Publications (110)
IGR J17329-2731: The birth of a symbiotic X-ray binary
E. Bozzo, A. Bahramian, C. Ferrigno +10
We report on the results of the multiwavelength campaign carried out after the discovery of the INTEGRAL transient IGR J17329-2731. The optical data collected with the SOAR telesco…
The Two Dimensional Projected Spatial Distribution of Globular Clusters: Method and Application to NGC4261
R. D'Abrusco, G. Fabbiano, J. Strader +7
We present a new method for the determination of the two-dimensional (2D) projected spatial distribution of globular clusters (GCs) in external galaxies. This method is based on th…
Detailed abundance analysis from integrated high-dispersion spectroscopy: Globular clusters in the Fornax Dwarf Spheroidal
S. S. Larsen, J. P. Brodie, J. Strader
Aims: We describe our newly developed approach to detailed abundance analysis from integrated-light high-dispersion spectra of star clusters. As a pilot project, we measure abundan…
HST/ACS Wide-Field Photometry of the Sombrero Galaxy Globular Cluster System
L. R. Spitler, S. S. Larsen, J. Strader +3
A detailed imaging analysis of the globular cluster (GC) system of the Sombrero galaxy (NGC 4594) has been accomplished using a six-image mosaic from the Hubble Space Telescope Adv…
Galactic Extinction: How Many Novae Does it Hide and How Does it Affect the Galactic Nova Rate?
A. Kawash, L. Chomiuk, J. A. Rodriguez +11
There is a longstanding discrepancy between the observed Galactic classical nova rate of yr and the predicted rate from Galactic models of --50 yr.…
The Swift Bulge Survey: Motivation, Strategy, and First X-ray Results
A. Bahramian, C. O. Heinke, J. A. Kennea +12
Very faint X-ray transients (VFXTs) are X-ray transients with peak X-ray luminosities () of erg/s, which are not well-understood. We carried out a survey…
The N2K Consortium. II. A Transiting Hot Saturn Around HD 149026 With a Large Dense Core
B. Sato, D. A. Fischer, G. W. Henry +18
Doppler measurements from Subaru and Keck have revealed radial velocity variations in the V=8.15, G0IV star HD 149026 consistent with a Saturn-Mass planet in a 2.8766 day orbit. Ph…
Gamma-ray Eclipses and Orbital Modulation Transitions in the Candidate Redback 4FGL J1702.7-5655
R. H. D. Corbet, L. Chomiuk, J. B. Coley +8
Observations with the Fermi Large Area Telescope (LAT) of the gamma-ray source 4FGL J1702.7-5655, previously classified as a candidate millisecond pulsar, show highly-significant m…
A panchromatic view of the restless SN2009ip reveals the explosive ejection of a massive star envelope
R. Margutti, D. Milisavljevic, A. M. Soderberg +54
The 2012 explosion of SN2009ip raises questions about our understanding of the late stages of massive star evolution. Here we present a comprehensive study of SN2009ip during its r…
Evidence That Hydra I is a Tidally Disrupting Milky Way Dwarf Galaxy
Jonathan R. Hargis, B. Kimmig, B. Willman +6
The Eastern Banded Structure (EBS) and Hydra~I halo overdensity are very nearby (d 10 kpc) objects discovered in SDSS data. Previous studies of the region have shown that EB…
Discovery of a new faint dwarf galaxy associated with NGC 253
D. J. Sand, D. CrnojeviÄ, J. Strader +6
We report the discovery of a new faint dwarf galaxy, which we dub Scl-MM-Dw1, at a projected distance of 65 kpc from the spiral galaxy NGC 253. The discovery results from the…
Constraints on mass loss of globular clusters in dwarf galaxies
S. S. Larsen, J. Strader, J. P. Brodie
The Fornax dwarf spheroidal galaxy is well known for its very high globular cluster specific frequency, SN=26. Furthermore, while the field star metallicity distribution peaks at […
Radio Variability from a Quiescent Stellar Mass Black Hole Jet
R. M. Plotkin, J. C. A. Miller-Jones, L. Chomiuk +5
Relativistic outflows are believed to be a common feature of black hole X-ray binaries at the lowest accretion rates, when they are in their `quiescent' spectral state. However, we…
SN 2017gmr: An energetic Type II-P supernova with asymmetries
Jennifer E. Andrews, D. J. Sand, S. Valenti +77
We present high-cadence ultraviolet (UV), optical, and near-infrared (NIR) data on the luminous Type II-P supernova SN 2017gmr from hours after discovery through the first 180 days…
An optical/NIR survey of globular clusters in early-type galaxies II. Ages of GC systems and the relation to galaxy morphology
A. L. Chies-Santos, S. S. Larsen, H. Kuntschner +5
Context: Some photometric studies of extragalactic globular cluster (GC) systems using the optical and near-infrared colour combination have suggested the presence of a large fract…
Tidal Signatures in the Faintest Milky Way Satellites: The Detailed Properties of Leo V, Pisces II and Canes Venatici II
D. J. Sand, J. Strader, B. Willman +5
We present deep wide-field photometry of three recently discovered faint Milky Way satellites: Leo V, Pisces II, and Canes Venatici II. Our main goals are to study the structure an…
The radial distribution of X-ray Binaries and Globular Clusters in NGC 4649 and their relation with the local stellar mass density
S. Mineo, G. Fabbiano, R. D'Abrusco +7
We investigate the radial distribution of the low-mass X-ray binary (LMXB) population in the elliptical galaxy NGC 4649, using Chandra and Hubble data to separate the field and glo…
UGPS J194310+183851: an Unusual Optical and X-ray Faint Cataclysmic Variable?
C. Morris, T. J. Maccarone, P. W. Lucas +7
The growing number of multi-epoch optical and infrared sky surveys are uncovering unprecedented numbers of new variable stars, of an increasing number of types. The short interval…
The MAVERIC Survey: Variable Jet-Accretion Coupling in Luminous Accreting Neutron Stars in Galactic Globular Clusters
T. Panurach, J. Strader, A. Bahramian +9
Accreting neutron stars in low-mass X-ray binaries show outflows -- and sometimes jets -- in the general manner of accreting black holes. However, the quantitative link between the…
Early spectral evolution of classical novae: consistent evidence for multiple distinct outflows
E. Aydi, L. Chomiuk, L. Izzo +18
The physical mechanism driving mass ejection during a nova eruption is still poorly understood. Possibilities include ejection in a single ballistic event, a common envelope intera…
Detailed abundance analysis of globular clusters in the Local Group: NGC 147, NGC 6822, and Messier 33
S. S. Larsen, J. P. Brodie, A. Wasserman +1
We present new abundance measurements for eleven GCs in the Local Group galaxies NGC 147, NGC 6822, and Messier 33. These are combined with previously published observations of fou…
ReveaLLAGN 0: First Look at JWST MIRI data of Sombrero and NGC 1052
K. Goold, A. Seth, M. Molina +28
We present the first results from the Revealing Low-Luminosity Active Galactic Nuclei (ReveaLLAGN) survey, a JWST survey of seven nearby LLAGN. We focus on two observations with th…
ASASSN-18ey: The Rise of a New Black-Hole X-ray Binary
M. A. Tucker, B. J. Shappee, T. W. -S. Holoien +21
We present the discovery of ASASSN-18ey (MAXI J1820+070), a new black hole low-mass X-ray binary discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN). A week after A…
The Ultraviolet Spectroscopic Evolution of the Low-Luminosity Tidal Disruption Event iPTF16fnl
J. S. Brown, C. S. Kochanek, T. W. -S. Holoien +14
We present the ultraviolet (UV) spectroscopic evolution of a tidal disruption event (TDE) for the first time. After the discovery of the nearby TDE iPTF16fnl, we obtained a series…
An AO-assisted variability study of four globular clusters
R. Salinas, R. Contreras Ramos, J. Strader +4
The image subtraction technique applied to study variable stars in globular clusters represented a leap in the number of new detections, with the drawback that many of these new li…
Chemical composition and constraints on mass loss for globular clusters in dwarf galaxies: WLM and IKN
S. S. Larsen, J. P. Brodie, D. A. Forbes +1
We determine the metallicities for globular clusters (GCs) in the WLM and IKN dwarf galaxies, using VLT/UVES and Keck/ESI spectroscopy. For the WLM GC we also measure detailed abun…
A Comprehensive Archival Search for Counterparts to Ultra-Compact High Velocity Clouds: Five Local Volume Dwarf Galaxies
D. J. Sand, D. CrnojeviÄ, P. Bennet +17
We report five Local Volume dwarf galaxies (two of which are presented here for the first time) uncovered during a comprehensive archival search for optical counterparts to ultra-c…
The Loudest Stellar Heartbeat: Characterizing the most extreme amplitude heartbeat star system
T. Jayasinghe, C. S. Kochanek, J. Strader +16
We characterize the extreme heartbeat star system MACHO 80.7443.1718 in the LMC using TESS photometry and spectroscopic observations from the Magellan Inamori Kyocera Echelle (MIKE…
Partly burnt runaway stellar remnants from peculiar thermonuclear supernovae
R. Raddi, M. A. Hollands, D. Koester +13
We report the discovery of three stars that, along with the prototype LP40-365, form a distinct class of chemically peculiar runaway stars that are the survivors of thermonuclear e…
Statistical Time-Resolved Spectroscopy: A higher fraction of short-period binaries for metal-rich F-type dwarfs in SDSS
T. Hettinger, C. Badenes, J. Strader +2
Stellar multiplicity lies at the heart of many problems in modern astrophysics, including the physics of star formation, the observational properties of unresolved stellar populati…
The early discovery of SN 2017ahn: signatures of persistent interaction in a fast declining Type II supernova
L. Tartaglia, D. J. Sand, J. H. Groh +25
We present high-cadence, comprehensive data on the nearby () Type II SN 2017ahn, discovered within 1 day of explosion, from the very early phases after e…
Searches After Gravitational-waves Using ARizona Observatories (SAGUARO): System Overview and First Results from Advanced LIGO/Virgo's Third Observing Run
M. J. Lundquist, K. Paterson, W. Fong +53
We present Searches After Gravitational-waves Using ARizona Observatories (SAGUARO), a comprehensive effort dedicated to the discovery and characterization of optical counterparts…
An optical/NIR survey of globular clusters in early-type galaxies. I. Introduction and data reduction procedures
A. L. Chies-Santos, S. S. Larsen, E. M. Wehner +3
Context: The combination of optical and near-infrared (NIR) colours has the potential to break the age/metallicity degeneracy and offers a better metallicity sensitivity than optic…
New Velocity Measurements of NGC 5128 Globular Clusters out to 130 kpc: Outer Halo Kinematics, Substructure and Dynamics
A. K. Hughes, D. J. Sand, A. Seth +11
We present new radial velocity measurements from the Magellan and the Anglo-Australian Telescopes for 174 previously known and 122 newly confirmed globular clusters (GCs) around NG…
The Optical Afterglow of GW170817: An Off-axis Structured Jet and Deep Constraints on a Globular Cluster Origin
Wen-fai Fong, P. K. Blanchard, K. D. Alexander +25
We present a revised and complete optical afterglow light curve of the binary neutron star merger GW170817, enabled by deep Hubble Space Telescope (HST) F606W observations at $\app…
Discovery of a Long-Lived, High Amplitude Dusty Infrared Transient
C. T. Britt, T. J. Maccarone, J. D. Green +15
We report the detection of an infrared selected transient which has lasted at least 5 years, first identified by a large mid-infrared and optical outburst from a faint X-ray source…
Stellar variability at the main-sequence turnoff of the intermediate-age LMC cluster NGC 1846
R. Salinas, M. A. Pajkos, A. K. Vivas +2
Intermediate-age star clusters in the LMC present extended main sequence turnoffs (MSTO) that have been attributed to either multiple stellar populations or an effect of stellar ro…
The Gamma-ray Blazar Quest: new optical spectra, state of art and future perspectives
F. Massaro, N. Ãlvarez Crespo, R. D'Abrusco +13
We recently developed a procedure to recognize gamma-ray blazar candidates within the positional uncertainty regions of the unidentified/unassociated gamma-ray sources (UGSs). Such…
Radio light curves and imaging of the helium nova V445 Puppis reveal seven years of synchrotron emission
M. M. Nyamai, L. Chomiuk, V. A. R. M. Ribeiro +3
V445 Puppis is the only helium nova observed to date; its eruption in late 2000 showed high velocities up to 8500 km/s and a remarkable bipolar morphology cinched by an equatorial…
Self-organized synthesis of patterned magnetic nanostructures with in-plane and perpendicular to the plane magnetization
H. Krishna, A. K. Gangopadhyay, J. Strader +1
Patterned arrays of ferromagnetic nanoparticles of Co, Ni, and Fe_{\text{50}} Co_{\text{50}} have been synthesized from their ultrathin metal films on SiO_{\text{2}} substrate by n…
The ASAS-SN Bright Supernova Catalog -- IV. 2017
T. W. -S. Holoien, J. S. Brown, P. J. Vallely +41
In this catalog we compile information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) as well as all other bright (), spectr…
Radio Observations of a Candidate Redback Millisecond Pulsar: 1FGL J0523.5-2529
O. A. Johnson, E. F. Keane, D. J. McKenna +4
Redback pulsars are a subclass of millisecond pulsar system with a low-mass non-degenerate companion star being ablated by the pulsar. They are of interest due to the insights they…
Discovery of the Galactic High-Mass Gamma-ray Binary 4FGL J1405.1-6119
R. H. D. Corbet, L. Chomiuk, M. J. Coe +8
We report the identification from multi-wavelength observations of the Fermi Large Area Telescope (LAT) source 4FGL J1405.1-6119 (= 3FGL J1405.4-6119) as a high-mass gamma-ray bina…
An optical/near-infrared survey of GCs in early-type galaxies
A. L. Chies-Santos, S. S. Larsen, E. M. Wehner +4
Optical/near-infrared observations for 14 globular cluster (GC) systems in early- type galaxies are presented. We investigate the recent claims (Yoon, Yi & Lee 2006) of colour bimo…
Incoherent transient radio emission from stellar-mass compact objects in the SKA era
S. Corbel, J. C. A. Miller-Jones, R. P. Fender +10
The universal link between the processes of accretion and ejection leads to the formation of jets and outflows around accreting compact objects. Incoherent synchrotron emission fro…
A variable ultraluminous X-ray source in a globular cluster in NGC 4649
T. P. Roberts, G. Fabbiano, B. Luo +9
We report the discovery of a new ultraluminous X-ray source (ULX) associated with a globular cluster in the elliptical galaxy NGC 4649. The X-ray source was initially detected with…
Catching a nova X-ray/UV flash in the visible? Early spectroscopy of the extremely slow Nova Velorum 2022 (Gaia22alz)
E. Aydi, L. Chomiuk, J. MikoÅajewska +22
We present early spectral observations of the very slow Galactic nova Gaia22alz, over its gradual rise to peak brightness that lasted 180 days. During the first 50 days, when the n…
Deep Chandra Monitoring Observations of NGC 4649: I. Catalog of Source Properties
B. Luo, G. Fabbiano, J. Strader +6
We present the X-ray source catalog for the Chandra monitoring observations of the elliptical galaxy, NGC 4649. The galaxy has been observed with Chandra ACIS-S3 in six separate po…
Star Cluster Candidates in M81
J. B. Nantais, J. P. Huchra, B. McLeod +2
We present a catalog of extended objects in the vicinity of M81 based a set of 24 Hubble Space Telescope Advanced Camera for Surveys (ACS) Wide Field Camera (WFC) F814W (I-band) im…
An arcsecond view at 1-2 GHz into the Galactic Bulge
E. C. Pattie, T. J. Maccarone, C. T. Britt +8
We present the results of a high angular resolution (1.1") and sensitivity (maximum of ~0.1 mJy) radio survey at 1-2 GHz in the Galactic Bulge. This complements the X-ray Chandra G…
Structure and Dynamics of the Accretion Process and Wind in TW Hya
A. K. Dupree, N. S. Brickhouse, S. R. Cranmer +3
Time-domain spectroscopy of the classical accreting T Tauri star, TW Hya, covering a decade and spanning the far UV to the near-infrared spectral regions can identify the radiation…
Hubble Space Telescope Imaging of Isolated Local Volume Dwarfs GALFA-Dw3 and Dw4
P. Bennet, D. J. Sand, D. CrnojeviÄ +16
We present observations of the dwarf galaxies GALFA Dw3 and GALFA Dw4 with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST). These galaxies were initially…
The Two-Dimensional Spatial Distributions of the Globular Clusters and Low-Mass X-Ray Binaries of NGC4649
R. D'Abrusco, G. Fabbiano, S. Mineo +5
We report significant anisotropies in the projected two-dimensional (2D) spatial distributions of Globular Clusters (GCs) of the giant Virgo elliptical galaxy NGC4649 (M60). Simila…
The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. III. Optical and UV Spectra of a Blue Kilonova From Fast Polar Ejecta
M. Nicholl, E. Berger, D. Kasen +31
We present optical and ultraviolet spectra of the first electromagnetic counterpart to a gravitational wave (GW) source, the binary neutron star merger GW170817. Spectra were obtai…
The chemical composition of globular clusters in the Local Group
S. S. Larsen, P. Eitner, E. Magg +5
We present detailed abundance measurements for 45 globular clusters (GCs) in galaxies in (and, in one case, beyond) the Local Group. The measurements are based on new high-resoluti…
Nitrogen abundances and multiple stellar populations in the globular clusters of the Fornax dSph
S. S. Larsen, J. P. Brodie, F. Grundahl +1
We use measurements of nitrogen abundances in red giants to search for multiple stellar populations in the four most metal-poor globular clusters (GCs) in the Fornax dwarf spheroid…
An HST/WFPC2 survey of bright young clusters in M31. IV. Ages and mass estimates
S. Perina, J. G. Cohen, P. Barmby +11
{Aims.} We present the main results of an imaging survey of possible young massive clusters (YMC) in M31 performed with the Wide Field and Planetary Camera2 (WFPC2) on the Hubble S…
oMEGACat. VII. Tracing Interstellar and Intracluster Medium of Centauri using Sodium Absorptions
Z. Wang, A. C. Seth, M. Latour +14
We investigate the foreground interstellar medium along the line of sight and intracluster medium of Centauri ( Cen) by measuring the equivalent width of Na I D absorption…
The Galactic Nova Rate: Estimates from the ASAS-SN and Gaia Surveys
A. Kawash, L. Chomiuk, J. Strader +13
We present the first estimate of the Galactic nova rate based on optical transient surveys covering the entire sky. Using data from the All-Sky Automated Survey for Supernovae (ASA…
A High-Precision Trigonometric Parallax to an Ancient Metal-Poor Globular Cluster
T. M. Brown, S. Casertano, J. Strader +5
Using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST), we have obtained a direct trigonometric parallax for the nearest metal-poor globular cluster, NGC 6397. Al…
Constraints on mass loss and self-enrichment scenarios for the globular clusters of the Fornax dSph
S. S. Larsen, J. Strader, J. P. Brodie
Recently, high-dispersion spectroscopy has demonstrated conclusively that four of the five globular clusters (GCs) in the Fornax dwarf spheroidal galaxy are very metal-poor with [F…
HST spectrum and timing of the ultra-compact X-ray binary candidate 47 Tuc X9
V. Tudor, J. C. A. Miller-Jones, C. Knigge +17
To confirm the nature of the donor star in the ultra-compact X-ray binary candidate 47 Tuc X9, we obtained optical spectra (3,00010,000 Ã ) with the Hubble Space Telescope / Spa…
The extended halo of Centaurus A: uncovering satellites, streams, and substructures
D. CrnojeviÄ, D. J. Sand, K. Spekkens +7
We present the widest-field resolved stellar map to date of the closest ( Mpc) massive elliptical galaxy NGC 5128 (Centaurus A; Cen A), extending out to a projected galac…
Thickness-dependent spontaneous dewetting morphology of ultrathin Ag films
H. Krishna, R. Sachan, J. Strader +3
We show here that the morphological pathway of spontaneous dewetting of ultrathin Ag films on SiO2 under nanosecond laser melting is found to be film thickness dependent. For films…
Fast Winds and Mass Loss from Metal-Poor Field Giants
A. K. Dupree, G. H. Smith, J. Strader
Spectra of the He I 10830 Angstrom line were obtained with NIRSPEC on the Keck 2 telescope for metal-deficient field giant stars. This line is ubiquitous in stars with T_eff greate…
The Swift Bulge Survey: optical and near-IR follow-up featuring a likely symbiotic X-ray binary & a focused wind CV
A. W. Shaw, C. O. Heinke, T. J. Maccarone +13
The nature of very faint X-ray transients (VFXTs) - transient X-ray sources that peak at luminosities - is poorly understood. The faint and of…
The ASAS-SN Bright Supernova Catalog -- III. 2016
T. W. -S. Holoien, J. S. Brown, K. Z. Stanek +36
This catalog summarizes information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) and all other bright (), spectroscopicall…
Discovery of a close pair of faint dwarf galaxies in the halo of Centaurus A
D. CrnojeviÄ, D. J. Sand, N. Caldwell +6
As part of the Panoramic Imaging Survey of Centaurus and Sculptor (PISCeS) we report the discovery of a pair of faint dwarf galaxies (CenA-MM-Dw1 and CenA-MM-Dw2) at a projected di…
A radio frequency study of the accreting millisecond X-ray pulsar, IGR J165973704, in the globular cluster NGC 6256
A. J. Tetarenko, A. Bahramian, R. Wijnands +14
We present Karl G. Jansky Very Large Array radio frequency observations of the new accreting millisecond X-ray pulsar (AMXP), IGR J165973704, located in the globular cluster NGC…
A Likely Redback Millisecond Pulsar Counterpart of 3FGL J0838.8-2829
J. P. Halpern, J. Strader, M. Li
We obtained new optical observations of the X-ray source XMMU J083850.38-282756.8, the previously proposed counterpart of the gamma-ray source 3FGL J0838.8-2829. Time-series photom…
A HST/WFPC2 survey of bright young clusters in M31. I. VdB0, a massive star cluster seen at ~= 25 Myr
S. Perina, P. Barmby, M. A. Beasley +12
{Aims.} We introduce our imaging survey of possible young massive globular clusters in M31 performed with the Wide Field and Planetary Camera 2 (WFPC2) on the Hubble Space Telescop…
ChaMPlane Discovery of Candidate Symbiotic Binaries in Baade's and Stanek's Windows
M. van den Berg, J. Grindlay, S. Laycock +10
We have searched the OGLE-II archive for candidate counterparts of X-ray sources detected in two low-extinction windows included in our Galactic bulge Chandra/HST survey. We find t…
Antlia B: A faint dwarf galaxy member of the NGC 3109 association
D. J. Sand, K. Spekkens, D. CrnojeviÄ +4
We report the discovery of Antlia B, a faint dwarf galaxy at a projected distance of 72 kpc from NGC 3109 (15 mag), the primary galaxy of the NGC 3109 dwarf a…
Spatially resolved spectroscopy of early-type galaxies over a range in mass
P. Sanchez-Blazquez, D. A. Forbes, J. Strader +2
Long-slit spectra have been obtained with the Keck telescope for a sample of 11 early-type galaxies covering a wide range in luminosity and hence mass. Rotation velocity and veloci…
MAXI J1848-015: The First Detection of Relativistically Moving Outflows from a Globular Cluster X-ray Binary
A. Bahramian, E. Tremou, A. J. Tetarenko +12
Over the past decade, observations of relativistic outflows from outbursting X-ray binaries in the Galactic field have grown significantly. In this work, we present the first detec…
Kinematic transitions and streams in galaxy halos
A. J. Romanowsky, J. A. Arnold, J. P. Brodie +7
The chemo-dynamics of galaxy halos beyond the Local Group may now be mapped out through the use of globular clusters and planetary nebulae as bright tracer objects, along with deep…
The first low-mass black hole X-ray binary identified in quiescence outside of a globular cluster
B. E. Tetarenko, A. Bahramian, R. M. Arnason +9
The observed relation between the X-ray and radio properties of low-luminosity accreting black holes has enabled the identification of multiple candidate black hole X-ray binaries…
Tracking the Enigmatic Globular Cluster Ultracompact X-ray Binary X1850--087: Extreme Radio Variability in the Hard State
T. Panurach, R. Urquhart, J. Strader +6
The conditions under which accreting neutron stars launch radio-emitting jets and/or outflows are still poorly understood. The ultracompact X-ray binary X1850--087, located in the…
A Luminous Gamma-ray Binary in the Large Magellanic Cloud
R. H. D. Corbet, L. Chomiuk, M. J. Coe +9
Gamma-ray binaries consist of a neutron star or a black hole interacting with a normal star to produce gamma-ray emission that dominates the radiative output of the system. Only a…
The ASAS-SN Bright Supernova Catalog -- V. 2018-2020
K. D. Neumann, T. W. -S. Holoien, C. S. Kochanek +55
We catalog the 443 bright supernovae discovered by the All-Sky Automated Survey for Supernovae (ASAS-SN) in along with the 519 supernovae recovered by ASAS-SN and 516 a…
Multiwavelength observations of nova SMCN 2016-10a --- one of the brightest novae ever observed
E. Aydi, K. L. Page, N. P. M. Kuin +17
We report on multiwavelength observations of nova SMCN 2016-10a. The present observational set is one of the most comprehensive for any nova in the Small Magellanic Cloud, includin…
Detailed abundances from integrated-light spectroscopy: Milky Way globular clusters
S. S. Larsen, J. P. Brodie, J. Strader
We test the performance of our analysis technique for integrated-light spectra by applying it to seven well-studied Galactic GCs that span a wide range of metallicities. Integrated…
Searches after Gravitational Waves Using ARizona Observatories (SAGUARO): Observations and Analysis from Advanced LIGO/Virgo's Third Observing Run
K. Paterson, M. J. Lundquist, J. C. Rastinejad +34
With the conclusion of the third observing run for Advanced LIGO/Virgo (O3), we present a detailed analysis of both triggered and serendipitous observations of 17 gravitational wav…
GS 2000+25: The Least Luminous Black Hole X-ray Binary
J. Rodriguez, R. Urquhart, R. M. Plotkin +6
Little is known about the properties of the accretion flows and jets of the lowest-luminosity quiescent black holes. We report new, strictly simultaneous radio and X-ray observatio…
An optical/NIR survey of globular clusters in early-type galaxies III. On the colour bimodality of GC systems
A. L. Chies-Santos, S. S. Larsen, M. Cantiello +4
The interpretation that bimodal colour distributions of globular clusters (GCs) reflect bimodal metallicity distributions has been challenged. Non-linearities in the colour to meta…
Young, blue, and isolated stellar systems in the Virgo Cluster. I. 2-D Optical spectroscopy
M. Bellazzini, L. Magrini, M. G. Jones +20
We use panoramic optical spectroscopy obtained with MUSE@VLT to investigate the nature of five candidate extremely isolated low-mass star forming regions (Blue Candidates, BCs here…
X-ray Constraints on Wandering Black Holes in Stripped Galaxy Nuclei in the Halo of NGC 5128
S. L. Feyan, R. Urquhart, J. Strader +6
A subset of galaxies have dense nuclei, and when these galaxies are accreted and tidally stripped, the nuclei can masquerade as globular clusters in the halos of large galaxies. If…
The faint end of the Centaurus A satellite luminosity function
D. CrnojeviÄ, D. J. Sand, P. N. Bennet +9
The Panoramic Imaging Survey of Centaurus and Sculptor (PISCeS) is constructing a wide-field map of the resolved stellar populations in the extended halos of these two nearby, prom…
Deep radio imaging of 47 Tuc identifies the peculiar X-ray source X9 as a new black hole candidate
J. C. A. Miller-Jones, J. Strader, C. O. Heinke +8
We report the detection of steady radio emission from the known X-ray source X9 in the globular cluster 47 Tuc. With a double-peaked C IV emission line in its ultraviolet spectrum…
Resolving the extended stellar halos of nearby galaxies: the wide-field PISCeS survey
D. CrnojeviÄ, D. J. Sand, N. Caldwell +6
In the wide-field Panoramic Imaging Survey of Centaurus and Sculptor (PISCeS), we investigate the resolved stellar halos of two nearby galaxies (the elliptical Centaurus A and the…
An HST/WFPC2 Survey of Bright Young Clusters in M31 III. Structural Parameters
P. Barmby, S. Perina, M. Bellazzini +6
Surface brightness profiles for 23 M31 star clusters were measured using images from the Wide Field Planetary Camera 2 on the Hubble Space Telescope, and fit to two types of models…
Globular Clusters in NGC 4365: New K-band Imaging and a Reassessment of the Case for Intermediate-age Clusters
S. S. Larsen, J. P. Brodie, J. Strader
We study the globular cluster (GC) system of the Virgo giant elliptical galaxy NGC 4365, using new wide-field VIK imaging. The GC colour distribution has (at least) two peaks, but…
Hubble Space Telescope Imaging of the Ultra-Compact High Velocity Cloud AGC 226067: A stripped remnant in the Virgo Cluster
D. J. Sand, A. C. Seth, D. CrnojeviÄ +10
We analyze the optical counterpart to the ultra-compact high velocity cloud AGC 226067, utilizing imaging taken with the Advanced Camera for Surveys (ACS) on the Hubble Space Teles…
Optical spectroscopic observations of -ray blazar candidates VI. Further observations from TNG, WHT, OAN, SOAR and Magellan telescopes
N. Ãlvarez Crespo, F. Massaro, D. Milisavljevic +16
Blazars, one of the most extreme class of active galaxies, constitute so far the largest known population of -ray sources and their number is continuously growing in the Fermi…
Spectro-photometric follow up of the outbursting AM CVn system ASASSN-21br
S. Painter, E. Aydi, M. Motsoaledi +8
We report on spectroscopic and photometric observations of the AM CVn system ASASSN-21br, which was discovered in outburst by the All-Sky Automated Survey for Supernovae in Februar…
Radio Pulsar Populations
D. R. Lorimer, N. Pol, K. Rajwade +9
Our understanding of the neutron star population is informed to a great degree by large-scale surveys that have been carried out by radio facilities during the past fifty years. We…
Multiwavelength observations of V407 Lupi (ASASSN-16kt) --- a very fast nova erupting in an intermediate polar
E. Aydi, M. Orio, A. P. Beardmore +19
We present a detailed study of the 2016 eruption of nova V407 Lupi (ASASSN-16kt), including optical, near-infrared, X-ray, and ultraviolet data from SALT, SMARTS, SOAR, Chandra, Sw…
An HST/WFPC Survey of Bright Young Clusters in M31. II. Photometry of Less Luminous Clusters in the Fields
P. W. Hodge, O. K. Krienke, M. Bellazzini +5
We report on the properties of 89 low mass star clusters located in the vicinity of luminous young clusters (blue globulars) in the disk of M31. 82 of the clusters are newly detect…
A Hot Saturn Planet Orbiting HD 88133, from the N2K Consortium
D. A. Fischer, G. Laughlin, R. P. Butler +20
The N2K consortium is carrying out a distributed observing campaign with the Keck, Magellan and Subaru telescopes, as well as the automatic photometric telescopes of Fairborn Obser…
X-ray and radio observations of central black holes in nearby low-mass early-type galaxies: Preliminary evidence for low Eddington fractions
R. Urquhart, L. I. McDermott, J. Strader +5
We present new radio and X-ray observations of two nearby ( Mpc) low-mass early-type galaxies with dynamically-confirmed central black holes: NGC 5102 and NGC 205. NGC 5102 sh…