Nova LMC 2009a as observed with XMM¿Newton, compared with other novae

We examine four high-resolution reflection grating spectrometers (RGS) spectra of the February 2009 outburst of the luminous recurrent nova LMC 2009a. They were very complex and rich in intricate absorption and emission features. The continuum was consistent with a dominant component originating in the atmosphere of a shell burning white dwarf (WD) with peak effective temperature between 810¿000 K and a million K, and mass in the 1.2¿1.4 M¿ range. A moderate blue shift of the absorption features of a few hundred km s¿1 can be explained with a residual nova wind depleting the WD surface at a rate of about 10¿8 M¿ yr¿1. The emission spectrum seems to be due to both photoionization and shock ionization in the ejecta. The supersoft X-ray flux was irregularly variable on time-scales of hours, with decreasing amplitude of the variability. We find that both the period and the amplitude of another, already known 33.3-s modulation varied within time-scales of hours. We compared N LMC 2009a with other Magellanic Clouds novae, including four serendipitously discovered as supersoft X-ray sources (SSS) among 13 observed within 16 yr after the eruption. The new detected targets were much less luminous than expected: we suggest that they were partially obscured by the accretion disc. Lack of SSS detections in the Magellanic Clouds novae more than 5.5 yr after the eruption constrains the average duration of the nuclear burning phase.M. Orio was supported by a NASA grant for XMM–Newton data analysis. A.D. was supported by the Slovak grant VEGA 1/0408/20, and by the Operational Programme Research and Innovation for the project: ‘Scientific and Research Centre of Excellence SlovakION for Material and Interdisciplinary Research’, project code ITMS2014+:313011W085, co-financed by the European Regional Development Fund

The RS Oph outburst of 2021 monitored in X-rays with NICER

The 2021 outburst of the symbiotic recurrent nova RS Oph was monitored with the Neutron Star Interior Composition Explorer Mission (NICER) in the 0.2-12 keV range from day one after the optical maximum, until day 88, producing an unprecedented, detailed view of the outburst development. The X-ray flux preceding the supersoft X-ray phase peaked almost 5 days after optical maximum and originated only in shocked ejecta for 21 to 25 days. The emission was thermal; in the first 5 days only a non-collisional-ionization equilibrium model fits the spectrum, and a transition to equilibrium occurred between days 6 and 12. The ratio of peak X-rays flux measured in the NICER range to that measured with Fermi in the 60 MeV-500 GeV range was about 0.1, and the ratio to the peak flux measured with H.E.S.S. in the 250 GeV-2.5 TeV range was about 100. The central supersoft X-ray source (SSS), namely the shell hydrogen burning white dwarf (WD), became visible in the fourth week, initially with short flares. A huge increase in flux occurred on day 41, but the SSS flux remained variable. A quasi-periodic oscillation every ~35 s was always observed during the SSS phase, with variations in amplitude and a period drift that appeared to decrease in the end. The SSS has characteristics of a WD of mass >1 M(solar). Thermonuclear burning switched off shortly after day 75, earlier than in 2006 outburst. We discuss implications for the nova physics.Comment: Accepted for publication in the Astrophysical Journa

The Influence of Outflow Feedback in Clumps

We analyzed the influence of outflow feedback from two perspectives: turbulent support and potential disruptive effect, of which 694 clumps and 188 have been identified as outflow candidates. For turbulent support, we find the slopes of E _turb − R _clump (turbulent energy and radius of the clump) and P _turb − R _clump (turbulent momentum and radius of the clump) have no difference and are consistent with expected values whether there is outflow feedback in clumps or not. The ratios of the outflow energy and momentum to the turbulence energy and momentum ( E _flow / E _turb , P _flow / P _turb ) show that the majority of clumps have not enough energy and momentum to support turbulence. Meanwhile, there is no correlation between the velocity dispersion and radius. For potential disruptive effects, we conclude that it is impossible for the outflow activities to disrupt entire clumps and as the mass of the clumps increases, the clumps becomes harder to destroy. Finally, we do not see evidence that the virial parameter changes significantly whether the clumps have outflow candidates or not

The RS Oph Outburst of 2021 Monitored in X-Rays with NICER

Funder: Europe Regional Development Fund; Grant(s): ITMS2014+: 313011W085Abstract The 2021 outburst of the symbiotic recurrent nova RS Oph was monitored with the Neutron Star Interior Composition Explorer Mission (NICER) in the 0.2–12 keV range from day one after the optical maximum, until day 88, producing an unprecedented, detailed view of the outburst development. The X-ray flux preceding the supersoft X-ray phase peaked almost 5 days after optical maximum and originated only in shocked ejecta for 21–25 days. The emission was thermal; in the first 5 days, only a non-collisional-ionization equilibrium model fits the spectrum, and a transition to equilibrium occurred between days 6 and 12. The ratio of peak X-ray flux measured in the NICER range to that measured with Fermi in the 60 MeV–500 GeV range was about 0.1, and the ratio to the peak flux measured with H.E.S.S. in the 250 GeV–2.5 TeV range was about 100. The central supersoft X-ray source (SSS), namely the shell hydrogen burning white dwarf (WD), became visible in the fourth week, initially with short flares. A huge increase in flux occurred on day 41, but the SSS flux remained variable. A quasi-periodic oscillation every ≃35 s was always observed during the SSS phase, with variations in amplitude and a period drift that appeared to decrease in the end. The SSS has characteristics of a WD of mass &gt;1 M ⊙. Thermonuclear burning switched off shortly after day 75, earlier than in the 2006 outburst. We discuss implications for the nova physics.</jats:p

The RS Oph Outburst of 2021 Monitored in X-Rays with NICER

The 2021 outburst of the symbiotic recurrent nova RS Oph was monitored with the Neutron Star Interior Composition Explorer Mission (NICER) in the 0.2-12 keV range from day one after the optical maximum, until day 88, producing an unprecedented, detailed view of the outburst development. The X-ray flux preceding the supersoft X-ray phase peaked almost 5 days after optical maximum and originated only in shocked ejecta for 21-25 days. The emission was thermal; in the first 5 days, only a non-collisional-ionization equilibrium model fits the spectrum, and a transition to equilibrium occurred between days 6 and 12. The ratio of peak X-ray flux measured in the NICER range to that measured with Fermi in the 60 MeV-500 GeV range was about 0.1, and the ratio to the peak flux measured with H.E.S.S. in the 250 GeV-2.5 TeV range was about 100. The central supersoft X-ray source (SSS), namely the shell hydrogen burning white dwarf (WD), became visible in the fourth week, initially with short flares. A huge increase in flux occurred on day 41, but the SSS flux remained variable. A quasi-periodic oscillation every ≃35 s was always observed during the SSS phase, with variations in amplitude and a period drift that appeared to decrease in the end. The SSS has characteristics of a WD of mass >1 M ⊙. Thermonuclear burning switched off shortly after day 75, earlier than in the 2006 outburst. We discuss implications for the nova physics.Fil: Orio, Marina. Istituto Nazionale di Astrofisica; Italia. University of Wisconsin; Estados UnidosFil: Gendreau, Keith. Center for Exploration and Space Studies; Estados Unidos. National Aeronautics and Space Administration; Estados UnidosFil: Giese, Morgan. University of Wisconsin; Estados UnidosFil: Luna, Gerardo Juan Manuel. Universidad de Buenos Aires; Argentina. Universidad Nacional de Hurlingham; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Magdolen, Jozef. Slovak University of Technology in Bratislava; EslovaquiaFil: Strohmayer, Tod E.. National Aeronautics and Space Administration; Estados UnidosFil: Zhang, Andy E.. University of Wisconsin; Estados UnidosFil: Altamirano, Diego. University of Southampton; Reino UnidoFil: Dobrotka, Andrej. Slovak University of Technology in Bratislava; EslovaquiaFil: Enoto, Teruaki. Riken Cluster For Pioneering Research; JapónFil: Ferrara, Elizabeth C.. University of Maryland; Estados Unidos. National Aeronautics and Space Administration; Estados UnidosFil: Ignace, Richard. East Tennessee State University; Estados UnidosFil: Heinz, Sebastian. University of Wisconsin; Estados UnidosFil: Markwardt, Craig. National Aeronautics and Space Administration; Estados UnidosFil: Nichols, Joy S.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Parker, Michael L.. University of Cambridge; Estados UnidosFil: Pasham, Dheeraj R.. Mit Kavli Institute For Astrophysics And Space Research; Estados UnidosFil: Pei, Songpeng. Liupanshui Normal University; ChinaFil: Pradhan, Pragati. Embry-riddle Aeronautical University, Prescott; China. Mit Kavli Institute For Astrophysics And Space Research; Estados UnidosFil: Remillard, Ron. Mit Kavli Institute For Astrophysics And Space Research; Estados UnidosFil: Steiner, James F.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Tombesi, Francesco. University of Maryland; Estados Unidos. Universita Tor Vergata; Italia. National Aeronautics and Space Administration; Estados Unido

The RS Oph Outburst of 2021 Monitored in X-Rays with NICER

The 2021 outburst of the symbiotic recurrent nova RS Oph was monitored with the Neutron Star Interior Composition Explorer Mission (NICER) in the 0.2–12 keV range from day one after the optical maximum, until day 88, producing an unprecedented, detailed view of the outburst development. The X-ray flux preceding the supersoft X-ray phase peaked almost 5 days after optical maximum and originated only in shocked ejecta for 21–25 days. The emission was thermal; in the first 5 days, only a non-collisional-ionization equilibrium model fits the spectrum, and a transition to equilibrium occurred between days 6 and 12. The ratio of peak X-ray flux measured in the NICER range to that measured with Fermi in the 60 MeV–500 GeV range was about 0.1, and the ratio to the peak flux measured with H.E.S.S. in the 250 GeV–2.5 TeV range was about 100. The central supersoft X-ray source (SSS), namely the shell hydrogen burning white dwarf (WD), became visible in the fourth week, initially with short flares. A huge increase in flux occurred on day 41, but the SSS flux remained variable. A quasi-periodic oscillation every ≃35 s was always observed during the SSS phase, with variations in amplitude and a period drift that appeared to decrease in the end. The SSS has characteristics of a WD of mass >1 M _⊙ . Thermonuclear burning switched off shortly after day 75, earlier than in the 2006 outburst. We discuss implications for the nova physics

The RS Oph outburst of 2021 monitored in x-rays with NICER

The 2021 outburst of the symbiotic recurrent nova RS Oph was monitored with the Neutron Star Interior Composition Explorer Mission (NICER) in the 0.2–12 keV range from day one after the optical maximum, until day 88, producing an unprecedented, detailed view of the outburst development. The X-ray flux preceding the supersoft X-ray phase peaked almost 5 days after optical maximum and originated only in shocked ejecta for 21–25 days. The emission was thermal; in the first 5 days, only a non-collisional-ionization equilibrium model fits the spectrum, and a transition to equilibrium occurred between days 6 and 12. The ratio of peak X-ray flux measured in the NICER range to that measured with Fermi in the 60 MeV–500 GeV range was about 0.1, and the ratio to the peak flux measured with H.E.S.S. in the 250 GeV–2.5 TeV range was about 100. The central supersoft X-ray source (SSS), namely the shell hydrogen burning white dwarf (WD), became visible in the fourth week, initially with short flares. A huge increase in flux occurred on day 41, but the SSS flux remained variable. A quasi-periodic oscillation every ≃35 s was always observed during the SSS phase, with variations in amplitude and a period drift that appeared to decrease in the end. The SSS has characteristics of a WD of mass &gt;1 M⊙. Thermonuclear burning switched off shortly after day 75, earlier than in the 2006 outburst. We discuss implications for the nova physics