activity
20242026
collaborators

10 papers

astro-ph.HE2026

Evidence for Millihertz Oscillations in the bright atoll source GX 3+1

Malu Sudha, Renee M. Ludlam, Diego Altamirano +2

We report evidence for millihertz (mHz) QPOs in the bright atoll neutron star low-mass X-ray binary (NS LMXB) source GX 3+1 using NICER in the 0.5--10 keV energy band. Across 7 obs…

astro-ph.HE2026

NuSTAR's Intentional Stray Light Observation of Scorpious X-1

S. Li, R. M. Ludlam, M. Sudha +8

We present the first spectral analysis of Scorpius X-1 (Sco X-1) using intentional stray light (SL) observations taken by NuSTAR. Unlike focused observations that have high telemet…

astro-ph.GA2026

The Secret Lives of Open Clusters: a Multiwavelength Examination of Three Open Clusters

Kristen C. Dage, Emily L. Hunt, Jasmine Anderson-Baldwin +11

Star clusters are well known for their dynamical interactions, an outcome of their high stellar densities; in this paper we use multiwavelength observations to search for the uniqu…

astro-ph.HE2025

Dual perspectives on GX 17+2: a simultaneous NICER and NuSTAR study

Malu Sudha, Renee M. Ludlam, Jeroen Homan +3

We performed the first simultaneous NICER & NuSTAR spectral and timing study of the Sco-like Z source GX 17+2. The source traced the full Z track during four observations. We detec…

physics.ed-ph2025

Observational Astrophysics Research through Cross Institutional Research Partnerships

Kristen C. Dage, Linda Strubbe, Rhianna Taub +16

Undergraduate research in STEM can be a transformative experience, especially for Community College students, many of whom come from under-represented backgrounds. However, undergr…

astro-ph.HE2025

The Structure of the Relativistic Fe Line in GX 340+0 as Viewed with XRISM/Resolve, NICER, and NuSTAR

R. M. Ludlam, R. Ballhausen, P. Chakraborty +13

We present a 152 ks XRISM/Resolve observation of the persistently accreting Z source GX 340+0. Simultaneous observations also occurred with NuSTAR and NICER for 22.47 ks and 2.7 ks…

astro-ph.HE2025

Radio Continuum Studies of Ultra-Compact and Short Orbital Period X-Ray Binaries

Kristen C. Dage, Teresa Panurach, Kwangmin Oh +14

We present the radio continuum counterparts to the enigmatic ultra-compact X-ray binaries (UCXBs); a black hole or neutron star accreting from a hydrogen-deficient white dwarf dono…

astro-ph.HE2024

A spectro-temporal view of normal branch oscillations in Cygnus X-2 as seen by NICER and NuSTAR

Malu Sudha, Renee M. Ludlam, Diego Altamirano +2

We report the spectro-temporal study of the neutron star low mass X-ray binary Cygnus X-2 using NICER and NuSTAR data while the source was in the normal branch (NB). We detect a no…

astro-ph.HE2024

NICER observes the full Z-track in GX 13+1

Mohamad Ali Kaddouh, Malu Sudha, Renee M. Ludlam

We present the temporal analysis of the persistent neutron star low-mass X-ray binary (NS LMXB) GX 13+1 using NICER data. Classification of this source has been ambiguous so far. W…

astro-ph.HE2024

Investigating the Ultra-Compact X-ray Binary Candidate SLX 1735-269 with NICER and NuSTAR

David Moutard, Renee Ludlam, Malu Sudha +8

We present two simultaneous NICER and NuSTAR observations of the ultra-compact X-ray binary (UCXB) candidate SLX 1735-269 while the source was in two different spectral states. Usi…