Multi-wavelength Constraints on the Transient EP250905a
Radboud University（拉德堡德大学）；The Cosmic Dawn Centre (DAWN)（宇宙黎明中心）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所）；Instituto de Alta Investigación, Universidad de Tarapacá（塔拉帕卡大学高等研究所）；University College Dublin（都柏林大学学院）；Instituto de Astrofísica de Canarias（加那利天体物理研究所）；Universidad de La Laguna（拉帕鲁纳大学）；University of Leicester（莱斯特大学）；INAF – Osservatorio Astronomico di Roma（意大利国家天文台罗马天文台）；Institute of Space Sciences (ICE, CSIC)（空间科学研究所）；Institut d’Estudis Espacials de Catalunya (IEEC)（加泰罗尼亚空间研究 institute）
J. Quirola-Vasquez, P. G. Jonker, A. Levan, D. B. Malesani, F. E. Bauer, A. Martin-Carrillo, G. Corcoran, D. Mata Sanchez, R. A. J. Eyles-Ferris, F. Carotenuto,… 展开作者
J. Quirola-Vasquez, P. G. Jonker, A. Levan, D. B. Malesani, F. E. Bauer, A. Martin-Carrillo, G. Corcoran, D. Mata Sanchez, R. A. J. Eyles-Ferris, F. Carotenuto, M. Ravasio, J. Sanchez-Sierras, J. Bright, J. A. Chacon, L. Cotter, F. J. Cowie, N. Sarin, M. A. P. Torres, J. N. D. van Dalen, A. P. C. van Hoof, V. D'Elia, P. Jakobsson, N. Habeeb, S. Kobayashi, A. Saccardi, M. De Pasquale, D. Xu, Y. H. Cheng, R. D. Liang, H. Sun, Y. Wang, W. Yuan, W. D. Zhang
Fast X-ray transients (FXTs) are a diverse class of high-energy suggested origins, ranging from stellar explosions to compact object mergers. The Einstein Probe (EP) satellite discovers approximately 100 FXTs per year. We aim to constrain the physical origin of EP250905a. We analyze X-ray, optical, near-infrared (NIR), and radio temporal and spectral properties of EP250905a. In addition, we assess the possible role of weak gravitational lensing in shaping its observed characteristics. EP250905a fades rapidly in X-rays, and we detect no NIR or radio emission, but we detect early optical emission that rapidly fades beyond the detection limits. Two nearby galaxies are identified for which we derive spectroscopic redshifts of $z=0.374$ (G1) and $z=2.714$ (G2). Our analysis favors G2 as the host of the FXT EP250905a. The angular separation of 2.56\arcsec\, between the FXT's optical counterpart and the center of the G1 galaxy suggests the emission of the FXT might be moderately magnified by lensing effects ($μ\approx3.9$) given the inferred Einstein radius of G1 ($θ_E\approx1.9$ arcsec). The data are best explained as an afterglow from a mildly off-axis structured jet at $z=2.714$, providing a consistent broadband interpretation that also allows for weakly lensed emission of EP250905a.
We report the results of a low frequency radio variability and slow transient search using archival observations from the Very Long Array. We selected six 325 MHz radio observations from the spring of 2006, each centered on the Spitzer-Space-Telescope Wide-area Infrared Extragalactic Survey (SWIRE) Deep Field: 1046+59. Observations were spaced between 1 day to 3 months, with a typical single-epoch peak flux sensitivity below 0.2 \mjb near the field pointing center. We describe the observation parameters, data post-processing, and search methodology used to identify variable and transient emiss…
Rotating Radio Transients (RRATs) are a subclass of pulsars first identified in 2006 that are detected only in searches for single pulses and not through their time averaged emission. Here, we present the results of observations of 19 RRATs using the first station of the Long Wavelength Array (LWA1) at frequencies between 30 MHz and 88 MHz. The RRATs observed here were first detected in higher frequency pulsar surveys. Of the 19 RRATs observed, 2 sources were detected and their dispersion measures, periods, pulse profiles, and flux densities are reported and compared to previous higher frequen…
The progenitor systems of the class of "Ca-rich transients" is a key open issue in time domain astrophysics. These intriguing objects exhibit unusually strong calcium line emissions months after explosion, fall within an intermediate luminosity range, are often found at large projected distances from their host galaxies, and may play a vital role in enriching galaxies and the intergalactic medium. Here we present multi-wavelength observations of iPTF15eqv in NGC 3430, which exhibits a unique combination of properties that bridge those observed in Ca-rich transients and Type Ib/c supernovae. iP…
Radio observations have resulted in some of the most fundamental and exciting discoveries in time-domain astronomy. Here I demonstrate the potential for the Next Generation Very Large Array (ngVLA) to localize prompt centimeter-wavelength counterparts to the coalescing binary supermassive black holes (SMBHs) to be detected by the LISA mission. The resulting redshift measurements of the hosts of LISA-detected coalescences will populate a Hubble diagram up to the epoch of the earliest galaxies. Analysis of the host environments and the electromagnetic coalescence signatures will provide crucial …
Nearly all fast radio RRAT-type transients that are pulsars with rare pulses have been previously detected using decimetre wavelengths. We present here 34 transients detected at metre wavelengths in our daily monitoring at declinations -9o < decl. < +42o. 25 transients are new RRATs. We confirmed the detection of 7 RRATs based on our early observations. One of the 34 detected transients was determined to be a new pulsar J1326+3346. At the same time, out of 35 RRATs detected at the decimetre wavelengths and included in the studied area, only one was detected by us J1848+1518. The periods of 6 R…
A spectacular multi-wavelength transient associated with an off-axis relativistic jet
California Institute of Technology（加州理工学院）；University of California Berkeley（加州大学伯克利分校）；National Radio Astronomy Observatory (NRAO)（美国国家射电天文台）；Tel Aviv University（特拉维夫大学）；University of Tokyo（东京大学）；The Hebrew University of Jerusalem（耶路撒冷希伯来大学）；Observatories of the Carnegie Institution for Science（卡内基科学研究所天文台）
We review the status of our knowledge on supergiant fast X-ray transients (SFXTs), a new hot topic in multi wavelength studies of binaries. We discuss the mechanisms believed to power these transients and then highlight the unique contribution Swift is giving to this field, and how new technology complements and sometimes changes the view of things.
Transients powered by interaction with the circumstellar medium (CSM) are often observed in wavelengths other than optical, and multi-wavelength modelling can be important when inferring the properties of the explosion and CSM, or for distinguishing from other powering mechanisms. We develop a model calculating time dependent emission spectrum of interaction-powered transients. We solve energy equations of electron-proton plasma in the shocked SN ejecta and CSM and a radiation transfer equation out to the outer edge of the CSM, incorporating the collisional relaxation and the comptonization of…
Understanding the preferences of transient types for host galaxies with certain characteristics is key to studies of transient physics and galaxy evolution, as well as to transient identification and classification in the LSST era. Here we describe a value-added database of extragalactic transients--supernovae, tidal disruption events, gamma-ray bursts, and other rare events--and their host galaxy properties. Based on reported coordinates, redshifts, and host galaxies (if known) of events, we cross-identify their host galaxies or most likely host candidates in various value-added or survey cat…
GOPREAUX I: Open-source Code and Data to Model Multi-wavelength Emission of Extragalactic Transients using Gaussian Processes
NASA Goddard Space Flight Center（NASA戈达德太空飞行中心）；University of Maryland（马里兰大学）；Department of Astronomy, University of Virginia（弗吉尼亚大学天文学系）；Department of Physics, Lehigh University（利哈伊大学物理系）；Rutgers University–New Brunswick, Department of Physics & Astronomy（罗格斯大学新不伦瑞克校区物理与天文学系）；University of Delaware Department of Physics and Astronomy（特拉华大学物理与天文学系）；University of Delaware Joseph R. Biden, Jr. School of Public Policy and Administration（特拉华大学小约瑟夫·R·拜登公共政策与管理学院）；University of Delaware Data Science Institute（特拉华大学数据科学研究所）
We study the hydrodynamic evolution of an explosion close to the stellar surface, and give predictions for the radiation from such an event. We show that such an event will give rise to a multi-wavelength transient. We apply this model to describe a precursor burst to the peculiar supernova iPTF14hls, which occurred in 1954, sixty year before the supernova. We propose that the new generation of optical surveys might detect similar transients, and they can be used to identify supernova progenitors well before the explosion.
The engines that produce extragalactic fast radio bursts (FRBs), and the mechanism by which the emission is generated, remain unknown. Many FRB models predict prompt multi-wavelength counterparts, which can be used to refine our knowledge of these fundamentals of the FRB phenomenon. However, several previous targeted searches for prompt FRB counterparts have yielded no detections, and have additionally not reached sufficient sensitivity with respect to the predictions. In this work, we demonstrate a technique to estimate the ratio, $η$, between the energy outputs of FRB counterparts at various…
Fast Luminous Extragalactic Transients in the VLA Sky Survey: Implications for the rates of Accretion-Induced Collapse Events, Fast Blue Optical Transients and Gamma Ray Burst Afterglows
Most violent and energetic processes in our universe, including mergers of compact objects, explosions of massive stars and extreme accretion events, produce copious amounts of X-rays. X-ray follow-up is an efficient tool for identifying transients because (1) X-rays can quickly localize transients with large error circles, and (2) X-rays reveal the nature of transients that may not have unique signatures at other wavelengths. In this white paper, we identify key science questions about several extragalactic multi-messenger and multi-wavelength transients, and demonstrate how X-ray follow-up h…
The H.E.S.S. Imaging Air Cherenkov Telescope system is very well suited to perform follow-up observations of detections at other wavelengths or messengers due to its fast reaction and its comparably low energy threshold. These advantages are fully exploited via a largely automatized system reacting to alerts from various partner observatories covering all wavelengths and astrophysical messengers. In this contribution we provide an overview and recent results from H.E.S.S. programs to follow up on multi-wavelength and multi-messenger alerts. We present ToO observations searching for high-energy…
We present a Chandra observation of SN 2016hnk, a candidate Ca-rich gap transient. This observation was specifically designed to test whether or not this transient was the result of the tidal detonation of a white dwarf by an intermediate-mass black hole. Since we detect no X-ray emission 28 days after the discovery of the transient, as predicted from fall-back accretion, we rule out this model. Our upper limit of $\sim 10$ M$_\odot$ does not allow us to rule out a neutron star or stellar-mass black hole detonator due limits on the sensitivity of Chandra to soft X-rays and unconstrained variab…
Probing fundamental physics with ALMA2040 mm-wavelength observations of neutron stars
Shanghai Astronomical Observatory, CAS（中国科学院上海天文台）；Max-Planck-Institut für Radioastronomie（马克斯·普朗克射电天文研究所）；Pontificia Universidad Católica de Chile（智利天主教 Pontificia 大学）；Universit‘a di Napoli “Federico II”（那不勒斯费德里科二世大学）；State University of New York at Oswego（纽约州立大学奥斯威戈分校）；National Astronomical Research Institute of Thailand (Public Organization)（泰国国家天文研究所）；University of Michigan（密歇根大学）；Peking University（北京大学）；Institut de Radioastronomie Millimétrique (IRAM)（毫米波射电天文研究所）；Julius-Maximilians-Universität Würzburg（维尔茨堡朱利叶斯-马克西米利安大学）
In this Letter, we report the discovery of an ultraluminous fast-evolving transient in rest-frame UV wavelengths, MUSSES2020J, soon after its occurrence by using the Hyper Suprime-Cam (HSC) mounted on the 8.2 m Subaru telescope. The rise time of about 5 days with an extremely high UV peak luminosity shares similarities to a handful of fast blue optical transients whose peak luminosities are comparable with the most luminous supernovae while their timescales are significantly shorter (hereafter "fast blue ultraluminous transient," FBUT). In addition, MUSSES2020J is located near the center of a …
The last decade has seen a significant gain in both space and ground-based monitoring capabilities, producing vastly better coverage of BH X-ray binaries during their (rare) transient events. This interval included two of the three brightest X-ray outbursts ever observed, namely V404 Cyg in 2015, and MAXI J1820+070 in 2018, as well as the outburst of Swift J1357.2-0933, the first such system to show variable period optical dipping. There are now superb multi-wavelength archives of these outbursts, both photometric and spectroscopic, that show substantial outflows in the form of jets and disc w…
I find that a 0.1-1Mo outflowing equatorial dusty disk (torus) that the binary system progenitor of an intermediate luminosity optical transient (ILOT) ejects several years to several months before and during the outburst can reduce the total emission to an equatorial observer by two orders of magnitude and shifts the emission to wavelengths of mainly >10mum. This is termed a type II ILOT (ILOT II). To reach this conclusion I use calculations of type II active galactic nuclei and apply them to the equatorial ejecta (disk/torus) of ILOTs II. This reduction in emission can last for tens of years…
An examination of late-time, optical spectra of type Ia supernovae revealed surprisingly narrow absorption features which only become visible a few months after maximum light. These features, most clearly seen in the late-time spectra of the bright, recent type Ia supernovae ASASSN-14lp and SN 2017bzc, appear as narrow absorptions at ~4840 A, ~5000 A, and as a sharp inflection at ~4760 A on the red side of the prominent late-time 4700 A feature. A survey of on-line archival data revealed similar features present in the spectra of ten other normal and 91T-like SNe Ia, including SN 2011fe. Unlik…
The Cherenkov Telescope Array (CTA) is a next generation ground-based very-high-energy gamma-ray observatory that will allow for observations in the >10 GeV range with unprecedented photon statistics and sensitivity. This will enable the investigation of the yet-marginally explored physics of short-time-scale transient events. CTA will thus become an invaluable instrument for the study of the physics of the most extreme and violent objects and their interactions with the surrounding environment. The CTA Transient program includes follow-up observations of a wide range of multi-wavelength and m…
The Cherenkov Telescope Array (CTA) is the next generation high-energy gamma-ray observatory. It will improve the sensitivity of current instruments up to an order of magnitude, while providing energy coverage for photons from 20 GeV to at least 300 TeV to reach high redshifts and extreme accelerators and will give access to the shortest time-scale phenomena. CTA is thus a uniquely powerful instrument for the exploration of the violent and variable universe. The ability to probe short timescales at the highest energies will allow CTA to explore the connection between accretion and ejection phe…
We observed the periodic radio transient GLEAM-X J162759.5-523504.3 (GLEAM-X J1627) using the Chandra X-ray Observatory for about 30-ks on January 22-23, 2022, simultaneously with radio observations from MWA, MeerKAT and ATCA. Its radio emission and 18-min periodicity led the source to be tentatively interpreted as an extreme magnetar or a peculiar highly magnetic white dwarf. The source was not detected in the 0.3-8 keV energy range with a 3-sigma upper-limit on the count rate of 3x10^{-4} counts/s. No radio emission was detected during our X-ray observations either. Furthermore, we studied t…
We present results from the first multi-epoch X-ray/IR fast-photometry campaign on the black-hole transient GX 339--4, during its 2015 outburst decay. We studied the evolution of the power spectral densities finding strong differences between the two bands. The X-ray power spectral density follows standard patterns of evolution, plausibly reflecting changes in the accretion flow. The IR power spectral density instead evolves very slowly, with a high-frequency break consistent with remaining constant at $0.63 \pm 0.03$ Hz throughout the campaign. We discuss this result in the context of the cur…
A review is given on the various aspects of gamma-ray burst afterglow observations, and the inferences derived from the data. After a short history of optical transient search and the BeppoSAX discoveries, the main topics included are prompt multiwavelength emission, dark bursts, spectral lines line and continuum variability, the early light curve behaviour, jet breaks, X-ray flares, late afterglow features, polarization, and orphan afterglows.
We investigate the gamma-ray and X-ray emission from the transient gamma-ray source Fermi J0035+6131, which was discovered with the Fermi Large Area Telescope (LAT) near the Galactic plane at $b=1.3^\circ$, and we discuss potential multi-wavelength counterparts of the gamma-ray source. Our analysis of over 9 years of Fermi LAT data revealed two flaring events lasting 10-30 hr during which the gamma-ray flux increased by a factor of >300 compared to the long-term average. We also analyzed X-ray data obtained with XMM-Newton and Swift and identified several sources with a hard X-ray spectrum ins…
We report on the detection and follow-up multi-wavelength observations of the new X-ray transient MAXI J1807+132 with the MAXI/GSC, Swift, and ground-based optical telescopes. The source was first recognized with the MAXI/GSC on 2017 March 13. About a week later, it reached the maximum intensity ($\sim$10 mCrab in 2-10 keV), and then gradually faded in $\sim$10 days by more than one order of magnitude. Time-averaged Swift/XRT spectra in the decaying phase can be described by a blackbody with a relatively low temperature (0.1-0.5 keV), plus a hard power-law component with a photon index of $\si…
The ability to quickly detect transient sources in optical images and trigger multi-wavelength follow up is key for the discovery of fast transients. These include events rare and difficult to detect such as kilonovae, supernova shock breakout, and "orphan" Gamma-ray Burst afterglows. We present the Mary pipeline, a (mostly) automated tool to discover transients during high-cadenced observations with the Dark Energy Camera (DECam) at CTIO. The observations are part of the "Deeper Wider Faster" program, a multi-facility, multi-wavelength program designed to discover fast transients, including c…
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.
Stellar tidal disruption events (TDEs) are typically discovered by transient emission due to accretion or shocks of the stellar debris. Yet this luminous flare can be reprocessed by gas or dust that inhabits a galactic nucleus, resulting in multiple reverberation signals. Nuclear dust heated by the TDE will lead to an echo at infrared wavelengths (1-10 $μ$m) and transient coronal lines in optical spectra of TDEs trace reverberation by gas that orbits the black hole. Both of these signal have been detected, here we review this rapidly developing field. We also review the results that have been …
Constraints on Late-Time Flaring from Luminous Fast Blue Optical Transients using the Transiting Exoplanet Survey Satellite and the Zwicky Transient Facility
Cornell University（康奈尔大学）；Texas Tech University（德克萨斯理工大学）；Weizmann Institute of Science（魏茨曼科学研究所）；Liverpool John Moores University（利物浦约翰摩尔斯大学）；California Institute of Technology（加州理工学院）；University of Minnesota（明尼苏达大学）
(abridged) In the hunt for rare time-domain events, confusing exotic extragalactic phenomena with more common Galactic foreground events is an important consideration. We show how observations from multiple wavebands, in this case optical and X-ray observations, can be used to facilitate the distinction between the two. We discovered an extremely bright and rapid transient event in optical observations of M31 with the intermediate Palomar Transient Factory (iPTF). The persistent optical counterpart of this transient was previously thought to be a variable star in M31 without any dramatic flux …
Cygnus X-3 is a unique microquasar which shows X-ray state changes, strong radio emission, and relativistic jets. It is also an unusual X-ray binary with the mass-donating companion being a high mass star Wolf-Rayet but the orbital modulation (as inferred from X-ray emission) is only 4.8 hours, a value more common in low-mass systems. It has recently been shown by AGILE and Fermi that Cygnus X-3, is a transient gamma-ray source (>100 MeV). To understand the environment, nature, and behavior of Cygnus X-3 multi-wavelength observations are necessary. In this proceedings we present the results ac…
We study linear transient dynamics in a thin Keplerian disc employing a method based on variational formulation of optimisation problem. It is shown that in a shearing sheet approximation due to a prominent excitation of density waves by vortices the most rapidly growing shearing harmonic has azimuthal wavelength, $λ_y$, of order of the disc thickness, $H$, and its initial shape is always nearly identical to a vortex having the same potential vorticity. Also, in the limit $λ_y\gg H$ the optimal growth $G\propto (Ω/κ)^4$, where $Ω$ and $κ$ stand for local rotational and epicyclic frequencies, r…
The large majority of high energy sources detected with Fermi-LAT are blazars, which are known to be very variable sources. High cadence long-term monitoring simultaneously at different wavelengths being prohibitive, the study of their transient activities can help shedding light on our understanding of these objects. The early detection of such potentially fast transient events is the key for triggering follow-up observations at other wavelengths. A Python tool, FLaapLUC, built on top of the Science Tools provided by the Fermi Science Support Center and the Fermi-LAT collaboration, has been d…
Forty years elapsed since the optical identification of the first isolated neutron star (INS), the Crab pulsar. 25 INSs have been now identified in the optical (O), near-ultraviolet (nUV), or near-infrared (nIR), hereafter UVOIR, including rotation-powered pulsars (RPPs), magnetars, and X-ray-dim INSs (XDINSs), while deep investigations have been carried out for compact central objects (CCOs), Rotating RAdio transients (RRATs), and high-magnetic field radio pulsars (HBRPs). In this review I describe the status of UVOIR observations of INSs, their emission properties, and I present recent resul…
Obscuring winds driven away from active supermassive black holes are rarely seen due to their transient nature. They have been observed with multi-wavelength observations in a few Seyfert 1 galaxies and one broad absorption line radio-quiet quasar so far. An X-ray obscuration event in MR 2251-178 was caught in late 2020, which triggered multi-wavelength (NIR to X-ray) observations targeting this radio-quiet quasar. In the X-ray band, the obscurer leads to a flux drop in the soft X-ray band from late 2020 to early 2021. X-ray obscuration events might have a quasi-period of two decades consideri…
Discovery of a Supernova Following the Einstein Probe Transient EP250302a at z = 1.131
Carnegie Mellon University（卡内基梅隆大学）；Ludwig-Maximilians-Universität München（慕尼黑大学）；University of North Carolina at Chapel Hill（北卡罗来纳大学教堂山分校）；University of Sydney（悉尼大学）
We report results of the spectral and timing analysis of the Be/X-ray pulsar SXP 4.78 using the data obtained during its recent outburst with NuSTAR, Swift, Chandra and NICER observatories. Using an overall evolution of the system luminosity, spectral analysis and variability power spectrum we obtain constraints on the neutron star magnetic field strength. We found a rapid evolution of the variability power spectrum during the rise of the outburst, and absence of the significant changes during the flux decay. Several low frequency quasi-periodic oscillation features are found to emerge on the …
We revisit the paradigm of the dependency of jet power on black hole spin in accreting black hole systems. In a previous paper we showed that the luminosity of compact jets continuously launched due to accretion onto black holes in X-ray binaries (analogous to those that dominate the kinetic feedback from AGN) do not appear to correlate with reported black hole spin measurements. It is therefore unclear whether extraction of the black hole spin energy is the main driver powering compact jets from accreting black holes. Occasionally, black hole X-ray binaries produce discrete, transient (ballis…
We report the discovery of a luminous late-time source at the position of the fast blue optical transient (FBOT) AT2018cow on images taken by the Hubble Space Telescope (HST) at 714 d and 1136 d after its explosion. This source is detected at both UV and optical wavelengths and has prominent H$α$ emission. It has a very stable brightness between the two epochs and a very blue spectral energy distribution (SED) consistent with $f_λ$ $\propto$ $λ^{-4.1 \pm 0.1}$, i.e. the Rayleigh-Jeans tail of a hot blackbody with a very high temperature of log($T$/K) $>$ 4.6 and luminosity of log($L$/$L_\odot$…
This paper is an extended summary of the talk I gave at IAU Symposium "New Horizons in Time Domain Astronomy" (Oxford, 2011). I first review the history of transients (which is intimately related to the advent of wide-field telescopic imaging; I then summarize wide field imaging projects. The motivations that led to the design of the Palomar Transient Factory (PTF) followed by a summary of the astronomical returns from PTF. I review the lessons learnt from PTF. I conclude that, during this decade, optical transient searches will continue to flourish and may even accelerate as surveys at other …
The Einstein Equivalence Principle (EEP) can be probed with astrophysical sources emitting simultaneously different types of neutral particles, or particles with varying energies, by testing their time of flight through the same gravitational field. Here we use the time delays between correlated photons from cosmological transients to constrain the accuracy of the EEP. We take data from two gamma-ray bursts as an example, and use, as a lower limit to the theoretical time delays between different energies, delays arising from only the gravitational field of our own galaxy. We then show that the…
This paper presents a search for radio transients at a frequency of 73.8 MHz (4 m wavelength) using the all-sky imaging capabilities of the Long Wavelength Demonstrator Array (LWDA). The LWDA was a 16-dipole phased array telescope, located on the site of the Very Large Array in New Mexico. The field of view of the individual dipoles was essentially the entire sky, and the number of dipoles was sufficiently small that a simple software correlator could be used to make all-sky images. From 2006 October to 2007 February, we conducted an all-sky transient search program, acquiring a total of 106 h…
High-angular-resolution cosmic microwave background experiments provide a unique opportunity to conduct a survey of time-variable sources at millimeter wavelengths, a population which has primarily been understood through follow-up measurements of detections in other bands. Here we report the first results of an astronomical transient survey with the South Pole Telescope (SPT) using the SPT-3G camera to observe 1500 square degrees of the southern sky. The observations took place from March to November 2020 in three bands centered at 95, 150, and 220 GHz. This survey yielded the detection of fi…
