Search

Your search keyword '"Iyer, KG [0000-0001-9298-3523]"' showing total 4 results
Start Over Author "Iyer, KG [0000-0001-9298-3523]"
4 results on '"Iyer, KG [0000-0001-9298-3523]"'

1. CEERS Key Paper. II. A First Look at the Resolved Host Properties of AGN at 3 < z < 5 with JWST

Author

Dale D. Kocevski, Guillermo Barro, Elizabeth J. McGrath, Steven L. Finkelstein, Micaela B. Bagley, Henry C. Ferguson, Shardha Jogee, Guang Yang, Mark Dickinson, Nimish P. Hathi, Bren E. Backhaus, Eric F. Bell, Laura Bisigello, Véronique Buat, Denis Burgarella, Caitlin M. Casey, Nikko J. Cleri, M. C. Cooper, Luca Costantin, Darren Croton, Emanuele Daddi, Adriano Fontana, Seiji Fujimoto, Jonathan P. Gardner, Eric Gawiser, Mauro Giavalisco, Andrea Grazian, Norman A. Grogin, Yuchen Guo, Pablo Arrabal Haro, Michaela Hirschmann, Benne W. Holwerda, Marc Huertas-Company, Taylor A. Hutchison, Kartheik G. Iyer, Brenda Jones, Stéphanie Juneau, Jeyhan S. Kartaltepe, Lisa J. Kewley, Allison Kirkpatrick, Anton M. Koekemoer, Peter Kurczynski, Aurélien Le Bail, Arianna S. Long, Jennifer M. Lotz, Ray A. Lucas, Casey Papovich, Laura Pentericci, Pablo G. Pérez-González, Nor Pirzkal, Marc Rafelski, Swara Ravindranath, Rachel S. Somerville, Amber N. Straughn, Sandro Tacchella, Jonathan R. Trump, Stephen M. Wilkins, Stijn Wuyts, L. Y. Aaron Yung, Jorge A. Zavala, Kocevski, DD [0000-0002-8360-3880], Barro, G [0000-0002-0786-7307], McGrath, EJ [0000-0001-8688-2443], Finkelstein, SL [0000-0001-8519-1130], Bagley, MB [0000-0002-9921-9218], Ferguson, HC [0000-0001-7113-2738], Jogee, S [0000-0002-1590-0568], Yang, G [0000-0001-8835-7722], Dickinson, M [0000-0001-5414-5131], Hathi, NP [0000-0001-6145-5090], Backhaus, BE [0000-0001-8534-7502], Bell, EF [0000-0002-5564-9873], Bisigello, L [0000-0003-0492-4924], Buat, V [0000-0003-3441-903X], Burgarella, D [0000-0002-4193-2539], Casey, CM [0000-0002-0930-6466], Cleri, NJ [0000-0001-7151-009X], Cooper, MC [0000-0003-1371-6019], Costantin, L [0000-0001-6820-0015], Croton, D [0000-0002-5009-512X], Daddi, E [0000-0002-3331-9590], Fontana, A [0000-0003-3820-2823], Fujimoto, S [0000-0001-7201-5066], Gardner, JP [0000-0003-2098-9568], Gawiser, E [0000-0003-1530-8713], Giavalisco, M [0000-0002-7831-8751], Grazian, A [0000-0002-5688-0663], Grogin, NA [0000-0001-9440-8872], Guo, Y [0000-0002-4162-6523], Haro, PA [0000-0002-7959-8783], Hirschmann, M [0000-0002-3301-3321], Holwerda, BW [0000-0002-4884-6756], Huertas-Company, M [0000-0002-1416-8483], Hutchison, TA [0000-0001-6251-4988], Iyer, KG [0000-0001-9298-3523], Juneau, S [0000-0002-0000-2394], Kartaltepe, JS [0000-0001-9187-3605], Kewley, LJ [0000-0001-8152-3943], Kirkpatrick, A [0000-0002-1306-1545], Koekemoer, AM [0000-0002-6610-2048], Kurczynski, P [0000-0002-8816-5146], Bail, AL [0000-0002-9466-2763], Long, AS [0000-0002-7530-8857], Lotz, JM [0000-0003-3130-5643], Lucas, RA [0000-0003-1581-7825], Papovich, C [0000-0001-7503-8482], Pentericci, L [0000-0001-8940-6768], Pérez-González, PG [0000-0003-4528-5639], Pirzkal, N [0000-0003-3382-5941], Rafelski, M [0000-0002-9946-4731], Ravindranath, S [0000-0002-5269-6527], Somerville, RS [0000-0002-6748-6821], Straughn, AN [0000-0002-4772-7878], Tacchella, S [0000-0002-8224-4505], Trump, JR [0000-0002-1410-0470], Wilkins, SM [0000-0003-3903-6935], Wuyts, S [0000-0003-3735-1931], Aaron Yung, LY [0000-0003-3466-035X], Zavala, JA [0000-0002-7051-1100], Apollo - University of Cambridge Repository, Kocevski, Dale D [0000-0002-8360-3880], Barro, Guillermo [0000-0002-0786-7307], McGrath, Elizabeth J [0000-0001-8688-2443], Finkelstein, Steven L [0000-0001-8519-1130], Bagley, Micaela B [0000-0002-9921-9218], Ferguson, Henry C [0000-0001-7113-2738], Jogee, Shardha [0000-0002-1590-0568], Yang, Guang [0000-0001-8835-7722], Dickinson, Mark [0000-0001-5414-5131], Hathi, Nimish P [0000-0001-6145-5090], Backhaus, Bren E [0000-0001-8534-7502], Bell, Eric F [0000-0002-5564-9873], Bisigello, Laura [0000-0003-0492-4924], Buat, Véronique [0000-0003-3441-903X], Burgarella, Denis [0000-0002-4193-2539], Casey, Caitlin M [0000-0002-0930-6466], Cleri, Nikko J [0000-0001-7151-009X], Costantin, Luca [0000-0001-6820-0015], Croton, Darren [0000-0002-5009-512X], Daddi, Emanuele [0000-0002-3331-9590], Fontana, Adriano [0000-0003-3820-2823], Fujimoto, Seiji [0000-0001-7201-5066], Gardner, Jonathan P [0000-0003-2098-9568], Gawiser, Eric [0000-0003-1530-8713], Giavalisco, Mauro [0000-0002-7831-8751], Grazian, Andrea [0000-0002-5688-0663], Grogin, Norman A [0000-0001-9440-8872], Guo, Yuchen [0000-0002-4162-6523], Haro, Pablo Arrabal [0000-0002-7959-8783], Hirschmann, Michaela [0000-0002-3301-3321], Holwerda, Benne W [0000-0002-4884-6756], Huertas-Company, Marc [0000-0002-1416-8483], Hutchison, Taylor A [0000-0001-6251-4988], Iyer, Kartheik G [0000-0001-9298-3523], Juneau, Stéphanie [0000-0002-0000-2394], Kartaltepe, Jeyhan S [0000-0001-9187-3605], Kewley, Lisa J [0000-0001-8152-3943], Kirkpatrick, Allison [0000-0002-1306-1545], Koekemoer, Anton M [0000-0002-6610-2048], Kurczynski, Peter [0000-0002-8816-5146], Bail, Aurélien Le [0000-0002-9466-2763], Long, Arianna S [0000-0002-7530-8857], Lotz, Jennifer M [0000-0003-3130-5643], Lucas, Ray A [0000-0003-1581-7825], Papovich, Casey [0000-0001-7503-8482], Pentericci, Laura [0000-0001-8940-6768], Pérez-González, Pablo G [0000-0003-4528-5639], Pirzkal, Nor [0000-0003-3382-5941], Rafelski, Marc [0000-0002-9946-4731], Ravindranath, Swara [0000-0002-5269-6527], Somerville, Rachel S [0000-0002-6748-6821], Straughn, Amber N [0000-0002-4772-7878], Tacchella, Sandro [0000-0002-8224-4505], Trump, Jonathan R [0000-0002-1410-0470], Wilkins, Stephen M [0000-0003-3903-6935], Wuyts, Stijn [0000-0003-3735-1931], and Zavala, Jorge A [0000-0002-7051-1100]

Subjects
Space and Planetary Science, 5101 Astronomical Sciences, Astronomy and Astrophysics, 51 Physical Sciences, Galaxies and Cosmology
Abstract

We report on the host properties of five X-ray-luminous active galactic nuclei (AGN) identified at 3 < z < 5 in the first epoch of imaging from the Cosmic Evolution Early Release Science Survey. Each galaxy has been imaged with the JWST Near-Infrared Camera, which provides rest-frame optical morphologies at these redshifts. We also derive stellar masses and star formation rates for each host by fitting its spectral energy distribution using a combination of galaxy and AGN templates. We find that three of the AGN hosts have spheroidal morphologies, one is a bulge-dominated disk, and one is dominated by pointlike emission. None are found to show strong morphological disturbances that might indicate a recent interaction or merger event. When compared to a sample of mass-matched inactive galaxies, we find that the AGN hosts have morphologies that are less disturbed and more bulge-dominated. Notably, all four of the resolved hosts have rest-frame optical colors consistent with a quenched or poststarburst stellar population. The presence of AGN in passively evolving galaxies at z > 3 is significant because a rapid feedback mechanism is required in most semianalytic models and cosmological simulations to explain the growing population of massive quiescent galaxies observed at these redshifts. Our findings show that AGN can continue to inject energy into these systems after their star formation is curtailed, potentially heating their halos and preventing renewed star formation. Additional observations will be needed to determine what role this feedback may play in helping to quench these systems and/or maintain their quiescent state.

Published
2023
Full Text
View/download PDF

2. Dusty Starbursts Masquerading as Ultra-high Redshift Galaxies in JWST CEERS Observations

Author

Zavala, JA, Buat, V, Casey, CM, Finkelstein, SL, Burgarella, D, Bagley, MB, Ciesla, L, Daddi, E, Dickinson, M, Ferguson, HC, Franco, M, Jiménez-Andrade, EF, Kartaltepe, JS, Koekemoer, AM, Bail, AL, Murphy, EJ, Papovich, C, Tacchella, S, Wilkins, SM, Aretxaga, I, Behroozi, P, Champagne, JB, Fontana, A, Giavalisco, M, Grazian, A, Grogin, NA, Kewley, LJ, Kocevski, DD, Kirkpatrick, A, Lotz, JM, Pentericci, L, Pérez-González, PG, Pirzkal, N, Ravindranath, S, Somerville, RS, Trump, Yang, G, Aaron Yung, LY, Almaini, O, Amorín, RO, Annunziatella, M, Haro, PA, Backhaus, BE, Barro, G, Bell, EF, Bhatawdekar, R, Bisigello, L, Buitrago, F, Calabrò, A, Castellano, M, Chávez Ortiz, ÓA, Chworowsky, K, Cleri, NJ, Cohen, SH, Cole, JW, Cooke, KC, Cooper, MC, Cooray, AR, Costantin, L, Cox, IG, Croton, D, Davé, R, Vega, ADL, Dekel, A, Elbaz, D, Estrada-Carpenter, V, Fernández, V, Finkelstein, KD, Freundlich, J, Fujimoto, S, García-Argumánez, Á, Gardner, JP, Gawiser, E, Gómez-Guijarro, C, Guo, Y, Hamilton, TS, Hathi, NP, Holwerda, BW, Hirschmann, M, Huertas-Company, M, Hutchison, TA, Iyer, KG, Jaskot, AE, Jha, SW, Jogee, S, Juneau, S, Jung, I, Kassin, SA, Kurczynski, P, Larson, RL, Leung, GCK, Long, AS, Lucas, RA, Magnelli, B, Mantha, KB, Matharu, J, McGrath, EJ, McIntosh, DH, Medrano, A, Merlin, E, Zavala, JA [0000-0002-7051-1100], Buat, V [0000-0003-3441-903X], Casey, CM [0000-0002-0930-6466], Finkelstein, SL [0000-0001-8519-1130], Burgarella, D [0000-0002-4193-2539], Bagley, MB [0000-0002-9921-9218], Ciesla, L [0000-0003-0541-2891], Daddi, E [0000-0002-3331-9590], Dickinson, M [0000-0001-5414-5131], Ferguson, HC [0000-0001-7113-2738], Franco, M [0000-0002-3560-8599], Jiménez-Andrade, EF [0000-0002-2640-5917], Kartaltepe, JS [0000-0001-9187-3605], Koekemoer, AM [0000-0002-6610-2048], Bail, AL [0000-0002-9466-2763], Murphy, EJ [0000-0001-7089-7325], Papovich, C [0000-0001-7503-8482], Tacchella, S [0000-0002-8224-4505], Wilkins, SM [0000-0003-3903-6935], Aretxaga, I [0000-0002-6590-3994], Behroozi, P [0000-0002-2517-6446], Champagne, JB [0000-0002-6184-9097], Fontana, A [0000-0003-3820-2823], Giavalisco, M [0000-0002-7831-8751], Grazian, A [0000-0002-5688-0663], Grogin, NA [0000-0001-9440-8872], Kewley, LJ [0000-0001-8152-3943], Kocevski, DD [0000-0002-8360-3880], Kirkpatrick, A [0000-0002-5537-8110], Lotz, JM [0000-0003-3130-5643], Pentericci, L [0000-0001-8940-6768], Pérez-González, PG [0000-0003-4528-5639], Pirzkal, N [0000-0003-3382-5941], Ravindranath, S [0000-0002-5269-6527], Somerville, RS [0000-0002-6748-6821], Trump, JR [0000-0002-1410-0470], Yang, G [0000-0001-8835-7722], Aaron Yung, LY [0000-0003-3466-035X], Almaini, O [0000-0001-9328-3991], Amorín, RO [0000-0001-5758-1000], Annunziatella, M [0000-0002-8053-8040], Haro, PA [0000-0002-7959-8783], Backhaus, BE [0000-0001-8534-7502], Barro, G [0000-0001-6813-875X], Bell, EF [0000-0002-5564-9873], Bhatawdekar, R [0000-0003-0883-2226], Bisigello, L [0000-0003-0492-4924], Buitrago, F [0000-0002-2861-9812], Calabrò, A [0000-0003-2536-1614], Castellano, M [0000-0001-9875-8263], Chávez Ortiz, ÓA [0000-0003-2332-5505], Chworowsky, K [0000-0003-4922-0613], Cleri, NJ [0000-0001-7151-009X], Cohen, SH [0000-0003-3329-1337], Cole, JW [0000-0002-6348-1900], Cooke, KC [0000-0002-2200-9845], Cooper, MC [0000-0003-1371-6019], Cooray, AR [0000-0002-3892-0190], Costantin, L [0000-0001-6820-0015], Cox, IG [0000-0002-1803-794X], Croton, D [0000-0002-5009-512X], Davé, R [0000-0003-2842-9434], Vega, ADL [0000-0002-6219-5558], Dekel, A [0000-0003-4174-0374], Elbaz, D [0000-0002-7631-647X], Estrada-Carpenter, V [0000-0001-8489-2349], Fernández, V [0000-0003-0531-5450], Finkelstein, KD [0000-0003-0792-5877], Freundlich, J [0000-0002-5245-7796], Fujimoto, S [0000-0001-7201-5066], García-Argumánez, Á [0000-0002-8365-5525], Gardner, JP [0000-0003-2098-9568], Gawiser, E [0000-0003-1530-8713], Gómez-Guijarro, C [0000-0002-4085-9165], Guo, Y [0000-0002-4162-6523], Hamilton, TS [0000-0002-9753-1769], Hathi, NP [0000-0001-6145-5090], Holwerda, BW [0000-0002-4884-6756], Hirschmann, M [0000-0002-3301-3321], Huertas-Company, M [0000-0002-1416-8483], Hutchison, TA [0000-0001-6251-4988], Iyer, KG [0000-0001-9298-3523], Jaskot, AE [0000-0002-6790-5125], Jha, SW [0000-0001-8738-6011], Jogee, S [0000-0002-1590-0568], Juneau, S [0000-0002-0000-2394], Jung, I [0000-0003-1187-4240], Kassin, SA [0000-0002-3838-8093], Kurczynski, P [0000-0002-8816-5146], Larson, RL [0000-0003-2366-8858], Leung, GCK [0000-0002-9393-6507], Long, AS [0000-0002-7530-8857], Lucas, RA [0000-0003-1581-7825], Magnelli, B [0000-0002-6777-6490], Matharu, J [0000-0002-7547-3385], McGrath, EJ [0000-0001-8688-2443], Merlin, E [0000-0001-6870-8900], and Apollo - University of Cambridge Repository

Subjects
5101 Astronomical Sciences, 5109 Space Sciences, 51 Physical Sciences, Galaxies and Cosmology
Abstract

Lyman-break galaxy (LBG) candidates at z ≳ 10 are rapidly being identified in James Webb Space Telescope (JWST)/NIRCam observations. Due to the (redshifted) break produced by neutral hydrogen absorption of rest-frame UV photons, these sources are expected to drop out in the bluer filters while being well detected in redder filters. However, here we show that dust-enshrouded star-forming galaxies at lower redshifts (z ≲ 7) may also mimic the near-infrared (near-IR) colors of z > 10 LBGs, representing potential contaminants in LBG candidate samples. First, we analyze CEERS-DSFG-1, a NIRCam dropout undetected in the F115W and F150W filters but detected at longer wavelengths. Combining the JWST data with (sub)millimeter constraints, including deep NOEMA interferometric observations, we show that this source is a dusty star-forming galaxy (DSFG) at z ≈ 5.1. We also present a tentative 2.6σ SCUBA-2 detection at 850 μm around a recently identified z ≈ 16 LBG candidate in the same field and show that, if the emission is real and associated with this candidate, the available photometry is consistent with a z ∼ 5 dusty galaxy with strong nebular emission lines despite its blue near-IR colors. Further observations on this candidate are imperative to mitigate the low confidence of this tentative submillimeter emission and its positional uncertainty. Our analysis shows that robust (sub)millimeter detections of NIRCam dropout galaxies likely imply z ∼ 4–6 redshift solutions, where the observed near-IR break would be the result of a strong rest-frame optical Balmer break combined with high dust attenuation and strong nebular line emission, rather than the rest-frame UV Lyman break. This provides evidence that DSFGs may contaminate searches for ultra-high redshift LBG candidates from JWST observations.

Published
2023

3. A Long Time Ago in a Galaxy Far, Far Away: A Candidate z ~ 12 Galaxy in Early JWST CEERS Imaging

Author

Finkelstein, SL, Bagley, MB, Haro, PA, Dickinson, M, Ferguson, HC, Kartaltepe, JS, Papovich, C, Burgarella, D, Kocevski, DD, Huertas-Company, M, Iyer, KG, Koekemoer, AM, Larson, RL, Pérez-González, PG, Rose, C, Tacchella, S, Wilkins, SM, Chworowsky, K, Medrano, A, Morales, AM, Somerville, RS, Aaron Yung, LY, Fontana, A, Giavalisco, M, Grazian, A, Grogin, NA, Kewley, LJ, Kirkpatrick, A, Kurczynski, P, Lotz, JM, Pentericci, L, Pirzkal, N, Ravindranath, S, Ryan, RE, Trump, Yang, G, Almaini, O, Amorín, RO, Annunziatella, M, Backhaus, BE, Barro, G, Behroozi, P, Bell, EF, Bhatawdekar, R, Bisigello, L, Bromm, V, Buat, V, Buitrago, F, Calabrò, A, Casey, CM, Castellano, M, Chávez Ortiz, ÓA, Ciesla, L, Cleri, NJ, Cohen, SH, Cole, JW, Cooke, KC, Cooper, MC, Cooray, AR, Costantin, L, Cox, IG, Croton, D, Daddi, E, Davé, R, De La Vega, A, Dekel, A, Elbaz, D, Estrada-Carpenter, V, Faber, SM, Fernández, V, Finkelstein, KD, Freundlich, J, Fujimoto, S, García-Argumánez, Á, Gardner, JP, Gawiser, E, Gómez-Guijarro, C, Guo, Y, Hamblin, K, Hamilton, TS, Hathi, NP, Holwerda, BW, Hirschmann, M, Hutchison, TA, Jaskot, AE, Jha, SW, Jogee, S, Juneau, S, Jung, I, Kassin, SA, Le Bail, A, Leung, GCK, Lucas, RA, Magnelli, B, Mantha, KB, Matharu, J, McGrath, EJ, McIntosh, DH, Merlin, E, Mobasher, B, Finkelstein, SL [0000-0001-8519-1130], Bagley, MB [0000-0002-9921-9218], Haro, PA [0000-0002-7959-8783], Dickinson, M [0000-0001-5414-5131], Ferguson, HC [0000-0001-7113-2738], Kartaltepe, JS [0000-0001-9187-3605], Papovich, C [0000-0001-7503-8482], Burgarella, D [0000-0002-4193-2539], Kocevski, DD [0000-0002-8360-3880], Huertas-Company, M [0000-0002-1416-8483], Iyer, KG [0000-0001-9298-3523], Koekemoer, AM [0000-0002-6610-2048], Larson, RL [0000-0003-2366-8858], Pérez-González, PG [0000-0003-4528-5639], Rose, C [0000-0002-8018-3219], Tacchella, S [0000-0002-8224-4505], Wilkins, SM [0000-0003-3903-6935], Chworowsky, K [0000-0003-4922-0613], Morales, AM [0000-0003-4965-0402], Somerville, RS [0000-0002-6748-6821], Aaron Yung, LY [0000-0003-3466-035X], Fontana, A [0000-0003-3820-2823], Giavalisco, M [0000-0002-7831-8751], Grazian, A [0000-0002-5688-0663], Grogin, NA [0000-0001-9440-8872], Kewley, LJ [0000-0001-8152-3943], Kirkpatrick, A [0000-0002-1306-1545], Kurczynski, P [0000-0002-8816-5146], Lotz, JM [0000-0003-3130-5643], Pentericci, L [0000-0001-8940-6768], Pirzkal, N [0000-0003-3382-5941], Ravindranath, S [0000-0002-5269-6527], Ryan, RE [0000-0003-0894-1588], Trump, JR [0000-0002-1410-0470], Yang, G [0000-0001-8835-7722], Almaini, O [0000-0001-9328-3991], Amorín, RO [0000-0001-5758-1000], Annunziatella, M [0000-0002-8053-8040], Backhaus, BE [0000-0001-8534-7502], Behroozi, P [0000-0002-2517-6446], Bell, EF [0000-0002-5564-9873], Bhatawdekar, R [0000-0003-0883-2226], Bisigello, L [0000-0003-0492-4924], Bromm, V [0000-0003-0212-2979], Buat, V [0000-0003-3441-903X], Buitrago, F [0000-0002-2861-9812], Calabrò, A [0000-0003-2536-1614], Casey, CM [0000-0002-0930-6466], Castellano, M [0000-0001-9875-8263], Chávez Ortiz, ÓA [0000-0003-2332-5505], Ciesla, L [0000-0003-0541-2891], Cleri, NJ [0000-0001-7151-009X], Cohen, SH [0000-0003-3329-1337], Cole, JW [0000-0002-6348-1900], Cooke, KC [0000-0002-2200-9845], Cooper, MC [0000-0003-1371-6019], Cooray, AR [0000-0002-3892-0190], Costantin, L [0000-0001-6820-0015], Cox, IG [0000-0002-1803-794X], Croton, D [0000-0002-5009-512X], Daddi, E [0000-0002-3331-9590], Davé, R [0000-0003-2842-9434], De La Vega, A [0000-0002-6219-5558], Dekel, A [0000-0003-4174-0374], Elbaz, D [0000-0002-7631-647X], Estrada-Carpenter, V [0000-0001-8489-2349], Fernández, V [0000-0003-0531-5450], Finkelstein, KD [0000-0003-0792-5877], Freundlich, J [0000-0002-5245-7796], Fujimoto, S [0000-0001-7201-5066], García-Argumánez, Á [0000-0002-8365-5525], Gardner, JP [0000-0003-2098-9568], Gawiser, E [0000-0003-1530-8713], Gómez-Guijarro, C [0000-0002-4085-9165], Guo, Y [0000-0002-4162-6523], Hamblin, K [0000-0002-6292-4589], Hamilton, TS [0000-0002-9753-1769], Hathi, NP [0000-0001-6145-5090], Holwerda, BW [0000-0002-4884-6756], Hirschmann, M [0000-0002-3301-3321], Hutchison, TA [0000-0001-6251-4988], Jaskot, AE [0000-0002-6790-5125], Jha, SW [0000-0001-8738-6011], Jogee, S [0000-0002-1590-0568], Juneau, S [0000-0002-0000-2394], Jung, I [0000-0003-1187-4240], Kassin, SA [0000-0002-3838-8093], Le Bail, A [0000-0002-9466-2763], Leung, GCK [0000-0002-9393-6507], Lucas, RA [0000-0003-1581-7825], Magnelli, B [0000-0002-6777-6490], Matharu, J [0000-0002-7547-3385], McGrath, EJ [0000-0001-8688-2443], Merlin, E [0000-0001-6870-8900], and Apollo - University of Cambridge Repository

Subjects
5101 Astronomical Sciences, 5109 Space Sciences, 51 Physical Sciences, Galaxies and Cosmology
Abstract

We report the discovery of a candidate galaxy with a photo-z of z ∼ 12 in the first epoch of the James Webb Space Telescope (JWST) Cosmic Evolution Early Release Science Survey. Following conservative selection criteria, we identify a source with a robust z phot = 11.8 − 0.2 + 0.3 (1σ uncertainty) with m F200W = 27.3 and ≳7σ detections in five filters. The source is not detected at λ < 1.4 μm in deep imaging from both Hubble Space Telescope (HST) and JWST and has faint ∼3σ detections in JWST F150W and HST F160W, which signal a Lyα break near the red edge of both filters, implying z ∼ 12. This object (Maisie’s Galaxy) exhibits F115W − F200W > 1.9 mag (2σ lower limit) with a blue continuum slope, resulting in 99.6% of the photo-z probability distribution function favoring z > 11. All data-quality images show no artifacts at the candidate’s position, and independent analyses consistently find a strong preference for z > 11. Its colors are inconsistent with Galactic stars, and it is resolved (r h = 340 ± 14 pc). Maisie’s Galaxy has log M */M ⊙ ∼ 8.5 and is highly star-forming (log sSFR ∼ −8.2 yr−1), with a blue rest-UV color (β ∼ −2.5) indicating little dust, though not extremely low metallicity. While the presence of this source is in tension with most predictions, it agrees with empirical extrapolations assuming UV luminosity functions that smoothly decline with increasing redshift. Should follow-up spectroscopy validate this redshift, our universe was already aglow with galaxies less than 400 Myr after the Big Bang.

Published
2022
Full Text
View/download PDF

4. Star Formation Variability as a Probe for the Baryon Cycle within Galaxies

Author

Eun-jin Shin, Sandro Tacchella, Ji-hoon Kim, Kartheik G. Iyer, Vadim A. Semenov, Shin, Eun-jin [0000-0002-4639-5285], Tacchella, Sandro [0000-0002-8224-4505], Kim, Ji-hoon [0000-0003-4464-1160], Iyer, Kartheik G. [0000-0001-9298-3523], Semenov, Vadim A. [0000-0002-6648-7136], Apollo - University of Cambridge Repository, Shin, EJ [0000-0002-4639-5285], Tacchella, S [0000-0002-8224-4505], Kim, JH [0000-0003-4464-1160], Iyer, KG [0000-0001-9298-3523], and Semenov, VA [0000-0002-6648-7136]

Subjects
5101 Astronomical Sciences, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astronomy and Astrophysics, 51 Physical Sciences, Galaxies and Cosmology, Astrophysics - Astrophysics of Galaxies
Abstract

We investigate the connection of the regulation of star formation and the cycling of baryons within and in and out of galaxies. We use idealized numerical simulations of Milky Way-mass galaxies, in which we systemically vary the galaxy morphology (bulge-to-total mass ratio) and stellar feedback strength (total eight setups with 80 simulations). By following individual gas parcels through the disk, spiral arms, and massive star-forming clumps, we quantify how gas moves and oscillates through the different phases of the interstellar medium (ISM) and forms stars. We show that the residence time of gas in the dense ISM phase ($\tau_{\rm SF}$), the nature of spiral arms (strength, number), and the clump properties (number, mass function, and young star fraction) depend on both the galaxy morphology and stellar feedback. Based on these results, we quantify signatures of the baryon cycle within galaxies using the temporal and spatial power spectrum density (PSD) of the star formation history (SFH). Stronger stellar feedback leads to more bursty star formation while the correlation timescale of the SFH is longer, because stronger feedback dissolves the dense, star-forming ISM phase, leading to a more homogeneous ISM and a decrease in $\tau_{\rm SF}$. The bulge strength has a similar effect: the deep gravitational potential in a bulge-dominant galaxy imposes a strong shear force that effectively breaks apart gas clumps in the ISM; this subsequently inhibits the fragmentation of cool gas and therefore the star formation in the disk, leading to a decrease in the spatial power on scales of $\sim$ 1 kpc. We conclude that measurements of the temporal and spatial PSD of the SFH can provide constraints on the baryon cycle and the star formation process., Comment: 22 pages including 17 figures. Submitted to ApJ

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results