arXiv subjects

Marianne Heida

Publications and source records attributed to Marianne Heida.

At least 19 recordsLinked to original sources

arXiv2026

JWST spectroscopy of SN 2010da/NGC 300 ULX-1: a surviving star hidden by dust

We present new James Webb Space Telescope ($JWST$) NIRSpec and MIRI integral-field spectroscopy of the remarkable system SN~2010da / NGC~300 ULX-1, the only known ultraluminous X-ray source powered by a neutron star with a supergiant donor. Our new data, taken in November 2024, reveal that the optical and near-infrared counterpart has dramatically faded since 2018 and no longer exhibits molecular absorption features characteristic of a red supergiant. Instead, the spectral energy distribution shows the donor has returned to its pre-outburst appearance, and is dominated by infrared continuum consistent with an optically thick warm ($\approx$900~K) dust shell. The bolometric luminosity indicates the presence of a surviving luminous source with $\log(L/L_{\odot})=4.11\pm0.02$. Radiative transfer modelling of the mid-infrared spectral energy distribution (SED) reveals a broad emission feature peaking near $\sim$11\,$μ$m, best reproduced by silicon carbide (SiC) dust grains, a composition typically associated with carbon-rich evolved stars. We rule out a failed supernova scenario, which would predict a large drop in luminosity and continued fading. Given the association of SiC dust with AGB stars, we suggest the donor star may be an AGB star that has survived and is now heavily enshrouded - having returned to a dust-obscured state following a transient post-outburst phase in which the system appeared as a red supergiant. We propose a revised evolutionary timeline in which the 2010 outburst initiated sustained super-Eddington accretion and temporarily altered the circumstellar environment. These observations provide rare insight into eruptive mass loss, dust formation, and binary interaction in a unique system.

astro-ph.HE↗

arXiv2025

A NuSTAR study of quasi-periodic oscillations from the ultraluminous X-ray sources in M82

The study of quasi-periodic oscillations in X-ray binaries provides valuable insights into the physics of accretion around compact objects. The M82 galaxy hosts two ultraluminous X-ray sources (ULXs), one of which is suspected to harbor an intermediate-mass black hole. Using 39 NuSTAR observations acquired between 2014--2024, we investigate the aperiodic X-ray variability in M82. In particular, we study in detail the evolution of the QPO from M82 X-1 in the range 20--300 mHz. We do not find additional timing features in the data, besides a frequent broad noise component at lower frequencies. The QPO behaves similarly to other classes of low-frequency oscillations in accreting compact objects, both black holes and neutron stars.

astro-ph.HE↗

arXiv2024

The NuSTAR Serendipitous Survey: the 80-month catalog and source properties of the high-energy emitting AGN and quasar population

We present a catalog of hard X-ray serendipitous sources detected in the first 80 months of observations by the Nuclear Spectroscopic Telescope Array (NuSTAR). The NuSTAR serendipitous survey 80-month (NSS80) catalog has an unprecedented $\sim$ 62 Ms of effective exposure time over 894 unique fields (a factor of three increase over the 40-month catalog), with an areal coverage of $\sim $36 deg$^2$, larger than all NuSTAR extragalactic surveys. NSS80 provides 1274 hard X-ray sources in the $3-24$ keV band (822 new detections compared to the previous 40-month catalog). Approximately 76% of the NuSTAR sources have lower-energy ($<10$ keV) X-ray counterparts from Chandra, XMM-Newton, and Swift-XRT. We have undertaken an extensive campaign of ground-based spectroscopic follow-up to obtain new source redshifts and classifications for 427 sources. Combining these with existing archival spectroscopy provides redshifts for 550 NSS80 sources, of which 547 are classified. The sample is primarily composed of active galactic nuclei (AGN), detected over a large range in redshift ($z$ = 0.012-3.43), but also includes 58 spectroscopically confirmed Galactic sources. In addition, five AGN/galaxy pairs, one dual AGN system, one BL Lac candidate, and a hotspot of 4C 74.26 (radio quasar) have been identified. The median rest-frame $10-40$ keV luminosity and redshift of the NSS80 are $\langle{L_\mathrm{10-40 keV}}\rangle$ = 1.2 $\times$ 10$^{44}$ erg s$^{-1}$ and $\langle z \rangle = 0.56$. We investigate the optical properties and construct composite optical spectra to search for subtle signatures not present in the individual spectra, finding an excess of redder BL AGN compared to optical quasar surveys predominantly due to the presence of the host-galaxy and, at least in part, due to dust obscuration.

astro-ph.HE↗

arXiv2023

A new sample of transient ultraluminous X-ray sources serendipitously discovered by Swift/XRT

Ultraluminous X-ray sources (ULXs) are our best laboratories for studying extreme super-Eddington accretion. Most studies of these objects are of relatively persistent sources, however there is growing evidence to suggest a large fraction of these sources are transient. Here we present a sample of five newly reported transient ULXs in the galaxies NGC 4945, NGC 7793 and M81 serendipitously discovered in Swift/XRT observations. Swift monitoring of these sources have provided well sampled lightcurves, allowing for us to model the lightcurves with the disk instability model of Hameury & Lasota (2020) which implies durations of 60-400 days and that the mass accretion rate through the disk is close to or greater than the Eddington rate. Of the three source regions with prior HST imaging, color magnitude diagrams of the potential stellar counterparts show varying ages of the possible stellar counterparts. Our estimation of the rates of these sources in these three galaxies is 0.4-1.3 year$^{-1}$. We find that while persistent ULXs dominate the high end of galaxy luminosity functions, the number of systems that produce ULX luminosities are likely dominated by transient sources.

astro-ph.HE↗

arXiv2023

Science with the Ultraviolet Explorer (UVEX)

UVEX is a proposed medium class Explorer mission designed to provide crucial missing capabilities that will address objectives central to a broad range of modern astrophysics. The UVEX design has two co-aligned wide-field imagers operating in the FUV and NUV and a powerful broadband medium resolution spectrometer. In its two-year baseline mission, UVEX will perform a multi-cadence synoptic all-sky survey 50/100 times deeper than GALEX in the NUV/FUV, cadenced surveys of the Large and Small Magellanic Clouds, rapid target of opportunity followup, as well as spectroscopic followup of samples of stars and galaxies. The science program is built around three pillars. First, UVEX will explore the low-mass, low-metallicity galaxy frontier through imaging and spectroscopic surveys that will probe key aspects of the evolution of galaxies by understanding how star formation and stellar evolution at low metallicities affect the growth and evolution of low-metallicity, low-mass galaxies in the local universe. Such galaxies contain half the mass in the local universe, and are analogs for the first galaxies, but observed at distances that make them accessible to detailed study. Second, UVEX will explore the dynamic universe through time-domain surveys and prompt spectroscopic followup capability will probe the environments, energetics, and emission processes in the early aftermaths of gravitational wave-discovered compact object mergers, discover hot, fast UV transients, and diagnose the early stages of stellar explosions. Finally, UVEX will become a key community resource by leaving a large all-sky legacy data set, enabling a wide range of scientific studies and filling a gap in the new generation of wide-field, sensitive optical and infrared surveys provided by the Rubin, Euclid, and Roman observatories. This paper discusses the scientific potential of UVEX, and the broad scientific program.

astro-ph.GA↗

arXiv2023

First on-sky results of ERIS at VLT

ERIS (Enhanced Resolution Imager and Spectrograph) is a new adaptive optics instrument installed at the Cassegrain focus of the VLT-UT4 telescope at the Paranal Observatory in Chile. ERIS consists of two near-infrared instruments: SPIFFIER, an integral field unit (IFU) spectrograph covering J to K bands, and NIX, an imager covering J to M bands. ERIS has an adaptive optics system able to work with both LGS and NGS. The Assembly Integration Verification (AIV) phase of ERIS at the Paranal Observatory was carried out starting in December 2021, followed by several commissioning runs in 2022. This contribution will describe the first preliminary results of the on-sky performance of ERIS during its commissioning and the future perspectives based on the preliminary scientific results.

astro-ph.IM↗

arXiv2022

Orbital decay in M82 X-2

M82 X-2 is the first pulsating ultraluminous X-ray source (PULX) discovered. The luminosity of these extreme pulsars, if isotropic, implies an extreme mass transfer rate. An alternative is to assume a much lower mass transfer rate, but with an apparent luminosity boosted by geometrical beaming. Only an independent measurement of the mass transfer rate can help discriminate between these two scenarios. In this Paper, we follow the orbit of the neutron star for seven years, measure the decay of the orbit ($\dot{P}_{orb}/{P}_{orb}\approx-8\cdot10^{-6}\mathrm{yr}^{-1}$), and argue that this orbital decay is driven by extreme mass transfer of more than 150 times the mass transfer limit set by the Eddington luminosity. If this is true, the mass available to the accretor is more than enough to justify its luminosity, with no need for beaming. This also strongly favors models where the accretor is a highly-magnetized neutron star.

astro-ph.HE↗

arXiv2022

BASS XXII: The BASS DR2 AGN Catalog and Data

We present the AGN catalog and optical spectroscopy for the second data release of the Swift BAT AGN Spectroscopic Survey (BASS DR2). With this DR2 release we provide 1425 optical spectra, of which 1181 are released for the first time, for the 858 hard X-ray selected AGN in the Swift BAT 70-month sample. The majority of the spectra (813/1425, 57%) are newly obtained from VLT/Xshooter or Palomar/Doublespec. Many of the spectra have both higher resolution (R>2500, N~450) and/or very wide wavelength coverage (3200-10000 A, N~600) that are important for a variety of AGN and host galaxy studies. We include newly revised AGN counterparts for the full sample and review important issues for population studies, with 44 AGN redshifts determined for the first time and 780 black hole mass and accretion rate estimates. This release is spectroscopically complete for all AGN (100%, 858/858) with 99.8% having redshift measurements (857/858) and 96% completion in black hole mass estimates of unbeamed AGN (outside the Galactic plane). This AGN sample represents a unique census of the brightest hard X-ray selected AGN in the sky, spanning many orders of magnitude in Eddington ratio (Ledd=10^-5-100), black hole mass (MBH=10^5-10^10 Msun), and AGN bolometric luminosity (Lbol=10^40-10^47 ergs/s).

astro-ph.GA↗

arXiv2022

The variability behavior of NGC 925 ULX-3

We report the results of a 2019-2021 monitoring campaign with Swift and associated target-of-opportunity observations with XMM-Newton and NuSTAR, examining the spectral and timing behavior of the highly variable ultraluminous X-ray source (ULX) NGC 925 ULX-3. We find that the source exhibits a 127-128 day periodicity, with fluxes typically ranging from 1e-13 to 8e-13 ergs/s/cm2. We do not find strong evidence for a change in period over the time that NGC 925 ULX-3 has been observed, although the source may have been in a much lower flux state when first observed with Chandra in 2005. We do not detect pulsations, and we place an upper limit on the pulsed fraction of ~40% in the XMM-Newton band, consistent with some previous pulsation detections at low energies in other ULXs. The source exhibits a typical ULX spectrum that turns over in the NuSTAR band and can be fitted using two thermal components. These components have a high temperature ratio that may indicate the lack of extreme inner disk truncation by a magnetar-level magnetic field. We examine the implications for a number of different models for superorbital periods in ULXs, finding that a neutron star with a magnetic field of ~10^12 G may be plausible for this source. The future detection of pulsations from this source would allow for the further testing and constraining of such models.

astro-ph.HE↗

arXiv2022

The Redshift Evolution of Ultraluminous X-Ray Sources out to z~0.5: Comparison with X-Ray Binary Populations and Contribution to the Cosmic X-Ray Background

Ultraluminous X-ray sources (ULXs) are thought to be powerful X-ray binaries (XRBs) and may contribute significantly to the redshift-dependent X-ray emission from star forming galaxies. We have assembled a uniform sample of 259 ULXs over the redshift range z=0.002-0.51 to constrain their physical nature and their contribution to the Cosmic X-Ray Background (CXB). The sample is constructed by crossmatching galaxies from the Sloan Digital Sky Survey with the Chandra Source Catalog and selecting off-nuclear X-ray sources after applying astrometric corrections. The fraction of contaminants is ~30% and shows no evolution with redshift. The host galaxy star formation rates (SFRs) are systematically elevated relative to the parent sample when matched in host stellar mass. The specific SFRs suggest a slight preference for high-mass XRBs, and the X-ray luminosity scaling relations with host galaxy stellar mass and SFR indicate that the highest redshift sources represent relatively luminous XRB populations that dominate their host galaxy X-ray emission. The fraction of galaxies hosting at least one ULX of a given luminosity increases with redshift over the full range of our sample, as expected if ULXs are preferentially found in galaxies with high SFRs and low metallicities. At z~0.5, the ULX X-ray flux is consistent with the X-ray emission from star-forming galaxies. Moreover, ULXs may account for up to ~40% of the integrated flux from XRBs in the normal galaxy population out to z~0.5, suggesting they may contribute significantly to the overall ionizing radiation from galaxies.

astro-ph.GA↗

arXiv2022

An 8.56 keV absorption line in the hyperluminous X-ray source in NGC 4045: ultra-fast outflow or cyclotron line?

We report on the discovery of an absorption line at $E=8.56^{+0.05}_{-0.11}$ keV detected with a significance of $>3.3σ$ in the NuSTAR and XMM-Newton spectra of a newly discovered hyperluminous X-ray source (HLX, $L_{\rm X}>10^{41}$ ergs$^{-1}$) in the galaxy NGC 4045 at a distance of 32 Mpc. The source was first discovered serendipitously in a Swift/XRT observation of the galaxy, and Swift monitoring reveals a highly variable source changing by over an order of magnitude from maximum to minimum. The origin of the absorption line appears likely to be by highly ionized iron with a blue shift of 0.19$c$, indicating an ultrafast outflow (UFO). However, the large equivalent width of the line (EW$=-0.22^{+0.08}_{-0.09}$ keV) paired with the lack of other absorption lines detected are difficult to reconcile with models. An alternative explanation is that the line is due to a cyclotron resonance scattering feature (CRSF), produced by the interaction of X-ray photons with the powerful magnetic field of a neutron star.

astro-ph.HE↗

arXiv2021

Evolution of the spin, spectrum and super-orbital period of the ultraluminous X-ray pulsar M51 ULX7

M51 ULX7 is among a small group of known ultraluminous X-ray pulsars (ULXP). The neutron star powering the source has a spin period of 2.8s, orbits its companion star with a period of 2 days, and a super-orbital period of 38 days is evident in its X-ray lightcurve. Here we present NuSTAR and XMM-Newton data on the source from 2019 obtained when the source was near its peak brightness. We detect the pulsations, having spun up at a rate of 3$\pm0.5\times10^{-10}$ s s$^{-1}$ since they were previously detected in 2018. The data also provide the first high-quality broadband spectrum of the source. We find it to be very similar to that of other ULXPs, with two disk-like components, and a high energy tail. When combined with XMM-Newton data obtained in 2018, we explore the evolution of the spectral components with super-orbital phase, finding that the luminosity of the hotter component drives the super-orbital flux modulation. The inclination the disk components appear to change with phase, which may support the idea that these super-orbital periods are caused by disk precession. We also reexamine the super-orbital period with 3 years of Swift/XRT monitoring, finding that the period is variable, increasing from 38.2$\pm0.5$ days in 2018--2019 to 44.2$\pm0.9$ days in 2020--2021, which rules out alternative explanations for the super-orbital period.

astro-ph.HE↗

arXiv2021

$ν$ Gem: a hierarchical triple system with an outer Be star

Time series of spectroscopic, speckle-interferometric, and optical long-baseline-interferometric observations confirm that $ν$ Gem is a hierarchical triple system. It consists of an inner binary composed of two B-type stars and an outer classical Be star. Several photospheric spectral lines of the inner components were disentangled, revealing two stars with very different rotational broadening ($\sim$260 and $\sim$140 kms$^{-1}$, respectively), while the photospheric lines of the Be star remain undetected. From the combined spectroscopic and astrometric orbital solution it is not possible to unambiguously cross-identify the inner astrometric components with the spectroscopic components. In the preferred solution based on modeling of the disentangled line profiles, the inner binary is composed of two stars with nearly identical masses of 3.3 M$_\odot$ and the more rapidly rotating star is the fainter one. These two stars are in a marginally elliptical orbit ($e$ = 0.06) about each other with a period of 53.8 d. The third star also has a mass of 3.3 M$_\odot$ and follows a more eccentric ($e$ = 0.24) orbit with a period of 19.1 yr. The two orbits are co-directional and, at inclinations of 79$^{\circ}$ and 76$^{\circ}$ of the inner and the outer orbit, respectively, about coplanar. No astrometric or spectroscopic evidence could be found that the Be star itself is double. The system appears dynamically stable and not subject to eccentric Lidov-Kozai oscillations. After disentangling, the spectra of the components of the inner binary do not exhibit peculiarities that would be indicative of past interactions. Motivations for a wide range of follow-up studies are suggested.

astro-ph.SR↗

arXiv2020

The (re)appearance of NGC 925 ULX-3, a new transient ULX

We report the discovery of a third ULX in NGC 925 (ULX-3), detected in November 2017 by Chandra at a luminosity of $L_{\rm X} = (7.8\pm0.8)\times10^{39}$ erg s$^{-1}$. Examination of archival data for NGC 925 reveals that ULX-3 was detected by Swift at a similarly high luminosity in 2011, as well as by XMM-Newton in January 2017 at a much lower luminosity of $L_{\rm X} = (3.8\pm0.5)\times10^{38}$ erg s$^{-1}$. With an additional Chandra non-detection in 2005, this object demonstrates a high dynamic range of flux of factor >26. In its high-luminosity detections, ULX-3 exhibits a hard power-law spectrum with $Γ=1.6\pm0.1$, whereas the XMM-Newton detection is slightly softer, with $Γ=1.8^{+0.2}_{-0.1}$ and also well-fitted with a broadened disc model. The long-term light curve is sparsely covered and could be consistent either with the propeller effect or with a large-amplitude superorbital period, both of which are seen in ULXs, in particular those with neutron star accretors. Further systematic monitoring of ULX-3 will allow us to determine the mechanism by which ULX-3 undergoes its extreme variability and to better understand the accretion processes of ULXs.

astro-ph.HE↗

arXiv2020

From SN2010da to NGC 300 ULX-1: Ten Years of Observations of an Unusual High Mass X-ray Binary in NGC 300

In 2010 May, an intermediate luminosity optical transient was discovered in the nearby galaxy NGC 300 by a South African amateur astronomer. In the decade since its discovery, multi-wavelength observations of the misnamed ``SN 2010da'' have continually re-shaped our understanding of this high mass X-ray binary system. In this review, we present an overview of the multi-wavelength observations and attempts to understand the 2010 transient event and, later, the re-classification of this system as NGC~300 ULX-1: a red supergiant + neutron star ultraluminous X-ray source.

astro-ph.HE↗

arXiv2019

Swift monitoring of M51: A 38-day super-orbital period for the pulsar ULX7 and a new transient ULX

We present the results from a monitoring campaign made with the Neil Gehrels Swift Observatory of the M51 galaxies, which contain several variable ultraluminous X-ray sources (ULXs). The ongoing campaign started in May 2018, and we report here on $\sim1.5$ years of observations. The campaign, which consists of 105 observations, has a typical cadence of 3--6 days, and has the goal of determining the long-term X-ray variability of the ULXs. Two of the most variable sources were ULX7 and ULX8, both of which are known to be powered by neutron stars that are exceeding their isotropic Eddington luminosities by factors of up to 100. This is further evidence that neutron star powered ULXs are the most variable. Our two main results are, first, that ULX7 exhibits a periodic flux modulation with a period of 38 days varying over a magnitude and a half in flux from peak to trough. Since the orbital period of the system is known to be 2 days, the modulation is super-orbital, which is a near-ubiquitous property of ULX pulsars. Secondly we identify a new transient ULX, M51 XT-1, the onset of which occurred during our campaign, reaching a peak luminosity of $\sim10^{40}$ erg s$^{-1}$, before gradually fading over the next $\sim200$ days until it slipped below the detection limit of our observations. Combined with the high-quality Swift/XRT lightcurve of the transient, serendipitous observations made with Chandra and XMM-Newton provide insights into the onset and evolution of a likely super-Eddington event.

astro-ph.HE↗

arXiv2019

All at once: transient pulsations, spin down and a glitch from the Pulsating Ultraluminous X-ray Source M82 X-2

M82 X-2 is the first pulsating ultraluminous X-ray source (PULX)to be identified. Since the discovery in 2014, NuSTAR has observed the M82 field 15 times throughout 2015 and 2016. In this paper, we report the results of pulsation searches in all these datasets, and find only one new detection. This new detection allows us to refine the orbital period of the source and measure an average spin down rate between 2014 and 2016 of 5x10^-11 Hz/s, which is in contrast to the strong spin up seen during the 2014 observations and represent the first detection of spin down in a PULX system. Thanks to the improved orbital solution allowed by this new detection, we are also able to detect pulsations in additional segments of the original 2014 dataset. We find a glitch superimposed on the very strong and variable spin-up already reported, the first positive glitch identified in a PULX system. We discuss the new findings in the context of current leading models for PULXs.

astro-ph.HE↗

arXiv2019

A broadband look at the old and new ULXs of NGC 6946

Two recent observations of the nearby galaxy NGC 6946 with NuSTAR, one simultaneous with an XMM-Newton observation, provide an opportunity to examine its population of bright accreting sources from a broadband perspective. We study the three known ultraluminous X-ray sources (ULXs) in the galaxy, and find that ULX-1 and ULX-2 have very steep power-law spectra with $Γ=3.6^{+0.4}_{-0.3}$ in both cases. Their properties are consistent with being super-Eddington accreting sources with the majority of their hard emission obscured and down-scattered. ULX-3 (NGC 6946 X-1) is significantly detected by both XMM-Newton and NuSTAR at $L_{\rm X}=(6.5\pm0.1)\times10^{39}$ erg s$^{-1}$, and has a power-law spectrum with $Γ=2.51\pm0.05$. We are unable to identify a high-energy break in its spectrum like that found in other ULXs, but the soft spectrum likely hinders our ability to detect one. We also characterise the new source, ULX-4, which is only detected in the joint XMM-Newton and NuSTAR observation, at $L_{\rm X}=(2.27\pm0.07)\times10^{39}$ erg s$^{-1}$, and is absent in a Chandra observation ten days later. It has a very hard cut-off power-law spectrum with $Γ=0.7\pm0.1$ and $E_{\rm cut}=11^{+9}_{-4}$ keV. We do not detect pulsations from ULX-4, but its transient nature can be explained either as a neutron star ULX briefly leaving the propeller regime or as a micro-tidal disruption event induced by a stellar-mass compact object.

astro-ph.HE↗