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A CEERS Discovery of an Accreting Supermassive Black Hole 570 Myr after the Big Bang: Identifying a Progenitor of Massive z > 6 Quasars
(IOP Publishing Ltd, 2023/08/01) Larson, Rebecca L., Finkelstein, Steven D., Kocevski, Dale A., Hutchison, Taylor R., Trump, Jonathan, Haro, Pablo Arrabal, Bromm, Volker J., Cleri, Nikko, Dickinson, Mark, Fujimoto, Seiji S., Kartaltepe, Jeyhan M., Koekemoer, Anton, Papovich, Casey, Pirzkal, Nor, Tacchella, Sandro A., Zavala, Jorge, Bagley, Micaela, Behroozi, Peter B., Champagne, Jaclyn W., Cole, Justin, Jung, Intae M., Morales, Alexa, Yang, Guang, Zhang, Haowen, Zitrin, Adi O., Amorin, Ricardo, Burgarella, Denis M., Casey, Caitlin, Ortiz, Oscar A. Chavez G., Cox, Isabella, Chworowsky, Katherine, Fontana, Adriano, Gawiser, Eric, Grazian, Andrea A., Grogin, Norman, Harish, Santosh P., Hathi, Nimish, Hirschmann, Michaela W., Holwerda, Benne, Juneau, Stephanie, Leung, Gene C. K. A., Lucas, Ray J., McGrath, Elizabeth G., Perez-Gonzalez, Pablo R., Rigby, Jane, Seille, Lise-Marie C., Simons, Raymond, de la Vega, Alexander J., Weiner, Benjamin M., Wilkins, Stephen, Yung, L. Y. Aaron
We report the discovery of an accreting supermassive black hole at z = 8.679. This galaxy, denoted here as CEERS_1019, was previously discovered as a Ly & alpha,-break galaxy by Hubble with a Ly & alpha, redshift from Keck. As part of the Cosmic Evolution Early Release Science (CEERS) survey, we have observed this source with JWST/NIRSpec, MIRI, NIRCam, and NIRCam/WFSS and uncovered a plethora of emission lines. The H & beta, line is best fit by a narrow plus a broad component, where the latter is measured at 2.5 & sigma, with an FWHM & SIM,1200 km s(-1). We conclude this originates in the broadline region of an active galactic nucleus (AGN). This is supported by the presence of weak high-ionization lines (N V, N IV], and C III]), as well as a spatial point-source component. The implied mass of the black hole (BH) is log (M (BH)/M (& ODOT,)) = 6.95 & PLUSMN, 0.37, and we estimate that it is accreting at 1.2 & PLUSMN, 0.5 times the Eddington limit. The 1-8 & mu,m photometric spectral energy distribution shows a continuum dominated by starlight and constrains the host galaxy to be massive (log M/M-& ODOT, & SIM,9.5) and highly star-forming (star formation rate, or SFR & SIM, 30 M-& ODOT, yr(-1), log sSFR & SIM, - 7.9 yr(-1)). The line ratios show that the gas is metal-poor (Z/Z (& ODOT,) & SIM, 0.1), dense (n (e) & SIM, 10(3) cm(-3)), and highly ionized (log U & SIM, - 2.1). We use this present highest-redshift AGN discovery to place constraints on BH seeding models and find that a combination of either super-Eddington accretion from stellar seeds or Eddington accretion from very massive BH seeds is required to form this object.
A CO funnel in the Galactic centre: Molecular counterpart of the northern Galactic chimney
(EDP SCIENCES S A, 2023/06/27) Veena, V. S., Riquelme, D., Kim, W. -J., Menten, K. M., Schilke, P., Sormani, M. C., Banda-Barragan, W. E., Wyrowski, F., Fuller, G. A., Cheema, A.
We report the discovery of a velocity coherent, funnel-shaped (CO)-C-13 emission feature in the Galactic centre (GC) using data from the SEDIGISM survey. The molecular cloud appears as a low-velocity structure (V-LSR  = [ - 3.5,   + 3.5] km s(-1)) with an angular extent of 0.95 & DEG, x1 & DEG,, extending towards positive Galactic latitudes. The structure is offset from Sgr A* towards negative Galactic longitudes, it spatially and morphologically correlates well with the northern lobe of the 430 pc radio bubble, believed to be the radio counterpart of the multiwavelength GC chimney. Spectral line observations in the frequency range of 85-116 GHz have been carried out using the IRAM 30-m telescope towards 12 positions along the funnel-shaped emission. We examine the C-12/C-13 isotopic ratios using various molecules and their isotopologues. The mean C-12/C-13 isotope ratio (30.6 & PLUSMN, 2.9) is consistent with the structure located within inner 3 kpc of the Galaxy and possibly in the GC. The velocity of the molecular funnel is consistent with previous radio recombination line measurements of the northern lobe of radio bubble. Our multiwavelength analysis suggests that the funnel-shaped structure extending over 100 pc above the Galactic plane is the molecular counterpart of the northern GC chimney.
A MUSE view of the multiple interacting system HCG 31
(OXFORD UNIV PRESS, 2023/04/21) Gomez-Espinoza, Diego A., Torres-Flores, S., Firpo, V, Amram, Philippe, Epinat, Benoit, Contini, Thierry, de Oliveira, Claudia Mendes
We present, for the first time, spatially resolved spectroscopy for the entire Hickson Compact Group 31 obtained with the MUSE instrument at the VLT and an in-depth analysis of this compact group. To obtain a complete understanding of the system, we derived radial velocity and dispersion velocity maps, maps of the ionization mechanism of the system, chemical abundances and their distribution over the whole system, star formation rates and ages of the different star-forming regions, and the spatial distribution of the Wolf-Rayet stellar population. We also reconstructed the star formation history of the galaxies HCG 31 A, C, B, and F, measured the emission-line fluxes, and performed a stellar population synthesis. Our main findings are: (i) that there is clearly disturbed kinematics due to the merger event that the system is experiencing, (ii) that the ionization is produced exclusively via star formation except for the nucleus of the galaxy HCG 31 A, where there is a small contribution of shocks, (iii) that there is low oxygen abundance distributed homogeneously through the system, (iv) that there is a prominent population of carbon Wolf-Rayet stars in the central zone of the group, and (v) that there are clear evidences of the tidal origin of the galaxies HCG 31 E, HCG 31 H, and HCG 31 F because they show quite high oxygen abundances for their stellar mass. All these findings are clear evidence that HCG 31 is currently in an early merging phase and manifesting a starburst in its central region.
A MUSE/VLT spatially resolved study of the emission structure of Green Pea galaxies
(EDP SCIENCES S A, 2023/09/15) Arroyo-Polonio, A., Iglesias-Paramo, J., Kehrig, C., Vilchez, J. M., Amorin, R., Breda, I., Perez-Montero, E., Perez-Diaz, B., Hayes, M.
Green Pea galaxies (GPs) present among the most intense starbursts known in the nearby Universe. These galaxies are regarded as local analogs of high-redshift galaxies, making them a benchmark in the understanding of the star formation processes and the galactic evolution in the early Universe. In this work, we performed an integral field spectroscopic (IFS) study for a set of 24 GPs to investigate the interplay between its ionized interstellar medium (ISM) and the massive star formation that these galaxies present. Observations were taken in the optical spectral range (lambda 4750 angstrom-lambda 9350 angstrom) with the MUSE spectrograph attached to the 8.2m telescope VLT. Spatial extension criteria were employed to verify which GPs are spatially resolved in the MUSE data cubes. We created and analyzed maps of spatially distributed emission lines (at di fferent stages of excitation), continuum emission, and properties of the ionized ISM (e.g., ionization structure indicators, physical-chemical conditions, dust extinction). We also took advantage of our IFS data to produce integrated spectra of selected galactic regions in order to study their physical-chemical conditions. Maps of relevant emission lines and emission line ratios show that higher-excitation gas is preferentially located in the center of the galaxy, where the starburst is present. The continuum maps, with an average angular extent of 4 '', exhibit more complex structures than the emission line maps. However, the [OIII]lambda 5007 angstrom emission line maps tend to extend beyond the continuum images (the average angular extent is 5.5 ''), indicating the presence of low surface brightness ionized gas in the outer parts of the galaxies. H alpha/H beta, [SII]/H alpha, and [OI]/H alpha maps trace low-extinction, optically thin regions. The line ratios [OIII]/H beta and [NII]/H alpha span extensive ranges, with values varying from 0.5 dex to 0.9 dex and from 1.7 dex to 0.8 dex, respectively. Regarding the integrated spectra, the line ratios were fit to derive physical properties including the electron densities n(e) = 30-530 cm(-3), and, in six GPs with a measurable [OIII]lambda 4363 angstrom line, electron temperatures of T-e = 11 500 K-15 500 K, so the direct method was applied in these objects to retrieve metallicities 12 + log(O/H) similar or equal to 8. We found the presence of the high-ionizing nebular HeII lambda 4686 angstrom line in three GPs, where two of them present among the highest sSFR values ( >8 x 10(8) yr(-1)) in this sample. Non-Wolf-Rayet (WR) features are detected in these galaxy spectra.
A reproduction of the Milky Way's Faraday rotation measure map in galaxy simulations from global to local scales
(NATURE PORTFOLIO, 2023/11/01) Reissl, Stefan, Klessen, Ralf S. S., Pellegrini, Eric W. W., Rahner, Daniel, Pakmor, Rudiger, Grand, Robert, Gomez, Facundo, Marinacci, Federico, Springel, Volker
Magnetic fields are of critical importance for our understanding of the origin and long-term evolution of the Milky Way. This is due to their decisive role in the dynamical evolution of the interstellar medium and their influence on the star-formation process(1-3). Faraday rotation measures along many different sightlines across the Galaxy are a primary means to infer the magnetic field topology and strength from observations(4-7). However, the interpretation of the data has been hampered by the failure of previous attempts to explain the observations in theoretical models and to synthesize a realistic multiscale all-sky rotation measures map(8-10). We here utilize a cosmological magnetohydrodynamic simulation of the formation of the Milky Way, augment it with a new star-cluster population-synthesis model for a more realistic structure of the local interstellar medium(11,12), and perform detailed polarized radiative transfer calculations on the resulting model(13). This yields an accurate first-principles prediction of the Faraday sky as observed on Earth. The results reproduce the observations of the Galaxy not only on global scales but also on local scales of individual star-forming clouds. They also indicate that the Local Bubble(14) containing our Sun dominates the rotation measures signal over large regions of the sky. Modern cosmological magnetohydrodynamic simulations of the Milky Way's formation, combined with a plausible model for star formation, stellar feedback and the distribution of free electrons in the interstellar medium, explain the rotation measures observations remarkably well, and thus contribute to a better understanding of the origin of magnetic fields in our Galaxy.
A trail of the invisible: blue globular clusters trace the radial density distribution of the dark matter - case study of NGC 4278
(OXFORD UNIV PRESS, 2023/03/31) Kluge, Matthias, Remus, Rhea-Silvia, Babyk, Iurii, V, Forbes, Duncan A., Dolfi, Arianna
We present new, deep optical observations of the early-type galaxy NGC 4278, which is located in a small loose group. We find that the galaxy lacks fine substructure, that is, it appears relaxed, out to a radius of similar to 70 kpc. Our g- and i-band surface brightness profiles are uniform down to our deepest levels of similar to 28 mag arcsec(-2). This spans an extremely large radial range of more than 14 half-mass radii. Combined with archival globular cluster (GC) number density maps and a new analysis of the total mass distribution obtained from archival Chandra X-ray data, we find that the red GC subpopulation traces well the stellar mass density profile from 2.4 out to even 14 half-mass radii, while the blue GC subpopulation traces the total mass density profile of the galaxy over a large radial range. Our results reinforce the scenario that red GCs form mostly in situ along with the stellar component of the galaxy, while the blue GCs are more closely aligned with the total mass distribution in the halo and were accreted along with halo matter. We conclude that for galaxies where the X-ray emission from the hot halo is too faint to be properly observable and as such is not available to measure the dark matter profile, the blue GC population can be used to trace this dark matter component out to large radii.
ABYSS. I. Targeting Strategy for the APOGEE and BOSS Young Star Survey in SDSS-V
(IOP Publishing Ltd, 2023/05/01) Kounkel, Marina, Zari, Eleonora, Covey, Kevin, Tkachenko, Andrew, Zuniga, Carlos Roman, Stassun, Keivan, Stutz, Amelia M., Stringfellow, Guy, Roman-Lopes, Alexandre, Hernandez, Jesus, Ramirez, Karla Pena, Bayo, Amelia, Kim, Jinyoung Serena, Cao, Lyra, Wolk, Scott J., Kollmeier, Juna, Lopez-Valdivia, Ricardo, Rojas-Ayala, Barbara
The fifth iteration of the Sloan Digital Sky Survey is set to obtain optical and near-infrared spectra of similar to 5 million stars of all ages and masses throughout the Milky Way. As a part of these efforts, APOGEE and BOSS Young Star Survey (ABYSS) will observe similar to 10(5) stars with ages <30 Myr that have been selected using a set of homogeneous selection functions that make use of different tracers of youth. The ABYSS targeting strategy we describe in this paper is aimed to provide the largest spectroscopic census of young stars to date. It consists of eight different types of selection criteria that take the position on the H-R diagram, infrared excess, variability, as well as the position in phase space in consideration. The resulting catalog of similar to 200,000 sources (of which a half are expected to be observed) provides representative coverage of the young Galaxy, including both nearby diffuse associations as well as more distant massive complexes, reaching toward the inner Galaxy and the Galactic center.
ALMA FIR View of Ultra-high-redshift Galaxy Candidates at z ∼ 11-17: Blue Monsters or Low-z Red Interlopers?
(IOP Publishing Ltd, 2023/10/01) Fujimoto, Seiji, Finkelstein, Steven L., Burgarella, Denis, Carilli, Chris L., Buat, Veronique, Casey, Caitlin M., Ciesla, Laure, Tacchella, Sandro, Zavala, Jorge A., Brammer, Gabriel, Fudamoto, Yoshinobu, Ouchi, Masami, Valentino, Francesco, Cooper, M. C., Dickinson, Mark, Franco, Maximilien, Giavalisco, Mauro, Hutchison, Taylor A., Kartaltepe, Jeyhan S., Koekemoer, Anton M., Kojima, Takashi, Larson, Rebecca L., Murphy, E. J., Papovich, Casey, Perez-Gonzalez, Pablo G., Somerville, Rachel S., Yoon, Ilsang, Wilkins, Stephen M., Akins, Hollis, Amorin, Ricardo O., Haro, Pablo Arrabal, Bagley, Micaela B., Chworowsky, Katherine, Cleri, Nikko J., Cooper, Olivia R., Costantin, Luca, Daddi, Emanuele, Ferguson, Henry C., Grogin, Norman A., Jimenez-Andrade, E. F., Juneau, Stephanie, Kirkpatrick, Allison, Kocevski, Dale D., Le Bail, Aurelien, Long, Arianna, Lucas, Ray A., Magnelli, Benjamin, McKinney, Jed, Rose, Caitlin, Seille, Lise-Marie, Simons, Raymond C., Weiner, Benjamin J., Yung, L. Y. Aaron
We present Atacama Large Millimeter/submillimeter Array (ALMA) Band 7 observations of a remarkably bright galaxy candidate at (M-UV = -21.6), S5-z17-1, identified in James Webb Space Telescope (JWST) Early Release Observation data of Stephen's Quintet. We do not detect the dust continuum at 866 mu m, ruling out the possibility that S5-z17-1 is a low-z dusty starburst with a star formation rate of greater than or similar to 30 M-circle dot yr(-1). We detect a 5.1s line feature at 338.726 +/- 0.007 GHz exactly coinciding with the JWST source position, with a 2% likelihood of the signal being spurious. The most likely line identification would be [O III]52 mu m at z = 16.01 or [C II]158 mu m at z = 4.61, whose line luminosities do not violate the nondetection of the dust continuum in both cases. Together with three other z greater than or similar to 11-13 candidate galaxies recently observed with ALMA, we conduct a joint ALMA and JWST spectral energy distribution (SED) analysis and find that the high-z solution at z similar to 11-17 is favored in every candidate as a very blue (UV continuum slope of similar or equal to-2.3) and luminous (M-UV similar or equal to [ - 24:-21]) system. Still, we find in several candidates that reasonable SED fits (Delta chi(2) less than or similar to 4) are reproduced by type II quasar and/or quiescent galaxy templates with strong emission lines at z similar to 3-5, where such populations predicted from their luminosity functions and EW([O iii]+H beta) distributions are abundant in survey volumes used for the identification of the z similar to 11-17 candidates. While these recent ALMA observation results have strengthened the likelihood of the high-z solutions, lower-z possibilities are not completely ruled out in several of the z similar to 11-17 candidates, indicating the need to consider the relative surface densities of the lower-z contaminants in the ultra-high-z galaxy search.
An ever-present Gaia snail shell triggered by a dark matter wake
(OXFORD UNIV PRESS, 2023/07/04) Grand, Robert J. J., Pakmor, Ruediger, Fragkoudi, Francesca, Gomez, Facundo A., Trick, Wilma, Simpson, Christine M., van de Voort, Freeke, Bieri, Rebekka
We utilize a novel numerical technique to model star formation in cosmological simulations of galaxy formation - called SUPERSTARS - to simulate a Milky Way-like galaxy with greater than or similar to 10(8) star particles to study the formation and evolution of out-of-equilibrium stellar disc structures in a full cosmological setting. In the plane defined by the coordinate and velocity perpendicular to the mid-plane [vertical phase space, (Z, V-Z)], stars in solar- like volumes at late times exhibit clear spirals qualitatively similar in shape and amplitude to the Gaia 'snail shell' phase spiral. We show that the phase spiral forms at a lookback time of similar to 6 Gyr during the pericentric passage of an similar to 10(10) M-circle dot satellite on a polar orbit. This satellite stimulates the formation of a resonant wake in the dark matter halo while losing mass at a rate of similar to 0.5-1 dex per orbit loop. The peak magnitude of the wake-induced gravitational torque at the solar radius is similar to 8 times that from the satellite, and triggers the formation of a disc warp that wraps up into a vertical phase spiral over time. As the wake decays, the phase spiral propagates several gigayears to present day and can be described as `ever-present' once stable disc evolution is established. These results suggest an alternative scenario to explain the Gaia phase spiral, which does not rely on a perturbation from bar buckling or a recent direct hit from a satellite.
Assessing model-based carbon and oxygen abundance derivation from ultraviolet emission lines in AGNs
(OXFORD UNIV PRESS, 2023/03/02) Perez-Montero, E., Amorin, R., Perez-Diaz, B., Vilchez, J. M., Garcia-Benito, R.
We present an adapted version of the code HII-CHI-mistry-UV to derive chemical abundances from emission lines in the ultraviolet, for use in narrow line regions (NLR) of active galactic nuclei (AGN). We evaluate different ultraviolet emission line ratios and how different assumptions about the models, including the presence of dust grains, the shape of the incident spectral energy distribution, or the thickness of the gas envelope around the central source, may affect the final estimates as a function of the set of emission lines used. We compare our results with other published recipes for deriving abundances using the same emission lines and show that deriving the carbon-to-oxygen abundance ratio using C iii] lambda 1909 angstrom and O iii] lambda 1665 angstrom emission lines is a robust indicator of the metal content in AGN that is nearly independent of the model assumptions, similar to the case of star-forming regions. Moreover, we show that a prior determination of C/O allows for a much more precise determination of the total oxygen abundance using carbon UV lines, as opposed to assuming an arbitrary relationship between O/H and C/O, which can lead to non-negligible discrepancies.
Backsplash galaxies and their impact on galaxy evolution: a three-stage, four-type perspective
(OXFORD UNIV PRESS, 2023/10/01) Ruiz, Andres N., Martinez, Hector J., Coenda, Valeria, Muriel, Hernan, Cora, Sofia A., de los Rios, Martin, Vega-Martinez, Cristian A.
We study the population of backsplash galaxies at z = 0 in the outskirts of massive, isolated clusters of galaxies taken from the MDPL 2- SAG semi-analytical catalogue. We consider four types of backsplash galaxies according to whether they are forming stars or passive at three stages in their lifetimes: before entering the cluster, during their first incursion through the cluster, and after they exit the cluster. We analyse several geometric, dynamic, and astrophysical aspects of the four types at the three stages. Galaxies that form stars at all stages account for the majority of the backsplash population (58 per cent) and have stellar masses typically below M-* similar to 3 x10(10) h(-1) M-circle dot that avoid the innermost cluster's regions and are only mildly affected by it. In a similar mass range, galaxies that become passive after exiting the cluster (26 per cent) follow orbits characterized by small pericentric distance and a strong deflection by the cluster potential well while suffering a strong loss of both dark matter and gas content. Only a small fraction of our sample (4 per cent) becomes passive while orbiting inside the cluster. These galaxies have experienced heavy pre-processing and the cluster's tidal stripping and ram pressure provide the final blow to their star formation. Finally, galaxies that are passive before entering the cluster for the first time (12 per cent) are typically massive and are not affected significantly by the cluster. Using the bulge/total mass ratio as a proxy for morphology, we find that a single incursion through a cluster does not result in significant morphological changes in all four types.
Bulge-disc decomposition of the Hydra cluster galaxies in 12 bands
(OXFORD UNIV PRESS, 2023/01/01) Lima-Dias, Ciria, Monachesi, Antonela, Torres-Flores, Sergio, Cortesi, Arianna, Hernandez-Lang, Daniel, P. Montaguth, Gissel, Jimenez-Teja, Yolanda, Panda, Swayamtrupta, Menendez-Delmestre, Karin, Goncalves, Thiago S., Mendez-Hernandez, Hugo, Telles, Eduardo, Dimauro, Paola, Bom, Clecio R., de Oliveira, Claudia Mendes, Kanaan, Antonio, Ribeiro, Tiago, Schoenell, William
When a galaxy falls into a cluster, its outermost parts are the most affected by the environment. In this paper, we are interested in studying the influence of a dense environment on different galaxy's components to better understand how this affects the evolution of galaxies. We use, as laboratory for this study, the Hydra cluster which is close to virialization, yet it still shows evidence of substructures. We present a multiwavelength bulge-disc decomposition performed simultaneously in 12 bands from S-PLUS (Southern Photometric Local Universe Survey) data for 52 galaxies brighter than m(r) = 16. We model the galaxies with a Sersic profile for the bulge and an exponential profile for the disc. We find that the smaller, more compact, and bulge-dominated galaxies tend to exhibit a redder colour at a fixed stellar mass. This suggests that the same mechanisms (ram-pressure and tidal stripping) that are causing the compaction in these galaxies are also causing them to stop forming stars. The bulge size is unrelated to the galaxy's stellar mass, while the disc size increases with greater stellar mass, indicating the dominant role of the disc in the overall galaxy mass-size relation found. Furthermore, our analysis of the environment unveils that quenched galaxies are prevalent in regions likely associated with substructures. However, these areas also harbour a minority of star-forming galaxies, primarily resulting from galaxy interactions. Lastly, we find that similar to 37 per cent of the galaxies exhibit bulges that are bluer than their discs, indicative of an outside-in quenching process in this type of dense environments.
Ca triplet metallicities and velocities for 12 globular clusters toward the galactic bulge
(EDP SCIENCES S A, 2023/01/20) Geisler, D., Parisi, M. C., Dias, B., Villanova, S., Mauro, F., Saviane, I., Cohen, R. E., Moni Bidin, C., Minniti, D.
Context. Globular clusters (GCs) are excellent tracers of the formation and early evolution of the Milky Way. The bulge GCs (BGCs) are particularly important because they can reveal vital information about the oldest in situ component of the Milky Way.Aims. Our aim is to derive the mean metallicities and radial velocities for 13 GCs that lie toward the bulge and are generally associated with this component. This region is observationally challenging because of high extinction and stellar density, which hampers optical studies of these and similar BGCs, making most previous determinations of these parameters quite uncertain.Methods. We used near-infrared low-resolution spectroscopy with the FORS2 instrument on the VLT to measure the wavelengths and equivalent widths of the CaII triplet (CaT) lines for a number of stars per cluster. We derived radial velocities, ascertained membership, and applied known calibrations to determine metallicities for cluster members, for a mean of 11 members per cluster. Unfortunately, one of our targets, VVV-GC002, which is the closest GC to the Galactic center, turned out not to have any members in our sample.Results. We derive mean cluster RV values to 3 km s(-1), and mean metallicities to 0.05 dex. We find general good agreement with previous determinations for both metallicity and velocity. On average, our metallicities are 0.07 dex more metal-rich than those of Harris (2010, arXiv:1012.3224), with a standard deviation of the difference of 0.25 dex. Our sample has metallicities between -0.21 and -1.64, and the values are distributed between the traditional metal-rich BGC peak near [Fe/H] -0.5 and a more metal-poor peak around [Fe/H] -1.1, which has recently been identified. These latter are candidates for the oldest GCs in the Galaxy, if blue horizontal branches are present, and include BH 261, NGC 6401, NGC 6540, NGC 6642, and Terzan 9. Finally, Terzan 10 is even more metal-poor. However, dynamically, Terzan 10 is likely an intruder from the halo, possibly associated with the Gaia-Enceladus or Kraken accretion events. Terzan 10 is also confirmed as an Oosterhoff type II GC based on our results.Conclusions. The CaT technique is an excellent method for deriving mean metallicities and velocities for heavily obscured GCs. Our sample provides reliable mean values for these two key properties via spectroscopy of a significant number of members per cluster for this important yet previously poorly studied sample of BGCs. We emphasize that the more metal-poor GCs are excellent candidates for being ancient relics of bulge formation. The lone halo intruder in our sample, Terzan 10, is conspicuous for also having by far the lowest metallicity, and casts doubt on the possibility of any bona fide BGCs at metallicities below about -1.5.
CAPOS: the bulge Cluster APOgee Survey IV elemental abundances of the bulge globular cluster NGC 6558
(MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2023-10-20) González-Díaz, D.; Fernández-Trincado, J. G.; Villanova, S.; Geisler, D.; Barbuy, B.; Minniti, D.; Beers, T. C.; Bidin, C. M.; Mauro, F.; Muñoz, C.; Tang, B. T.; Soto, M.; Monachesi, A.; Lane, R. R.; Frelijj, H.
This study presents the results concerning six red giant stars members of the globular cluster NGC 6558. Our analysis utilized high-resolution near-infrared spectra obtained through the CAPOS initiative (the APOgee Surv e y of Clusters in the Galactic Bulge), which focuses on surv e ying clusters within the Galactic Bulge, as a component of the Apache Point Observatory Galactic Evolution Experiment II surv e y (APOGEE-2). We employ the Brussels Automatic Code for Characterizing High accUracy Spectra ( BACCHUS ) code to provide line-by-line elemental-abundances for Fe-peak (Fe, Ni), alpha-(O, Mg, Si, Ca, Ti), light-(C, N), odd-Z (Al), and the s-process element (Ce) for the four stars with high-signal-to-noise ratios. This is the first reliable measure of the CNO abundances for NGC 6558. Our analysis yields a mean metallicity for NGC 6558 of ([Fe/H]) = -1.15 +/- 0.08, with no evidence for a metallicity spread. We find a Solar Ni abundance, ([Ni/Fe]) similar to + 0.01, and a moderate enhancement of alpha-elements, ranging between + 0.16 and < + 0.42, and a slight enhancement of the s-process element ([Ce/Fe]) similar to + 0.19. We also found low levels of ([Al/Fe]) similar to + 0.09, but with a strong enrichment of nitrogen, [N/Fe] > + 0.99, along with a low level of carbon, [C/Fe] < -0.12. This behaviour of Nitrogen-Carbon is a typical chemical signature for the presence of multiple stellar populations in virtually all GCs; this is the first time that it is reported in NGC 6558. We also observed a remarkable consistency in the behaviour of all the chemical species compared to the other CAPOS bulge GCs of the same metallicity.
CAPOS: the bulge Cluster APOgee Survey IV elemental abundances of the bulge globular cluster NGC 6558
(OXFORD UNIV PRESS, 2023/10/20) Gonzalez-Diaz, Danilo, Fernandez-Trincado, Jose G., Villanova, Sandro, Geisler, Doug, Barbuy, Beatriz, Minniti, Dante, Beers, Timothy C., Bidin, Christian Moni, Mauro, Francesco, Munoz, Cesar, Tang, Baitian, Soto, Mario, Monachesi, Antonela, Lane, Richard R., Frelijj, Heinz
This study presents the results concerning six red giant stars members of the globular cluster NGC 6558. Our analysis utilized high-resolution near-infrared spectra obtained through the CAPOS initiative (the APOgee Surv e y of Clusters in the Galactic Bulge), which focuses on surv e ying clusters within the Galactic Bulge, as a component of the Apache Point Observatory Galactic Evolution Experiment II surv e y (APOGEE-2). We employ the Brussels Automatic Code for Characterizing High accUracy Spectra ( BACCHUS ) code to provide line-by-line elemental-abundances for Fe-peak (Fe, Ni), alpha-(O, Mg, Si, Ca, Ti), light-(C, N), odd-Z (Al), and the s-process element (Ce) for the four stars with high-signal-to-noise ratios. This is the first reliable measure of the CNO abundances for NGC 6558. Our analysis yields a mean metallicity for NGC 6558 of ([Fe/H]) = -1.15 +/- 0.08, with no evidence for a metallicity spread. We find a Solar Ni abundance, ([Ni/Fe]) similar to + 0.01, and a moderate enhancement of alpha-elements, ranging between + 0.16 and < + 0.42, and a slight enhancement of the s-process element ([Ce/Fe]) similar to + 0.19. We also found low levels of ([Al/Fe]) similar to + 0.09, but with a strong enrichment of nitrogen, [N/Fe] > + 0.99, along with a low level of carbon, [C/Fe] < -0.12. This behaviour of Nitrogen-Carbon is a typical chemical signature for the presence of multiple stellar populations in virtually all GCs, this is the first time that it is reported in NGC 6558. We also observed a remarkable consistency in the behaviour of all the chemical species compared to the other CAPOS bulge GCs of the same metallicity.
Cataclysmic Variables from Sloan Digital Sky Survey - V. The search for period bouncers continues
(OXFORD UNIV PRESS, 2023/09/01) Inight, K., Gansicke, Boris T., Schwope, A., Anderson, S. F., Badenes, C., Breedt, E., Chandra, V, Davies, B. D. R., Fusillo, N. P. Gentile, Green, M. J., Hermes, J. J., Huamani, I. Achaica, Hwang, H., Knauff, K., Kurpas, J., Long, K. S., Malanushenko, V, Morrison, S., Quiroz C, I. J., Aichele Ramos, G. N., Roman-Lopes, A., Schreiber, M. R., Standke, A., Stuetz, L., Thorstensen, J. R., Toloza, O., Tovmassian, G., Zakamska, N. L.
SDSS-V is carrying out a dedicated survey for white dwarfs, single, and in binaries, and we report the analysis of the spectroscopy of 118 cataclysmic variables (CVs) and CV candidates obtained during the final plug plate observations of SDSS. We identify eight new CVs, spectroscopically confirm 53 and refute 11 published CV candidates, and we report 21 new or improved orbital periods. The orbital period distribution of the SDSS-V CVs does not clearly exhibit a period gap. In common with previous studies, the distribution shows that spectroscopically identified CVs have a larger proportion of short-period systems compared to samples identified from photometric variability. Remarkably, despite a systematic search, we find very few period bouncers. We estimate the space density of period bouncers to be similar or equal to 0.2 x10(-6) pc(-3) , i.e. they represent only a few percent of the total CV population. This suggests that during their final phase of evolution, CVs either destroy the donor, e.g. via a merger, or that they become detached and cease mass transfer.
CEERS Key Paper. III. The Diversity of Galaxy Structure and Morphology at z=3-9 with JWST
(IOP Publishing Ltd, 2023/03/01) Kartaltepe, Jeyhan S., Rose, Caitlin, Vanderhoof, Brittany N., McGrath, Elizabeth J., Costantin, Luca, Cox, Isabella G., Yung, L. Y. Aaron, Kocevski, Dale D., Wuyts, Stijn, Ferguson, Henry C., Bagley, Micaela B., Finkelstein, Steven L., Amorin, Ricardo O., Andrews, Brett H., Haro, Pablo Arrabal, Backhaus, Bren E., Behroozi, Peter, Bisigello, Laura, Calabro, Antonello, Casey, Caitlin M., Coogan, Rosemary T., Cooper, M. C., Croton, Darren, de la Vega, Alexander, Dickinson, Mark, Fontana, Adriano, Franco, Maximilien, Grazian, Andrea, Grogin, Norman A., Hathi, Nimish P., Holwerda, Benne W., Huertas-Company, Marc, Iyer, Kartheik G., Jogee, Shardha, Jung, Intae, Kewley, Lisa J., Kirkpatrick, Allison, Koekemoer, Anton M., Liu, James, Lotz, Jennifer M., Lucas, Ray A., Newman, Jeffrey A., Pacifici, Camilla, Pandya, Viraj, Papovich, Casey, Pentericci, Laura, Perez-Gonzalez, Pablo G., Petersen, Jayse, Pirzkal, Nor, Rafelski, Marc, Ravindranath, Swara, Simons, Raymond C., Snyder, Gregory F., Somerville, Rachel S., Stanway, Elizabeth R., Straughn, Amber N., Tacchella, Sandro, Trump, Jonathan R., Vega-Ferrero, Jesus, Wilkins, Stephen M., Yang, Guang, Zavala, Jorge A.
We present a comprehensive analysis of the evolution of the morphological and structural properties of a large sample of galaxies at z = 3-9 using early James Webb Space Telescope (JWST) CEERS NIRCam observations. Our sample consists of 850 galaxies at z > 3 detected in both Hubble Space Telescope (HST)/WFC3 and CEERS JWST/NIRCam images, enabling a comparison of HST and JWST morphologies. We conduct a set of visual classifications, with each galaxy in the sample classified three times. We also measure quantitative morphologies across all NIRCam filters. We find that galaxies at z > 3 have a wide diversity of morphologies. Galaxies with disks make up 60% of galaxies at z = 3, and this fraction drops to similar to 30% at z = 6-9, while galaxies with spheroids make up similar to 30%-40% across the redshift range, and pure spheroids with no evidence for disks or irregular features make up similar to 20%. The fraction of galaxies with irregular features is roughly constant at all redshifts (similar to 40%-50%), while those that are purely irregular increases from similar to 12% to similar to 20% at z > 4.5. We note that these are apparent fractions, as many observational effects impact the visibility of morphological features at high redshift. On average, Spheroid-only galaxies have a higher Sersic index, smaller size, and higher axis ratio than disk or irregular galaxies. Across all redshifts, smaller spheroid and disk galaxies tend to be rounder. Overall, these trends suggest that galaxies with established disks and spheroids exist across the full redshift range of this study, and further work with large samples at higher redshift is needed to quantify when these features first formed.
CEERS Spectroscopic Confirmation of NIRCam-selected z ≳ 8 Galaxy Candidates with JWST/NIRSpec: Initial Characterization of Their Properties
(IOP Publishing Ltd, 2023/06/01) Fujimoto, Seiji, Haro, Pablo Arrabal, Dickinson, Mark, Finkelstein, Steven L., Kartaltepe, Jeyhan S., Larson, Rebecca L., Burgarella, Denis, Bagley, Micaela B., Behroozi, Peter, Chworowsky, Katherine, Hirschmann, Michaela, Trump, Jonathan R., Wilkins, Stephen M., Yung, L. Y. Aaron, Koekemoer, Anton M., Papovich, Casey, Pirzkal, Nor, Ferguson, Henry C., Fontana, Adriano, Grogin, Norman A., Grazian, Andrea, Kewley, Lisa J., Kocevski, Dale D., Lotz, Jennifer M., Pentericci, Laura, Ravindranath, Swara, Somerville, Rachel S., Wilkins, Stephen M., Amorin, Ricardo O., Backhaus, Bren E., Calabro, Antonello, Casey, Caitlin M., Cooper, M. C., Fernandez, Vital, Franco, Maximilien, Giavalisco, Mauro, Hathi, Nimish P., Harish, Santosh, Hutchison, Taylor A., Iyer, Kartheik G., Jung, Intae, Lucas, Ray A., Zavala, Jorge A.
We present JWST NIRSpec spectroscopy for 11 galaxy candidates with photometric redshifts of z similar or equal to 9 - 13 and M-UV is an element of [ -21, -18] newly identified in NIRCam images in the Cosmic Evolution Early Release Science Survey. We confirm emission line redshifts for 7 galaxies at z = 7.762-8.998 using spectra at similar to 1-5 mu m either with the NIRSpec prism or its three medium-resolution (R similar to 1000) gratings. For z similar or equal to 9 photometric candidates, we achieve a high confirmation rate of similar or equal to 90%, which validates the classical dropout selection from NIRCam photometry. No robust emission lines are identified in three galaxy candidates at z > 10, where the strong [O iii] and H beta lines would be redshifted beyond the wavelength range observed by NIRSpec, and the Ly alpha continuum break is not detected with the sensitivity of the current data. Compared with Hubble Space Telescope-selected bright galaxies (M-UV similar or equal to -22) that are similarly spectroscopically confirmed at z similar or equal to 8 - 9, these NIRCam-selected galaxies are characterized by lower star formation rates (SFRs, SFR similar or equal to 4 M-circle dot yr(-1)) and lower stellar masses (similar or equal to 10(8)M(circle dot)), but with higher specific SFR (similar or equal to 40 Gyr(-1)), higher [O iii]+H beta equivalent widths (similar or equal to 1100 angstrom), and elevated production efficiency of ionizing photons (log(xi(ion)/Hz erg(-1)) similar or equal to 25.8) induced by young stellar populations (<10 Myr) accounting for similar or equal to 20% of the galaxy mass, highlighting the key contribution of faint galaxies to cosmic reionization. Taking advantage of the homogeneous selection and sensitivity, we also investigate metallicity and ISM conditions with empirical calibrations using the [O iii](5008)/H beta ratio. We find that galaxies at z similar or equal to 8 - 9 have higher SFRs and lower metallicities than galaxies at similar stellar masses at z similar or equal to 2 - 6, which is generally consistent with the current galaxy formation and evolution models.
Chemo-dynamical tagging in the outskirts: The origins of stellar substructures in the Magellanic Clouds
(EDP SCIENCES S A, 2023/12/12) Munoz, Cesar, Monachesi, Antonela, Nidever, David L., Majewski, Steven R., Cheng, Xinlun, Olsen, Knut, Choi, Yumi, Zivick, Paul, Geisler, Douglas, Almeida, Andres, Munoz, Ricardo R., Nitschelm, Christian, Roman-Lopes, Alexandre, Lane, Richard R., Fernandez-Trincado, Jose G.
We present the first detailed chemical analysis from APOGEE-2S observations of stars in six regions of recently discovered substructures in the outskirts of the Magellanic Clouds extending to 20(degrees) from the Large Magellanic Cloud (LMC) center. We also present, for the first time, the metallicity and alpha-abundance radial gradients of the LMC and the Small Magellanic Cloud (SMC) out to 11(degrees) and 6(degrees), respectively. Our chemical tagging includes 13 species including light, alpha-, and Fe-peak elements. We find that the abundances of all of these chemical elements in stars populating two regions in the northern periphery, along the northern stream-like feature, show good agreement with the chemical patterns of the LMC, and thus likely have an LMC origin. For substructures located in the southern periphery of the LMC we find more complex chemical and kinematical signatures, indicative of a mix of LMC-like and SMC-like populations. The southern region closest to the LMC shows better agreement with the LMC, whereas that closest to the SMC shows a much better agreement with the SMC chemical pattern. When combining this information with 3D kinematical information for these stars, we conclude that the southern region closest to the LMC likely has an LMC origin, whereas that closest to the SMC has an SMC origin and the other two southern regions have a mix of LMC and SMC origins. Our results add to the evidence that the southern substructures of the LMC periphery are the product of close interactions between the LMC and SMC, and thus likely hold important clues that can constrain models of their detailed dynamical histories.
Clash of Titans: the impact of cluster mergers in the galaxy cluster red sequence
(OXFORD UNIV PRESS, 2023/10/01) Aldas, Franklin, Zenteno, Alfredo, Gomez, Facundo A., Hernandez-Lang, Daniel, Carrasco, Eleazar R., Vega-Martinez, Cristian A., Castellon, J. L. Nilo
Merging of galaxy clusters are some of the most energetic events in the Universe, and they provide a unique environment to study galaxy evolution. We use a sample of 84 merging and relaxed SPT galaxy clusters candidates, observed with the Dark Energy Camera in the 0.11 < z < 0.88 redshift range, to build colour-magnitude diagrams to characterize the impact of cluster mergers on the galaxy population. We divided the sample between relaxed and disturbed, and in two redshifts bin at z = 0.55. When comparing the high-z to low-z clusters we find the high-z sample is richer in blue galaxies, independently of the cluster dynamical state. In the high-z bin, we find that disturbed clusters exhibit a larger scatter in the red sequence, with wider distribution and an excess of bluer galaxies compared to relaxed clusters, while in the low-z bin we find a complete agreement between the relaxed and disturbed clusters. Our results support the scenario in which massive cluster halos at z < 0.55 galaxies are quenched as satellites of another structure, i.e. outside the cluster, while at z >= 0.55 the quenching is dominated by in situ processes.