Peak Luminosity Research Articles

Fundamental scaling relationships revealed in the optical light curves of tidal disruption events

ABSTRACT We present fundamental scaling relationships between properties of the optical/UV light curves of tidal disruption events (TDEs) and the mass of the black hole that disrupted the star. We have uncovered these relations from the late-time emission of TDEs. Using a sample of 63 optically selected TDEs, the latest catalogue to date, we observed flattening of the early-time emission into a near-constant late-time plateau for at least two-thirds of our sources. Compared to other properties of the TDE light curves (e.g. peak luminosity or decay rate) the plateau luminosity shows the tightest correlation with the total mass of host galaxy (p-value of 2 × 10−6, with a residual scatter of 0.3 dex). Physically this plateau stems from the presence of an accretion flow. We demonstrate theoretically and numerically that the amplitude of this plateau emission is strongly correlated with black hole mass. By simulating a large population (N = 106) of TDEs, we determine a plateau luminosity-black hole mass scaling relationship well described by $\log _{10} \left({{M_{\bullet }}/M_\odot }\right) = 1.50 \log _{10} \left({ L_{\rm plat}}/10^{43} \, {\rm erg\, s^{-1}}\right) + 9.0$ (here Lplat is measured at 6 × 1014 Hz in the rest frame). The observed plateau luminosities of TDEs and black hole masses in our large sample are in excellent agreement with this simulation. Using the black hole mass predicted from the observed TDE plateau luminosity, we reproduce the well-known scaling relations between black hole mass and galaxy velocity dispersion. The large black hole masses of 10 of the TDEs in our sample allow us to provide constraints on their black hole spins, favouring rapidly rotating black holes. Finally, we also discover two significant correlations between early time properties of optical TDE light curves (the g-band peak luminosity and radiated energy) and the TDEs black hole mass.

An Optically Discovered Outburst from XTE J1859+226

Using the Zwicky Transient Facility, in 2021 February we identified the first known outburst of the black hole X-ray transient XTE J1859+226 since its discovery in 1999. The outburst was visible at X-ray, UV, and optical wavelengths for less than 20 days, substantially shorter than its full outburst of 320 days in 1999, and the observed peak luminosity was 2 orders of magnitude lower. Its peak bolometric luminosity was only 2 × 1035 erg s−1, implying an Eddington fraction of about 3 × 10−4. The source remained in the hard spectral state throughout the outburst. From optical spectroscopy measurements we estimate an outer disk radius of 1011 cm. The low observed X-ray luminosity is not sufficient to irradiate the entire disk, but we observe a surprising exponential decline in the X-ray light curve. These observations highlight the potential of optical and infrared synoptic surveys to discover low-luminosity activity from X-ray transients.

R-process Nucleosynthesis of Subminimal Neutron Star Explosions

We show that a minimum-mass neutron star undergoes delayed explosion after mass removal from its surface. We couple the Newtonian hydrodynamics to a nuclear reaction network of ∼4500 isotopes to study the nucleosynthesis and neutrino emission during the explosion. An electron antineutrino burst with a peak luminosity of ∼3 × 1050 erg s−1 is emitted while the ejecta is heated to ∼109 K. A robust r-process nucleosynthesis is realized in the ejecta. Lanthanides and heavy elements near the second and third r-process peaks are synthesized as end products of nucleosynthesis, suggesting that subminimal neutron star explosions could be an important source of solar chemical elements.

SN 2022jli: A Type Ic Supernova with Periodic Modulation of Its Light Curve and an Unusually Long Rise

We present multiwavelength photometry and spectroscopy of SN 2022jli, an unprecedented Type Ic supernova discovered in the galaxy NGC 157 at a distance of ≈ 23 Mpc. The multiband light curves reveal many remarkable characteristics. Peaking at a magnitude of g = 15.11 ± 0.02, the high-cadence photometry reveals periodic undulations of 12.5 ± 0.2 days superimposed on the 200-day supernova decline. This periodicity is observed in the light curves from nine separate filter and instrument configurations with peak-to-peak amplitudes of ≃ 0.1 mag. This is the first time that repeated periodic oscillations, over many cycles, have been detected in a supernova light curve. SN 2022jli also displays an extreme early excess that fades over ≈25 days, followed by a rise to a peak luminosity of L opt = 1042.1 erg s−1. Although the exact explosion epoch is not constrained by data, the time from explosion to maximum light is ≳ 59 days. The luminosity can be explained by a large ejecta mass (M ej ≈ 12 ± 6 M ⊙) powered by 56Ni, but we find it difficult to quantitatively model the early excess with circumstellar interaction and cooling. Collision between the supernova ejecta and a binary companion is a possible source of this emission. We discuss the origin of the periodic variability in the light curve, including interaction of the SN ejecta with nested shells of circumstellar matter and neutron stars colliding with binary companions.

GRB-SN Association within the Binary-driven Hypernova Model

Observations of supernovae (SNe) Ic occurring after the prompt emission of long gamma-ray bursts (GRBs) are addressed within the binary-driven hypernova (BdHN) model where GRBs originate from a binary composed of a ∼10M ⊙ carbon–oxygen (CO) star and a neutron star (NS). The CO core collapse gives the trigger, leading to a hypernova with a fast-spinning newborn NS (νNS) at its center. The evolution depends strongly on the binary period, P bin. For P bin ∼ 5 min, BdHNe I occur with energies 1052–1054 erg. The accretion of SN ejecta onto the NS leads to its collapse, forming a black hole (BH) originating the MeV/GeV radiation. For P bin ∼ 10 min, BdHNe II occur with energies 1050–1052 erg and for P bin ∼ hours, BdHNe III occur with energies below 1050 erg. In BdHNe II and III, no BH is formed. The 1–1000 ms νNS originates, in all BdHNe, the X-ray-optical-radio afterglows by synchrotron emission. The hypernova follows an independent evolution, becoming an SN Ic, powered by nickel decay, observable after the GRB prompt emission. We report 24 SNe Ic associated with BdHNe. Their optical peak luminosity and time of occurrence are similar and independent of the associated GRBs. From previously identified 380 BdHN I comprising redshifts up to z = 8.2, we analyze four examples with their associated hypernovae. By multiwavelength extragalactic observations, we identify seven new episodes, theoretically explained, fortunately not yet detected in Galactic sources, opening new research areas. Refinement of population synthesis simulations is needed to map the progenitors of such short-lived binary systems inside our galaxy.

An accretion disc with magnetic outflows triggered by a sudden mass accretion event in changing-look active galactic nucleus 1ES 1927+654

ABSTRACT 1ES 1927+654 was known as a type 2 Seyfert galaxy, which exhibited drastic variability recently in ultraviolet (UV)/optical and X-ray bands. An UV/optical outburst was observed in the end of 2017, and it reached the peak luminosity ∼50 d later. The high-cadence observations showed a rapid X-ray flux decline with complete disappearance of the power-law hard X-ray component when the soft X-ray thermal emission reached its lowest level about 150 d after the UV/optical peak. The power-law X-ray component reappeared with thermal X-ray emission brightening from its lowest flux within next ∼100 d. We assume an episodic accretion event taking place in the outer region of the disc surrounding a central black hole (BH), which is probably due to a red giant star tidally disrupted by the BH. The inner thin disc with corona is completely swept by the accretion event when the gas reaches the innermost circular stable orbit. The field threading the disrupted star is dragged inwards by the disc formed after the tidal disruption event, which accelerates outflows from the disc. The disc dimmed since a large fraction of the energy released in the disc is tapped into the outflows. The accretion rate of the episodic accretion event declines, and ultimately, it turns out to be a thin disc, which is inefficient for field advection, and the outflows are switched off. A thin disc with corona reappears later after the outburst.

AT2018dyk revisited: a tidal disruption event candidate with prominent infrared echo and delayed X-ray emission in a LINER galaxy

ABSTRACT The multiwavelength data of nuclear transient AT2018dyk, initially discovered as a changing-look low-ionization nuclear emission-line region (LINER) galaxy, has been revisited by us and found being in agreement with a tidal disruption event (TDE) scenario. The optical light curve of AT2018dyk declines as a power-law form approximately with index –5/3 yet its X-ray emission lags behind the optical peak by ∼140 d, both of which are typical characteristics for TDEs. The X-ray spectra are softer than normal active galactic nuclei (AGNs) although they show a slight trend of hardening. Interestingly, its rising time-scale belongs to the longest among TDEs while it is nicely consistent with the theoretical prediction from its relatively large supermassive black hole (SMBH) mass (∼107.38M⊙). Moreover, a prominent infrared echo with peak luminosity ∼7.4 × 1042 erg s−1 has been also detected in AT2018dyk, implying an unusually dusty subparsec nuclear environment in contrast with other TDEs. In our sample, LINERs share similar covering factors with AGNs, which indicates the existence of the dusty torus in these objects. Our work suggests that the nature of nuclear transients in LINERs needs to be carefully identified and their infrared echoes offer us a unique opportunity for exploring the environment of SMBHs at low accretion rate, which has been so far poorly explored but is crucial for understanding the SMBH activity.

The Iron Yield of Core-collapse Supernovae

We present a systematic analysis of 191 stripped-envelope supernovae (SE SNe), aimed at computing their 56Ni masses from the luminosity in their radioactive tails () and/or in their maximum light, and the mean 56Ni and iron yields of SE SNe and core-collapse SNe. Our sample consists of SNe IIb, Ib, and Ic from the literature and from the Zwicky Transient Facility Bright Transient Survey. To calculate luminosities from optical photometry, we compute bolometric corrections using 49 SE SNe with optical and near-IR photometry, and develop corrections to account for the unobserved UV and IR flux. We find that the equation of Khatami & Kasen for radioactive 56Ni-powered transients with a single free parameter does not fit the observed peak time–luminosity relation of SE SNe. Instead, we find a correlation between , peak time, peak luminosity, and decline rate, which allows for measuring individual 56Ni masses to a precision of 14%. Applying this method to the whole sample, we find, for SNe IIb, Ib, and Ic, mean 56Ni masses of 0.066 ± 0.006, 0.082 ± 0.009, and 0.132 ± 0.011 M ⊙, respectively. After accounting for their relative rates, for SE SNe as a whole, we compute mean 56Ni and iron yields of 0.090 ± 0.005 and 0.097 ± 0.007 M ⊙, respectively. Combining these results with the recent Type II SN mean 56Ni mass derived by Rodríguez et al., core-collapse SNe, as a whole, have mean 56Ni and iron yields of 0.055 ± 0.006 and 0.058 ± 0.007 M ⊙, respectively. We also find that radioactive 56Ni-powered models typically underestimate the peak luminosity of SE SNe by 60%–70%, suggesting the presence of an additional power source contributing to the luminosity at peak.

Multidimensional Radiation Hydrodynamics Simulations of Pulsational Pair-instability Supernovae

Stars with masses of 80–130 M ⊙ can encounter pulsational pair-instability at the end of their lives, which triggers consecutive episodes of explosive burning that eject multiple massive shells. Collisions between these shells produce bright transients known as pulsational pair-instability supernovae (PPI SNe) that may explain some extreme supernovae. In this paper, we present the first 2D and 3D radiation hydrodynamics simulations of PPI SNe with the CASTRO code. Radiative cooling causes the collided shells to evolve into thin, dense structures with hot spots that can enhance the peak luminosity of the SN by factors of 2–3. The light curve peaks at 1.9–2.1 × 1043 erg s−1 for 50 days and then plateaus at 2–3 × 1042 erg s−1 for 200 days, depending on the viewing angle. The presence of 12C and 16O and the absence of 28Si and 56Fe in its spectra can uniquely identify this transient as a PPI SN in follow-up observations. Our models suggest that multidimensional radiation hydrodynamics is required to model the evolution and light curves of all shell-collision SNe, such as Type IIne, not just PPI SNe.

Detection Possibility of Continuous Gravitational Waves from Rotating Magnetized Neutron Stars

In recent decades, several neutron stars (NSs), particularly pulsars, with masses of M > 2 M ⊙ have been observed. On the other hand, the existence of massive white dwarfs, even violating the Chandrasekhar mass limit, was inferred from the peak luminosities of Type Ia supernovae. Hence, there is a generic question of the origin of massive compact objects. Here we explore the existence of massive, magnetized, rotating NSs with the soft and steep equations of state by solving axisymmetric stationary stellar equilibria in general relativity. For our purposes, we consider the Einstein equation solver for stellar structure XNS code. Such rotating NSs with magnetic fields and rotation axes misaligned, and hence a nonzero obliquity angle, can emit continuous gravitational waves (GWs), which can be detected by upcoming detectors, e.g., the Einstein Telescope, etc. We discuss the decay of the magnetic field, angular velocity, and obliquity angle with time due to angular momentum extraction by GWs and dipole radiation, which determine the timescales related to the GW emission. Further, in the Alfvén timescale, a differentially rotating, massive proto-NS rapidly settles into a uniformly rotating, less massive NS due to magnetic braking and viscosity. These explorations suggest that detecting massive NSs is challenging and sets a timescale for detection. We calculate the signal-to-noise ratio of GW emission, which confirms that any detector cannot detect them immediately, but that they are detectable by the Einstein Telescope and Cosmic Explorer over months of integration time, leading to direct detection of NSs.

Environmental dependence of Type IIn supernova properties

Type IIn supernovae occur when stellar explosions are surrounded by dense hydrogen-rich circumstellar matter. The dense circumstellar matter is likely formed by extreme mass loss from their progenitors shortly before they explode. The nature of Type IIn supernova progenitors and the mass-loss mechanism forming the dense circumstellar matter are still unknown. In this work, we investigate whether Type IIn supernova properties and their local environments are correlated. We use Type IIn supernovae with well-observed light curves and host-galaxy integral field spectroscopic data so that we can estimate both supernova and environmental properties. We find that Type IIn supernovae with a higher peak luminosity tend to occur in environments with lower metallicity and/or younger stellar populations. The circumstellar matter density around Type IIn supernovae is not significantly correlated with metallicity, so the mass-loss mechanism forming the dense circumstellar matter around Type IIn supernovae might be insensitive to metallicity.

Observational Properties of a Bright Type lax SN 2018cni and a Faint Type Iax SN 2020kyg

We present the optical photometric and spectroscopic analysis of two Type Iax supernovae (SNe), 2018cni and 2020kyg. SN 2018cni is a bright Type Iax SN (M V,peak = −17.81 ± 0.21 mag), whereas SN 2020kyg (M V,peak = −14.52 ± 0.21 mag) is a faint one. We derive 56Ni mass of 0.07 and 0.002 M ⊙ and ejecta mass of 0.48 and 0.14 M ⊙ for SNe 2018cni and 2020kyg, respectively. A combined study of the bright and faint Type Iax SNe in R/r-band reveals that the brighter objects tend to have a longer rise time. However, the correlation between the peak luminosity and decline rate shows that bright and faint Type Iax SNe exhibit distinct behavior. Comparison with standard deflagration models suggests that SN 2018cni is consistent with the deflagration of a CO white dwarf, whereas the properties of SN 2020kyg can be better explained by the deflagration of a hybrid CONe white dwarf. The spectral features of both the SNe point to the presence of similar chemical species but with different mass fractions. Our spectral modeling indicates stratification at the outer layers and mixed inner ejecta for both of the SNe.

Belle II status and prospects for studies of neutral currents

The Belle II experiment at the SuperKEKB energy-asymmetric electron-positron collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. Belle II collected a sample of 362 fb-1 at the Υ(4S) resonance between 2019 and 2022, with a maximum peak luminosity of 4.7 × 1034 cm-2 s -1. Belle II is currently facing a long shutdown period, required for several upgrades of the detector and the collider. Data taking will resume at the end of 2023. We report the recent measurements which involve neutral current transitions in B meson decays. In particular, we present the current status and future prospects for the branching fractions measurements of the radiative decays B → K*γ and the fully inclusive B → Xsγ, the search for B + → K + νν̅ decays, the measurement of the branching fractions of B → J/ψ(→ℓℓ)K and B → K * ℓℓ. Finally, we show the perspectives of the search for B → K * ττ and the searches of lepton flavor violating channels B → K (*) ℓℓ', with ℓ = e, μ, τ.

Measured and projected beam backgrounds in the Belle II experiment at the SuperKEKB collider

The Belle II experiment at the SuperKEKB electron–positron collider aims to collect an unprecedented data set of 50ab−1 to study CP-violation in the B-meson system and to search for Physics beyond the Standard Model. SuperKEKB is already the world’s highest-luminosity collider. In order to collect the planned data set within approximately one decade, the target is to reach a peak luminosity of 6 × 1035cm−2s−1 by further increasing the beam currents and reducing the beam size at the interaction point by squeezing the betatron function down to βy∗=0.3mm. To ensure detector longevity and maintain good reconstruction performance, beam backgrounds must remain well controlled. We report on current background rates in Belle II and compare these against simulation. We find that a number of recent refinements have significantly improved the background simulation accuracy. Finally, we estimate the safety margins going forward. We predict that backgrounds should remain high but acceptable until a luminosity of at least 2.8 × 1035cm−2s−1 is reached for βy∗=0.6mm. At this point, the most vulnerable Belle II detectors, the Time-of-Propagation (TOP) particle identification system and the Central Drift Chamber (CDC), have predicted background hit rates from single-beam and luminosity backgrounds that add up to approximately half of the maximum acceptable rates.

Multi-stage oxidation of iron particles in a flame-generated hot laminar flow

The paper presents multi-parameter high-speed optical diagnostics of single iron particle oxidation in a hot laminar flow consisting of O2, H2O, CO2, and N2. Prior to luminous combustion, micron-sized particles are visualized using diffuse-backlight-illumination with high temporal and spatial resolutions, enabling in situ particle sizing. The incandescent burning particles are then monitored by direct high-speed imaging. This approach allows for a successful determination of the multiple oxidation stages of individual iron particles, including the solid phase, melting, and liquid phase. Two characteristic timescales are quantified as a function of the resolved particle diameter at various O2 volume fractions, namely the solid-phase oxidation time (SOT, defined as the time between the onset of rapid particle heating and melting) and the liquid-phase combustion time (LCT, defined as the duration between melting initiation and peak luminosity). SOT shows a linear dependence on the inverse O2 mass fractions at relatively high O2 levels but it tends to plateau when the O2 content is below 20vol.%. LCT is inversely proportional to the O2 mass fraction, suggesting that liquid-phase oxidation of iron particles is limited by external oxygen diffusion. The experimental LCT quantitatively agrees with a theoretical mode developed for nonvolatile particle combustion in the diffusion-limited regime, considering O2 as the only oxidant. This also implies that at the presence of O2, the oxidizing effect of H2O and CO2 on diffusion-limited iron particle combustion is negligible.

Very-high-energy Gamma-Ray Afterglows of GRB 201015A and GRB 201216C

Gamma-ray bursts (GRBs) 201015A and 201216C are valuable cases where very-high-energy (VHE) gamma-ray afterglows have been detected. By analyzing their prompt emission data, we find that GRB 201216C is an extremely energetic, long GRB with a hard gamma-ray spectrum, while GRB 201015A is a relative subenergetic, soft-spectrum GRB. Attributing their radio–optical–X-ray afterglows to the synchrotron radiation of the relativistic electrons accelerated in their jets, we fit their afterglow lightcurves with the standard external shock model and infer their VHE afterglows from the synchrotron self-Compton scattering process of the electrons. It is found that the jet of GRB 201015A is midrelativistic (Γ0 = 44), surrounded by a very dense medium (n = 1202 cm−3), and the jet of GRB 201216C is ultrarelativistic (Γ0 = 331), surrounded by a moderate dense medium (n = 5 cm−3). The inferred peak luminosity of the VHE gamma-ray afterglows of GRB 201216C is approximately 10−9 erg cm−2 s−1 at 57–600 s after the GRB trigger, making it detectable with the MAGIC telescopes at a high confidence level, even though the GRB is at a redshift of 1.1. Comparing their intrinsic VHE gamma-ray lightcurves and spectral energy distributions with GRBs 180720B, 190114C, and 190829A, we show that their intrinsic peak luminosity of VHE gamma-ray afterglows at 104 s after the GRB trigger is variable from 1045 to 5 × 1048 erg s−1, and their kinetic energy, initial Lorentz factor, and medium density are diverse among bursts.

RX J0440.9+4431: another supercritical X-ray pulsar

ABSTRACT In the beginning of 2023, the Be transient X-ray pulsar RX J0440.9+4431 underwent a first-ever giant outburst observed from the source peaking in the beginning of February and reaching peak luminosity of ≈4.3 × 1037 erg s−1. Here, we present the results of a detailed spectral and temporal study of the source based on NuSTAR, Swift, INTEGRAL, and NICER observations performed during this period and covering wide range of energies and luminosities. We find that both the pulse profile shape and spectral hardness change abruptly around ≈2.8 × 1037 erg s−1, which we associate with a transition to supercritical accretion regime and erection of the accretion column. The observed pulsed fraction decreases gradually with energy up to 20 keV (with a local minimum around fluorescence iron line), which is unusual for an X-ray pulsar, and then rises rapidly at higher energies with the pulsations significantly detected up to ≈120 keV. The broad-band energy spectra of RX J0440.9+4431 at different luminosity states can be approximated with a two-hump model with peaks at energies of about 10–20 and 50–70 keV previously suggested for other pulsars without additional features. In particular, an absorption feature around 30 keV previously reported and interpreted as a cyclotron line in the literature appears to be absent when using this model, so the question regarding the magnetic field strength of the neutron star remains open. Instead, we attempted to estimate field using several indirect methods and conclude that all of them point to a relatively strong field of around B ∼ 1013 G.

Optically informed searches of high-energy neutrinos from interaction-powered supernovae

ABSTRACT The interaction between the ejecta of supernovae (SNe) of Type IIn and a dense circumstellar medium can efficiently generate thermal ultraviolet/optical radiation and lead to the emission of neutrinos in the 1–103 TeV range. We investigate the connection between the neutrino signal detectable at the IceCube Neutrino Observatory and the electromagnetic signal observable by optical wide-field, high-cadence surveys to outline the best strategy for upcoming follow-up searches. We outline a semi-analytical model that connects the optical light-curve properties to the SN parameters and find that a large peak luminosity (${L_{\rm {peak}}\gtrsim 10^{43}{-}10^{44}\, \mathrm{erg \, s^{-1}}}$) and an average rise time (trise ≳ 10−40 d) are necessary for copious neutrino emission. Nevertheless, the most promising Lpeak and trise can be obtained for SN configurations that are not optimal for neutrino emission. Such ambiguous correspondence between the optical light-curve properties and the number of IceCube neutrino events implies that relying on optical observations only, a range of expected neutrino events should be considered (e.g. the expected number of neutrino events can vary up to two orders of magnitude for some among the brightest SNe IIn observed by the Zwicky Transient Facility up to now, SN 2020usa and SN 2020in). In addition, the peak in the high-energy neutrino curve should be expected a few trise after the peak in the optical light curve. Our findings highlight that it is crucial to infer the SN properties from multiwavelength observations rather than focusing on the optical band only to enhance upcoming neutrino searches.

X-Ray Studies of Blazar 1ES 1959+650 Using Swift and XMM-Newton Satellite

High synchrotron energy peaked blazar 1ES 1959+650 was studied with the Swift and XMM-Newton satellites in a total of 127 observations during the period 2018 June–2020 December. We extensively studied its flux and spectral variability on intraday and long-term timescales. Discrete correlation function analysis between soft and hard X-ray bands indicates soft as well as hard lags. The results were used to constrain the magnetic field of the emitting region, which was found to be 0.64 ± 0.05 G. On long-term timescales, the distribution of fluxes shows lognormal behavior, which could be attributed to the minijets-in-a-jet model or might be due to the propagation of relativistic shocks down the jet. The spectral energy distribution around the synchrotron peak is well described by the log-parabola model. Spectral parameters like the peak energy E p , curvature β, and peak luminosity L p were derived from spectral analysis. Their correlations were studied to constrain the acceleration processes of the emitting particles. E p shows strong correlation with L p during the high state of the source, which indicates spectral changes might be caused by the variations of the average electron energy. Low values of the curvature parameter β and a weak correlation between E p and β indicate the coexistence of stochastic/statistical acceleration of electrons in the emitting region. Implications of other results are also discussed.

Implementation of ACTS for STCF track reconstruction

With an electron-positron collider operating at center-of-mass-energy 2–7 GeV and a peak luminosity above 0.5 × 1035 cm-2 s-1, the STCF physics program will provide an unique platform for in-depth studies of hadron structure and non-perturbative strong interaction as well as probing new physics beyond the Standard Model in the τ-Charm sector, succeeding the present Beijing Electron-Positron Collider. To fulfill the physics targets and further maximize the physics potential at STCF, the STCF tracking software should have capability to reconstruct charged particles with high efficiency and excellent momentum resolution, especially for the charged particles with low transverse momentum down to 50 MeV. A Common Tracking Software (ACTS) providing a set of detector-independent tracking algorithms is adopted for reconstructing charged tracks with the information of two sub-detectors, a μRWELL-based inner tracker and a drift chamber, at STCF. This is the first demonstration of ACTS for a drift chamber. The implementation details and performance of track reconstruction are presented.