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289 results on '"Dey, Arjun"'

21. The frequency of metal enrichment of cool helium-atmosphere white dwarfs using the DESI early data release.

Author

Manser, Christopher J, Gänsicke, Boris T, Izquierdo, Paula, Swan, Andrew, Najita, Joan, Rockosi, C, Carrillo, Andreia, Kim, Bokyoung, Xu, Siyi, Dey, Arjun, Aguilar, J, Ahlen, S, Blum, R, Brooks, D, Claybaugh, T, Dawson, K, de la Macorra, A, Doel, P, Gaztañaga, E, and Gontcho A Gontcho, S

Subjects
WHITE dwarf stars, DATA release, PLANETARY systems, DARK energy, METALS
Abstract

There is an overwhelming evidence that white dwarfs host planetary systems; revealed by the presence, disruption, and accretion of planetary bodies. A lower limit on the frequency of white dwarfs that host planetary material has been estimated to be ≃ 25–50 per cent; inferred from the ongoing or recent accretion of metals on to both hydrogen-atmosphere and warm helium-atmosphere white dwarfs. Now with the unbiased sample of white dwarfs observed by the Dark Energy Spectroscopic Instrument (DESI) survey in their Early Data Release (EDR), we have determined the frequency of metal enrichment around cool-helium atmosphere white dwarfs as 21 ± 3 per cent using a sample of 234 systems. This value is in good agreement with values determined from previous studies. With the current samples we cannot distinguish whether the frequency of planetary accretion varies with system age or host-star mass, but the DESI data release 1 will contain roughly an order of magnitude more white dwarfs than DESI EDR and will allow these parameters to be investigated. [ABSTRACT FROM AUTHOR]

Published
2024
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22. Redshift-dependent RSD bias from intrinsic alignment with DESI Year 1 spectra.

Author

Lamman, Claire, Eisenstein, Daniel, Aguilar, Jessica Nicole, Ahlen, Steven, Brooks, David, Claybaugh, Todd, de la Macorra, Axel, Dey, Arjun, Dey, Biprateep, Doel, Peter, Ferraro, Simone, Font-Ribera, Andreu, Forero-Romero, Jaime E, Gontcho, Satya Gontcho A, Guy, Julien, Kehoe, Robert, Kremin, Anthony, Le Guillou, Laurent, Levi, Michael, and Manera, Marc

Subjects
EMISSION-line galaxies, DARK energy, LARGE scale structure (Astronomy), STATISTICAL correlation, REDSHIFT
Abstract

We estimate the redshift-dependent, anisotropic clustering signal in the Dark Energy Spectroscopic Instrument (DESI) Year 1 Survey created by tidal alignments of Luminous Red Galaxies (LRGs) and a selection-induced galaxy orientation bias. To this end, we measured the correlation between LRG shapes and the tidal field with DESI's Year 1 redshifts, as traced by LRGs and Emission-Line Galaxies. We also estimate the galaxy orientation bias of LRGs caused by DESI's aperture-based selection, and find it to increase by a factor of seven between redshifts 0.4−1.1 due to redder, fainter galaxies falling closer to DESI's imaging selection cuts. These effects combine to dampen measurements of the quadrupole of the correlation function (ξ2) caused by structure growth on scales of 10–80 h −1 Mpc by about 0.15 per cent for low redshifts (0.4 < z < 0.6) and 0.8 per cent for high (0.8 < z < 1.1), a significant fraction of DESI's error budget. We provide estimates of the ξ2 signal created by intrinsic alignments that can be used to correct this effect, which is necessary to meet DESI's forecasted precision on measuring the growth rate of structure. While imaging quality varies across DESI's footprint, we find no significant difference in this effect between imaging regions in the Legacy Imaging Survey. [ABSTRACT FROM AUTHOR]

Published
2024
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23. Bilateral congenital choanal atresia in a preterm neonate - a rare neonatal emergency: A case report and review of literature.

Author

Zaidi, Ayesha, Dey, Arjun Chandra, Sabra, Omar, and James, Jemila

Subjects
LITERATURE reviews, HUMAN abnormalities, NEWBORN infants, PULMONARY atresia, NASAL cavity, EARLY diagnosis
Abstract

Congenital choanal atresia results from the developmental failure of the nasal cavity to connect posteriorly with the nasopharynx. Although congenital choanal atresia is a well-recognized developmental disorder, it is an uncommon condition with an overall incidence of approximately 1 per 10,000 live births. The authors aim to highlight that in very preterm neonates, early diagnosis of bilateral congenital choanal atresia needs a high index of suspicion to avoid life-threatening events. It is considered as one of the neonatal emergencies, and repair is recommended in the first few weeks of life. The authors report an uncommon presentation of a very preterm neonate born at 31 weeks of gestation, diagnosed to have bilateral congenital choanal atresia with repeated failure of a trial of extubation. A transnasal endoscopic repair was performed in the eighth week of life to relieve the life-threatening nasal obstruction. [ABSTRACT FROM AUTHOR]

Published
2024
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25. ProtoDESI : First On-Sky Technology Demonstration for the Dark Energy Spectroscopic Instrument

Author

Fagrelius, Parker, Abareshi, Behzad, Allen, Lori, Ballester, Otger, Baltay, Charles, Besuner, Robert, Buckley-Geer, Elizabeth, Butler, Karen, Cardiel, Laia, Dey, Arjun, Duan, Yutong, Elliott, Ann, Emmet, William, Gershkovich, Irena, Honscheid, Klaus, Illa, Jose M., Jimenez, Jorge, Joyce, Richard, Karcher, Armin, Kent, Stephen, Lambert, Andrew, Lampton, Michael, Levi, Michael, Manser, Christopher, Marshall, Robert, Martini, Paul, Paat, Anthony, Probst, Ronald, Rabinowitz, David, Reil, Kevin, Robertson, Amy, Rockosi, Connie, Schlegel, David, Schubnell, Michael, Serrano, Santiago, Silber, Joseph, Soto, Christian, Sprayberry, David, Summers, David, Tarlé, Greg, and Weaver, Benjamin A.

Published
2018

29. X-ray spectrometers on-board Aditya-L1 for solar flare studies

Author

Sankarasubramanian, K., Sudhakar, Manju, Nandi, Anuj, Ramadevi, M. C., Adoni, Abhijit Avinash, Kushwaha, Ankur, Agarwal, Anil, Dey, Arjun, Joshi, Bhuwan, Singh, Brajpal, Girish, V., Tomar, Ishan, Majhi, Kamal Kumar, Olekar, Manjunath, Bug, Monoj, Pala, Manohar, Thakur, Mukund Kumar, Badagandi, Rajeev R., Ravishankar, B. T., Garg, Sarthak, Sitaramamurthy, N., Sridhara, N., Umapathy, C. N., Gupta, Vinod Kumar, Agrawal, Vivek Kumar, and Yougandar, B.

Published
2017

30. Project Overview of the Beijing–Arizona Sky Survey

Author

Zou, Hu, Zhou, Xu, Fan, Xiaohui, Zhang, Tianmeng, Zhou, Zhimin, Nie, Jundan, Peng, Xiyan, McGreer, Ian, Jiang, Linhua, Dey, Arjun, Fan, Dongwei, He, Boliang, Jiang, Zhaoji, Lang, Dustin, Lesser, Michael, Ma, Jun, Mao, Shude, Schlegel, David, and Wang, Jiali

Published
2017

36. Siena Galaxy Atlas 2020.

Author

Moustakas, John, Lang, Dustin, Dey, Arjun, Juneau, Stéphanie, Meisner, Aaron, Myers, Adam D., Schlafly, Edward F., Schlegel, David J., Valdes, Francisco, Weaver, Benjamin A., and Zhou, Rongpu

Published
2023
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37. Target selection for the DESI Peculiar Velocity Survey.

Author

Saulder, Christoph, Howlett, Cullan, Douglass, Kelly A, Said, Khaled, BenZvi, Segev, Ahlen, Steven, Aldering, Greg, Bailey, Stephen, Brooks, David, Davis, Tamara M, de la Macorra, Axel, Dey, Arjun, Font-Ribera, Andreu, Forero-Romero, Jaime E, Gontcho A. Gontcho, Satya, Honscheid, Klaus, Kim, Alex G, Kisner, Theodore, Kremin, Anthony, and Landriau, Martin

Subjects
STATISTICAL measurement, VELOCITY, GALAXY clusters, DARK energy, MORPHOLOGY
Abstract

We describe the target selection and characteristics of the DESI Peculiar Velocity Survey, the largest survey of peculiar velocities (PVs) using both the fundamental plane (FP) and the Tully–Fisher (TF) relationship planned to date. We detail how we identify suitable early-type galaxies (ETGs) for the FP and suitable late-type galaxies (LTGs) for the TF relation using the photometric data provided by the DESI Legacy Imaging Survey DR9. Subsequently, we provide targets for 373 533 ETGs and 118 637 LTGs within the Dark Energy Spectroscopic Instrument (DESI) 5-yr footprint. We validate these photometric selections using existing morphological classifications. Furthermore, we demonstrate using survey validation data that DESI is able to measure the spectroscopic properties to sufficient precision to obtain PVs for our targets. Based on realistic DESI fibre assignment simulations and spectroscopic success rates, we predict the final DESI PV Survey will obtain ∼133 000 FP-based and ∼53 000 TF-based PV measurements over an area of 14 000 deg2. We forecast the ability of using these data to measure the clustering of galaxy positions and PVs from the combined DESI PV and Bright Galaxy Surveys (BGS), which allows for cancellation of cosmic variance at low redshifts. With these forecasts, we anticipate a 4 per cent statistical measurement on the growth rate of structure at z < 0.15. This is over two times better than achievable with redshifts from the BGS alone. The combined DESI PV and BGS will enable the most precise tests to date of the time and scale dependence of large-scale structure growth at z < 0.15. [ABSTRACT FROM AUTHOR]

Published
2023
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47. Vitamin-D Status and Clinical Outcomes in Critically Ill Children.

Author

Loni, Ramaning, Zameer, Sara, Hasan, Fareedul Ahmed, Abbas, Ittrat, Mesrati, Hager, George, John, Fox, Gabriel, Dey, Arjun C., and Finan, Alan

Subjects
INTENSIVE care units, LENGTH of stay in hospitals, CRITICALLY ill, PATIENTS, DISEASES, PEDIATRICS, CHOLECALCIFEROL, VITAMIN D, ARTIFICIAL respiration, INFANT mortality, VITAMIN D deficiency, CHILD mortality, CHILDREN
Abstract

Aims and background: To study if 25-hydroxy cholecalciferol levels correlate with clinical outcomes in a cohort of critically ill children requiring pediatric intensive care unit (PICU) admission. Materials and methods: All children between the ages of 1 month and 14 years admitted to a PICU were included in this study. The vitamin-D level was measured within 24 hours of admission to the PICU for each patient. The patient's clinical details, vitamin-D levels, and biochemical parameters were collected. Results: There were 119 critically ill children (47 females and 72 males) admitted to our PICU. A total of 56 children were in the vitamin-Ddeficient group, giving a prevalence of 47.05%. Sixty-three children had either insufficient or normal levels of 25(OH)D. Mean serum 25-OH cholecalciferol was 22.82 ± 16.48 nmol/L. There were no significant differences in O2 utilization, ventilation requirement, length of PICU stay, or the frequencies of use of antibiotics and steroids between the groups. The overall mortality rate in this study was 5.8% (three children died in the deficient group as compared with four in the insufficient/normal group). Conclusion: Even though vitamin-D deficiency was highly prevalent in the PICU, there were no statistically significant differences in O2 utilization, length of PICU stay, duration of mechanical ventilation, the use of antibiotics/steroids, and mortality outcome for both deficient and insufficient/normal groups. [ABSTRACT FROM AUTHOR]

Published
2023
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