☆ 4.6 Article

DISCOVERY OF THREE DISTANT, COLD BROWN DWARFS IN THE WFC3 INFRARED SPECTROSCOPIC PARALLELS SURVEY

ASTROPHYSICAL JOURNAL LETTERS (2012)

Journal

ASTROPHYSICAL JOURNAL LETTERS

Volume 752, Issue 1, Pages -

Publisher

IOP PUBLISHING LTD

DOI: 10.1088/2041-8205/752/1/L14

Keywords

brown dwarfs; Galaxy: abundances; infrared: stars; stars: luminosity function, mass function

Categories

Astronomy & Astrophysics

Funding

Carnegie Observatories Graduate Research Fellowship
STFC [ST/G001774/1, ST/H002456/1] Funding Source: UKRI
Science and Technology Facilities Council [ST/G001774/1, ST/H002456/1] Funding Source: researchfish

Ask authors/readers for more resources

Protocol

Community support

Reagent

Community support

Abstract

We present the discovery of three late-type (>= T4.5) brown dwarfs, including a probable Y dwarf, in the WFC3 Infrared Spectroscopic Parallels (WISP) survey. We use the G141 grism spectra to determine the spectral types of the dwarfs and derive distance estimates based on a comparison with nearby T dwarfs with known parallaxes. These are the most distant spectroscopically confirmed T/Y dwarfs, with the farthest at an estimated distance of similar to 400 pc. We compare the number of cold dwarfs found in the WISP survey with simulations of the brown dwarf mass function. The number found is generally consistent with an initial stellar mass function dN/dM alpha M-alpha with alpha = 0.0-0.5, although the identification of a Y dwarf is somewhat surprising and may be indicative of either a flatter absolute magnitude/spectral-type relation than previously reported or an upturn in the number of very-late-type brown dwarfs in the observed volume.

Authors

I am an author on this paper

Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.6

Not enough ratings

Secondary Ratings

Novelty

-

Significance

-

Scientific rigor

-

Rate this paper

Recommended

Article Astronomy & Astrophysics

A spectrophotometric analysis of cool white dwarfs in the Gaia and pan-STARRS footprint

Alexandre Caron, P. Bergeron, Simon Blouin, S. K. Leggett

Summary: In this study, we present a analysis of 2880 cool white dwarfs within 100 pc of the Sun and cooler than T-eff similar to 10 000 K, with rigorous photometry and parallax measurement. We find evidence of a transformation from DA stars to He-atmosphere white dwarfs in the range T-eff = 6500-5500 K, while most DC white dwarfs have H atmospheres at even cooler temperatures (T-eff ? 5200 K). We also discover that DQ, DZ, and DC white dwarfs may form a more homogeneous population than previously believed.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2023)

Add to Collection

Article Astronomy & Astrophysics

On the precision of full-spectrum fitting of simple stellar populations - II. The dependence on star cluster mass in the wavelength range 0.3-5.0 μm

Paul Goudfrooij, Randa S. Asa'd

Summary: This paper explores the impact of star cluster mass on the accuracy and precision of age and metallicity determination in simple stellar populations (SSPs) using the full-spectrum fitting technique. The study compares simulated spectra of star clusters across different mass ranges with SSP model spectra in various wavelength regimes to determine best-fitting ages and metallicities. The research highlights the significance of the mid-IR wavelength regime in identifying young massive clusters in dusty star-forming regions in distant galaxies.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2021)

Add to Collection

Article Astronomy & Astrophysics

Local stellar formation history from the 40 pc white dwarf sample

E. Cukanovaite, P-e Tremblay, S. Toonen, K. D. Temmink, Christopher J. Manser, M. W. O'Brien, J. McCleery

Summary: We use the Gaia-defined 40 pc white dwarf sample to derive the local stellar formation history. This is the largest sample of white dwarfs with available spectroscopy, allowing for classification of chemical abundances and accurate determination of atmospheric parameters. Our population synthesis model shows that a uniform stellar formation history over the past 10.5 billion years fits well with the observed distribution of absolute Gaia G magnitudes. We test the robustness of our model by varying several assumptions, and find that the relative stellar formation rate is not significantly affected, although the onset of stellar formation is sensitive to input parameters like white dwarf cooling models.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2023)

Add to Collection

Article Astronomy & Astrophysics

Completing the protostellar luminosity function in Cygnus-X with SOFIA/FORCAST imaging

Yingjie Cheng, Robert A. Gutermuth, Stella Offner, Mark Heyer, Hans Zinnecker, S. Thomas Megeath, Riwaj Pokhrel

Summary: We present a new SOFIA/FORCAST mid-infrared survey of luminous protostars and crowded star-forming environments in Cygnus X. By combining data from Spitzer, UKIDSS, and SOFIA/FORCAST, we derive bolometric luminosities for over 1000 sources in the region and identify 63 new luminous protostar candidates. Our study reveals an excess of high luminosity sources in regions of high stellar density or gas column density.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2022)

Add to Collection

Article Astronomy & Astrophysics

The statistical properties of stars at redshift, z=5, compared with the present epoch

Matthew R. Bate

Summary: We report the statistical properties of stars and brown dwarfs in three radiation hydrodynamical simulations of star cluster formation at different metallicities. The simulations take into account the cosmic microwave background radiation appropriate for star formation at redshift z = 5. We find that the metallicity affects the characteristic stellar mass, with higher metallicity leading to larger characteristic mass and a deficit of brown dwarfs and low-mass stars. The multiplicity of M-dwarfs also decreases with increasing metallicity at z = 5.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2023)

Add to Collection

Article Astronomy & Astrophysics

New constraints on the minimum mass for thermonuclear lithium burning in brown dwarfs

E. L. Martin, N. Lodieu, C. del Burgo

Summary: The theory of substellar evolution predicts the existence of a mass boundary between lithium and non-lithium brown dwarfs. This study presents new observations of binary systems and confirms the sharp transition in mass for lithium depletion in brown dwarfs as predicted by theoretical calculations.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2022)

Add to Collection

Article Astronomy & Astrophysics

Top-heavy stellar mass distribution in galactic nuclei inferred from the universally high abundance ratio of [Fe/Mg]

Daisuke Toyouchi, Kohei Inayoshi, Miho N. Ishigaki, Nozomu Tominaga

Summary: Recent observations of active galactic nuclei (AGNs) have shown a high Fe II/Mg II line-flux ratio in their broad-line regions, nearly independent of redshift up to z greater than or similar to 6. The high flux ratio requires rapid production of iron in galactic nuclei to reach an abundance ratio of [Fe/Mg] greater than or similar to 0.2 as high as those observed in matured galaxies in the local universe. We propose a possible explanation of rapid iron enrichment in AGNs by massive star formation that follows a top-heavy initial mass function (IMF) with a power-law index of Gamma larger than the canonical value of Gamma = -2.35 for a Salpeter IMF. Taking into account metal production channels from different types of SNe, we find that the high value of [Fe/Mg] greater than or similar to 0.2 requires the IMF to be characterized with Gamma greater than or similar to -1 (Gamma greater than or similar to 0) and a high-mass cutoff at M-max similar or equal to 100-150 M-circle dot (M-max greater than or similar to 250 M-circle dot). Given the conditions, core-collapse SNe with M-* greater than or similar to 70 M-circle dot and pair-instability SNe give a major contribution for iron enrichment. Such top-heavy stellar IMFs would be a natural consequence from mass growth of stars formed in dense AGN discs under Bondi-like gas accretion that is regulated by feedback at M-* greater than or similar to 10 M-circle dot. The massive stellar population formed in AGN discs also leave stellar-mass black hole remnants, whose mergers associated with gravitational-wave emission account for at most 10 per cent of the merger rate inferred from LIGONirgo observations to simultaneously explain the high [Fe/Mg] ratio with metal ejection.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2022)

Add to Collection

Article Astronomy & Astrophysics

The Gaia DR2 halo white dwarf population: the luminosity function, mass distribution, and its star formation history

Santiago Torres, Alberto Rebassa-Mansergas, Maria E. Camisassa, Roberto Raddi

Summary: Analysis of 95 halo white dwarf candidates using Gaia data reveals interesting findings, such as possible evidence of a cut-off in the luminosity function and an estimated age of about 12 billion years for the halo population. The mass distribution peaks at 0.589 solar masses, with majority of white dwarfs below 0.6 solar masses and only a few more massive ones. Three white dwarfs in the sample have ages exceeding 12 billion years, with J1312-4728 being the oldest known white dwarf at 12.41 billion years. The star formation history indicates a burst of activity around 10 to 12 billion years ago, extending up to 8 billion years, with a peak around 11 billion years, consistent with the Gaia-Enceladus encounter.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2021)

Add to Collection

Article Astronomy & Astrophysics

The Pristine Inner Galaxy Survey (PIGS) VII: a discovery of the first inner Galaxy CEMP-r/s star

L. Mashonkina, A. Arentsen, D. S. Aguado, A. Smogorzhevskii, M. Hampel, A. Karakas, F. Sestito, N. F. Martin, K. A. Venn, J. I. Gonzalez Hernandez

Summary: This study presents high-resolution spectroscopic follow-up of the carbon-enhanced metal-poor star Pristine 184237. The atmospheric parameters and abundances for 32 elements were determined, revealing unique element abundance patterns. It is the first star of the CEMP-r/s subclass identified in the inner Galaxy.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2023)

Add to Collection

Article Astronomy & Astrophysics

First observations of warm and cold methanol in Class 0/I proto-brown dwarfs

B. Riaz, W-F Thi, M. N. Machida

Summary: We conducted the first molecular line survey to search for methanol (CH3OH) in 14 Class 0/I protobrown dwarfs (proto-BDs). The results showed emission in 14 CH3OH transition lines, with upper state energy levels ranging from 7-49 K and critical densities of 10(5)-10(9) cm(-3). The high-excitation lines likely probe the warm corino region in the proto-BDs, while the low-excitation lines trace the cold gas. The column density for the cold component is higher than the warm component, and the ortho-to-para ratios of CH3OH range between 0.3 and 2.3.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2023)

Add to Collection

Article Astronomy & Astrophysics

Deuterium chemistry and D/H ratios in Class 0/I proto-brown dwarfs

B. Riaz, W-F Thi

Summary: In this study, a detailed observational survey of deuterated species in proto-brown dwarfs and brown dwarfs was conducted. The results show higher ratios and narrower ranges for certain deuterium-hydrogen ratios, indicating the importance of both gas-phase and grain surface reactions in deuterium fractionation. The dense and cold interior of proto-brown dwarfs provides suitable conditions for efficient deuterium fractionation, with no correlation between deuterium-hydrogen ratios and evolutionary stage or CO depletion factors.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2022)

Add to Collection

Article Astronomy & Astrophysics

A survey of HDCO and D2CO towards Class 0/I proto-brown dwarfs

B. Riaz, W-F Thi

Summary: Deuterium fractionation can provide insights into the physical and chemical conditions during the early stage of brown dwarf formation. Observations of formaldehyde isotopologues in proto-brown dwarfs reveal similar abundance ratios of D2CO/HDCO, HDCO/H2CO, and D2CO/H2CO as seen in low-mass protostars, suggesting the formation of HDCO and D2CO through grain surface reactions in the cold interiors of proto-brown dwarfs at an early stage of formation.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2022)

Add to Collection

Article Astronomy & Astrophysics

A machine learning approach to mapping baryons on to dark matter haloes using the EAGLE and C-EAGLE simulations

Christopher C. Lovell, Stephen M. Wilkins, Peter A. Thomas, Matthieu Schaller, Carlton M. Baugh, Giulio Fabbian, Yannick Bahe

Summary: This study introduces a new method using a machine learning framework to explore the relationship between galaxies and dark matter halos in the universe, enabling predictions of galaxy properties at a lower computational cost. By training the model in different environments, researchers can infer the bias of galaxy evolution, allowing application to larger volumes of dark-matter-only simulations.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2022)

Add to Collection

Article Astronomy & Astrophysics

A population synthesis fitting of the Gaia resolved white dwarf binary population within 100 pc

S. Torres, P. Canals, F. M. Jimenez-Esteban, A. Rebassa-Mansergas, E. Solano

Summary: The Gaia mission has provided valuable information about the white dwarf population in our Galaxy, with a sample that can be considered as practically complete. Through comoving pairs identification, a precise fraction of double-degenerate and white dwarf plus main-sequence stars among all white dwarfs has been estimated. With population synthesis modeling, important parameters such as binary fraction, initial mass ratio distribution, and initial separation distribution have been obtained. The modeling results are consistent with the observed fractions, providing insights into the white dwarf population.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2022)

Add to Collection

Article Astronomy & Astrophysics

The first spectroscopically confirmed brown dwarfs in NGC 2264

Samuel Pearson, Aleks Scholz, Paula S. Teixeira, Koraljka Muzic, Victor Almendros-Abad

Summary: Based on spectroscopic observations of 68 candidates in NGC 2264, researchers confirmed 13 brown dwarfs and 19 M-type stars, with ages predominantly younger than the known cluster population, indicating distinct formation processes. The estimated total of 200-600 brown dwarfs in NGC 2264 suggests a star-to-brown dwarf ratio between 2.5:1 and 7.5:1, with a consistent substellar mass function slope of alpha = 0.43(-0.56)(+0.41) across various young clusters, indicating a uniformity in substellar mass functions within star-forming environments.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2021)

Add to Collection

Article Astronomy & Astrophysics

JWST PEARLS. Prime Extragalactic Areas for Reionization and Lensing Science: Project Overview and First Results

Rogier A. Windhorst, Seth H. Cohen, Rolf A. Jansen, Jake Summers, Scott Tompkins, Christopher J. Conselice, Simon P. Driver, Haojing Yan, Dan Coe, Brenda Frye, Norman Grogin, Anton Koekemoer, Madeline A. Marshall, Rosalia O'Brien, Nor Pirzkal, Aaron Robotham, Russell E. Ryan, Christopher N. A. Willmer, Timothy Carleton, Jose M. Diego, William C. Keel, Paolo Porto, Caleb Redshaw, Sydney Scheller, Stephen M. Wilkins, S. P. Willner, Adi Zitrin, Nathan J. Adams, Duncan Austin, Richard G. Arendt, John F. Beacom, Rachana A. Bhatawdekar, Larry D. Bradley, Tom Broadhurst, Cheng Cheng, Francesca Civano, Liang Dai, Herve Dole, Jordan C. J. D'Silva, Kenneth J. Duncan, Giovanni G. Fazio, Giovanni Ferrami, Leonardo Ferreira, Steven L. Finkelstein, Lukas J. Furtak, Hansung B. Gim, Alex Griffiths, Heidi B. Hammel, Kevin C. Harrington, Nimish P. Hathi, Benne W. Holwerda, Rachel Honor, Jia-Sheng Huang, Minhee Hyun, Myungshin Im, Bhavin A. Joshi, Patrick S. Kamieneski, Patrick Kelly, Rebecca L. Larson, Juno Li, Jeremy Lim, Zhiyuan Ma, Peter Maksym, Giorgio Manzoni, Ashish Kumar Meena, Stefanie N. Milam, Mario Nonino, Massimo Pascale, Andreea Petric, Justin D. R. Pierel, Maria del Carmen Polletta, Huub J. A. Roettgering, Michael J. Rutkowski, Ian Smail, Amber N. Straughn, Louis-Gregory Strolger, Andi Swirbul, James A. A. Trussler, Lifan Wang, Brian Welch, J. Stuart B. Wyithe, Min Yun, Erik Zackrisson, Jiashuo Zhang, Xiurui Zhao

Summary: This paper provides an overview and details the rationale, methods, and initial findings of the PEARLS project, which utilizes NIRCam images to survey extragalactic areas. The project aims to study galaxy assembly, AGN growth, and First Light, and is expected to contribute significant insights to the field of astronomy.

ASTRONOMICAL JOURNAL (2023)

Add to Collection

Article Astronomy & Astrophysics

Early Results from GLASS-JWST. X. Rest-frame UV-optical Properties of Galaxies at 7 < z < 9

N. Leethochawalit, M. Trenti, P. Santini, L. Yang, E. Merlin, M. Castellano, A. Fontana, T. Treu, C. Mason, K. Glazebrook, T. Jones, B. Vulcani, T. Nanayakkara, D. Marchesini, S. Mascia, T. Morishita, G. Roberts-Borsani, A. Bonchi, D. Paris, K. Boyett, V Strait, A. Calabro, L. Pentericci, M. Bradac, X. Wang, C. Scarlata

Summary: This study presents the first determination of galaxy properties at 7 < z < 9 based on broadband imaging data from the James Webb Space Telescope/NIRCam. Thirteen galaxies with high signal-to-noise ratio were identified using dropout and photometric redshift selection. The physical properties of these galaxies, including their mass and age, were characterized using a Bayesian spectral energy distribution fitting method. The results demonstrate the potential of JWST in unveiling unprecedented details of galaxy formation in the early universe.

ASTROPHYSICAL JOURNAL LETTERS (2023)

Add to Collection

Article Astronomy & Astrophysics

Early Results from GLASS-JWST. XI. Stellar Masses and Mass-to-light Ratio of z > 7 Galaxies

P. Santini, A. Fontana, M. Castellano, N. Leethochawalit, M. Trenti, T. Treu, D. Belfiori, S. Birrer, A. Bonchi, E. Merlin, C. Mason, T. Morishita, M. Nonino, D. Paris, G. Polenta, P. Rosati, L. Yang, K. Boyett, M. Bradac, A. Calabro, A. Dressler, K. Glazebrook, D. Marchesini, S. Mascia, T. Nanayakkara, L. Pentericci, G. Roberts-Borsani, C. Scarlata, B. Vulcani, Xin Wang

Summary: We utilize JWST NIRCam observations to study galaxy stellar masses at z > 7. Our findings show that JWST observations significantly reduce uncertainties on stellar mass and reveal a wide range of M/L (UV) values for a given luminosity, indicating diverse physical conditions and star formation histories. Previous estimates of cosmic stellar-mass density based on average correlation between UV luminosity and stellar mass can be biased by a factor of 6. This highlights the significance of JWST in understanding stellar masses and galaxy growth at z > 7.

ASTROPHYSICAL JOURNAL LETTERS (2023)

Add to Collection

Article Astronomy & Astrophysics

Investigating the Dominant Environmental Quenching Process in UVCANDELS/COSMOS Groups

Maxwell Kuschel, Claudia Scarlata, Vihang Mehta, Harry Teplitz, Marc Rafelski, Xin Wang, Ben Sunnquist, Laura Prichard, Norman Grogin, Anton Koekemoer, Rogier Windhorst, Michael Rutkowski, Anahita Alavi, Nima Chartab, Christopher J. Conselice, Y. Sophia Dai, Eric Gawiser, Mauro Giavalisco, Pablo Arrabal Haro, Nimish Hathi, Rolf A. Jansen, Zhiyuan Ji, Ray A. Lucas, Kameswara Mantha, Bahram Mobasher, Robert W. O'Connell, Brant Robertson, Zahra Sattari, L. Y. Aaron Yung, Romeel Dave, Duilia DeMello, Mark Dickinson, Henry Ferguson, Steven L. Finkelstein, Matt Hayes, Justin Howell, Sugata Kaviraj, John W. Mackenty, Brian Siana

Summary: We investigate the environmental quenching process in 0.2 < z < 0.8 groups by analyzing the fraction of quenched galaxies with respect to distance, redshift, and stellar mass. New UV data from the UVCANDELS project and existing photometry are used to derive galaxy properties. Our analysis shows that the probability of quenching increases slowly with decreasing redshift, indicating a dominant process characterized by slow timescales. The estimated quenching time is approximately 4.91(-1.47)(+0.91) Gyr, supporting the theories of strangulation and delayed-then-rapid quenching.

ASTROPHYSICAL JOURNAL (2023)

Add to Collection

Article Astronomy & Astrophysics

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

Jonathan R. Trump, Pablo Arrabal Haro, Raymond C. Simons, Bren E. Backhaus, Ricardo O. Amorin, Mark Dickinson, Vital Fernandez, 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, Veronique Buat, Denis Burgarella, Antonello Calabro, 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, Stephanie 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. Perez-Gonzalez, Nor Pirzkal, Marc Rafelski, Caitlin Rose, Lise-Marie Seille, Rachel S. Somerville, Amber N. Straughn, Sandro Tacchella, Brittany N. Vanderhoof, Benjamin J. Weiner, Stijn Wuyts, L. Y. Aaron Yung, Jorge A. Zavala

Summary: We measured rest-frame optical emission-line flux ratios for five z > 5 galaxies observed by NIRSpec in the SMACS 0723 Early Release Observations. We added quality-control and post-processing steps to ensure reliable relative flux calibration. The observations indicate high ionization, low metallicity, and high pressure for the interstellar medium in galaxies at cosmic dawn.

ASTROPHYSICAL JOURNAL (2023)

Add to Collection

Article Astronomy & Astrophysics

HST Imaging of Star-forming Clumps in Six GASP Ram-pressure-stripped Galaxies

Eric Giunchi, Marco Gullieuszik, Bianca M. Poggianti, Alessia Moretti, Ariel Werle, Claudia Scarlata, Anita Zanella, Benedetta Vulcani, Daniela Calzetti

Summary: Using Hubble Space Telescope images, we studied star-forming clumps in six galaxies undergoing ram pressure stripping. Detected in H alpha and near-UV, the clumps trace star formation on different timescales. We found that most clumps are smaller than 140 pc and the star formation is turbulence-driven and scale-free. The clumps in both the disks and tails show enhanced H alpha luminosity compared to main-sequence galaxies, indicating the influence of ram pressure.

ASTROPHYSICAL JOURNAL (2023)

Add to Collection

Article Astronomy & Astrophysics

First Look at z > 1 Bars in the Rest-frame Near-infrared with JWST Early CEERS Imaging

Yuchen Guo, Shardha Jogee, Steven L. Finkelstein, Zilei Chen, Eden Wise, Micaela B. Bagley, Guillermo Barro, Stijn Wuyts, Dale D. Kocevski, Jeyhan S. Kartaltepe, Elizabeth J. McGrath, Henry C. Ferguson, Bahram Mobasher, Mauro Giavalisco, Ray A. Lucas, Jorge A. Zavala, Jennifer M. Lotz, Norman A. Grogin, Marc Huertas-Company, Jesus Vega-Ferrero, Nimish P. Hathi, Pablo Arrabal Haro, Mark Dickinson, Anton M. Koekemoer, Casey Papovich, Nor Pirzkal, L. Y. Aaron Yung, Bren E. Backhaus, Eric F. Bell, Antonello Calabro, Nikko J. Cleri, Rosemary T. Coogan, M. C. Cooper, Luca Costantin, Darren Croton, Kelcey Davis, Avishai Dekel, Maximilien Franco, Jonathan P. Gardner, Benne W. Holwerda, Taylor A. Hutchison, Viraj Pandya, Pablo G. Perez-Gonzalez, Swara Ravindranath, Caitlin Rose, Jonathan R. Trump, Alexander de la Vega, Weichen Wang

Summary: This study presents the first quantitative identification and characterization of stellar bars at z > 1 using JWST CEERS NIRCam images. The results reveal the early onset and persistence of stellar bars, suggesting their significant impact on galaxies over long periods of time.

ASTROPHYSICAL JOURNAL LETTERS (2023)

Add to Collection

Article Astronomy & Astrophysics

CEERS Key Paper. I. An Early Look into the First 500 Myr of Galaxy Formation with JWST

Steven L. Finkelstein, Micaela B. Bagley, Henry C. Ferguson, Stephen M. Wilkins, Jeyhan S. Kartaltepe, Casey Papovich, L. Y. Aaron Yung, Pablo Arrabal Haro, Peter Behroozi, Mark Dickinson, Dale D. Kocevski, Anton M. Koekemoer, Rebecca L. Larson, Aurelien Le Bail, Alexa M. Morales, Pablo G. Perez-Gonzalez, Denis Burgarella, Romeel Dave, Michaela Hirschmann, Rachel S. Somerville, Stijn Wuyts, Volker Bromm, Caitlin M. Casey, Adriano Fontana, Seiji Fujimoto, Jonathan P. Gardner, Mauro Giavalisco, Andrea Grazian, Norman A. Grogin, Nimish P. Hathi, Taylor A. Hutchison, Saurabh W. Jha, Shardha Jogee, Lisa J. Kewley, Allison Kirkpatrick, Arianna S. Long, Jennifer M. Lotz, Laura Pentericci, Justin D. R. Pierel, Nor Pirzkal, Swara Ravindranath, Russell E. Ryan, Jonathan R. Trump, Guang Yang, Rachana Bhatawdekar, Laura Bisigello, Veronique Buat, Antonello Calabro, Marco Castellano, Nikko J. Cleri, M. C. Cooper, Darren Croton, Emanuele Daddi, Avishai Dekel, David Elbaz, Maximilien Franco, Eric Gawiser, Benne W. Holwerda, Marc Huertas-Company, Anne E. Jaskot, Gene C. K. Leung, Ray A. Lucas, Bahram Mobasher, Viraj Pandya, Sandro Tacchella, Benjamin J. Weiner, Jorge A. Zavala

Summary: We conducted an investigation into the first 500 million years of galaxy evolution using the CEERS survey. By analyzing the CEERS NIRCam imaging data, we identified a sample of 26 galaxy candidates at z similar to 9-16, suggesting that the number density of galaxies at this redshift range remains relatively constant. These findings highlight the potential of JWST to discover more ultrahigh-redshift galaxies in the future.

ASTROPHYSICAL JOURNAL LETTERS (2023)

Add to Collection

Article Astronomy & Astrophysics

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

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, Veronique 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, Stephanie Juneau, Jeyhan S. Kartaltepe, Lisa J. Kewley, Allison Kirkpatrick, Anton M. Koekemoer, Peter Kurczynski, Aurelien Le Bail, Arianna S. Long, Jennifer M. Lotz, Ray A. Lucas, Casey Papovich, Laura Pentericci, Pablo G. Perez-Gonzalez, 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

Summary: We report on the properties of five X-ray-luminous active galactic nuclei (AGN) at 3 < z < 5, including their morphologies, stellar masses, and star formation rates. Compared to inactive galaxies with similar masses, the AGN hosts have less disturbed and more bulge-dominated morphologies. All four resolved hosts show optical colors consistent with quenched or post-starburst stellar populations. The presence of AGN in passively evolving galaxies at high redshifts has implications for understanding the growth of massive quiescent galaxies and the role of AGN feedback in maintaining their quiescent state.

ASTROPHYSICAL JOURNAL LETTERS (2023)

Add to Collection

Article Astronomy & Astrophysics

CEERS Key Paper. VI. JWST/MIRI Uncovers a Large Population of Obscured AGN at High Redshifts

G. Yang, K. I. Caputi, C. Papovich, P. Arrabal Haro, M. B. Bagley, P. Behroozi, E. F. Bell, L. Bisigello, V. Buat, D. Burgarella, Y. Cheng, N. J. Cleri, R. Dave, M. Dickinson, D. Elbaz, H. C. Ferguson, S. L. Finkelstein, N. A. Grogin, N. P. Hathi, M. Hirschmann, B. W. Holwerda, M. Huertas-Company, T. A. Hutchison, E. Iani, J. S. Kartaltepe, A. Kirkpatrick, D. D. Kocevski, A. M. Koekemoer, V. Kokorev, R. L. Larson, R. A. Lucas, P. G. Perez-Gonzalez, P. Rinaldi, L. Shen, J. R. Trump, A. de la Vega, L. Y. A. Yung, J. A. Zavala

Summary: Mid-infrared (mid-IR) observations are used to identify heavily obscured active galactic nuclei (AGN) that are difficult to detect in other wavelengths. The Mid-Infrared Instrument (MIRI) on the James Webb Space Telescope provides data for such studies. Utilizing MIRI imaging data, researchers investigated the AGN population in the distant universe and classified them into different types based on their spectral energy distribution (SED). The study shows that MIRI can identify a large population of heavily obscured AGN missed by X-ray surveys at high redshifts.

ASTROPHYSICAL JOURNAL LETTERS (2023)

Add to Collection

Article Astronomy & Astrophysics

The Universe is at Most 88% Neutral at z=10.6

Sean Bruton, Yu-Heng Lin, Claudia Scarlata, Matthew J. J. Hayes

Summary: Recent observations of GN-z11 with JWST have found a Ly alpha emission line with an EW of 18 +/- 2 angstrom. Using reionization simulations, we derive the distribution of Ly alpha EW after passing through the neutral intergalactic medium with varying x (H I). We compare our results to different reionization history models and find that models favoring higher escape fractions for faint galaxies are supported by the new data.

ASTROPHYSICAL JOURNAL LETTERS (2023)

Add to Collection

Article Astronomy & Astrophysics

Constraints on the inner regions of lensing galaxies from central images using a recent AGN offset distribution

D. Perera, L. L. R. Williams, C. Scarlata

Summary: In gravitational lensing, central images in quads can provide valuable information about the inner regions of lens galaxies. The presence of an offset central supermassive black hole can affect the time-delay surface and result in the formation of three central images. We used a quad-lens macro-model to simulate the constraints on lens galaxy parameters based on the detection or non-detection of central images. Our results show that the detection of central images favors larger distances between the supermassive black hole and the galaxy core. We recommend observational searches for central images to obtain stronger constraints on lens galaxy parameters.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2023)

Add to Collection

Article Astronomy & Astrophysics

On the evolution of the size of Lyman alpha haloes across cosmic time: no change in the circumgalactic gas distribution when probed by line emission

Axel Runnholm, Matthew J. Hayes, Yu-Heng Lin, Jens Melinder, Claudia Scarlata, Angela Adamo, Ramona Augustin, Arjan Bik, Jeremy Blaizot, John M. Cannon, Sebastiano Cantalupo, Thibault Garel, Max Gronke, Edmund C. Herenz, Floriane Leclercq, Goeran Oestlin, Celine Peroux, Armin Rasekh, Michael J. Rutkowski, Anne Verhamme, Lutz Wisotzki

Summary: Ly alpha is commonly used to study high-redshift galaxies and can trace neutral hydrogen. We observed a sample of galaxies with redshift 0.23 to 0.31 and detect significant extended Ly alpha emission around six out of seven targets. Ly alpha escape fractions range from 0.7 to 37 percent. We find that the Ly alpha halo to UV scale length ratios are slightly lower than high-redshift observations and the halo flux fractions are consistent with high-redshift observations. Deeper H alpha data is needed to determine the origin of Ly alpha halo emission.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2023)

Add to Collection

Article Astronomy & Astrophysics

Intercomparison of Brown Dwarf Model Grids and Atmospheric Retrieval Using Machine Learning

Anna Lueber, Daniel Kitzmann, Chloe E. E. Fisher, Brendan P. P. Bowler, Adam J. J. Burgasser, Mark Marley, Kevin Heng

Summary: Using the random forest supervised machine-learning method, this study investigates the information content and predictive power of 14 previously published model grids of brown dwarfs. It is found that the effective temperature of brown dwarfs can be robustly predicted independent of the model grid chosen, while inference of the surface gravity is model-dependent. The challenges associated with understanding the influence of clouds in brown dwarf atmospheres and validating the models remain.

ASTROPHYSICAL JOURNAL (2023)

Add to Collection

Article Astronomy & Astrophysics

Early Time Spectropolarimetry of the Aspherical Type II Supernova SN 2023ixf

Sergiy S. Vasylyev, Yi Yang, Alexei V. Filippenko, Kishore C. Patra, Thomas G. Brink, Lifan Wang, Ryan Chornock, Raffaella Margutti, Elinor L. Gates, Adam J. Burgasser, Preethi R. Karpoor, Natalie Lebaron, Emma Softich, Christopher A. Theissen, Eli Wiston, WeiKang Zheng

Summary: The study presents observations of the early polarimetry of the supernova SN 2023ixf, revealing the evolution of continuum polarization and polarization position angle, which may be related to the disappearance of highly ionized material. The results suggest that there is an asymmetric mass loss process during the supernova explosion.

ASTROPHYSICAL JOURNAL LETTERS (2023)

Add to Collection

No Data Available

© Peeref 2019-2024. All rights reserved.