Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Abstract： Quantifying the connection between galaxies and their host dark matter halos has been key for testing cosmological models on various scales. Below $M_\star \sim 10^9\,M_\odot$, such studies have primarily relied on the satellite galaxy population orbiting the Milky Way. Here we present new constraints on the connection between satellite galaxies and their host dark matter subhalos using the largest sample of satellite galaxies in the Local Volume ($D \lesssim 12\,\mathrm{Mpc}$) to date. We use $250$ confirmed and $71$ candidate dwarf satellites around 27 Milky Way (MW)-like hosts from the Exploration of Local VolumE Satellites (ELVES) Survey and use the semi-analytical SatGen model for predicting the population of dark matter subhalos expected in the same volume. Through a Bayesian model comparison of the observed and the forward-modeled satellite stellar mass functions (SSMF), we infer the satellite stellar-to-halo mass relation. We find that the observed SSMF is best reproduced when subhalos are populated by a relation of the form $M_\star \propto M^\alpha_\mathrm{peak}$, with a moderate slope of $\alpha=2.0 \pm 0.1$, and a scatter that grows with decreasing $M_\mathrm{peak}$. We find a significantly larger scatter towards lower peak halo masses, compared to prior studies that relied mainly on MW satellites. We conclude that this scatter results from a combination of star formation stochasticity and host-to-host scatter. Our new model for the satellite-subhalo connection has important implications for both of these baryonic-impacted effects, as well as on dark matter physics.
Peer Review Status:
Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Abstract： Ultra-Diffuse Galaxies are both extreme products of galaxy evolution and extreme environments in which to test our understanding of star formation. In this work, we contrast the spatially resolved star formation activity of a sample of 22 HI-selected UDGs and 35 low-mass galaxies from the NASA Sloan Atlas (NSA) within 120 Mpc. We employ a new joint SED fitting method to compute star formation rate and stellar mass surface density maps that leverage the high spatial resolution optical imaging data of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) and the UV coverage of GALEX, along with HI radial profiles estimated from a subset of galaxies that have spatially resolved HI maps. We find that the UDGs have low star formation efficiencies as a function of their atomic gas down to scales of 500 pc. We additionally find that the stellar mass-weighted sizes of our UDG sample are unremarkable when considered as a function of their HI mass -- their stellar sizes are comparable to the NSA dwarfs at fixed HI mass. This is a natural result in the picture where UDGs are forming stars normally, but at low efficiencies. We compare our results to predictions from contemporary models of galaxy formation, and find in particular that our observations are difficult to reproduce in models where UDGs undergo stellar expansion due to vigorous star formation feedback should bursty star formation be required down to $z=0$.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Jiaxuan Li
Song Huang
Alexie Leauthaud
John Moustakas
Shany Danieli
Jenny E. Greene
Roberto Abraham
Felipe Ardila
Erin Kado-Fong
Deborah Lokhorst
Robert Lupton
Paul Price
Abstract： The outer light (stellar halos) of massive galaxies has recently emerged as a
possible low scatter tracer of dark matter halo mass. To test the robustness of
outer light measurements across different data sets, we compare the surface
brightness profiles of massive galaxies using four independent data sets: the
Hyper Suprime-Cam survey (HSC), the Dark Energy Camera Legacy Survey (DECaLS),
the Sloan Digital Sky Survey (SDSS), and the Dragonfly Wide Field Survey
(Dragonfly). We use customized pipelines for HSC and DECaLS to achieve better
sky background subtraction. For galaxies at $z<0.05$, Dragonfly has the best
control of systematics, reaching surface brightness levels of $\mu_r \sim 30$
mag/arcsec$^{2}$. At $0.19
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Jiaxuan Li
Jenny E. Greene
Johnny Greco
Rachael Beaton
Shany Danieli
Andy Goulding
Song Huang
Erin Kado-Fong
Abstract： Recent observations have reignited interest in a population of dwarf galaxies that are large and diffuse for their mass, often called ultra-diffuse galaxies. However, the origin and evolution of these mass-size outliers and the role of environment are still unclear. Using the exquisitely deep and wide Hyper Suprime-Cam Strategic Survey images, we search for ultra-puffy galaxies, defined as being $1.5\sigma$ larger than the average size for their mass, around Milky-Way--like galaxies. We present the size and radial distributions of mass-size outliers, and derive their quenched fraction to explore the impact of environment. Surprisingly, despite being outliers in size, the ultra-puffy galaxies have a similar quenched fraction as normal-sized satellites of Milky Way analogs in both observations and simulations, suggesting that quenching is not tied to being a mass-size outlier. The quenched fraction is higher for the ultra-puffy galaxies associated with redder hosts as well as those that are closer to the host in projection. In contrast, the ultra-diffuse galaxies are overall redder and more quiescent compared with normal satellites. We show that the classic definition of ultra-diffuse galaxies is heavily weighted towards quenched galaxies and thus cannot be used for a study of quenching of mass-size outliers.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Dominika Wylezalek
Andrey Vayner
David S. N. Rupke
Nadia L. Zakamska
Sylvain Veilleux
Yuzo Ishikawa
Caroline Bertemes
Weizhe Liu
Jorge K. Barrera-Ballesteros
Hsiao-Wen Chen
Andy D. Goulding
Jenny E. Greene
Kevin N. Hainline
Nora Lützgendorf
Fred Hamann
Timothy Heckman
Sean D. Johnson
Dieter Lutz
Vincenzo Mainieri
Roberto Maiolino
Abstract： Extremely red quasars, with bolometric luminosities exceeding $10^{47}$ erg s$^{-1}$, are a fascinating high-redshift population that is absent in the local universe. They are the best candidates for supermassive black holes accreting at rates at or above the Eddington limit, and they are associated with the most rapid and powerful outflows of ionized gas known to date. They are also hosted by massive galaxies. Here we present the first integral field unit (IFU) observations of a high-redshift quasar obtained by the Near Infrared Spectrograph (NIRSpec) on board the James Webb Space Telescope (JWST), which targeted SDSSJ165202.64+172852.3, an extremely red quasar at $z=2.94$. JWST observations reveal extended ionized gas - as traced by [OIII]$\lambda$5007\AA - in the host galaxy of the quasar, its outflow, and the circumgalactic medium. The complex morphology and kinematics imply that the quasar resides in a very dense environment with several interacting companion galaxies within projected distances of 10-15 kpc. The high density of the environment and the large velocities of the companion galaxies suggest that this system may represent the core of a forming cluster of galaxies. The system is a good candidate for a merger of two or more dark matter halos, each with a mass of a few $10^{13}$ M$_\odot$ and traces potentially one of the densest knots at $z\sim3$.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Abstract： Isolated dwarf galaxies nearly always exhibit robust star formation but satellite dwarf galaxies are often devoid of young stars, even in Milky Way-mass groups. Dwarf galaxies thus offer an important laboratory into the environmental processes that cease star formation. We explore the balance of quiescent and star-forming galaxies (quenched fractions) for a sample of ~400 satellite galaxies around 30 Local Volume hosts from the Exploration of Local VolumE Satellites (ELVES) Survey. We present quenched fractions as a function of satellite stellar mass, projected radius, and host halo mass, to conclude that overall, the quenched fractions are similar to the Milky Way, dropping below 50\% at satellite M*~10^8 Msun. There is a ~10% difference in quenched fraction for satellites within and outside of ~R_vir/2 at fixed satellite mass. Finally, the satellite mass at which quenching grows inefficient grows steadily with host halo mass. Through comparison with the semi-analytic modeling code SatGen, we are also able to infer average quenching times as a function of satellite mass in host halo-mass bins. There is a gradual increase in quenching time with satellite stellar mass rather than the abrupt change from rapid to slow quenching that has been inferred for the Milky Way. We also generally infer longer average quenching times than recent hydrodynamical simulations. Our results vindicate models that suggest a wide range of quenching times are possible via ram pressure stripping, depending on the clumpiness of the circumgalactic medium, the orbits of the satellites, and the degree of earlier preprocessing.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Jiaxuan Li
Jenny E. Greene
Johnny P. Greco
Song Huang
Peter Melchior
Rachael Beaton
Kirsten Casey
Shany Danieli
Andy Goulding
Remy Joseph
Erin Kado-Fong
Ji Hoon Kim
Lauren A. MacArthur
Abstract： Large diffuse galaxies are hard to find, but understanding the environments where they live, their numbers, and ultimately their origins, is of intense interest and importance for galaxy formation and evolution. Using Subaru's Hyper Suprime-Cam Strategic Survey Program, we perform a systematic search for low surface brightness galaxies and present novel and effective methods for detecting and modeling them. As a case study, we surveyed 922 Milky Way analogs in the nearby Universe ($0.01 < z < 0.04$) and build a large sample of satellite galaxies that are outliers in the mass-size relation. These ``ultra-puffy'' galaxies (UPGs), defined to be $1.5\sigma$ above the average mass-size relation, represent the tail of the satellite size distribution. We find that each MW analog hosts $N_{\rm UPG} = 0.31\pm 0.05$ ultra-puffy galaxies on average, which is consistent with but slightly lower than the observed abundance at this halo mass in the Local Volume. We also construct a sample of ultra-diffuse galaxies (UDGs) in MW analogs and find an abundance of $N_{\rm UDG} = 0.44\pm0.05$ per host. With literature results, we confirm that the UDG abundance scales with the host halo mass following a sublinear power law. We argue that our definition for ultra-puffy galaxies, which is based on the mass-size relation, is more physically-motivated than the common definition of ultra-diffuse galaxies, which depends on surface brightness and size cuts and thus yields different surface mass density cuts for quenched and star-forming galaxies.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Lukas J. Furtak
Adi Zitrin
Adèle Plat
Seiji Fujimoto
Bingjie Wang
Erica J. Nelson
Ivo Labbé
Rachel Bezanson
Gabriel B. Brammer
Pieter van Dokkum
Ryan Endsley
Karl Glazebrook
Jenny E. Greene
Joel Leja
Sedona H. Price
Renske Smit
Daniel P. Stark
John R. Weaver
Katherine E. Whitaker
Hakim Atek
Abstract： Recent JWST/NIRcam imaging taken for the ultra-deep UNCOVER program reveal a very red, triply imaged, compact dropout object at $z_{\mathrm{phot}}\simeq7.66$ which is prominently lensed by the galaxy cluster Abell 2744 ($z_{\mathrm{d}}=0.308$). All three images are very compact, i.e. unresolved, with an inferred de-lensed size upper limit of $r_{e}\lesssim35$ pc. The observed F444W magnitude of the three images is $m\sim25-26$ AB and the source's absolute UV magnitude is $M_{\mathrm{UV},1450}=-16.81\pm0.09$, after correcting for magnification. From the sum of observed fluxes and from a spectral energy distribution (SED) fit we obtain lower limits on the bolometric luminosities of $L_{\mathrm{bol}}\gtrsim10^{43} \frac{\mathrm{erg}}{\mathrm{s}}$ and $L_{\mathrm{bol}}\gtrsim10^{44} \frac{\mathrm{erg}}{\mathrm{s}}$ for the source, respectively. Based on its compact, point-like appearance, its positions in color-color and $M_{\mathrm{UV}}$-size diagrams and the SED analysis, we tentatively conclude that this object could be a faint quasar-like object, i.e., an extreme emission line object whose nebular emission is boosted by an active galactic nucleus (AGN). We discuss various alternative origins for the object's emission features, including a massive star cluster, a cluster of Population III, supermassive, or dark stars, or a direct-collapse black hole. Although populations of red galaxies at similar photometric redshifts have been detected with JWST, this object is unique in that its high-redshift nature is corroborated geometrically by lensing, that it is unresolved despite being magnified -- and thus intrinsically even more compact -- and that it occupies notably distinct regions in both size-luminosity and color-color space. The planned UNCOVER JWST/NIRSpec observations (scheduled in Cycle 1) will enable a more detailed analysis of this object.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Matthew E. Quenneville
John P. Blakeslee
Chung-Pei Ma
Jenny E. Greene
Stephen D. J. Gwyn
Stephanie Ciccone
Blanka Nyiri
Abstract： We present wide-field, deep $K$-band photometry of 98 luminous early-type galaxies (ETGs) from the MASSIVE survey based on observations taken with the WIRCam instrument on the Canada-France-Hawaii Telescope. Using these images, we extract accurate total $K$-band luminosities ($L_K$) and half-light radii ($R_e$) for this sample of galaxies. We use these new values to explore the size-luminosity and Faber-Jackson relations for massive ETGs. Within this volume-limited sample, we find clear evidence for curvature in both relations, indicating that the most luminous galaxies tend to have larger sizes and smaller velocity dispersions than expected from a simple power-law fit to less luminous galaxies. Our measured relations are qualitatively consistent with the most massive elliptical galaxies forming largely through dissipationless mergers. When the sample is separated into fast and slow rotators, we find the slow rotators to exhibit similar changes in slope with increasing $L_K$, suggesting that low-mass and high-mass slow rotators have different formation histories. The curvatures in the $R_e-L_K$ and $\sigma-L_K$ relations cancel, leading to a relation between dynamical mass and luminosity that is well described by a single power-law: $R_e\sigma^2 \propto {L_K}^b$ with $b\approx 1.2$. This is consistent with the tilt of the fundamental plane observed in lower mass elliptical galaxies.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
John R. Weaver
Sam E. Cutler
Richard Pan
Katherine E. Whitaker
Ivo Labbe
Sedona H. Price
Rachel Bezanson
Gabriel Brammer
Danilo Marchesini
Joel Leja
Bingjie Wang
Lukas J. Furtak
Adi Zitrin
Hakim Atek
Dan Coe
Pratika Dayal
Pieter van Dokkum
Robert Feldmann
Natascha Forster Schreiber
Marijn Franx
Abstract： In November 2022, the James Webb Space Telescope (JWST) returned deep near-infrared images of Abell~2744 -- a powerful lensing cluster capable of magnifying distant, incipient galaxies beyond it. Together with the existing Hubble Space Telescope (HST) imaging, this publicly available dataset opens a fundamentally new discovery space to understand the remaining mysteries of the formation and evolution of galaxies across cosmic time. In this work, we detect and measure some 50,000 objects across the 45 arcmin$^2$ JWST footprint down to a $5\,\sigma$ limiting magnitude of $\sim$29.9\,mag in 0.32" apertures. Photometry is performed using circular apertures on images matched to the point spread function of the reddest NIRCam band, F444W, and cleaned of bright cluster galaxies and the related intra-cluster light. To give an impression of the photometric performance, we measure photometric redshifts and achieve a $\sigma_{\rm NMAD}\approx0.03$ based on known, but relatively small, spectroscopic samples. With this paper, we publicly release HST and JWST PSF-matched photometric catalogs optimized for bright and extended sources (0.7" apertures) and compact and faint sources (0.32" apertures) along with basic photometric redshifts, rest-frame colors, and individual magnification estimates. These catalogs will set the stage for efficient and deep spectroscopic follow-up of the first JWST-selected samples in Summer 2023.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Abstract： We report the detection of a long-timescale negative lag, where the blue bands lag the red bands, in the nearby Seyfert 1 galaxy Fairall 9. Active Galactic Nuclei (AGN) light curves show variability over a wide range of timescales. By measuring time lags between different wavelengths, the otherwise inaccessible structure and kinematics of the accretion disk can be studied. One common approach, reverberation mapping, quantifies the continuum and line lags moving outwards through the disk at the light-travel time, revealing the size and temperature profile of the disk. Inspired by numerical simulations, we expect longer lags to exist in AGN light curves that travel inward on longer timescales, tracing the accretion process itself. By analyzing AGN light curves in both temporal and frequency space, we report the detection of long-timescale lags ($\sim -70$ days) in Fairall 9 which propagate in the opposite direction to the reverberation lag. The short continuum lag ($<10$ days) is also detected and is consistent with reverberation lags reported in the literature. When fitting the longer lag as a function of frequency with a model motivated by the thin disk model, we find that the disk scale height likely increases outward in the disk. This detection raises the exciting prospect of mapping accretion disk structures across a wide range of AGN parameters.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Rachel Bezanson
Ivo Labbe
Katherine E. Whitaker
Joel Leja
Sedona H. Price
Marijn Franx
Gabe Brammer
Danilo Marchesini
Adi Zitrin
Bingjie Wang
John R. Weaver
Lukas J. Furtak
Hakim Atek
Dan Coe
Sam E. Cutler
Pratika Dayal
Pieter van Dokkum
Robert Feldmann
Natascha Forster Schreiber
Seiji Fujimoto
Abstract： In this paper we describe the survey design for the Ultradeep NIRSpec and NIRCam ObserVations before the Epoch of Reionization (UNCOVER) Cycle 1 JWST Treasury program, which executed its early imaging component in November 2022. The UNCOVER survey includes ultradeep ($\sim29-30\mathrm{AB}$) imaging of $\sim$45 arcmin$^2$ on and around the well-studied Abell 2744 galaxy cluster at $z=0.308$ and will follow-up ${\sim}500$ galaxies with extremely deep low-resolution spectroscopy with the NIRSpec/PRISM during the summer of 2023. We describe the science goals, survey design, target selection, and planned data releases. We also present and characterize the depths of the first NIRCam imaging mosaic, highlighting previously unparalleled resolved and ultradeep 2-4 micron imaging of known objects in the field. The UNCOVER primary NIRCam mosaic spans 28.8 arcmin$^2$ in seven filters (F115W, F150W, F200W, F277W, F356W, F410M, F444W) and 16.8 arcmin$^2$ in our NIRISS parallel (F115W, F150W, F200W, F356W, and F444W). To maximize early community use of the Treasury data set, we publicly release full reduced mosaics of public JWST imaging including 45 arcmin$^2$ NIRCam and 17 arcmin$^2$ NIRISS mosaics on and around the Abell 2744 cluster, including the Hubble Frontier Field primary and parallel footprints.
Peer Review Status:Awaiting Review
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