Publications (78)
CMZoom: Survey Overview and First Data Release
Cara Battersby, Eric Keto, Daniel Walker +19
We present an overview of the CMZoom survey and its first data release. CMZoom is the first blind, high-resolution survey of the Central Molecular Zone (CMZ; the inner 500 pc of th…
Magnetic Fields and Massive Star Formation
Qizhou Zhang, Keping Qiu, Josep M. Girart +17
Massive stars ( \msun) typically form in parsec-scale molecular clumps that collapse and fragment, leading to the birth of a cluster of stellar objects. We investigate the r…
Core and filament formation in magnetized, self-gravitating isothermal layers
Sven Van Loo, Eric Keto, Qizhou Zhang
We examine the role of the gravitational instability in an isothermal, self-gravitating layer threaded by magnetic fields on the formation of filaments and dense cores. Using numer…
A Wideband Chemical Survey of Massive Star-forming Regions at Subarcsecond Resolution with the Submillimeter Array
Charles J. Law, Qizhou Zhang, Arielle C. Frommer +7
Massive star-forming regions exhibit a rich chemistry with complex gas distributions, especially on small scales. While surveys have yielded constraints on typical gas conditions,…
Dynamics and Depletion in Thermally Supercritical Starless Cores
Eric Keto, Paola Caselli
In previous studies we identified two classes of starless cores, thermally subcritical and supercritical, distinguished by different dynamical behavior and internal structure. Here…
Stability of an Ionization Front in Bondi Accretion
Eric Keto, Rolf Kuiper
Spherical Bondi accretion is used in astrophysics as an approximation to investigate many types of accretion processes. Two-phase accretion flows that transition from neutral to io…
From the Convergence of Filaments to Disk-Outflow Accretion: Massive-Star Formation in W33A
Roberto Galván-Madrid, Qizhou Zhang, Eric Keto +5
Interferometric observations of the W33A massive star-formation region, performed with the Submillimeter Array (SMA) and the Very Large Array (VLA) at resolutions from 5 arcsec (0.…
First detection of water vapor in a pre-stellar core
Paola Caselli, Eric Keto, Edwin A. Bergin +11
Water is a crucial molecule in molecular astrophysics as it controls much of the gas/grain chemistry, including the formation and evolution of more complex organic molecules in ice…
A Physical Model for the Ice Coma of the Interstellar, Hyperactive Comet 3I/ATLAS
Eric Keto, Abraham Loeb
A previous study suggests that the observed exponential character of the surface brightness profiles in the coma around the interstellar comet 3I/ATLAS at 4 au can be explained as…
Radiation hydrodynamic simulations of massive star formation via gravitationally trapped HII regions - Spherically symmetric ionised accretion flows
Kristin Lund, Kenneth Wood, Diego Falceta-Gonçalves +5
This paper investigates the gravitational trapping of HII regions predicted by steady-state analysis using radiation hydrodynamical simulations. We present idealised spherically sy…
Magnetically regulated collapse in the B335 protostar ? I. ALMA observations of the polarized dust emission
Anaëlle J. Maury, Josep Miquel Girart, Qizhou Zhang +6
The role of the magnetic field during protostellar collapse is poorly constrained from an observational point of view, although it could be significant if we believe state-of-the-a…
The dynamics of collapsing cores and star formation
Eric Keto, Paola Caselli, Jonathan Rawlings
Low-mass stars are generally understood to form by the gravitational collapse of the dense molecular clouds known as starless cores. Continuum observations have not been able to di…
The Decrease of Specific Angular Momentum and the Hot Toroid Formation: The Massive Clump G10.6-0.4
Hauyu Baobab Liu, Paul T. P. Ho, Qizhou Zhang +3
This is the first paper of our series of high resolution (1") studies of the massive star forming region G10.6--0.4. We present the emission line observations of the hot core type…
An observational correlation between magnetic field, angular momentum and fragmentation in the envelopes of Class 0 protostars?
Maud Galametz, Anaelle Maury, Josep M. Girart +8
To assess the potential role of magnetic fields in regulating the envelope rotation and the fragmentation of Class 0 protostars, we carried out observations of the dust polarized e…
Two Populations of Molecular Clouds in the Antennae Galaxies
Lisa H. Wei, Eric Keto, Luis C. Ho
Super star clusters --- extremely massive clusters found predominately in starburst environments --- are essential building blocks in the formation of galaxies and thought to domin…
The Scientific Investigation of Unidentified Aerial Phenomena (UAP) Using Multimodal Ground-Based Observatories
Wesley Andrés Watters, Abraham Loeb, Frank Laukien +35
(Abridged) Unidentified Aerial Phenomena (UAP) have resisted explanation and have received little formal scientific attention for 75 years. A primary objective of the Galileo Proje…
The standard model of star formation applied to massive stars: accretion disks and envelopes in molecular lines
Eric Keto, Qizhou Zhang
We address the question of whether the formation of high-mass stars is similar to or differs from that of solar-mass stars through new molecular line observations and modeling of t…
H II regions: Witnesses to massive star formation
Thomas Peters, Robi Banerjee, Ralf S. Klessen +3
We describe the first three-dimensional simulation of the gravitational collapse of a massive, rotating molecular cloud that includes heating by both non-ionizing and ionizing radi…
Detection of Moving Objects in Earth Observation Satellite Images: Verification
Eric Keto, Wesley Andres Watters
In multi-spectral images made by Earth observation satellites that use push-broom scanning, such as those operated by Planet Labs Corp., moving objects can be identified by the app…
Detection of Moving Objects in Earth Observation Satellite Images
Eric Keto, Wesley Andres Watters
Moving objects have characteristic signatures in multi-spectral images made by Earth observation satellites that use push broom scanning. While the general concept is applicable to…
An Interferometric Spectral-line Survey of IRC+10216 in the 345 GHz Band
Nimesh A. Patel, Ken H. Young, Carl A. Gottlieb +10
We report a spectral-line survey of the extreme carbon star IRC+10216 carried out between 293.9 and 354.8 GHz with the Submillimeter Array. A total of 442 lines were detected, more…
Quasi-equilibrium chemical evolution in starless cores
Jonathan Rawlings, Eric Keto, Paola Caselli
The chemistry of H2O, CO and other small molecular species in an isolated pre-stellar core, L1544, has been assessed in the context of a comprehensive gas-grain chemical model, cou…
Oscillations of starless cores
Eric Keto, Avery Broderick, Charles J. Lada +1
If the split, asymmetric molecular spectral line profiles that are seen in many starless cores are interpreted as indicative of global collapse or expansion of the core then one po…
Dynamics of Molecular Clouds
George Field, Eric Blackman, Eric Keto
We further develop the model of molecular cloud fragmentation introduced in Field, Blackman and Keto (2007; FBK). We show that external pressure acting on fragments establishes a s…
Spherical Infall in G10.6-0.4: Accretion Through an Ultracompact HII Region
Peter K. Sollins, Qizhou Zhang, Eric Keto +1
We present high resolution (0.''12 x 0.''079) observations of the ultracompact HII region G10.6-0.4 in 23 GHz radio continuum and the NH3(3,3) line. Our data show that the infall i…
Dark cloud cores and gravitational decoupling from turbulent flows
Eric Keto, George Field
We test the hypothesis that the starless cores may be gravitationally bound clouds supported largely by thermal pressure by comparing observed molecular line spectra to theoretical…
The Physics of Cometary Anti-tails as Observed in 3I/ATLAS
Eric Keto, Abraham Loeb
Observations of interstellar comet 3I/ATLAS at 3.8 au show an elongated coma similar to a cometary tail but pointing in the direction of the Sun, possibly the first instance of thi…
Testing the stability of supersonic ionized Bondi accretion flows with radiation hydrodynamics
Bert Vandenbroucke, Nina S. Sartorio, Kenneth Wood +6
We investigate the general stability of 1D spherically symmetric ionized Bondi accretion onto a massive object in the specific context of accretion onto a young stellar object. We…
The standard model of low-mass star formation applied to massive stars: multi-wavelength modelling of IRAS 20126+4104
Katharine G. Johnston, Eric Keto, Thomas P. Robitaille +1
In order to investigate whether massive stars form similarly to their low-mass counterparts, we have used the standard envelope plus disc geometry successfully applied to low-mass…
Modeling molecular hyperfine line emission
Eric Keto, George Rybicki
In this paper we discuss two approximate methods previously suggested for modeling hyperfine spectral line emission for molecules whose collisional transitions rates between hyperf…
Observations on the Formation of Massive Stars by Accretion
Eric Keto, Kenneth Wood
Observations of the H66a recombination line from the ionized gas in the cluster of newly formed massive stars, G10.6-0.4, show that most of the continuum emission derives from the…
The Early Evolution of Massive Stars: Radio Recombination Line Spectra
Eric Keto, Qizhou Zhang, Stanley Kurtz
Velocity shifts and differential broadening of radio recombination lines are used to estimate the densities and velocities of the ionized gas in several hypercompact and ultracompa…
Intensity-Corrected Herschel Observations of Nearby Isolated Low-Mass Clouds
Sarah I. Sadavoy, Eric Keto, Tyler L. Bourke +8
We present intensity-corrected Herschel maps at 100 um, 160 um, 250 um, 350 um, and 500 um for 56 isolated low-mass clouds. We determine the zero-point corrections for Herschel PAC…
Commissioning An All-Sky Infrared Camera Array for Detection Of Airborne Objects
Laura Dominé, Ankit Biswas, Richard Cloete +13
To date there is little publicly available scientific data on Unidentified Aerial Phenomena (UAP) whose properties and kinematics purportedly reside outside the performance envelop…
Chemistry and Radiative Transfer of Water in Cold, Dense Clouds
Eric Keto, Jonathan Rawlings, Paola Caselli
The Herschel Space Observatory's recent detections of water vapor in the cold, dense cloud L1544 allow a direct comparison between observations and chemical models for oxygen speci…
A Keplerian-like disk around the forming O-type star AFGL 4176
Katharine G. Johnston, Thomas P. Robitaille, Henrik Beuther +6
We present Atacama Large Millimeter/submillimeter Array (ALMA) line and continuum observations at 1.2mm with ~0.3" resolution that uncover a Keplerian-like disk around the forming…
Is protostellar heating sufficient to halt fragmentation? A case study of the massive protocluster G8.68-0.37
Steven N. Longmore, Thushara Pillai, Eric Keto +2
If star formation proceeds by thermal fragmentation and the subsequent gravitational collapse of the individual fragments, how is it possible to form fragments massive enough for O…
Stability and Solution of the Time-Dependent Bondi-Parker Flow
Eric Keto
Bondi (1952) and Parker (1958} derived a steady-state solution for Bernouilli's equation in spherical symmetry around a point mass for two cases, respectively, an inward accretion…
A Hot and Massive Accretion Disk around the High-Mass Protostar IRAS 20126+4104
Huei-Ru Vivien Chen, Eric Keto, Qizhou Zhang +3
We present new spectral line observations of the CH3CN molecule in the accretion disk around the massive protostar IRAS 20126+4104 with the Submillimeter Array that for the first t…
Scales of Stability and Turbulence in the Molecular ISM
Eric Keto
We re-analyze the data of the BU-FCRAO Galactic Ring Survey (GRS) to understand the dynamics of the turbulent molecular interstellar medium. We define molecular clo…
A Model of Cloud Fragmentation
George B. Field, Eric G. Blackman, Eric Keto
We present a model in which the supersonic motions observed in molecular clouds are driven by gravitational energy released as large structures fragment into smaller ones. The frag…
Hierarchical configurations for cross-correlation interferometers with many elements
Eric Keto
Array configurations built on a hierarchy of simple elements have excellent properties for cross-correlation imaging interferometers including a smooth distribution of measured Fou…
Mid-Infrared Imaging of Young Stellar Objects
Michael C. Liu, James R. Graham, A. M. Ghez +6
We present arcsecond resolution mid-infrared (8--13 m) images and photometry of four young stellar objects (YSOs)~--- L1551-IRS5, HL~Tau, AS~205, and AS~209 (V1121~Oph)~--- tak…
M82, Starbursts, Star Clusters, and the Formation of Globular Clusters
Eric Keto, Luis C. Ho, K. Y. Lo
We observed the nearby starburst galaxy M82 in CO in the higher frequency (2--1) transition to achieve an angular resolution below 1 arc second or 17 pc at the target. We resolved…
Sub-arcsecond Imaging of the Complex Organic Chemistry in Massive Star-forming Region G10.6-0.4
Charles J. Law, Qizhou Zhang, Karin I. Ãberg +4
Massive star-forming regions exhibit an extremely rich and diverse chemistry, which in principle provides a wealth of molecular probes, as well as laboratories for interstellar pre…
Velocity Analysis of Moving Objects in Earth Observation Satellite Images Using Multi-Spectral Push Broom Scanning
Eric Keto, Wesley Andres Watters
In this study, we present a method for detecting and analyzing the velocities of moving objects in Earth observation satellite images, specifically using data from Planet Labs' pus…
Oscillating Starless Cores: The Nonlinear Regime
Avery E. Broderick, Eric Keto, Charles J. Lada +1
In a previous paper, we modeled the oscillations of a thermally-supported (Bonnor-Ebert) sphere as non-radial, linear perturbations following a standard analysis developed for stel…
Clustered Formation of Massive Stars within an Ionized Rotating Disk
Roberto Galván-Madrid, Qizhou Zhang, Andrés Izquierdo +7
We present ALMA observations with a 800 au resolution and radiative-transfer modelling of the inner part ( au) of the ionized accretion flow around a compact star clu…
Time Variation in G24.78+0.08 A1: Evidence for an Accreting Hypercompact H II Region?
Roberto Galván-Madrid, Luis F. RodrÃguez, Paul T. P. Ho +1
Over a timescale of a few years, an observed change in the optically thick radio continuum flux can indicate whether an unresolved H II region around a newly formed massive star is…
Radiative Transfer and Starless Cores
Eric Keto, George B. Rybicki, Edwin A. Bergin +1
We develop a method of analyzing radio frequency spectral line observations to derive data on the temperature, density, velocity, and molecular abundance of the emitting gas. The m…
CMZoom III: Spectral Line Data Release
Daniel Callanan, Steven N. Longmore, Cara Battersby +21
We present an overview and data release of the spectral line component of the SMA Large Program, \textit{CMZoom}. \textit{CMZoom} observed CO(2-1), CO(2-1) and C$^{18…
The Central 1000 au of a Pre-stellar Core Revealed with ALMA. II. Almost Complete Freeze-out
Paola Caselli, Jaime E. Pineda, Olli Sipilä +18
Pre-stellar cores represent the initial conditions in the process of star and planet formation. Their low temperatures (10 K) allow the formation of thick icy dust mantles, whic…
The Formation of Massive Stars by Accretion Through Trapped Hypercompact HII Regions
Eric Keto
The formation of massive stars may take place at relatively low accretion rates over a long period of time if the accretion can continue past the onset of core hydrogen ignition. T…
Analytic Modeling of CO Surface-Density Profiles in the M31 Molecular Clouds
Eric Keto, Charles Lada, Jan Forbrich
We analyze CO observations of molecular clouds in the Andromeda galaxy (M31) with a new method to derive surface-density profiles and compare directly with projected solutions of t…
Time Variability in Simulated Ultracompact and Hypercompact HII Regions
Roberto Galván-Madrid, Thomas Peters, Eric Keto +3
Ultracompact and hypercompact HII regions appear when a star with a mass larger than about 15 solar masses starts to ionize its own environment. Recent observations of time variabi…
The Mid-infrared Fine-structure Lines of Neon as an Indicator of Star For mation Rate in Galaxies
Luis C. Ho, Eric Keto
The fine-structure lines of singly ([Ne II] 12.8 micron) and doubly ([Ne III] 15.6 micron) ionized neon are among the most prominent features in the mid-infrared spectra of star-fo…
The Different Structures of the Two Classes of Starless Cores
Eric Keto, Paola Caselli
We describe a model for the thermal and dynamical equilibrium of starless cores that includes the radiative transfer of the gas and dust and simple CO chemistry. The model shows th…
Apparent Stability in Self-Gravitating Turbulence and the Evolution of Molecular Clouds
Eric Keto
Recent observations of hydrostatic structure and virial equilibrium in supersonically turbulent, self-gravitating molecular clouds imply a stability that contrasts with the transci…
First-generation Science Cases for Ground-based Terahertz Telescopes
Hiroyuki Hirashita, Patrick M. Koch, Satoki Matsushita +33
Ground-based observations at terahertz (THz) frequencies are a newly explorable area of astronomy for the next ten years. We discuss science cases for a first-generation 10-m class…
High velocity bipolar outflow and disk-like envelope in the carbon star V Hya
Naomi Hirano, Hiroko Shinnaga, Dinh-V-Trung +7
Using the partially completed Submillimeter Array with five antennas, we have observed the CO J=2-1 and 3-2 emission from the envelope surrounding the carbon star V Hya. The high-a…
CMZoom II: Catalog of Compact Submillimeter Dust Continuum Sources in the Milky Way's Central Molecular Zone
H Perry Hatchfield, Cara Battersby, Eric Keto +19
In this paper we present the CMZoom Survey's catalog of compact sources (< 10'', ~0.4pc) within the Central Molecular Zone (CMZ). CMZoom is a Submillimeter Array (SMA) large progra…
The Ionization of Accretion Flows in High Mass Star Formation: W51e2
Eric Keto, Pamela Klaassen
Previous observations show that the hypercompact HII region W51e2 is surrounded by a massive molecular accretion flow centered on the HII region. New observations of the H53alpha r…
Equilibrium Simplified Chemistries for H2O and CO in three-phase astrochemical models
Jonathan Rawlings, Eric Keto, Paola Caselli
Astrochemical models can be greatly simplified, with obvious computational advantages, if the reaction networks for key species can be reduced to a bare minimum. In addition, if ch…
Embedded Oscillating Starless Cores
Avery E. Broderick, Ramesh Narayan, Eric Keto +1
In a previous paper we demonstrated that non-radial hydrodynamic oscillations of a thermally-supported (Bonnor-Ebert) sphere embedded in a low-density, high-temperature medium pers…
The Evolution of Cloud Cores and the Formation of Stars
Avery E. Broderick, Eric Keto
For a number of starless cores, self-absorbed molecular line and column density observations have implied the presence of large-amplitude oscillations. We examine the consequences…
SMA observations of the polarized dust emission in solar-type Class 0 protostars: the magnetic field properties at envelope scales
Maud Galametz, Anaelle Maury, Josep M. Girart +6
Although, from a theoretical point of view, magnetic fields are believed to have a significant role during the early stages of star formation, especially during the main accretion…
Formation of an O-Star Cluster by Hierarchical Accretion in G20.08-0.14 N
Roberto Galván-Madrid, Eric Keto, Qizhou Zhang +3
Spectral line and continuum observations of the ionized and molecular gas in G20.08-0.14 N explore the dynamics of accretion over a range of spatial scales in this massive star-for…
The formation of massive stars: accretion, disks and the development of hypercompact HII regions
Eric Keto
The hypothesis that massive stars form by accretion can be investigated by simple analytical calculations that describe the effect that the formation of a massive star has on its o…
An Infalling Torus of Molecular Gas Around the Ultra-Compact HII Region G28.20-0.05
Peter K. Sollins, Qizhou Zhang, Eric Keto +1
We present new observations of the ultra-compact HII region G28.20-0.05 in 23 GHz continuum, and the NH3(1,1), NH3(2.2), and NH3(3,3) lines. To explain the complicated kinematics o…
Circumstellar Structure around Evolved Stars in the Cygnus-X Star Formation Region
Kathleen E. Kraemer, Joseph L. Hora, Michael P. Egan +15
We present observations of newly discovered 24 micron circumstellar structures detected with the Multiband Imaging Photometer for Spitzer (MIPS) around three evolved stars in the C…
A Hardware and Software Platform for Aerial Object Localization
Matthew Szenher, Alex Delacroix, Eric Keto +5
To date, there are little reliable data on the position, velocity and acceleration characteristics of Unidentified Aerial Phenomena (UAP). The dual hardware and software system des…
A Turbulent-Entropic Instability and the Fragmentation of Star-Forming Clouds
Eric Keto, George B. Field, Eric G. Blackman
The kinetic energy of supersonic turbulence within interstellar clouds is subject to cooling by dissipation in shocks and subsequent line radiation. The clouds are therefore suscep…
Does External Pressure Explain Recent Results for Molecular Clouds?
George Field, Eric Blackman, Eric Keto
The recent paper by Heyer et al (2009) indicates that observations of size, linewidth and column density of interstellar clouds do not agree with simple virial equilibrium (VE) as…
The Dynamics of Ultracompact HII Regions
Nathaniel Roth, Steven W. Stahler, Eric Keto
Many ultracompact HII regions exhibit a cometary morphology in radio continuum emission. In such regions, a young massive star is probably ablating, through its ultraviolet radiati…
From Filaments to Oscillating Starless Cores
Eric Keto, Andreas Burkert
Long wavelength sonic oscillations are observed or inferred in many of the small, dark molecular clouds, the starless cores, that are the precursors to protostars. The oscillations…
A Brief Update on the CMZoom Survey
Cara Battersby, Eric Keto, Qizhou Zhang +16
The inner few hundred parsecs of the Milky Way, the Central Molecular Zone (CMZ), is our closest laboratory for understanding star formation in the extreme environments (hot, dense…
The central 1000 AU of a pre-stellar core revealed with ALMA. I. 1.3 mm continuum observations
Paola Caselli, Jaime E. Pineda, Bo Zhao +8
Stars like our Sun form in self-gravitating dense and cold structures within interstellar clouds, called pre-stellar cores. Although much is known about the physical structure of d…
Radiative Transfer Modelling of the Accretion Flow onto a Star-Forming Core in W51
Lisa M. Young, Eric Keto, Paul T. P. Ho
We present an analysis of the temperature, density, and velocity of the molecular gas in the star-forming core around W51 e2. A previous paper (Ho and Young 1996) describes the kin…