TY - JOUR
T1 - NICER observations reveal doubled timescales in Ansky s quasi-periodic eruptions
AU - Hernandez-Garcia, L.
AU - Sánchez-Sáez, P.
AU - Chakraborty, J.
AU - Cuadra, J.
AU - Miniutti, G.
AU - Arcodia, R.
AU - Arévalo, P.
AU - Giustini, M.
AU - Kara, E.
AU - Ricci, C.
AU - Pasham, D. R.
AU - Arzoumanian, Z.
AU - Gendreau, K.
AU - Lira, P.
N1 - Publisher Copyright:
© The Authors 2025.
PY - 2025/11/1
Y1 - 2025/11/1
N2 - Quasi-periodic eruptions (QPEs) are recurring X-ray bursts originating from the vicinity of supermassive black holes, but their driving mechanisms remain under debate. This study analyzes new NICER observations of QPEs in Ansky (a transient event in the nucleus of the galaxy SDSS J1335+0728), taken between January and June 2025. By examining flare durations, peak-to-peak recurrence times, and profiles, we compare the 2025 data with those from 2024 to investigate changes in energy, timescales, and flare shapes. The 2025 QPEs are found to be four times more energetic, with recurrence times of approximately 10 days and flare durations ranging from 2.5 to 4 days, making them both about twice as long as in 2024. Additionally, the flare profiles have become more asymmetric, showing longer decays. We explore different theoretical scenarios to explain the observed properties of the QPEs in Ansky, including evolving streama- disk interactions in an extreme mass-ratio inspiral system as a potential mechanism behind the observed changes in recurrence time and energetics, while also considering alternative models based on mass transfer and accretion disk instabilities. Continued observational efforts will be crucial for unveiling the nature of Ansky.
AB - Quasi-periodic eruptions (QPEs) are recurring X-ray bursts originating from the vicinity of supermassive black holes, but their driving mechanisms remain under debate. This study analyzes new NICER observations of QPEs in Ansky (a transient event in the nucleus of the galaxy SDSS J1335+0728), taken between January and June 2025. By examining flare durations, peak-to-peak recurrence times, and profiles, we compare the 2025 data with those from 2024 to investigate changes in energy, timescales, and flare shapes. The 2025 QPEs are found to be four times more energetic, with recurrence times of approximately 10 days and flare durations ranging from 2.5 to 4 days, making them both about twice as long as in 2024. Additionally, the flare profiles have become more asymmetric, showing longer decays. We explore different theoretical scenarios to explain the observed properties of the QPEs in Ansky, including evolving streama- disk interactions in an extreme mass-ratio inspiral system as a potential mechanism behind the observed changes in recurrence time and energetics, while also considering alternative models based on mass transfer and accretion disk instabilities. Continued observational efforts will be crucial for unveiling the nature of Ansky.
KW - Galaxies: active
KW - Galaxies: individual: SDSS1335+0728
KW - Galaxies: nuclei
KW - X-rays: individuals: Ansky
UR - https://www.scopus.com/pages/publications/105022499565
U2 - 10.1051/0004-6361/202555258
DO - 10.1051/0004-6361/202555258
M3 - Article
AN - SCOPUS:105022499565
SN - 0004-6361
VL - 703
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A263
ER -