141 citations · 587 across the 16 of their papers we have counts for
17 papers
Chemo-Dynamical Tagging in the Outskirts: The Origins of Stellar Substructures in the Magellanic Clouds
César Muñoz, Antonela Monachesi, David L. Nidever +12
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 e…
HubPUG: Proper Motions for Local Group Dwarfs observed with HST utilizing Gaia as a Reference Frame
Jack T. Warfield, Nitya Kallivayalil, Paul Zivick +6
We present the method behind HubPUG, a software tool built for recovering systemic proper motions (PMs) of Hubble Space Telescope (HST) fields with two epochs of observations by ut…
Structural parameters and possible association of the Ultra-Faint Dwarfs Pegasus III and Pisces II from deep Hubble Space Telescope photometry
Hannah Richstein, Ekta Patel, Nitya Kallivayalil +17
We present deep Hubble Space Telescope (HST) photometry of the ultra-faint dwarf (UFD) galaxies Pegasus III (Peg III) and Pisces II (Psc II), two of the most distant satellites in…
The recent LMC-SMC collision: Timing and impact parameter constraints from comparison of Gaia LMC disk kinematics and N-body simulations
Yumi Choi, Knut A. G. Olsen, Gurtina Besla +4
We present analysis of the proper-motion (PM) field of the red clump stars in the Large Magellanic Cloud (LMC) disk using the Gaia Early Data Release 3 catalog. Using a kinematic m…
Stellar proper motions in the outskirts of classical dwarf spheroidal galaxies with Gaia EDR3
Yuewen Qi, Paul Zivick, Andrew B. Pace +2
We use Gaia EDR3 data to identify stars associated with six classical dwarf spheroidals (Draco, Ursa Minor, Sextans, Sculptor, Fornax, Carina) at their outermost radii, beyond thei…
Star Formation Histories of Ultra-Faint Dwarf Galaxies: environmental differences between Magellanic and non-Magellanic satellites?
Elena Sacchi, Hannah Richstein, Nitya Kallivayalil +18
We present the color-magnitude diagrams and star formation histories (SFHs) of seven ultra-faint dwarf galaxies: Horologium 1, Hydra 2, Phoenix 2, Reticulum 2, Sagittarius 2, Trian…
Dark and luminous mass components of Omega Centauri with stellar kinematics
Addy J. Evans, Louis E. Strigari, Paul Zivick
We combine proper motion data from EDR3 and HST with line-of-sight velocity data to study the stellar kinematics of the Omega Centauri globular cluster. Using a steady-state…
Deciphering the Kinematic Structure of the Small Magellanic Cloud through its Red Giant Population
Paul Zivick, Nitya Kallivayalil, Roeland P. van der Marel
We present a new kinematic model for the Small Magellanic Cloud (SMC), using data from the \gaia\ Data Release 2 catalog. We identify a sample of astrometrically well-behaved red g…
On the nature of a shell of young stars in the outskirts of the Small Magellanic Cloud
David Martinez-Delgado, A. Katherina Vivas, Eva K. Grebel +35
Understanding the evolutionary history of the Magellanic Clouds requires an in-depth exploration and characterization of the stellar content in their outer regions, which ultimatel…
The Proper Motion Field Along the Magellanic Bridge: a New Probe of the LMC-SMC Interaction
Paul Zivick, Nitya Kallivayalil, Gurtina Besla +6
We present the first detailed kinematic analysis of the proper motions (PMs) of stars in the Magellanic Bridge, from both the \textit{Gaia} Data Release 2 catalog and from \textit{…
The Missing Satellites of the Magellanic Clouds? Gaia Proper Motions of the Recently Discovered Ultra-Faint Galaxies
Nitya Kallivayalil, Laura Sales, Paul Zivick +7
According to LCDM theory, hierarchical evolution occurs on all mass scales, implying that satellites of the Milky Way should also have companions. The recent discovery of ultra-fai…
The Proper Motion Field of the Small Magellanic Cloud: Kinematic Evidence for its Tidal Disruption
Paul Zivick, Nitya Kallivayalil, Roeland P. van der Marel +9
We present a new measurement of the systemic proper motion of the Small Magellanic Cloud (SMC), based on an expanded set of 30 fields containing background quasars and spanning a $…
The Orbit and Origin of the Ultra-faint Dwarf Galaxy Segue 1
T. K. Fritz, M. Lokken, N. Kallivayalil +4
We present the first proper motion measurement for an ultra-faint dwarf spheroidal galaxy, Segue 1, using SDSS and LBC data as the first and second epochs separated by a baseline o…
The Proper Motion of Pyxis: the first use of Adaptive Optics in tandem with HST on a faint halo object
Tobias K. Fritz, Sean T. Linden, Paul Zivick +13
We present a proper motion measurement for the halo globular cluster Pyxis, using HST/ACS data as the first epoch, and GeMS/GSAOI Adaptive Optics data as the second, separated by a…
Astrometry with MCAO at Gemini and at ELTs
Tobias K. Fritz, Nitya Kallivayalil, Eleazar R. Carrasco +11
We present in this study a first analysis of the astrometric error budget of absolute astrometry relative to background galaxies using adaptive optics. We use for this analysis mul…
Using cosmic voids to distinguish f(R) gravity in future galaxy surveys
Paul Zivick, P. M. Sutter, Benjamin D. Wandelt +2
We use properties of void populations identified in -body simulations to forecast the ability of upcoming galaxy surveys to differentiate models of f(R) gravity from \lcdm~cosmo…
VIDE: The Void IDentification and Examination toolkit
P. M. Sutter, Guilhem Lavaux, Nico Hamaus +7
We present VIDE, the Void IDentification and Examination toolkit, an open-source Python/C++ code for finding cosmic voids in galaxy redshift surveys and N-body simulations, charact…