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Your search keyword '"Matharu, J"' showing total 18 results
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18 results on '"Matharu, J"'

1. JWST FRESCO: a comprehensive census of H$\beta$+[OIII] emitters at 6.8<z<9.0 in the GOODS fields

Author

Meyer, R. A., Oesch, P. A., Giovinazzo, E., Weibel, A., Brammer, G., Matthee, J., Naidu, R. P., Bouwens, R. J., Chisholm, J., Covelo-Paz, A., Fudamoto, Y., Maseda, M., Nelson, E., Shivaei, I., Xiao, M., Herard-Demanche, T., Illingworth, G. D., Kerutt, J., Kramarenko, I., Labbe, I., Leonova, E., Magee, D., Matharu, J., Lyon, G. Prieto, Reddy, N., Schaerer, D., Shapley, A., Stefanon, M., Wozniak, M. A., and Wuyts, S.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

We present the census of H$\beta$+[OIII] 4960,5008 \AA emitters at 6.87$ galaxies. We report a rapid decline of the [OIII] luminosity density at $z\gtrsim 6-7$ which cannot be explained by the evolution of the cosmic star-formation rate density. Finally we find that FRESCO detects in only 2h galaxies likely accounting for $\sim 10-20\%$ of the ionising budget at $z=7-8$ (assuming an escape fraction of 10%), raising the prospect of directly detecting a significant fraction of the sources of reionisation with JWST., Comment: 20 pages + appendices. Accepted in MNRAS. Public catalogue release at https://github.com/rameyer/fresco. V3: matching accepted version

Published
2024
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2. Resolved UV and optical color gradients reveal environmental influence on galaxy evolution at redshift z$\sim$1.6

Author

Cramer, William J., Noble, A. G., Rudnick, G., Pigarelli, A., Wilson, G., Bahé, Y. M., Cooper, M. C., Demarco, R., Matharu, J., Miller, T. B., Muzzin, A., Nantais, J., Sportsman, W., van Kampen, E., Webb, T. M. A., and Yee, H. K. C.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

The changes in colors across a galaxy are intimately connected to the galaxy's formation, growth, quenching history, and dust content. A particularly important epoch in the growth of galaxies is near $z \sim 2$ often referred to as `cosmic noon', where galaxies on average reach the peak of their star formation. We study a population of 125 cluster galaxies at $z \sim 1.6$ in three Hubble Space Telescope (HST) filters, F475W, F625W, and F160W, roughly corresponding to the rest-frame FUV, NUV, and r band, respectively. By comparing to a control sample of 200 field galaxies at similar redshift, we reveal clear, statistically significant differences in the overall spatially resolved colors and color gradients in galaxies across these two different environments. On average, cluster galaxies have redder UV colors in both the inner and outer regions bounded by $r_{\mathrm{50}}$, as well as an overall wider dispersion of outside-in color gradients. The presence of these observed differences, along with evidence from ancillary data from previous studies, strongly suggests that the environment drives these population-level color differences, by affecting the stellar populations and/or dust content., Comment: Accepted for publication in ApJ

Published
2024

3. Intracluster light in the core of z~2 galaxy proto-clusters

Author

Werner, S. V., Hatch, N. A., Matharu, J., Gonzalez, A. H., Bahé, Y. M., Mei, S., Noirot, G., and Wylezalek, D.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

Intracluster light is thought to originate from stars that were ripped away from their parent galaxies by gravitational tides and galaxy interactions during the build up of the cluster. The stars from such interactions will accumulate over time, so semi-analytic models suggest that the abundance of intracluster stars is negligible in young proto-clusters at z~2 and grows to around a quarter of the stellar mass in the oldest, most mature clusters. In contrast to these theoretical expectations, we report on the detection of intracluster light within two proto-clusters at z=2 using deep HST images. We use the colour of the intracluster light to estimate its mass-to-light ratio in annuli around the brightest cluster galaxies (BCG), up to a radius of 100 kpc. We find that $54\pm5$% and $71\pm3$% of the stellar mass in these regions is located more than 10 kpc away from the BCGs in the two proto-clusters. This low concentration is similar to BCGs in lower redshift clusters, and distinct from other massive proto-cluster galaxies. This suggests that intracluster stars are already present within the core 100 kpc of proto-clusters. We compare these observations to the Hydrangea hydrodynamical galaxy cluster simulations and find that intracluster stars are predicted to be a generic feature of group-sized halos at z=2. These intracluster stars will gradually move further away from the BCG as the proto-cluster assembles into a cluster., Comment: 14 pages, 9 figures, accepted for publication in MNRAS

Published
2023
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4. The JWST FRESCO Survey: Legacy NIRCam/Grism Spectroscopy and Imaging in the two GOODS Fields

Author

Oesch, P. A., Brammer, G., Naidu, R. P., Bouwens, R. J., Chisholm, J., Illingworth, G. D., Matthee, J., Nelson, E., Qin, Y., Reddy, N., Shapley, A., Shivaei, I., van Dokkum, P., Weibel, A., Whitaker, K., Wuyts, S., Covelo-Paz, A., Endsley, R., Fudamoto, Y., Giovinazzo, E., Herard-Demanche, T., Kerutt, J., Kramarenko, I., Labbe, I., Leonova, E., Lin, J., Magee, D., Marchesini, D., Maseda, M., Mason, C., Matharu, J., Meyer, R. A., Neufeld, C., Lyon, G. Prieto, Schaerer, D., Sharma, R., Shuntov, M., Smit, R., Stefanon, M., Wyithe, J. S. B., and Xiao, M.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

We present the JWST Cycle 1 53.8hr medium program FRESCO, short for "First Reionization Epoch Spectroscopically Complete Observations". FRESCO covers 62 arcmin$^2$ in each of the two GOODS/CANDELS fields for a total area of 124 arcmin$^2$ exploiting JWST's powerful new grism spectroscopic capabilities at near-infrared wavelengths. By obtaining ~2 hr deep NIRCam/grism observations with the F444W filter, FRESCO yields unprecedented spectra at R~1600 covering 3.8 to 5.0 $\mu$m for most galaxies in the NIRCam field-of-view. This setup enables emission line measurements over most of cosmic history, from strong PAH lines at z~0.2-0.5, to Pa$\alpha$ and Pa$\beta$ at z~1-3, HeI and [SIII] at z~2.5-4.5, H$\alpha$ and [NII] at z~5-6.5, up to [OIII] and H$\beta$ for z~7-9 galaxies, and possibly even [OII] at z~10-12. FRESCO's grism observations provide total line fluxes for accurately estimating galaxy stellar masses and calibrating slit-loss corrections of NIRSpec/MSA spectra in the same field. Additionally, FRESCO results in a mosaic of F182M, F210M, and F444W imaging in the same fields to a depth of ~28.2 mag (5 $\sigma$ in 0.32" diameter apertures). Together with this publication, the v1 imaging mosaics are released as high-level science products via MAST. Here, we describe the overall survey design and the key science goals that can be addressed with FRESCO. We also highlight several, early science results, including: spectroscopic redshifts of Lyman break galaxies that were identified almost 20 years ago, the discovery of broad-line active galactic nuclei at z>4, and resolved Pa$\alpha$ maps of galaxies at z~1.4. These results demonstrate the enormous power for serendipitous discovery of NIRCam/grism observations., Comment: 12 pages, 11 figures; MNRAS in press; for more information on the survey and data releases, see http://jwst-fresco.astro.unige.ch/ and https://archive.stsci.edu/hlsp/fresco

Published
2023

5. A large-scale kinematic study of molecular gas in high-z cluster galaxies: Evidence for high levels of kinematic asymmetry

Author

Cramer, W. J., Noble, A. G., Massingill, K., Cairns, J., Clements, D. L., Cooper, M. C., Demarco, R., Matharu, J., McDonald, M., Muzzin, A., Nantais, J., Rudnick, G., Übler, H., van Kampen, E., Webb, T. M. A., Wilson, G., and Yee, H. K. C.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

We investigate the resolved kinematics of the molecular gas, as traced by ALMA in CO (2-1), of 25 cluster member galaxies across three different clusters at a redshift of $z\sim1.6$. This is the first large-scale analysis of the molecular gas kinematics of cluster galaxies at this redshift. By separately estimating the rotation curve of the approaching and receding side of each galaxy via kinematic modeling, we quantify the difference in total circular velocity to characterize the overall kinematic asymmetry of each galaxy. 3/14 of the galaxies in our sample that we are able to model have similar degrees of asymmetry as that observed in galaxies in the field at similar redshift. However, this leaved 11/14 galaxies in our sample with significantly higher asymmetry, and some of these galaxies have degrees of asymmetry of up to $\sim$50 times higher than field galaxies observed at similar redshift. Some of these extreme cases also have one-sided tail-like morphology seen in the molecular gas, supporting a scenario of tidal and/or ram pressure interaction. Such stark differences in the kinematic asymmetry in clusters versus the field suggest the evolutionary influence of dense environments, established as being a major driver of galaxy evolution at low-redshift, is also active in the high-redshift universe., Comment: Submission pre-referee report

Published
2022
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6. A Large-scale Kinematic Study of Molecular Gas in High-z Cluster Galaxies: Evidence for High Levels of Kinematic Asymmetry

Author

Cramer, WJ, Noble, AG, Massingill, K, Cairns, J, Clements, DL, Cooper, MC, Demarco, R, Matharu, J, McDonald, M, Muzzin, A, Nantais, J, Rudnick, G, Übler, H, van Kampen, E, Webb, TMA, Wilson, G, and Yee, HKC

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

Abstract: We investigate the resolved kinematics of the molecular gas, as traced by the Atacama Large Millimeter/submillimeter Array in CO (2−1), of 25 cluster member galaxies across three different clusters at a redshift of z ∼ 1.6. This is the first large-scale analysis of the molecular gas kinematics of cluster galaxies at this redshift. By separately estimating the rotation curve of the approaching and receding sides of each galaxy via kinematic modeling, we quantify the difference in total circular velocity to characterize the overall kinematic asymmetry of each galaxy. 3/14 of the galaxies in our sample that we are able to model have similar degrees of asymmetry as that observed in galaxies in the field at similar redshift based on observations of mainly ionized gas. However, this leaves 11/14 galaxies in our sample with significantly higher asymmetry, and some of these galaxies have degrees of asymmetry of up to ∼50 times higher than field galaxies observed at similar redshift. Some of these extreme cases also have one-sided tail-like morphology seen in the molecular gas, supporting a scenario of tidal and/or ram pressure interaction. Such stark differences in the kinematic asymmetry in clusters versus the field suggest the evolutionary influence of dense environments, established as being a major driver of galaxy evolution at low redshift, is also active in the high-redshift universe.

Published
2023

7. The JWST FRESCO survey: legacy NIRCam/grism spectroscopy and imaging in the two GOODS fields

Author

Oesch, P A, primary, Brammer, G, additional, Naidu, R P, additional, Bouwens, R J, additional, Chisholm, J, additional, Illingworth, G D, additional, Matthee, J, additional, Nelson, E, additional, Qin, Y, additional, Reddy, N, additional, Shapley, A, additional, Shivaei, I, additional, van Dokkum, P, additional, Weibel, A, additional, Whitaker, K, additional, Wuyts, S, additional, Covelo-Paz, A, additional, Endsley, R, additional, Fudamoto, Y, additional, Giovinazzo, E, additional, Herard-Demanche, T, additional, Kerutt, J, additional, Kramarenko, I, additional, Labbe, I, additional, Leonova, E, additional, Lin, J, additional, Magee, D, additional, Marchesini, D, additional, Maseda, M, additional, Mason, C, additional, Matharu, J, additional, Meyer, R A, additional, Neufeld, C, additional, Prieto Lyon, G, additional, Schaerer, D, additional, Sharma, R, additional, Shuntov, M, additional, Smit, R, additional, Stefanon, M, additional, Wyithe, J S B, additional, and Xiao, M, additional

Published
2023
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9. 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

10. 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
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11. The JWST FRESCO survey:legacy NIRCam/grism spectroscopy and imaging in the two GOODS fields

Author

Oesch, P A, Brammer, G, Naidu, R P, Bouwens, R J, Chisholm, J, Illingworth, G D, Matthee, J, Nelson, E, Qin, Y, Reddy, N, Shapley, A, Shivaei, I, Van dokkum, P, Weibel, A, Whitaker, K, Wuyts, S, Covelo-paz, A, Endsley, R, Fudamoto, Y, Giovinazzo, E, Herard-demanche, T, Kerutt, J, Kramarenko, I, Labbe, I, Leonova, E, Lin, J, Magee, D, Marchesini, D, Maseda, M, Mason, C, Matharu, J, Meyer, R A, Neufeld, C, Prieto lyon, G, Schaerer, D, Sharma, R, Shuntov, M, Smit, R, Stefanon, M, Wyithe, J S B, Xiao, M, Oesch, P A, Brammer, G, Naidu, R P, Bouwens, R J, Chisholm, J, Illingworth, G D, Matthee, J, Nelson, E, Qin, Y, Reddy, N, Shapley, A, Shivaei, I, Van dokkum, P, Weibel, A, Whitaker, K, Wuyts, S, Covelo-paz, A, Endsley, R, Fudamoto, Y, Giovinazzo, E, Herard-demanche, T, Kerutt, J, Kramarenko, I, Labbe, I, Leonova, E, Lin, J, Magee, D, Marchesini, D, Maseda, M, Mason, C, Matharu, J, Meyer, R A, Neufeld, C, Prieto lyon, G, Schaerer, D, Sharma, R, Shuntov, M, Smit, R, Stefanon, M, Wyithe, J S B, and Xiao, M

Published
2023

13. A Large-scale Kinematic Study of Molecular Gas in High-z Cluster Galaxies:Evidence for High Levels of Kinematic Asymmetry

Author

Cramer, W. J., Noble, A. G., Massingill, K., Cairns, J., Clements, D. L., Cooper, M. C., Demarco, R., Matharu, J., McDonald, M., Muzzin, A., Nantais, J., Rudnick, G., uebler, H., van Kampen, E., Webb, T. M. A., Wilson, G., Yee, H. K. C., Cramer, W. J., Noble, A. G., Massingill, K., Cairns, J., Clements, D. L., Cooper, M. C., Demarco, R., Matharu, J., McDonald, M., Muzzin, A., Nantais, J., Rudnick, G., uebler, H., van Kampen, E., Webb, T. M. A., Wilson, G., and Yee, H. K. C.

Abstract

We investigate the resolved kinematics of the molecular gas, as traced by the Atacama Large Millimeter/submillimeter Array in CO (2-1), of 25 cluster member galaxies across three different clusters at a redshift of z similar to 1.6. This is the first large-scale analysis of the molecular gas kinematics of cluster galaxies at this redshift. By separately estimating the rotation curve of the approaching and receding sides of each galaxy via kinematic modeling, we quantify the difference in total circular velocity to characterize the overall kinematic asymmetry of each galaxy. 3/14 of the galaxies in our sample that we are able to model have similar degrees of asymmetry as that observed in galaxies in the field at similar redshift based on observations of mainly ionized gas. However, this leaves 11/14 galaxies in our sample with significantly higher asymmetry, and some of these galaxies have degrees of asymmetry of up to similar to 50 times higher than field galaxies observed at similar redshift. Some of these extreme cases also have one-sided tail-like morphology seen in the molecular gas, supporting a scenario of tidal and/or ram pressure interaction. Such stark differences in the kinematic asymmetry in clusters versus the field suggest the evolutionary influence of dense environments, established as being a major driver of galaxy evolution at low redshift, is also active in the high-redshift universe.

Published
2023

14. The open I

Author

Matharu, J

Subjects
Philosophy, Ordinary Language Philosop, Metaphysics, Phenomenology, Philosophy of mind
Abstract

This essay brings together insights from Edmund Husserl in the phenomenological tradition and from Elizabeth Anscombe in the ‘ordinary language’ philosophical tradition, to resolve a puzzle of how it is that we can think of non-existents. This involves distinguishing two senses of ‘to think of—’, and arguing that each has a distinctive sort of object. Their distinction is conceptually related to our capacity to be fallible or infallible about things, and our status as subjects of thought, irreducible to any physical object, but not equivalent to a special non-physical substance. To be a subject of thought is to be presented in mind with things about which one’s infallible. But the subject as such is not a ‘thing’. It is that which is individuated by which objects are presented infallibly to it, rather than by a substance with whom these or other objects come into material contact. An entity that doesn’t exist is not simply ‘nothing’. It has features determined either by what someone would say infallibly, granting honesty and correct use of terms, in answer to, “What are you thinking of?”, or by reference to a text, like a fictional story. Both routes are a matter of sentences determining what it is correct or incorrect to say in answer to, “What is it?” questions, which therefore determine what descriptions of the thing (e.g. as a tree or something else) are true or false. Existent things are those entities facts about which are determined by what would be perceptually experienced infallibly given a certain position in the physical environment. This implies, I argue, that the world in the broadest sense (to include both what is real and unreal) is inherently capable of being thought of. What is objectively the case isn’t hidden from us, but given only through subjective experience. So there is nothing that is ‘beyond’ experience, even if many things exist about which we’ve not yet thought or which we cannot, given our perceptual apparatus, personally experience except as the objects of other beings’ experience. This is consistent with Husserl’s version of transcendental idealism. The means by which I come to the conclusions I do involves a close reading of Anscombe’s paper, “The Intentionality of Sensation”. This involves distinguishing objects of thought that are things (real or unreal) from objects of thought that aren’t ‘things’ in really any sense at all. I call these simply ‘individuals as such’. They can only be individuated by reference to special types of question in which they count as ‘given’ by one’s describing not them directly but things and objects which non-identical with one another and non-equivalent to the individual they ‘are’. This idea of individuals through questions is brought together with Husserl’s methodological strategy of drawing ‘brackets’ round a certain attitude to the world, in order to reflect on the conditions of possibility for our taking such an attitude and having objective knowledge by way of it at all. That strategy and the notion of a ‘pure’ individual, together indicate a way of thinking about thoughts, thinkers and what is thought of that puts immersion into shared practices with language, particularly with questions, at the heart of philosophical method.

Published
2022

15. Resolving CO (2−1) in z ∼ 1.6 Gas-rich Cluster Galaxies with ALMA: Rotating Molecular Gas Disks with Possible Signatures of Gas Stripping

Author

MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology. Department of Physics, Noble, AG, Muzzin, A, McDonald, Michael A., Rudnick, G, Matharu, J, Cooper, MC, Demarco, R, Lidman, C, Nantais, J, van Kampen, E, Webb, TMA, Wilson, G, Yee, HKC, MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology. Department of Physics, Noble, AG, Muzzin, A, McDonald, Michael A., Rudnick, G, Matharu, J, Cooper, MC, Demarco, R, Lidman, C, Nantais, J, van Kampen, E, Webb, TMA, Wilson, G, and Yee, HKC

Abstract

© 2019. The American Astronomical Society. All rights reserved. We present the first spatially resolved observations of molecular gas in a sample of cluster galaxies beyond z > 0.1. Using ALMA, we detect CO (2-1) in eight z ∼ 1.6 cluster galaxies, all within a single 70″ primary beam. The cluster, SpARCS-J0225, was discovered by the Spitzer Adaptation of the Red-sequence Cluster Survey, and is replete with gas-rich galaxies in close proximity, thus affording an efficient multiplexing strategy to amass the first sample of resolved CO in distant clusters. Mapping out the kinematic structure and morphology of molecular gas on ∼3.5 kpc scales reveals rotating gas disks in the majority of the galaxies, and some kinematic peculiarities, including a central gas void, a merger, and one-sided gas tails. We find that the extent of the molecular gas is slightly smaller than that of the optical HST stellar component; this is even more pronounced in low-redshift Virgo cluster galaxies. However, limited by small sample sizes of spatially resolved CO, we are unable to differentiate the distribution of stellar-to-gas radii between cluster and field environments at high redshift. Thus, at first glance, while the cluster galaxies generally look like galaxies infalling from the field, with typical main-sequence star formation rates and massive molecular gas reservoirs situated in rotating disks, they have potentially remarkable attributes, including elevated gas fractions, slightly smaller CO disks, and asymmetric gas tails. Taken in tandem, these signatures are tentative evidence for gas stripping in the z ∼ 1.6 cluster, though verification of these trends will require larger samples.

Published
2022

16. The Physical Conditions of Emission-line Galaxies at Cosmic Dawn from JWST/NIRSpec Spectroscopy in the SMACS 0723 Early Release Observations

Author

Jonathan R. Trump, Pablo Arrabal Haro, Raymond C. Simons, Bren E. Backhaus, Ricardo O. Amorín, Mark Dickinson, Vital Fernández, Casey Papovich, David C. Nicholls, Lisa J. Kewley, Samantha W. Brunker, John J. Salzer, Stephen M. Wilkins, Omar Almaini, Micaela B. Bagley, Danielle A. Berg, Rachana Bhatawdekar, Laura Bisigello, Véronique Buat, Denis Burgarella, Antonello Calabrò, Caitlin M. Casey, Laure Ciesla, Nikko J. Cleri, Justin W. Cole, M. C. Cooper, Asantha R. Cooray, Luca Costantin, Darren Croton, Henry C. Ferguson, Steven L. Finkelstein, Seiji Fujimoto, Jonathan P. Gardner, Eric Gawiser, Mauro Giavalisco, Andrea Grazian, Norman A. Grogin, Nimish P. Hathi, Michaela Hirschmann, Benne W. Holwerda, Marc Huertas-Company, Taylor A. Hutchison, Shardha Jogee, Stéphanie Juneau, Intae Jung, Jeyhan S. Kartaltepe, Allison Kirkpatrick, Dale D. Kocevski, Anton M. Koekemoer, Jennifer M. Lotz, Ray A. Lucas, Benjamin Magnelli, Jasleen Matharu, Pablo G. Pérez-González, Nor Pirzkal, Marc Rafelski, Caitlin Rose, Lise-Marie Seillé, Rachel S. Somerville, Amber N. Straughn, Sandro Tacchella, Brittany N. Vanderhoof, Benjamin J. Weiner, Stijn Wuyts, L. Y. Aaron Yung, Jorge A. Zavala, Trump, Jonathan R [0000-0002-1410-0470], Haro, Pablo Arrabal [0000-0002-7959-8783], Simons, Raymond C [0000-0002-6386-7299], Backhaus, Bren E [0000-0001-8534-7502], Amorín, Ricardo O [0000-0001-5758-1000], Dickinson, Mark [0000-0001-5414-5131], Fernández, Vital [0000-0003-0531-5450], Papovich, Casey [0000-0001-7503-8482], Nicholls, David C [0000-0003-0892-5203], Kewley, Lisa J [0000-0001-8152-3943], Brunker, Samantha W [0000-0001-6776-2550], Salzer, John J [0000-0001-8483-603X], Wilkins, Stephen M [0000-0003-3903-6935], Almaini, Omar [0000-0001-9328-3991], Bagley, Micaela B [0000-0002-9921-9218], Berg, Danielle A [0000-0002-4153-053X], Bhatawdekar, Rachana [0000-0003-0883-2226], Bisigello, Laura [0000-0003-0492-4924], Buat, Véronique [0000-0003-3441-903X], Burgarella, Denis [0000-0002-4193-2539], Calabrò, Antonello [0000-0003-2536-1614], Casey, Caitlin M [0000-0002-0930-6466], Ciesla, Laure [0000-0003-0541-2891], Cleri, Nikko J [0000-0001-7151-009X], Cole, Justin W [0000-0002-6348-1900], Cooper, MC [0000-0003-1371-6019], Cooray, Asantha R [0000-0002-3892-0190], Costantin, Luca [0000-0001-6820-0015], Croton, Darren [0000-0002-5009-512X], Ferguson, Henry C [0000-0001-7113-2738], Finkelstein, Steven L [0000-0001-8519-1130], 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], Hathi, Nimish P [0000-0001-6145-5090], 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], Jogee, Shardha [0000-0002-1590-0568], Juneau, Stéphanie [0000-0002-0000-2394], Jung, Intae [0000-0003-1187-4240], Kartaltepe, Jeyhan S [0000-0001-9187-3605], Kirkpatrick, Allison [0000-0002-1306-1545], Kocevski, Dale D [0000-0002-8360-3880], Koekemoer, Anton M [0000-0002-6610-2048], Lotz, Jennifer M [0000-0003-3130-5643], Lucas, Ray A [0000-0003-1581-7825], Magnelli, Benjamin [0000-0002-6777-6490], Matharu, Jasleen [0000-0002-7547-3385], Pérez-González, Pablo G [0000-0003-4528-5639], Pirzkal, Nor [0000-0003-3382-5941], Rafelski, Marc [0000-0002-9946-4731], Rose, Caitlin [0000-0002-8018-3219], Seillé, Lise-Marie [0000-0001-7755-4755], Somerville, Rachel S [0000-0002-6748-6821], Straughn, Amber N [0000-0002-4772-7878], Tacchella, Sandro [0000-0002-8224-4505], Vanderhoof, Brittany N [0000-0002-8163-0172], Weiner, Benjamin J [0000-0001-6065-7483], Wuyts, Stijn [0000-0003-3735-1931], Aaron Yung, LY [0000-0003-3466-035X], Zavala, Jorge A [0000-0002-7051-1100], Apollo - University of Cambridge Repository, Trump, JR [0000-0002-1410-0470], Haro, PA [0000-0002-7959-8783], Simons, RC [0000-0002-6386-7299], Backhaus, BE [0000-0001-8534-7502], Amorín, RO [0000-0001-5758-1000], Dickinson, M [0000-0001-5414-5131], Fernández, V [0000-0003-0531-5450], Papovich, C [0000-0001-7503-8482], Nicholls, DC [0000-0003-0892-5203], Kewley, LJ [0000-0001-8152-3943], Brunker, SW [0000-0001-6776-2550], Salzer, JJ [0000-0001-8483-603X], Wilkins, SM [0000-0003-3903-6935], Almaini, O [0000-0001-9328-3991], Bagley, MB [0000-0002-9921-9218], Berg, DA [0000-0002-4153-053X], Bhatawdekar, R [0000-0003-0883-2226], Bisigello, L [0000-0003-0492-4924], Buat, V [0000-0003-3441-903X], Burgarella, D [0000-0002-4193-2539], Calabrò, A [0000-0003-2536-1614], Casey, CM [0000-0002-0930-6466], Ciesla, L [0000-0003-0541-2891], Cleri, NJ [0000-0001-7151-009X], Cole, JW [0000-0002-6348-1900], Cooray, AR [0000-0002-3892-0190], Costantin, L [0000-0001-6820-0015], Croton, D [0000-0002-5009-512X], Ferguson, HC [0000-0001-7113-2738], Finkelstein, SL [0000-0001-8519-1130], 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], Hathi, NP [0000-0001-6145-5090], 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], Jogee, S [0000-0002-1590-0568], Juneau, S [0000-0002-0000-2394], Jung, I [0000-0003-1187-4240], Kartaltepe, JS [0000-0001-9187-3605], Kirkpatrick, A [0000-0002-1306-1545], Kocevski, DD [0000-0002-8360-3880], Koekemoer, AM [0000-0002-6610-2048], Lotz, JM [0000-0003-3130-5643], Lucas, RA [0000-0003-1581-7825], Magnelli, B [0000-0002-6777-6490], Matharu, J [0000-0002-7547-3385], Pérez-González, PG [0000-0003-4528-5639], Pirzkal, N [0000-0003-3382-5941], Rafelski, M [0000-0002-9946-4731], Rose, C [0000-0002-8018-3219], Seillé, LM [0000-0001-7755-4755], Somerville, RS [0000-0002-6748-6821], Straughn, AN [0000-0002-4772-7878], Tacchella, S [0000-0002-8224-4505], Vanderhoof, BN [0000-0002-8163-0172], Weiner, BJ [0000-0001-6065-7483], Wuyts, S [0000-0003-3735-1931], and Zavala, JA [0000-0002-7051-1100]

Subjects
similar-to 2, SIMILAR-TO 2, NEAR-INFRARED SPECTROSCOPY, COLLISION STRENGTHS, near-infrared spectroscopy, MASS-METALLICITY RELATION, FOS: Physical sciences, CHEMICAL-COMPOSITION, Galaxies and Cosmology, collision strengths, LY-ALPHA, atomic database, STAR-FORMING GALAXIES, MOSDEF SURVEY, mosdef survey, NEBULAR EMISSION, Astronomy and Astrophysics, mass-metallicity relation, star-forming galaxies, Astrophysics - Astrophysics of Galaxies, ATOMIC DATABASE, ly-alpha, nebular emission, Space and Planetary Science, 5101 Astronomical Sciences, Astrophysics of Galaxies (astro-ph.GA), chemical-composition, 51 Physical Sciences
Abstract

We present rest-frame optical emission-line flux ratio measurements for five $z>5$ galaxies observed by the JWST Near-Infared Spectrograph (NIRSpec) in the SMACS 0723 Early Release Observations. We add several quality-control and post-processing steps to the NIRSpec pipeline reduction products in order to ensure reliable relative flux calibration of emission lines that are closely separated in wavelength, despite the uncertain \textit{absolute} spectrophotometry of the current version of the reductions. Compared to $z\sim3$ galaxies in the literature, the $z>5$ galaxies have similar [OIII]$\lambda$5008/H$\beta$ ratios, similar [OIII]$\lambda$4364/H$\gamma$ ratios, and higher ($\sim$0.5 dex) [NeIII]$\lambda$3870/[OII]$\lambda$3728 ratios. We compare the observations to MAPPINGS V photoionization models and find that the measured [NeIII]$\lambda$3870/[OII]$\lambda$3728, [OIII]$\lambda$4364/H$\gamma$, and [OIII]$\lambda$5008/H$\beta$ emission-line ratios are consistent with an interstellar medium that has very high ionization ($\log(Q) \simeq 8-9$, units of cm~s$^{-1}$), low metallicity ($Z/Z_\odot \lesssim 0.2$), and very high pressure ($\log(P/k) \simeq 8-9$, units of cm$^{-3}$). The combination of [OIII]$\lambda$4364/H$\gamma$ and [OIII]$\lambda$(4960+5008)/H$\beta$ line ratios indicate very high electron temperatures of $4.1, Comment: Accepted for publication in AAS Journals. 14 pages, 6 figures, 3 tables

Published
2023
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17. Formation of a low-mass galaxy from star clusters in a 600-million-year-old Universe.

Author

Mowla L, Iyer K, Asada Y, Desprez G, Tan VYY, Martis N, Sarrouh G, Strait V, Abraham R, Bradač M, Brammer G, Muzzin A, Pacifici C, Ravindranath S, Sawicki M, Willott C, Estrada-Carpenter V, Jahan N, Noirot G, Matharu J, Rihtaršič G, and Zabl J

Abstract

The most distant galaxies detected were seen when the Universe was a scant 5% of its current age. At these times, progenitors of galaxies such as the Milky Way were about 10,000 times less massive. Using the James Webb Space Telescope (JWST) combined with magnification from gravitational lensing, these low-mass galaxies can not only be detected but also be studied in detail. Here we present JWST observations of a strongly lensed galaxy at z spec  = 8.296 ± 0.001, showing massive star clusters (the Firefly Sparkle) cocooned in a diffuse arc in the Canadian Unbiased Cluster Survey (CANUCS) 1 . The Firefly Sparkle exhibits traits of a young, gas-rich galaxy in its early formation stage. The mass of the galaxy is concentrated in 10 star clusters (49-57% of total mass), with individual masses ranging from 10 5 M ⊙ to 10 6 M ⊙ . These unresolved clusters have high surface densities (>10 3 M ⊙  pc - 2 ), exceeding those of Milky Way globular clusters and young star clusters in nearby galaxies. The central cluster shows a nebular-dominated spectrum, low metallicity, high gas density and high electron temperature, hinting at a top-heavy initial mass function. These observations provide our first spectrophotometric view of a typical galaxy in its early stages, in a 600-million-year-old Universe., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Published
2024
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18. Evaluating the Risk of Suicide and Violence in Severe Mental Illness: A Feasibility Study of Two Risk Assessment Tools (OxMIS and OxMIV) in General Psychiatric Settings.

Author

Beaudry G, Canal-Rivero M, Ou J, Matharu J, Fazel S, and Yu R

Abstract

Background: Two OxRisk risk assessment tools, the Oxford Mental Illness and Suicide (OxMIS) and the Oxford Mental Illness and Violence (OxMIV), were developed and validated using national linked registries in Sweden, to assess suicide and violence risk in individuals with severe mental illness (schizophrenia-spectrum disorders and bipolar disorders). In this study, we aim to examine the feasibility and acceptability of the tools in three different clinical services., Method: We employed a two-step mixed-methods approach, by combining quantitative analyses of risk scores of 147 individual patients, and thematic analyses of qualitative data. First, 38 clinicians were asked to use OxMIS and OxMIV when conducting their routine risk assessments in patients with severe mental illness. The risk scores for each patient (which provide a probability of the outcome over 12 months) were then compared to the unstructured clinical risk assessment made by the treating clinician. Second, we carried out semi-structured interviews with the clinicians on the acceptability and utility of the tools. Thematic analysis was conducted on the qualitative data to identify common themes, in terms of the utility, accuracy, and acceptability of the tools. The investigations were undertaken in three general adult psychiatric clinics located in the cities of Barcelona and Sevilla (Spain), and Changsha (China)., Results: Median risk probabilities over 12 months for OxMIS were 1.0% in the Spanish patient sample and 1.9% in the Chinese sample. For OxMIV, they were 0.7% (Spanish) and 0.8% (Chinese). In the thematic analysis, clinicians described the tools as easy to use, and thought that the risk score improved risk management. Potential additions to predictors were suggested, including family history and the patient's support network. Concordance rates of risk estimates between the tools and clinicians was high for violence (94.4%; 68/72) and moderate for suicide (50.0%; 36/72)., Conclusion: Both OxMIS and OxMIV are feasible and practical in different general adult psychiatric settings. Clinicians interviewed found that both tools provide a useful structured approach to estimate the risk of suicide and violence. Risk scores from OxMIS and OxMIV can also be used to assist clinical decision-making for future management., Competing Interests: SF was part of the study team that first developed OxMIV and OxMIS. He has not received any compensation in relation to their development, use or translation. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Beaudry, Canal-Rivero, Ou, Matharu, Fazel and Yu.)

Published
2022
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