5 papers
Newly Identified Planetary Nebula Candidates in M31 using Deep-Learning Search of Hubble Space Telescope Images
Yiğit C. Atılgan, Aleyna Demirci, Nazım Aksaker +3
The Hubble Space Telescope has imaged approximately a quarter of a billion stars in M31's disc, yet only slightly over a thousand planetary nebulae (PNe) are known, mostly from gro…
Spectral and timing variability of the transient ultraluminous X-ray source NGC 4631 X-4
Sinan Allak, Wei Yu, Lorenzo Ducci +4
Ultraluminous X-ray sources (ULXs) are among the best laboratories for studying super-Eddington accretion onto compact objects. We present a detailed spectral and timing analysis o…
A candidate cyclotron line at 1.89 keV in the ultraluminous X-ray source NGC 4861 X-2
Sinan Allak, Lorenzo Ducci, Valery F. Suleimanov +6
In this Letter, we report the detection of an absorption-like feature at ~1.89 keV in Chandra/ACIS spectra of the ultraluminous X-ray source NGC 4861 X-2, based on the deepest obse…
Photoionization Modeling of Planetary Nebulae in the Galactic Bulge
N. Aksaker, A. Demirci, N. Erzincan +1
In this study, we present the results of photoionization modeling for 124 planetary nebulae (PNe) in the Galactic bulge. Utilizing the {\scshape cloudy} code, we derived the effect…
Analysis of Planetary Nebulae in the Milky Way: Physical Properties, Chemical Abundances, and Galactic Distributions
N. Erzincan, N. Aksaker, A. Akyuz +1
In this study, we investigate the physical and chemical properties of planetary nebulae (PNe) from the Milky Way Galaxy using the largest number of sources to date, with 1,449 True…