-Yu, Ting, Yuan-Sen, Kim, Bokyoung, Carrillo, Andreia, Wang, Wenting, Silva, Leandro Beraldo e, Han, Jiwon Jesse, Ding, Jiani, Sanchez-Conde, Miguel, Aguilar, Jessica N., Ahlen, Steven, Bailey, Stephen, Belokurov, Vasily, Brooks, David, Cunha, Katia, Dawson, Kyle, de la Macorra, Axel, Doel, Peter, Eisenstein, Daniel J., Fagrelius, Parker, Fanning, Kevin, Font-Ribera, Andreu, Forero-Romero, Jaime E., Gaztanaga, Enrique, Gontcho, Satya Gontcho A, Guy, Julien, Honscheid, Klaus, Kehoe, Robert, Kisner, Theodore, Kremin, Anthony, Landriau, Martin, Levi, Michael E., Martini, Paul, Meisner, Aaron M., Miquel, Ramon, Moustakas, John, Nie, Jundan, Palanque-Delabrouille, Nathalie, Percival, Will J., Poppett, Claire, Prada, Francisco, Rehemtulla, Nabeel, Schlafly, Edward, Schlegel, David, Schubnell, Michael, Sharples, Ray M., Tarle, Gregory, Wechsler, Risa H., Weinberg, David H., Zhou, Zhimin, and Zou, Hu

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We describe the Milky Way Survey (MWS) that will be undertaken with the Dark Energy Spectroscopic Instrument (DESI) on the Mayall 4m telescope at the Kitt Peak National Observatory. Over the next 5 yr DESI MWS will observe approximately seven million stars at Galactic latitudes |b|>20 degrees, with an inclusive target selection scheme focused on the thick disk and stellar halo. MWS will also include several high-completeness samples of rare stellar types, including white dwarfs, low-mass stars within 100pc of the Sun, and horizontal branch stars. We summarize the potential of DESI to advance understanding of Galactic structure and stellar evolution. We introduce the final definitions of the main MWS target classes and estimate the number of stars in each class that will be observed. We describe our pipelines for deriving radial velocities, atmospheric parameters, and chemical abundances. We use ~500,000 spectra of unique stellar targets from the DESI Survey Validation program (SV) to demonstrate that our pipelines can measure radial velocities to ~1 km/s and [Fe/H] accurate to ~0.2 dex for typical stars in our main sample. We find the stellar parameter distributions from ~100 sq. deg of SV observations with >90% completeness on our main sample are in good agreement with expectations from mock catalogs and previous surveys., Comment: Accepted for publication in ApJ, 44 pages, 25 figures, 4 tables, one of a suite of 8 papers detailing targeting for DESI; v2 added links to data shown in figures, added citations to other DESI papers, corrected author list and minor typos; v3 fixed minor errors in Fig. 6 and clarified associated text; v4 updated to include minor changes in response to review

Published
2022
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39. Target Selection and Validation of DESI Emission Line Galaxies

Author

Raichoor, A., Moustakas, J., Newman, Jeffrey A., Karim, T., Ahlen, S., Alam, Shadab, Bailey, S., Brooks, D., Dawson, K., de la Macorra, A., de Mattia, A., Dey, A., Dey, Biprateep, Dhungana, G., Eftekharzadeh, S., Eisenstein, D. J., Fanning, K., Font-Ribera, A., Garcia-Bellido, J., Gaztanaga, E., Gontcho, S. Gontcho A, Guy, J., Honscheid, K., Ishak, M., Kehoe, R., Kisner, T., Kremin, A., Lan, Ting-Wen, Landriau, M., Guillou, L. Le, Levi, Michael E., Magneville, C., Martini, P., Meisner, Aaron M., Myers, Adam D., Nie, Jundan, Palanque-Delabrouille, N., Percival, W. J., Poppett, C., Prada, F., Ross, A. J., Ruhlmann-Kleider, V., Sabiu, C. G., Schlafly, E. F., Schlegel, D., Tarle, Gregory, Weaver, B. A., Yeche, Christophe, Zhou, Rongpu, Zhou, Zhimin, and Zou, H.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The Dark Energy Spectroscopic Instrument (DESI) will precisely constrain cosmic expansion and the growth of structure by collecting $\sim$40 million extra-galactic redshifts across $\sim$80\% of cosmic history and one third of the sky. The Emission Line Galaxy (ELG) sample, which will comprise about one-third of all DESI tracers, will be used to probe the Universe over the $0.6 < z < 1.6$ range, which includes the $1.1

Published
2022
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40. DESI Bright Galaxy Survey: Final Target Selection, Design, and Validation

Author

Hahn, ChangHoon, Wilson, Michael J., Ruiz-Macias, Omar, Cole, Shaun, Weinberg, David H., Moustakas, John, Kremin, Anthony, Tinker, Jeremy L., Smith, Alex, Wechsler, Risa H., Ahlen, Steven, Alam, Shadab, Bailey, Stephen, Brooks, David, Cooper, Andrew P., Davis, Tamara M., Dawson, Kyle, Dey, Arjun, Dey, Biprateep, Eftekharzadeh, Sarah, Eisenstein, Daniel J., Fanning, Kevin, Forero-Romero, Jaime E., Frenk, Carlos S., Gaztañaga, Enrique, Gontcho, Satya Gontcho A, Guy, Julien, Honscheid, Klaus, Ishak, Mustapha, Juneau, Stéphanie, Kehoe, Robert, Kisner, Theodore, Lan, Ting-Wen, Landriau, Martin, Guillou, Laurent Le, Levi, Michael E., Magneville, Christophe, Martini, Paul, Meisner, Aaron, Myers, Adam D., Nie, Jundan, Norberg, Peder, Palanque-Delabrouille, Nathalie, Percival, Will J., Poppett, Claire, Prada, Francisco, Raichoor, Anand, Ross, Ashley J., Safonova, Sasha, Saulder, Christoph, Schlafly, Eddie, Schlegel, David, Sierra-Porta, David, Tarle, Gregory, Weaver, Benjamin A., Yèche, Christophe, Zarrouk, Pauline, Zhou, Rongpu, Zhou, Zhimin, and Zou, Hu

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

Over the next five years, the Dark Energy Spectroscopic Instrument (DESI) will use 10 spectrographs with 5000 fibers on the 4m Mayall Telescope at Kitt Peak National Observatory to conduct the first Stage-IV dark energy galaxy survey. At $z < 0.6$, the DESI Bright Galaxy Survey (BGS) will produce the most detailed map of the Universe during the dark energy dominated epoch with redshifts of >10 million galaxies over 14,000 deg$^2$. In this work, we present and validate the final BGS target selection and survey design. From the Legacy Surveys, BGS will target a $r < 19.5$ magnitude-limited sample (BGS Bright); a fainter $19.5 < r < 20.175$ sample, color-selected to have high redshift efficiency (BGS Faint); and a smaller low-z quasar sample. BGS will observe these targets using exposure times, scaled to achieve uniform completeness, and visit each point on the footprint three times. We use observations from the Survey Validation programs conducted prior to the main survey along with realistic simulations to show that BGS can complete its strategy and make optimal use of `bright' time. We demonstrate that BGS targets have stellar contamination <1% and that their densities do not depend strongly on imaging properties. We also confirm that BGS Bright will achieve >80% fiber assignment efficiency. Finally, we show that BGS Bright and Faint will achieve >95% redshift success rates with no significant dependence on observing conditions. BGS meets the requirements for an extensive range of scientific applications. BGS will yield the most precise Baryon Acoustic Oscillations and Redshift-Space Distortions measurements at $z < 0.4$. It also presents opportunities to exploit new methods that require highly complete and dense galaxy samples (e.g. N-point statistics, multi-tracers). BGS further provides a powerful tool to study galaxy populations and the relations between galaxies and dark matter., Comment: AJ, submitted, 34 pages, 22 figures, one of a suite of 8 papers detailing targeting for DESI

Published
2022
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41. Target Selection and Validation of DESI Quasars

Author

Chaussidon, Edmond, Yèche, Christophe, Palanque-Delabrouille, Nathalie, Alexander, David M., Yang, Jinyi, Ahlen, Steven, Bailey, Stephen., Brooks, David, Cai, Zheng, Chabanier, Solène, Davis, Tamara M., Dawson, Kyle, de la Macorra, Axel, Dey, Arjun, Dey, Biprateep, Eftekharzadeh, Sarah, Eisenstein, Daniel J., Fanning, Kevin, Font-Ribera, Andreu, Gaztañaga, Enrique, Gontcho, Satya Gontcho A, Gonzalez-Morales, Alma X., Guy, Julien, Herrera-Alcantar, Hiram K., Honscheid, Klaus, Ishak, Mustapha, Jiang, Linhua, Juneau, Stephanie, Kehoe, Robert, Kisner, Theodore, Kovács, Andras, Kremin, Anthony, Lan, Ting-Wen, Landriau, Martin, Guillou, Laurent Le, Levi, Michael E., Magneville, Christophe, Martini, Paul, Meisner, Aaron M., Moustakas, John, Muñoz-Gutiérrez, Andrea, Myers, Adam D., Newman, Jeffrey A., Nie, Jundan, Percival, Will J., Poppett, Claire, Prada, Francisco, Raichoor, Anand, Ravoux, Corentin, Ross, Ashley J., Schlafly, Edward, Schlegel, David, Tan, Ting, Tarlé, Gregory, Zhou, Rongpu, Zhou, Zhimin, and Zou, Hu

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The Dark Energy Spectroscopic Instrument (DESI) survey will measure large-scale structures using quasars as direct tracers of dark matter in the redshift range 0.92.1. We present several methods to select candidate quasars for DESI, using input photometric imaging in three optical bands (g, r, z) from the DESI Legacy Imaging Surveys and two infrared bands (W1, W2) from the Wide-field Infrared Explorer (WISE). These methods were extensively tested during the Survey Validation of DESI. In this paper, we report on the results obtained with the different methods and present the selection we optimized for the DESI main survey. The final quasar target selection is based on a Random Forest algorithm and selects quasars in the magnitude range 16.599% purity for a nominal effective exposure time of ~1000s. With a 310 per sq. deg. target density, the main selection allows DESI to select more than 200 QSOs per sq. deg. (including 60 quasars with z>2.1), exceeding the project requirements by 20%. The redshift distribution of the selected quasars is in excellent agreement with quasar luminosity function predictions., Comment: 21 pages, 21 figures, typos corrected, references added

Published
2022
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42. Target Selection and Validation of DESI Emission Line Galaxies

Author

Raichoor, A, Moustakas, J, Newman, Jeffrey A, Karim, T, Ahlen, S, Alam, Shadab, Bailey, S, Brooks, D, Dawson, K, de la Macorra, A, de Mattia, A, Dey, A, Dey, Biprateep, Dhungana, G, Eftekharzadeh, S, Eisenstein, DJ, Fanning, K, Font-Ribera, A, García-Bellido, J, Gaztañaga, E, Gontcho, S Gontcho A, Guy, J, Honscheid, K, Ishak, M, Kehoe, R, Kisner, T, Kremin, Anthony, Lan, Ting-Wen, Landriau, M, Le Guillou, L, Levi, Michael E, Magneville, C, Manera, M, Martini, P, Meisner, Aaron M, Myers, Adam D, Nie, Jundan, Palanque-Delabrouille, N, Percival, WJ, Poppett, C, Prada, F, Ross, AJ, Ruhlmann-Kleider, V, Sabiu, CG, Schlafly, EF, Schlegel, D, Tarlé, Gregory, Weaver, BA, Yèche, Christophe, Zhou, Rongpu, Zhou, Zhimin, and Zou, H

Subjects
Space Sciences, Physical Sciences, Astronomical and Space Sciences, Astronomy & Astrophysics, Astronomical sciences, Particle and high energy physics
Abstract

The Dark Energy Spectroscopic Instrument (DESI) will precisely constrain cosmic expansion and the growth of structure by collecting ∼40 million extragalactic redshifts across ∼80% of cosmic history and one-third of the sky. The Emission Line galaxy (ELG) sample, which will comprise about one-third of all DESI tracers, will be used to probe the universe over the 0.6 < z < 1.6 range, including the 1.1 < z < 1.6 range, which is expected to provide the tightest constraints. We present the target selection for the DESI Survey Validation (SV) and Main Survey ELG samples, which relies on the imaging of the Legacy Surveys. The Main ELG selection consists of a g-band magnitude cut and a (g − r) versus (r − z) color box, while the SV selection explores extensions of the Main selection boundaries. The Main ELG sample is composed of two disjoint subsamples, which have target densities of about 1940 deg−2 and 460 deg−2, respectively. We first characterize their photometric properties and density variations across the footprint. We then analyze the DESI spectroscopic data that have been obtained from 2020 December to 2021 December in the SV and Main Survey. We establish a preliminary criterion for selecting reliable redshifts, based on the [O ii] flux measurement, and assess its performance. Using this criterion, we are able to present the spectroscopic efficiency of the Main ELG selection, along with its redshift distribution. We thus demonstrate that the Main selection 1940 deg−2 subsample alone should provide 400 deg−2 and 460 deg−2 reliable redshifts in the 0.6 < z < 1.1 and the 1.1 < z < 1.6 ranges, respectively.

Published
2023

43. Target Selection and Validation of DESI Quasars

Author

Chaussidon, Edmond, Yèche, Christophe, Palanque-Delabrouille, Nathalie, Alexander, David M, Yang, Jinyi, Ahlen, Steven, Bailey, Stephen, Brooks, David, Cai, Zheng, Chabanier, Solène, Davis, Tamara M, Dawson, Kyle, de laMacorra, Axel, Dey, Arjun, Dey, Biprateep, Eftekharzadeh, Sarah, Eisenstein, Daniel J, Fanning, Kevin, Font-Ribera, Andreu, Gaztañaga, Enrique, Gontcho, Satya Gontcho A, Gonzalez-Morales, Alma X, Guy, Julien, Herrera-Alcantar, Hiram K, Honscheid, Klaus, Ishak, Mustapha, Jiang, Linhua, Juneau, Stephanie, Kehoe, Robert, Kisner, Theodore, Kovács, Andras, Kremin, Anthony, Lan, Ting-Wen, Landriau, Martin, Le Guillou, Laurent, Levi, Michael E, Magneville, Christophe, Martini, Paul, Meisner, Aaron M, Moustakas, John, Muñoz-Gutiérrez, Andrea, Myers, Adam D, Newman, Jeffrey A, Nie, Jundan, Percival, Will J, Poppett, Claire, Prada, Francisco, Raichoor, Anand, Ravoux, Corentin, Ross, Ashley J, Schlafly, Edward, Schlegel, David, Tan, Ting, Tarlé, Gregory, Zhou, Rongpu, Zhou, Zhimin, and Zou, Hu

Subjects
Space Sciences, Physical Sciences, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics, Astronomical sciences, Particle and high energy physics, Space sciences
Abstract

The Dark Energy Spectroscopic Instrument (DESI) survey will measure large-scale structures using quasars as direct tracers of dark matter in the redshift range 0.9 < z < 2.1 and using Lyα forests in quasar spectra at z > 2.1. We present several methods to select candidate quasars for DESI, using input photometric imaging in three optical bands (g, r, z) from the DESI Legacy Imaging Surveys and two infrared bands (W1, W2) from the Wide-field Infrared Survey Explorer. These methods were extensively tested during the Survey Validation of DESI. In this paper, we report on the results obtained with the different methods and present the selection we optimized for the DESI main survey. The final quasar target selection is based on a random forest algorithm and selects quasars in the magnitude range of 16.5 < r < 23. Visual selection of ultra-deep observations indicates that the main selection consists of 71% quasars, 16% galaxies, 6% stars, and 7% inconclusive spectra. Using the spectra based on this selection, we build an automated quasar catalog that achieves a fraction of true QSOs higher than 99% for a nominal effective exposure time of ∼1000 s. With a 310 deg−2 target density, the main selection allows DESI to select more than 200 deg−2 quasars (including 60 deg−2 quasars with z > 2.1), exceeding the project requirements by 20%. The redshift distribution of the selected quasars is in excellent agreement with quasar luminosity function predictions.

Published
2023

44. Target Selection and Validation of DESI Luminous Red Galaxies

Author

Zhou, Rongpu, Dey, Biprateep, Newman, Jeffrey A, Eisenstein, Daniel J, Dawson, K, Bailey, S, Berti, A, Guy, J, Lan, Ting-Wen, Zou, H, Aguilar, J, Ahlen, S, Alam, Shadab, Brooks, D, de la Macorra, A, Dey, A, Dhungana, G, Fanning, K, Font-Ribera, A, Gontcho, S Gontcho A, Honscheid, K, Ishak, Mustapha, Kisner, T, Kovács, A, Kremin, A, Landriau, M, Levi, Michael E, Magneville, C, Manera, Marc, Martini, P, Meisner, Aaron M, Miquel, R, Moustakas, J, Myers, Adam D, Nie, Jundan, Palanque-Delabrouille, N, Percival, WJ, Poppett, C, Prada, F, Raichoor, A, Ross, AJ, Schlafly, E, Schlegel, D, Schubnell, M, Tarlé, Gregory, Weaver, BA, Wechsler, RH, Yéche, Christophe, and Zhou, Zhimin

Subjects
Astronomical and Space Sciences, Astronomy & Astrophysics
Abstract

The Dark Energy Spectroscopic Instrument (DESI) is carrying out a five-year survey that aims to measure the redshifts of tens of millions of galaxies and quasars, including 8 million luminous red galaxies (LRGs) in the redshift range 0.4 < z ≲ 1.0. Here we present the selection of the DESI LRG sample and assess its spectroscopic performance using data from Survey Validation (SV) and the first two months of the Main Survey. The DESI LRG sample, selected using g, r, z, and W1 photometry from the DESI Legacy Imaging Surveys, is highly robust against imaging systematics. The sample has a target density of 605 deg−2 and a comoving number density of 5 × 10−4 h3 Mpc−3 in 0.4 < z < 0.8; this is a significantly higher density than previous LRG surveys (such as SDSS, BOSS, and eBOSS) while also extending to z ∼ 1. After applying a bright star veto mask developed for the sample, 98.9% of the observed LRG targets yield confident redshifts (with a catastrophic failure rate of 0.2% in the confident redshifts), and only 0.5% of the LRG targets are stellar contamination. The LRG redshift efficiency varies with source brightness and effective exposure time, and we present a simple model that accurately characterizes this dependence. In the appendices, we describe the extended LRG samples observed during SV.

Published
2023

45. The DESI Survey Validation: Results from Visual Inspection of Bright Galaxies, Luminous Red Galaxies, and Emission-line Galaxies

Author

Lan, Ting-Wen, Tojeiro, R, Armengaud, E, Prochaska, J Xavier, Davis, TM, Alexander, David M, Raichoor, A, Zhou, Rongpu, Yèche, Christophe, Balland, C, BenZvi, S, Berti, A, Canning, R, Carr, A, Chittenden, H, Cole, S, Cousinou, M-C, Dawson, K, Dey, Biprateep, Douglass, K, Edge, A, Escoffier, S, Glanville, A, Gontcho, S Gontcho A, Guy, J, Hahn, C, Howlett, C, Hwang, Ho Seong, Jiang, L, Kovács, A, Mezcua, M, Moore, S, Nadathur, S, Oh, M, Parkinson, D, Rocher, A, Ross, AJ, Ruhlmann-Kleider, V, Sabiu, CG, Said, K, Saulder, C, Sierra-Porta, D, Weiner, B, Yu, J, Zarrouk, P, Zhang, Y, Zou, H, Ahlen, S, Bailey, S, Brooks, D, Cooper, AP, de la Macorra, A, Dey, A, Dhungana, G, Doel, P, Eftekharzadeh, S, Fanning, K, Font-Ribera, A, Garrison, L, Gaztañaga, E, Kehoe, R, Kisner, T, Kremin, A, Landriau, M, Le Guillou, L, Levi, Michael E, Magneville, C, Meisner, Aaron M, Miquel, R, Moustakas, J, Myers, Adam D, Newman, Jeffrey A, Nie, JD, Palanque-Delabrouille, N, Percival, WJ, Poppett, C, Prada, F, Schubnell, M, Tarlé, Gregory, Weaver, BA, Zhang, K, and Zhou, Zhimin

Subjects
Astronomical Sciences, Physical Sciences, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics, Astronomical sciences, Particle and high energy physics, Space sciences
Abstract

The Dark Energy Spectroscopic Instrument (DESI) Survey has obtained a set of spectroscopic measurements of galaxies to validate the final survey design and target selections. To assist in these tasks, we visually inspect DESI spectra of approximately 2500 bright galaxies, 3500 luminous red galaxies (LRGs), and 10,000 emission-line galaxies (ELGs) to obtain robust redshift identifications. We then utilize the visually inspected redshift information to characterize the performance of the DESI operation. Based on the visual inspection (VI) catalogs, our results show that the final survey design yields samples of bright galaxies, LRGs, and ELGs with purity greater than 99%. Moreover, we demonstrate that the precision of the redshift measurements is approximately 10 km s−1 for bright galaxies and ELGs and approximately 40 km s−1 for LRGs. The average redshift accuracy is within 10 km s−1 for the three types of galaxies. The VI process also helps improve the quality of the DESI data by identifying spurious spectral features introduced by the pipeline. Finally, we show examples of unexpected real astronomical objects, such as Lyα emitters and strong lensing candidates, identified by VI. These results demonstrate the importance and utility of visually inspecting data from incoming and upcoming surveys, especially during their early operation phases.

Published
2023

46. Overview of the Instrumentation for the Dark Energy Spectroscopic Instrument

Author

Abareshi, B., Aguilar, J., Ahlen, S., Alam, Shadab, Alexander, David M., Alfarsy, R., Allen, L., Prieto, C. Allende, Alves, O., Ameel, J., Armengaud, E., Asorey, J., Aviles, Alejandro, Bailey, S., Balaguera-Antolínez, A., Ballester, O., Baltay, C., Bault, A., Beltran, S. F., Benavides, B., BenZvi, S., Berti, A., Besuner, R., Beutler, Florian, Bianchi, D., Blake, C., Blanc, P., Blum, R., Bolton, A., Bose, S., Bramall, D., Brieden, S., Brodzeller, A., Brooks, D., Brownewell, C., Buckley-Geer, E., Cahn, R. N., Cai, Z., Canning, R., Rosell, A. Carnero, Carton, P., Casas, R., Castander, F. J., Cervantes-Cota, J. L., Chabanier, S., Chaussidon, E., Chuang, C., Circosta, C., Cole, S., Cooper, A. P., da Costa, L., Cousinou, M. -C., Cuceu, A., Davis, T. M., Dawson, K., de la Cruz-Noriega, R., de la Macorra, A., de Mattia, A., Della Costa, J., Demmer, P., Derwent, M., Dey, A., Dey, B., Dhungana, G., Ding, Z., Dobson, C., Doel, P., Donald-McCann, J., Donaldson, J., Douglass, K., Duan, Y., Dunlop, P., Edelstein, J., Eftekharzadeh, S., Eisenstein, D. J., Enriquez-Vargas, M., Escoffier, S., Evatt, M., Fagrelius, P., Fan, X., Fanning, K., Fawcett, V. A., Ferraro, S., Ereza, J., Flaugher, B., Font-Ribera, A., Forero-Romero, J. E., Frenk, C. S., Fromenteau, S., Gänsicke, B. T., Garcia-Quintero, C., Garrison, L., Gaztañaga, E., Gerardi, F., Gil-Marín, H., Gontcho, S. Gontcho A, Gonzalez-Morales, Alma X., Gonzalez-de-Rivera, G., Gonzalez-Perez, V., Gordon, C., Graur, O., Green, D., Grove, C., Gruen, D., Gutierrez, G., Guy, J., Hahn, C., Harris, S., Herrera, D., Herrera-Alcantar, Hiram K., Honscheid, K., Howlett, C., Huterer, D., Iršič, V., Ishak, M., Jelinsky, P., Jiang, L., Jimenez, J., Jing, Y. P., Joyce, R., Jullo, E., Juneau, S., Karaçaylı, N. G., Karamanis, M., Karcher, A., Karim, T., Kehoe, R., Kent, S., Kirkby, D., Kisner, T., Kitaura, F., Koposov, S. E., Kovács, A., Kremin, A., Krolewski, Alex, L'Huillier, B., Lahav, O., Lambert, A., Lamman, C., Lan, Ting-Wen, Landriau, M., Lane, S., Lang, D., Lange, J. U., Lasker, J., Guillou, L. Le, Leauthaud, A., Van Suu, A. Le, Levi, Michael E., Li, T. S., Magneville, C., Manera, M., Manser, Christopher J., Marshall, B., McCollam, W., McDonald, P., Meisner, Aaron M., Mezcua, J. Mena-Fernández M., Miller, T., Miquel, R., Montero-Camacho, P., Moon, J., Martini, J. Paul, Meneses-Rizo, J., Moustakas, J., Mueller, E., Muñoz-Gutiérrez, Andrea, Myers, Adam D., Nadathur, S., Najita, J., Napolitano, L., Neilsen, E., Newman, Jeffrey A., Nie, J. D., Ning, Y., Niz, G., Norberg, P., Noriega, Hernán E., O'Brien, T., Obuljen, A., Palanque-Delabrouille, N., Palmese, A., Zhiwei, P., Pappalardo, D., Peng, X., Percival, W. J., Perruchot, S., Pogge, R., Poppett, C., Porredon, A., Prada, F., Prochaska, J., Pucha, R., Pérez-Fernández, A., Pérez-Ráfols, I., Rabinowitz, D., Raichoor, A., Ramirez-Solano, S., Ramírez-Pérez, César, Ravoux, C., Reil, K., Rezaie, M., Rocher, A., Rockosi, C., Roe, N. A., Roodman, A., Ross, A. J., Rossi, G., Ruggeri, R., Ruhlmann-Kleider, V., Sabiu, C. G., Safonova, S., Said, K., Saintonge, A., Catonga, Javier Salas, Samushia, L., Sanchez, E., Saulder, C., Schaan, E., Schlafly, E., Schlegel, D., Schmoll, J., Scholte, D., Schubnell, M., Secroun, A., Seo, H., Serrano, S., Sharples, Ray M., Sholl, Michael J., Silber, Joseph Harry, Silva, D. R., Sirk, M., Siudek, M., Smith, A., Sprayberry, D., Staten, R., Stupak, B., Tan, T., Tarlé, Gregory, Tie, Suk Sien, Tojeiro, R., Ureña-López, L. A., Valdes, F., Valenzuela, O., Valluri, M., Vargas-Magaña, M., Verde, L., Walther, M., Wang, B., Wang, M. S., Weaver, B. A., Weaverdyck, C., Wechsler, R., Wilson, Michael J., Yang, J., Yu, Y., Yuan, S., Yèche, Christophe, Zhang, H., Zhang, K., Zhao, Cheng, Zhou, Rongpu, Zhou, Zhimin, Zou, H., Zou, J., Zou, S., and Zu, Y.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The Dark Energy Spectroscopic Instrument (DESI) has embarked on an ambitious five-year survey to explore the nature of dark energy with spectroscopy of 40 million galaxies and quasars. DESI will determine precise redshifts and employ the Baryon Acoustic Oscillation method to measure distances from the nearby universe to z > 3.5, as well as measure the growth of structure and probe potential modifications to general relativity. In this paper we describe the significant instrumentation we developed for the DESI survey. The new instrumentation includes a wide-field, 3.2-deg diameter prime-focus corrector that focuses the light onto 5020 robotic fiber positioners on the 0.812 m diameter, aspheric focal surface. The positioners and their fibers are divided among ten wedge-shaped petals. Each petal is connected to one of ten spectrographs via a contiguous, high-efficiency, nearly 50 m fiber cable bundle. The ten spectrographs each use a pair of dichroics to split the light into three channels that together record the light from 360 - 980 nm with a resolution of 2000 to 5000. We describe the science requirements, technical requirements on the instrumentation, and management of the project. DESI was installed at the 4-m Mayall telescope at Kitt Peak, and we also describe the facility upgrades to prepare for DESI and the installation and functional verification process. DESI has achieved all of its performance goals, and the DESI survey began in May 2021. Some performance highlights include RMS positioner accuracy better than 0.1", SNR per \sqrt{\AA} > 0.5 for a z > 2 quasar with flux 0.28e-17 erg/s/cm^2/A at 380 nm in 4000s, and median SNR = 7 of the [OII] doublet at 8e-17 erg/s/cm^2 in a 1000s exposure for emission line galaxies at z = 1.4 - 1.6. We conclude with highlights from the on-sky validation and commissioning of the instrument, key successes, and lessons learned. (abridged), Comment: 78 pages, 32 figures, submitted to AJ

Published
2022
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47. Model BOSS & eBOSS Luminous Red Galaxies at 0.2 < z < 1.0 using SubHalo Abundance Matching with 3 parameters

Author

Yu, Jiaxi, Zhao, Cheng, Chuang, Chia-Hsun, Bautista, Julian, Favole, Ginevra, Kneib, Jean-Paul, Mohammad, Faizan, Ross, Ashley, Raichoor, Anand, Tao, Charling, Dawson, Kyle, and Rossi, Graziano

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

SubHalo Abundance Matching (SHAM) is an empirical method for constructing galaxy catalogues based on high-resolution $N$-body simulations. We apply SHAM on the UNIT simulation to simulate SDSS BOSS/eBOSS Luminous Red Galaxies (LRGs) within a wide redshift range of $0.2 < z < 1.0$. Besides the typical SHAM scatter parameter $\sigma$, we include $v_{\rm smear}$ and $V_{\rm ceil}$ to take into account the redshift uncertainty and the galaxy incompleteness respectively. These two additional parameters are critical for reproducing the observed 2PCF multipoles on 5--25$\,h^{-1}\,{\rm Mpc}$. The redshift uncertainties obtained from the best-fitting $v_{\rm smear}$ agree with those measured from repeat observations for all SDSS LRGs except for the LOWZ sample. We explore several potential systematics but none of them can explain the discrepancy found in LOWZ. Our explanation is that the LOWZ galaxies might contain another type of galaxies which needs to be treated differently. The evolution of the measured $\sigma$ and $V_{\rm ceil}$ also reveals that the incompleteness of eBOSS galaxies decreases with the redshift. This is the consequence of the magnitude lower limit applied in eBOSS LRG target selection. Our SHAM also set upper limits for the intrinsic scatter of the galaxy--halo relation given a complete galaxy sample: $\sigma_{\rm int}<0.31$ for LOWZ at $0.2

Published
2022
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48. Model BOSS and eBOSS luminous red galaxies at 0.2 < z < 1.0 using SubHalo Abundance Matching with three parameters

Author

Yu, Jiaxi, Zhao, Cheng, Chuang, Chia-Hsun, Bautista, Julian E, Favole, Ginevra, Kneib, Jean-Paul, Mohammad, Faizan G, Ross, Ashley J, Raichoor, Anand, Tao, Charling, Dawson, Kyle, and Rossi, Graziano

Subjects
Astronomical and Space Sciences, Astronomy & Astrophysics
Abstract

ABSTRACT SubHalo Abundance Matching (SHAM) is an empirical method for constructing galaxy catalogues based on high-resolution N-body simulations. We apply SHAM on the UNIT simulation to simulate SDSS BOSS/eBOSS luminous red galaxies (LRGs) within a wide redshift range of 0.2 < $z$ < 1.0. Besides the typical SHAM scatter parameter σ, we include $v$smear and Vceil to take into account the redshift uncertainty and the galaxy incompleteness, respectively. These two additional parameters are critical for reproducing the observed 2PCF multipoles on 5–25$\, h^{-1}\, {\rm Mpc}$. The redshift uncertainties obtained from the best-fitting $v$smear agree with those measured from repeat observations for all SDSS LRGs except for the LOWZ sample. We explore several potential systematics but none of them can explain the discrepancy found in LOWZ. Our explanation is that the LOWZ galaxies might contain another type of galaxies that needs to be treated differently. The evolution of the measured σ and Vceil also reveals that the incompleteness of eBOSS galaxies decreases with the redshift. This is the consequence of the magnitude lower limit applied in eBOSS LRG target selection. Our SHAM also set upper limits for the intrinsic scatter of the galaxy–halo relation, given a complete galaxy sample: σint < 0.31 for LOWZ at 0.2 < $z$ < 0.33, σint < 0.36 for LOWZ at 0.33 < $z$ < 0.43, and σint < 0.46 for CMASS at 0.43 < $z$ < 0.51. The projected 2PCFs of our SHAM galaxies also agree with the observational ones on the 2PCF fitting range.

Published
2022

49. Angular systematics-free cosmological analysis of galaxy clustering in configuration space

Author

Paviot, Romain, de la Torre, Sylvain, de Mattia, Arnaud, Zhao, Cheng, Bautista, Julian, Burtin, Etienne, Dawson, Kyle, Escoffier, Stéphanie, Jullo, Eric, Raichoor, Anand, Ross, Ashley J., and Rossi, Graziano

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

Galaxy redshift surveys are subject to incompleteness and inhomogeneous sampling due to the various constraints inherent to spectroscopic observations. This can introduce systematic errors on the summary statistics of interest, which need to be mitigated in cosmological analysis to achieve high accuracy. Standard practices involve applying weighting schemes based on completeness estimates across the survey footprint, possibly supplemented with additional weighting schemes accounting for density-dependent effects. In this work, we concentrate on pure angular systematics and describe an alternative approach consisting in analysing the galaxy two-point correlation function where angular modes are nulled. By construction, this procedure removes all possible known and unknown sources of angular observational systematics, but also part of the cosmological signal.We use a modified Landy-Szalay estimator for the two-point correlation function that relies on an additional random catalogue where angular positions are randomly drawn from the galaxy catalogue, and provide an analytical model to describe this modified statistic. We test the model by performing an analysis of the full anisotropic clustering in mock catalogues of luminous red and emission-line galaxies at 0.43 < z < 1.1. We find that the model fully accounts for the modified correlation function in redshift space, without introducing new nuisance parameters. The derived cosmological parameters from the analysis of baryon acoustic oscillations and redshift-space distortions display slightly larger statistical uncertainties, mostly for the growth rate of structure parameter fs8 that exhibits a 50% statistical error increase, but free from angular systematic error., Comment: 16 pages, submitted to MNRAS

Published
2021
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50. Preliminary Target Selection for the DESI Luminous Red Galaxy (LRG) Sample

Author

Zhou, Rongpu, Newman, Jeffrey A., Dawson, Kyle S., Eisenstein, Daniel J., Brooks, David D., Dey, Arjun, Dey, Biprateep, Duan, Yutong, Eftekharzadeh, Sarah, Gaztañaga, Enrique, Kehoe, Robert, Landriau, Martin, Levi, Michael E., Licquia, Timothy C., Meisner, Aaron M., Moustakas, John, Myers, Adam D., Palanque-Delabrouille, Nathalie, Poppett, Claire, Prada, Francisco, Raichoor, Anand, Schlegel, David J., Schubnell, Michael, Staten, Ryan, Tarlé, Gregory, and Yèche, Christophe

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The DESI survey will observe more than 8 million candidate luminous red galaxies (LRGs) in the redshift range $0.3

Published
2020
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