Zobrazeno 1 - 10
of 4 440
pro vyhledávání: '"Ludlam, A."'
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 normal branch oscillation (NBO) feature at ~ 5.41 Hz that appears in the
Externí odkaz:
http://arxiv.org/abs/2411.12803
Autor:
La Monaca, Fabio, Di Marco, Alessandro, Ludlam, Renee M., Bobrikova, Anna, Poutanen, Juri, Li, Songwei, Xie, Fei
Publikováno v:
A&A 691, A253 (2024)
We report the first detection of X-ray polarization in the horizontal branch for GX 340+0 as obtained by Imaging X-ray Polarimetry Explorer (IXPE). A polarization degree of 4.3%$\pm$0.3% is obtained. This value is in agreement with the previous polar
Externí odkaz:
http://arxiv.org/abs/2410.00972
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. We investigate the evolution of the source in its hardness-intensity di
Externí odkaz:
http://arxiv.org/abs/2409.16941
Autor:
Moutard, David L., Ludlam, Renee M., Cackett, Edward M., García, Javier A., Miller, Jon M., Wilkins, Dan R.
In this study, we examine 51 archival NICER observations and 6 archival NuSTAR observations of the neutron star (NS) ultra-compact X-ray binary (UCXB) 4U 0614+091, which span over 5 years. The source displays persistent reflection features, so we use
Externí odkaz:
http://arxiv.org/abs/2409.10279
Autor:
Chakraborty, Priyanka, Ferland, Gary, Fabian, Andrew, Sarkar, Arnab, Ludlam, Renee, Bianchi, Stefano, Hall, Hayden, Kosec, Peter
X-ray binaries (XRBs) often exhibit spectral residuals in the 0.5 to 2 keV range, known as the "1 keV residual/1 keV feature", with variable centroid and intensity across different systems. Yet a comprehensive scientific explanation of the variabilit
Externí odkaz:
http://arxiv.org/abs/2407.02360
Autor:
Salmi, Tuomo, Choudhury, Devarshi, Kini, Yves, Riley, Thomas E., Vinciguerra, Serena, Watts, Anna L., Wolff, Michael T., Arzoumanian, Zaven, Bogdanov, Slavko, Chakrabarty, Deepto, Gendreau, Keith, Guillot, Sebastien, Ho, Wynn C. G., Huppenkothen, Daniela, Ludlam, Renee M., Morsink, Sharon M., Ray, Paul S.
Publikováno v:
ApJ 974 294 (2024)
We report an updated analysis of the radius, mass, and heated surface regions of the massive pulsar PSR J0740+6620 using Neutron Star Interior Composition Explorer (NICER) data from 2018 September 21 to 2022 April 21, a substantial increase in data s
Externí odkaz:
http://arxiv.org/abs/2406.14466
Autor:
Earnshaw, Hannah P, Bachetti, Matteo, Brightman, Murray, Fürst, Felix, Harrison, Fiona A., Middleton, Matthew, Ludlam, Renee, Pike, Sean N., Stern, Daniel, Walton, Dominic J.
We observed the nearby and relatively understudied ultraluminous X-ray source (ULX) NGC 4190 ULX-1 jointly with NICER and NuSTAR to investigate its broadband spectrum, timing properties, and spectral variation over time. We found NGC 4190 ULX-1 to ha
Externí odkaz:
http://arxiv.org/abs/2403.13973
Autor:
Ludlam, Renee M.
Neutron star low-mass X-ray binaries accrete via Roche-lobe overflow from a stellar companion that is $\lesssim$ 1 M$_{\odot}$. The accretion disk in these systems can be externally illuminated by X-rays that are reprocessed by the accreting material
Externí odkaz:
http://arxiv.org/abs/2401.15787
Autor:
Moutard, David, Ludlam, Renee, Sudha, Malu, Buisson, Douglas, Cackett, Edward, Degenaar, Nathalie, Fabian, Andrew, Gandhi, Poshak, Garcia, Javier, Shaw, Aarran, Tomsick, John
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. Using various reflection modeling techniques, we find that xillverCO, a m
Externí odkaz:
http://arxiv.org/abs/2401.12371
Autor:
Ludlam, R. M., Malacaria, C., Sokolova-Lapa, E., Fuerst, F., Pradhan, P., Shaw, A. W., Pottschmidt, K., Pike, S., Vasilopoulos, G., Wilms, J., García, J. A., Madsen, K., Stern, D., Maitra, C., Del Santo, M., Walton, D. J., Brumback, M. C., Eijnden, J. van den
Accreting neutron stars (NSs) represent a unique laboratory for probing the physics of accretion in the presence of strong magnetic fields ($B\gtrsim 10^8$ G). Additionally, the matter inside the NS itself exists in an ultra-dense, cold state that ca
Externí odkaz:
http://arxiv.org/abs/2311.04687