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1. Heavy element production in a compact object merger observed by JWST

Author

Levan, Andrew, Gompertz, Benjamin P., Salafia, Om Sharan, Bulla, Mattia, Burns, Eric, Hotokezaka, Kenta, Izzo, Luca, Lamb, Gavin P., Malesani, Daniele B., Oates, Samantha R., Ravasio, Maria Edvige, Rouco Escorial, Alicia, Schneider, Benjamin, Sarin, Nikhil, Schulze, Steve, Tanvir, Nial R., Ackley, Kendall, Anderson, Gemma, Brammer, Gabriel B., Christensen, Lise, Dhillon, Vikram S., Evans, Phil A., Fausnaugh, Michael, Fong, Wen-fai, Fruchter, Andrew S., Fryer, Chris, Fynbo, Johan P. U., Gaspari, Nicola, Heintz, Kasper E., Hjorth, Jens, Kennea, Jamie A., Kennedy, Mark R., Laskar, Tanmoy, Leloudas, Giorgos, Mandel, Ilya, Martin-Carrillo, Antonio, Metzger, Brian D., Nicholl, Matt, Nugent, Anya, Palmerio, Jesse T., Pugliese, Giovanna, Rastinejad, Jillian, Rhodes, Lauren, Rossi, Andrea, Saccardi, Andrea, Smartt, Stephen J., Stevance, Heloise F., Tohuvavohu, Aaron, van der Horst, Alexander, Vergani, Susanna D., Watson, Darach, Barclay, Thomas, Bhirombhakdi, Kornpob, Breedt, Elmé, Breeveld, Alice A., Brown, Alexander J., Campana, Sergio, Chrimes, Ashley A., D’Avanzo, Paolo, D’Elia, Valerio, De Pasquale, Massimiliano, Dyer, Martin J., Galloway, Duncan K., Garbutt, James A., Green, Matthew J., Hartmann, Dieter H., Jakobsson, Páll, Kerry, Paul, Kouveliotou, Chryssa, Langeroodi, Danial, Le Floc’h, Emeric, Leung, James K., Littlefair, Stuart P., Munday, James, O’Brien, Paul, Parsons, Steven G., Pelisoli, Ingrid, Sahman, David I., Salvaterra, Ruben, Sbarufatti, Boris, Steeghs, Danny, Tagliaferri, Gianpiero, Thöne, Christina C., de Ugarte Postigo, Antonio, Kann, David Alexander, Levan, Andrew, Gompertz, Benjamin P., Salafia, Om Sharan, Bulla, Mattia, Burns, Eric, Hotokezaka, Kenta, Izzo, Luca, Lamb, Gavin P., Malesani, Daniele B., Oates, Samantha R., Ravasio, Maria Edvige, Rouco Escorial, Alicia, Schneider, Benjamin, Sarin, Nikhil, Schulze, Steve, Tanvir, Nial R., Ackley, Kendall, Anderson, Gemma, Brammer, Gabriel B., Christensen, Lise, Dhillon, Vikram S., Evans, Phil A., Fausnaugh, Michael, Fong, Wen-fai, Fruchter, Andrew S., Fryer, Chris, Fynbo, Johan P. U., Gaspari, Nicola, Heintz, Kasper E., Hjorth, Jens, Kennea, Jamie A., Kennedy, Mark R., Laskar, Tanmoy, Leloudas, Giorgos, Mandel, Ilya, Martin-Carrillo, Antonio, Metzger, Brian D., Nicholl, Matt, Nugent, Anya, Palmerio, Jesse T., Pugliese, Giovanna, Rastinejad, Jillian, Rhodes, Lauren, Rossi, Andrea, Saccardi, Andrea, Smartt, Stephen J., Stevance, Heloise F., Tohuvavohu, Aaron, van der Horst, Alexander, Vergani, Susanna D., Watson, Darach, Barclay, Thomas, Bhirombhakdi, Kornpob, Breedt, Elmé, Breeveld, Alice A., Brown, Alexander J., Campana, Sergio, Chrimes, Ashley A., D’Avanzo, Paolo, D’Elia, Valerio, De Pasquale, Massimiliano, Dyer, Martin J., Galloway, Duncan K., Garbutt, James A., Green, Matthew J., Hartmann, Dieter H., Jakobsson, Páll, Kerry, Paul, Kouveliotou, Chryssa, Langeroodi, Danial, Le Floc’h, Emeric, Leung, James K., Littlefair, Stuart P., Munday, James, O’Brien, Paul, Parsons, Steven G., Pelisoli, Ingrid, Sahman, David I., Salvaterra, Ruben, Sbarufatti, Boris, Steeghs, Danny, Tagliaferri, Gianpiero, Thöne, Christina C., de Ugarte Postigo, Antonio, and Kann, David Alexander

Abstract

The mergers of binary compact objects such as neutron stars and black holes are of central interest to several areas of astrophysics, including as the progenitors of gamma-ray bursts (GRBs)1, sources of high-frequency gravitational waves (GW)2 and likely production sites for heavy element nucleosynthesis via rapid neutron capture (the r-process)3. Here we present observations of the exceptionally bright gamma-ray burst GRB 230307A. We show that GRB 230307A belongs to the class of long-duration gamma-ray bursts associated with compact object mergers4–6, and contains a kilonova similar to AT2017gfo, associated with the gravitational-wave merger GW1708177–12. We obtained James Webb Space Telescope mid-infrared (mid-IR) imaging and spectroscopy 29 and 61 days after the burst. The spectroscopy shows an emission line at 2.15 microns which we interpret as tellurium (atomic mass A=130), and a very red source, emitting most of its light in the mid-IR due to the production of lanthanides. These observations demonstrate that nucleosynthesis in GRBs can create r-process elements across a broad atomic mass range and play a central role in heavy element nucleosynthesis across the Universe.

Published
2024

2. Heavy element production in a compact object merger observed by JWST

Author

Levan, Andrew, Gompertz, Benjamin P., Salafia, Om Sharan, Bulla, Mattia, Burns, Eric, Hotokezaka, Kenta, Izzo, Luca, Lamb, Gavin P., Malesani, Daniele B., Oates, Samantha R., Ravasio, Maria Edvige, Escorial, Alicia Rouco, Schneider, Benjamin, Sarin, Nikhil, Schulze, Steve, Tanvir, Nial R., Ackley, Kendall, Anderson, Gemma, Brammer, Gabriel B., Christensen, Lise, Dhillon, Vikram S., Evans, Phil A., Fausnaugh, Michael, Fong, Wen-fai, Fruchter, Andrew S., Fryer, Chris, Fynbo, Johan P. U., Gaspari, Nicola, Heintz, Kasper E., Hjorth, Jens, Kennea, Jamie A., Kennedy, Mark R., Laskar, Tanmoy, Leloudas, Giorgos, Mandel, Ilya, Martin-Carrillo, Antonio, Metzger, Brian D., Nicholl, Matt, Nugent, Anya, Palmerio, Jesse T., Pugliese, Giovanna, Rastinejad, Jillian, Rhodes, Lauren, Saccardi, Andrea, Smartt, Stephen J., Stevance, Heloise F., Tohuvavohu, Aaron, Horst, Alexander van der, Vergani, Susanna D., Watson, Darach, Barclay, Thomas, Bhirombhakdi, Kornpob, Breedt, Elmé, Breeveld, Alice A., Brown, Alexander J., Campana, Sergio, Chrimes, Ashley A., D’Avanzo, Paolo, D’Elia, Valerio, Pasquale, Massimiliano De, Dyer, Martin J., Galloway, Duncan K., Garbutt, James A., Hartmann, Dieter H., Jakobsson, Páll, Kerry, Paul, Kouveliotou, Chryssa, Langeroodi, Danial, Floc’h, Emeric Le, Leung, James K., Littlefair, Stuart P., Munday, James, O’Brien, Paul, Parsons, Steven G., Pelisoli, Ingrid, Sahman, David I., Salvaterra, Ruben, Sbarufatti, Boris, Steeghs, Danny, Tagliaferri, Gianpiero, Thöne, Christina C., Postigo, Antonio de Ugarte, Kann, David Alexander, Levan, Andrew, Gompertz, Benjamin P., Salafia, Om Sharan, Bulla, Mattia, Burns, Eric, Hotokezaka, Kenta, Izzo, Luca, Lamb, Gavin P., Malesani, Daniele B., Oates, Samantha R., Ravasio, Maria Edvige, Escorial, Alicia Rouco, Schneider, Benjamin, Sarin, Nikhil, Schulze, Steve, Tanvir, Nial R., Ackley, Kendall, Anderson, Gemma, Brammer, Gabriel B., Christensen, Lise, Dhillon, Vikram S., Evans, Phil A., Fausnaugh, Michael, Fong, Wen-fai, Fruchter, Andrew S., Fryer, Chris, Fynbo, Johan P. U., Gaspari, Nicola, Heintz, Kasper E., Hjorth, Jens, Kennea, Jamie A., Kennedy, Mark R., Laskar, Tanmoy, Leloudas, Giorgos, Mandel, Ilya, Martin-Carrillo, Antonio, Metzger, Brian D., Nicholl, Matt, Nugent, Anya, Palmerio, Jesse T., Pugliese, Giovanna, Rastinejad, Jillian, Rhodes, Lauren, Saccardi, Andrea, Smartt, Stephen J., Stevance, Heloise F., Tohuvavohu, Aaron, Horst, Alexander van der, Vergani, Susanna D., Watson, Darach, Barclay, Thomas, Bhirombhakdi, Kornpob, Breedt, Elmé, Breeveld, Alice A., Brown, Alexander J., Campana, Sergio, Chrimes, Ashley A., D’Avanzo, Paolo, D’Elia, Valerio, Pasquale, Massimiliano De, Dyer, Martin J., Galloway, Duncan K., Garbutt, James A., Hartmann, Dieter H., Jakobsson, Páll, Kerry, Paul, Kouveliotou, Chryssa, Langeroodi, Danial, Floc’h, Emeric Le, Leung, James K., Littlefair, Stuart P., Munday, James, O’Brien, Paul, Parsons, Steven G., Pelisoli, Ingrid, Sahman, David I., Salvaterra, Ruben, Sbarufatti, Boris, Steeghs, Danny, Tagliaferri, Gianpiero, Thöne, Christina C., Postigo, Antonio de Ugarte, and Kann, David Alexander

Abstract

The mergers of binary compact objects such as neutron stars and black holes are of central interest to several areas of astrophysics, including as the progenitors of gamma-ray bursts (GRBs) 1, sources of high-frequency gravitational waves (GWs) 2 and likely production sites for heavy-element nucleosynthesis by means of rapid neutron capture (the r-process) 3. Here we present observations of the exceptionally bright GRB 230307A. We show that GRB 230307A belongs to the class of long-duration GRBs associated with compact object mergers 4–6 and contains a kilonova similar to AT2017gfo, associated with the GW merger GW170817 (refs. 7–12). We obtained James Webb Space Telescope (JWST) mid-infrared imaging and spectroscopy 29 and 61 days after the burst. The spectroscopy shows an emission line at 2.15 microns, which we interpret as tellurium (atomic mass A = 130) and a very red source, emitting most of its light in the mid-infrared owing to the production of lanthanides. These observations demonstrate that nucleosynthesis in GRBs can create r-process elements across a broad atomic mass range and play a central role in heavy-element nucleosynthesis across the Universe.

Published
2024

3. Heavy-element production in a compact object merger observed by JWST

Author

Levan, Andrew J., Gompertz, Benjamin P., Salafia, Om Sharan, Bulla, Mattia, Burns, Eric, Hotokezaka, Kenta, Izzo, Luca, Lamb, Gavin P., Malesani, Daniele B., Oates, Samantha R., Ravasio, Maria Edvige, Rouco Escorial, Alicia, Schneider, Benjamin, Sarin, Nikhil, Schulze, Steve, Tanvir, Nial R., Ackley, Kendall, Anderson, Gemma, Brammer, Gabriel B., Christensen, Lise, Dhillon, Vikram S., Evans, Phil A., Fausnaugh, Michael, Fong, Wen-fai, Fruchter, Andrew S., Fryer, Chris, Fynbo, Johan P. U., Gaspari, Nicola, Heintz, Kasper E., Hjorth, Jens, Kennea, Jamie A., Kennedy, Mark R., Laskar, Tanmoy, Leloudas, Giorgos, Mandel, Ilya, Martin-carrillo, Antonio, Metzger, Brian D., Nicholl, Matt, Nugent, Anya, Palmerio, Jesse T., Pugliese, Giovanna, Rastinejad, Jillian, Rhodes, Lauren, Rossi, Andrea, Saccardi, Andrea, Smartt, Stephen J., Stevance, Heloise F., Tohuvavohu, Aaron, Van Der Horst, Alexander, Vergani, Susanna D., Watson, Darach, Barclay, Thomas, Bhirombhakdi, Kornpob, Breedt, Elmé, Breeveld, Alice A., Brown, Alexander J., Campana, Sergio, Chrimes, Ashley A., D’avanzo, Paolo, D’elia, Valerio, De Pasquale, Massimiliano, Dyer, Martin J., Galloway, Duncan K., Garbutt, James A., Green, Matthew J., Hartmann, Dieter H., Jakobsson, Páll, Kerry, Paul, Kouveliotou, Chryssa, Langeroodi, Danial, Le Floc’h, Emeric, Leung, James K., Littlefair, Stuart P., Munday, James, O’brien, Paul, Parsons, Steven G., Pelisoli, Ingrid, Sahman, David I., Salvaterra, Ruben, Sbarufatti, Boris, Steeghs, Danny, Tagliaferri, Gianpiero, Thöne, Christina C., De Ugarte Postigo, Antonio, Kann, David Alexander, Levan, Andrew J., Gompertz, Benjamin P., Salafia, Om Sharan, Bulla, Mattia, Burns, Eric, Hotokezaka, Kenta, Izzo, Luca, Lamb, Gavin P., Malesani, Daniele B., Oates, Samantha R., Ravasio, Maria Edvige, Rouco Escorial, Alicia, Schneider, Benjamin, Sarin, Nikhil, Schulze, Steve, Tanvir, Nial R., Ackley, Kendall, Anderson, Gemma, Brammer, Gabriel B., Christensen, Lise, Dhillon, Vikram S., Evans, Phil A., Fausnaugh, Michael, Fong, Wen-fai, Fruchter, Andrew S., Fryer, Chris, Fynbo, Johan P. U., Gaspari, Nicola, Heintz, Kasper E., Hjorth, Jens, Kennea, Jamie A., Kennedy, Mark R., Laskar, Tanmoy, Leloudas, Giorgos, Mandel, Ilya, Martin-carrillo, Antonio, Metzger, Brian D., Nicholl, Matt, Nugent, Anya, Palmerio, Jesse T., Pugliese, Giovanna, Rastinejad, Jillian, Rhodes, Lauren, Rossi, Andrea, Saccardi, Andrea, Smartt, Stephen J., Stevance, Heloise F., Tohuvavohu, Aaron, Van Der Horst, Alexander, Vergani, Susanna D., Watson, Darach, Barclay, Thomas, Bhirombhakdi, Kornpob, Breedt, Elmé, Breeveld, Alice A., Brown, Alexander J., Campana, Sergio, Chrimes, Ashley A., D’avanzo, Paolo, D’elia, Valerio, De Pasquale, Massimiliano, Dyer, Martin J., Galloway, Duncan K., Garbutt, James A., Green, Matthew J., Hartmann, Dieter H., Jakobsson, Páll, Kerry, Paul, Kouveliotou, Chryssa, Langeroodi, Danial, Le Floc’h, Emeric, Leung, James K., Littlefair, Stuart P., Munday, James, O’brien, Paul, Parsons, Steven G., Pelisoli, Ingrid, Sahman, David I., Salvaterra, Ruben, Sbarufatti, Boris, Steeghs, Danny, Tagliaferri, Gianpiero, Thöne, Christina C., De Ugarte Postigo, Antonio, and Kann, David Alexander

Published
2024

4. Heavy-element production in a compact object merger observed by JWST

Author

Levan, Andrew J., Gompertz, Benjamin P., Salafia, Om Sharan, Bulla, Mattia, Burns, Eric, Hotokezaka, Kenta, Izzo, Luca, Lamb, Gavin P., Malesani, Daniele B., Oates, Samantha R., Ravasio, Maria Edvige, Rouco Escorial, Alicia, Schneider, Benjamin, Sarin, Nikhil, Schulze, Steve, Tanvir, Nial R., Ackley, Kendall, Anderson, Gemma, Brammer, Gabriel B., Christensen, Lise, Dhillon, Vikram S., Evans, Phil A., Fausnaugh, Michael, Fong, Wen-fai, Fruchter, Andrew S., Fryer, Chris, Fynbo, Johan P. U., Gaspari, Nicola, Heintz, Kasper E., Hjorth, Jens, Kennea, Jamie A., Kennedy, Mark R., Laskar, Tanmoy, Leloudas, Giorgos, Mandel, Ilya, Martin-carrillo, Antonio, Metzger, Brian D., Nicholl, Matt, Nugent, Anya, Palmerio, Jesse T., Pugliese, Giovanna, Rastinejad, Jillian, Rhodes, Lauren, Rossi, Andrea, Saccardi, Andrea, Smartt, Stephen J., Stevance, Heloise F., Tohuvavohu, Aaron, Van Der Horst, Alexander, Vergani, Susanna D., Watson, Darach, Barclay, Thomas, Bhirombhakdi, Kornpob, Breedt, Elmé, Breeveld, Alice A., Brown, Alexander J., Campana, Sergio, Chrimes, Ashley A., D’avanzo, Paolo, D’elia, Valerio, De Pasquale, Massimiliano, Dyer, Martin J., Galloway, Duncan K., Garbutt, James A., Green, Matthew J., Hartmann, Dieter H., Jakobsson, Páll, Kerry, Paul, Kouveliotou, Chryssa, Langeroodi, Danial, Le Floc’h, Emeric, Leung, James K., Littlefair, Stuart P., Munday, James, O’brien, Paul, Parsons, Steven G., Pelisoli, Ingrid, Sahman, David I., Salvaterra, Ruben, Sbarufatti, Boris, Steeghs, Danny, Tagliaferri, Gianpiero, Thöne, Christina C., De Ugarte Postigo, Antonio, Kann, David Alexander, Levan, Andrew J., Gompertz, Benjamin P., Salafia, Om Sharan, Bulla, Mattia, Burns, Eric, Hotokezaka, Kenta, Izzo, Luca, Lamb, Gavin P., Malesani, Daniele B., Oates, Samantha R., Ravasio, Maria Edvige, Rouco Escorial, Alicia, Schneider, Benjamin, Sarin, Nikhil, Schulze, Steve, Tanvir, Nial R., Ackley, Kendall, Anderson, Gemma, Brammer, Gabriel B., Christensen, Lise, Dhillon, Vikram S., Evans, Phil A., Fausnaugh, Michael, Fong, Wen-fai, Fruchter, Andrew S., Fryer, Chris, Fynbo, Johan P. U., Gaspari, Nicola, Heintz, Kasper E., Hjorth, Jens, Kennea, Jamie A., Kennedy, Mark R., Laskar, Tanmoy, Leloudas, Giorgos, Mandel, Ilya, Martin-carrillo, Antonio, Metzger, Brian D., Nicholl, Matt, Nugent, Anya, Palmerio, Jesse T., Pugliese, Giovanna, Rastinejad, Jillian, Rhodes, Lauren, Rossi, Andrea, Saccardi, Andrea, Smartt, Stephen J., Stevance, Heloise F., Tohuvavohu, Aaron, Van Der Horst, Alexander, Vergani, Susanna D., Watson, Darach, Barclay, Thomas, Bhirombhakdi, Kornpob, Breedt, Elmé, Breeveld, Alice A., Brown, Alexander J., Campana, Sergio, Chrimes, Ashley A., D’avanzo, Paolo, D’elia, Valerio, De Pasquale, Massimiliano, Dyer, Martin J., Galloway, Duncan K., Garbutt, James A., Green, Matthew J., Hartmann, Dieter H., Jakobsson, Páll, Kerry, Paul, Kouveliotou, Chryssa, Langeroodi, Danial, Le Floc’h, Emeric, Leung, James K., Littlefair, Stuart P., Munday, James, O’brien, Paul, Parsons, Steven G., Pelisoli, Ingrid, Sahman, David I., Salvaterra, Ruben, Sbarufatti, Boris, Steeghs, Danny, Tagliaferri, Gianpiero, Thöne, Christina C., De Ugarte Postigo, Antonio, and Kann, David Alexander

Published
2024

5. Photometric follow-up of 43 new eclipsing white dwarf plus main-sequence binaries from the ZTF survey

Author

Brown, Alex J., Parsons, Steven G., van Roestel, Jan, Rebassa-Mansergas, Alberto, Breedt, Elmé, Dhillon, Vik S., Dyer, Martin J., Green, Matthew J., Kerry, Paul, Littlefair, Stuart P., Marsh, Thomas R., Munday, James, Pelisoli, Ingrid, Sahman, David I., Wild, James F., Brown, Alex J., Parsons, Steven G., van Roestel, Jan, Rebassa-Mansergas, Alberto, Breedt, Elmé, Dhillon, Vik S., Dyer, Martin J., Green, Matthew J., Kerry, Paul, Littlefair, Stuart P., Marsh, Thomas R., Munday, James, Pelisoli, Ingrid, Sahman, David I., and Wild, James F.

Abstract

Wide-field time-domain photometric sky surveys are now finding hundreds of eclipsing white dwarf plus M dwarf binaries, a population encompassing a wealth of information and potential insight into white dwarf and close binary astrophysics. Precise follow-up observations are essential in order to fully constrain these systems and capitalise on the power of this sample. We present the first results from our program of high-speed, multi-band photometric follow-up. We develop a method to measure temperatures, (model-dependent) masses, and radii for both components from the eclipse photometry alone and characterize 34 white dwarf binaries, finding general agreement with independent estimates using an alternative approach while achieving around a factor of two increase in parameter precision. In addition to these parameter estimates, we discover a number of interesting systems -- finding four with sub-stellar secondaries, doubling the number of eclipsing examples, and at least six where we find the white dwarf to be strongly magnetic, making these the first eclipsing examples of such systems and key to investigating the mechanism of magnetic field generation in white dwarfs. We also discover the first two pulsating white dwarfs in detached and eclipsing post-common-envelope binaries -- one with a low-mass, likely helium core, and one with a relatively high mass, towards the upper end of the known sample of ZZ Cetis. Our results demonstrate the power of eclipse photometry, not only as a method of characterising the population, but as a way of discovering important systems that would have otherwise been missed by spectroscopic follow-up., Comment: 12 pages with a 5 page appendix and 14 figures. Accepted for publication in MNRAS

Published
2023
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6. TIC 378898110: A Bright, Short-Period AM CVn Binary in TESS

Author

Green, Matthew J., Hermes, J. J., Barlow, Brad N., Marsh, T. R., Pelisoli, Ingrid, Gänsicke, Boris T., Kaiser, Ben C., Romero, Alejandra, Amaral, Larissa Antunes, Corcoran, Kyle, Grupe, Dirk, Kennedy, Mark R., Kepler, S. O., Munday, James, Ashley, R. P., Baran, Andrzej S., Breedt, Elmé, Brown, Alex J., Dhillon, V. S., Dyer, Martin J., Kerry, Paul, King, George W., Littlefair, S. P., Parsons, Steven G., Sahman, David I., Green, Matthew J., Hermes, J. J., Barlow, Brad N., Marsh, T. R., Pelisoli, Ingrid, Gänsicke, Boris T., Kaiser, Ben C., Romero, Alejandra, Amaral, Larissa Antunes, Corcoran, Kyle, Grupe, Dirk, Kennedy, Mark R., Kepler, S. O., Munday, James, Ashley, R. P., Baran, Andrzej S., Breedt, Elmé, Brown, Alex J., Dhillon, V. S., Dyer, Martin J., Kerry, Paul, King, George W., Littlefair, S. P., Parsons, Steven G., and Sahman, David I.

Abstract

AM CVn-type systems are ultracompact, helium-accreting binary systems which are evolutionarily linked to the progenitors of thermonuclear supernovae and are expected to be strong Galactic sources of gravitational waves detectable to upcoming space-based interferometers. AM CVn binaries with orbital periods $\lesssim$ 20--23 min exist in a constant high state with a permanently ionised accretion disc. We present the discovery of TIC 378898110, a bright ($G=14.3$ mag), nearby ($309.3 \pm 1.8$ pc), high-state AM CVn binary discovered in TESS two-minute-cadence photometry. At optical wavelengths this is the third-brightest AM CVn binary known. The photometry of the system shows a 23.07172(6) min periodicity, which is likely to be the `superhump' period and implies an orbital period in the range 22--23 min. There is no detectable spectroscopic variability. The system underwent an unusual, year-long brightening event during which the dominant photometric period changed to a shorter period (constrained to $20.5 \pm 2.0$ min), which we suggest may be evidence for the onset of disc-edge eclipses. The estimated mass transfer rate, $\log (\dot{M} / \mathrm{M_\odot} \mathrm{yr}^{-1}) = -6.8 \pm 1.0$, is unusually high and may suggest a high-mass or thermally inflated donor. The binary is detected as an X-ray source, with a flux of $9.2 ^{+4.2}_{-1.8} \times 10^{-13}$ erg cm$^{-2}$ s$^{-1}$ in the 0.3--10 keV range. TIC 378898110 is the shortest-period binary system discovered with TESS, and its large predicted gravitational-wave amplitude makes it a compelling verification binary for future space-based gravitational wave detectors., Comment: 15 pages, 14 figures. Accepted to MNRAS

Published
2023

7. Photometric follow-up of 43 new eclipsing white dwarf plus main-sequence binaries from the ZTF survey

Author

Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. GAA - Grup d'Astronomia i Astrofísica, Brown, Alexander James, Parsons, Steven G., van Roestel, Jan, Rebassa Mansergas, Alberto, Breedt, Elmé, Dhillon, Vikram S., Dyer, Martin J., Green, Matthew J., Kerry, Paul, Littlefair, Stuart P., Marsh, Thomas R., Munday, James, Pelisoli, Ingrid, Sahman, David I., Wild, James F., Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. GAA - Grup d'Astronomia i Astrofísica, Brown, Alexander James, Parsons, Steven G., van Roestel, Jan, Rebassa Mansergas, Alberto, Breedt, Elmé, Dhillon, Vikram S., Dyer, Martin J., Green, Matthew J., Kerry, Paul, Littlefair, Stuart P., Marsh, Thomas R., Munday, James, Pelisoli, Ingrid, Sahman, David I., and Wild, James F.

Abstract

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2023 A. J. Brown et al. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved., Wide-field time-domain photometric sky surveys are now finding hundreds of eclipsing white dwarf plus M dwarf binaries, a population encompassing a wealth of information and potential insight into white dwarf and close binary astrophysics. Precise follow-up observations are essential in order to fully constrain these systems and capitalize on the power of this sample. We present the first results from our programme of high-speed multiband photometric follow-up. We develop a method to measure temperatures, (model-dependent) masses, and radii for both components from the eclipse photometry alone and characterize 34 white dwarf binaries, finding general agreement with independent estimates using an alternative approach while achieving around a factor of 2 increase in parameter precision. In addition to these parameter estimates, we discover a number of interesting systems – finding four with sub-stellar secondaries, doubling the number of eclipsing examples, and at least six, where we find the white dwarf to be strongly magnetic, making these the first eclipsing examples of such systems and key to investigating the mechanism of magnetic field generation in white dwarfs. We also discover the first two pulsating white dwarfs in detached and eclipsing post-common-envelope binaries – one with a low-mass, likely helium core, and one with a relatively high mass, towards the upper end of the known sample of ZZ Cetis. Our results demonstrate the power of eclipse photometry, not only as a method of characterizing the population, but as a way of discovering important systems that would have otherwise been missed by spectroscopic follow-up., SGP acknowledges the support of the UK’s Science and Technology Facilities Council (STFC) Ernest Rutherford Fellowship. ARM acknowledges support from Grant RYC-2016-20254 funded by MCIN/AEI/10.13039/501100011033 and by ESF Investing in your future and from MINECO under the PID2020-117252GB-I00 grant. VSD, HiPERCAM, and ULTRACAM are supported by the STFC. IP and TRM acknowledge support from the STFC, grant ST/T000406/1 and a Leverhulme Research Fellowship. JM was supported by funding from a Science and Technology Facilities Council (STFC) studentship. Based on observations collected at the European Southern Observatory under ESO programme 0106.D-0824. Based on observations made with the Gran Telescopio Canarias (GTC), installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, in the island of La Palma. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. For the purpose of open access, the author has applied a Creative Commons Attribution (CC BY) licence to any Author Accepted Manuscript version arising. We thank the anonymous referee for their helpful comments., Peer Reviewed, Postprint (published version)

Published
2023

8. A pulsating white dwarf in an eclipsing binary

Author

Parsons, Steven G., Brown, Alexander J., Littlefair, Stuart P., Dhillon, Vikram S., Marsh, Thomas R., Hermes, J.J., Istrate, Alina G., Green, Matthew J., Sahman, David I., Parsons, Steven G., Brown, Alexander J., Littlefair, Stuart P., Dhillon, Vikram S., Marsh, Thomas R., Hermes, J.J., Istrate, Alina G., Green, Matthew J., and Sahman, David I.

Abstract

Contains fulltext : 221207.pdf (publisher's version ) (Closed access) Contains fulltext : 221207pre.pdf (Author’s version preprint ) (Open Access)

Published
2020

9. Spectroscopic and Photometric Periods of Six Ultracompact Accreting Binaries

Author

Green, Matthew J., Marsh, Thomas R., Carter, Philip J., Steeghs, Danny, Breedt, Elmé, Dhillon, V. S., Littlefair, S. P., Parsons, Steven G., Kerry, Paul, Fusillo, Nicola P. Gentile, Ashley, R. P., Bours, Madelon C. P., Cunningham, Tim, Dyer, Martin J., Gänsicke, Boris T., Izquierdo, Paula, Pala, Anna F., Pattama, Chuangwit, Outmani, Sabrina, Sahman, David I., Sukaum, Boonchoo, Wild, James, Green, Matthew J., Marsh, Thomas R., Carter, Philip J., Steeghs, Danny, Breedt, Elmé, Dhillon, V. S., Littlefair, S. P., Parsons, Steven G., Kerry, Paul, Fusillo, Nicola P. Gentile, Ashley, R. P., Bours, Madelon C. P., Cunningham, Tim, Dyer, Martin J., Gänsicke, Boris T., Izquierdo, Paula, Pala, Anna F., Pattama, Chuangwit, Outmani, Sabrina, Sahman, David I., Sukaum, Boonchoo, and Wild, James

Abstract

Ultracompact accreting binary systems each consist of a stellar remnant accreting helium-enriched material from a compact donor star. Such binaries include two related sub-classes, AM CVn-type binaries and helium cataclysmic variables, in both of which the central star is a white dwarf. We present a spectroscopic and photometric study of six accreting binaries with orbital periods in the range of 40--70 min, including phase-resolved VLT spectroscopy and high-speed ULTRACAM photometry. Four of these are AM CVn systems and two are helium cataclysmic variables. For four of these binaries we are able to identify orbital periods (of which three are spectroscopic). SDSS J1505+0659 has an orbital period of 67.8 min, significantly longer than previously believed, and longer than any other known AM CVn binary. We identify a WISE infrared excess in SDSS J1505+0659 that we believe to be the first direct detection of an AM CVn donor star in a non-direct impacting binary. The mass ratio of SDSS J1505+0659 is consistent with a white dwarf donor. CRTS J1028-0819 has an orbital period of 52.1 min, the shortest period of any helium cataclysmic variable. MOA 2010-BLG-087 is co-aligned with a K-class star that dominates its spectrum. ASASSN-14ei and ASASSN-14mv both show a remarkable number of echo outbursts following superoutbursts (13 and 10 echo outbursts respectively). ASASSN-14ei shows an increased outburst rate over the years following its superoutburst, perhaps resulting from an increased accretion rate., Comment: 22 pages, 21 figures. Accepted for publication by MNRAS

Published
2020
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10. A pulsating white dwarf in an eclipsing binary

Author

Parsons, Steven G., Brown, Alexander J., Littlefair, Stuart P., Dhillon, Vikram S., Marsh, Thomas R., Hermes, J. J., Istrate, Alina G., Breedt, Elmé, Dyer, Martin J., Green, Matthew J., Sahman, David I., Parsons, Steven G., Brown, Alexander J., Littlefair, Stuart P., Dhillon, Vikram S., Marsh, Thomas R., Hermes, J. J., Istrate, Alina G., Breedt, Elmé, Dyer, Martin J., Green, Matthew J., and Sahman, David I.

Abstract

White dwarfs are the burnt out cores of Sun-like stars and are the final fate of 97% of all stars in our Galaxy. The internal structure and composition of white dwarfs are hidden by their high gravities, which causes all elements, apart from the lightest ones, to settle out of their atmospheres. The most direct method to probe the inner structure of stars and white dwarfs in detail is via asteroseismology. Here we present the first known pulsating white dwarf in an eclipsing binary system, enabling us to place extremely precise constraints on the mass and radius of the white dwarf from the light curve, independent of the pulsations. This 0.325M$_\odot$ white dwarf --- one member of SDSS J115219.99+024814.4 --- will serve as a powerful benchmark to constrain empirically the core composition of low-mass stellar remnants and investigate the effects of close binary evolution on the internal structure of white dwarfs., Comment: Accepted for publication in Nature Astronomy

Published
2020
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11. A pulsating white dwarf in an eclipsing binary

Author

Parsons, Steven G., Brown, Alexander J., Littlefair, Stuart P., Dhillon, Vikram S., Marsh, Thomas R., Hermes, J.J., Istrate, Alina G., Green, Matthew J., Sahman, David I., Parsons, Steven G., Brown, Alexander J., Littlefair, Stuart P., Dhillon, Vikram S., Marsh, Thomas R., Hermes, J.J., Istrate, Alina G., Green, Matthew J., and Sahman, David I.

Abstract

Contains fulltext : 221207.pdf (publisher's version ) (Closed access) Contains fulltext : 221207pre.pdf (Author’s version preprint ) (Open Access)

Published
2020

12. A pulsating white dwarf in an eclipsing binary

Author

Parsons, Steven G., Brown, Alexander J., Littlefair, Stuart P., Dhillon, Vikram S., Marsh, Thomas R., Hermes, J.J., Istrate, Alina G., Green, Matthew J., Sahman, David I., Parsons, Steven G., Brown, Alexander J., Littlefair, Stuart P., Dhillon, Vikram S., Marsh, Thomas R., Hermes, J.J., Istrate, Alina G., Green, Matthew J., and Sahman, David I.

Abstract

Contains fulltext : 221207.pdf (publisher's version ) (Closed access) Contains fulltext : 221207pre.pdf (Author’s version preprint ) (Open Access)

Published
2020

13. Spectroscopic and Photometric Periods of Six Ultracompact Accreting Binaries

Author

Green, Matthew J., Marsh, Thomas R., Carter, Philip J., Steeghs, Danny, Breedt, Elmé, Dhillon, V. S., Littlefair, S. P., Parsons, Steven G., Kerry, Paul, Fusillo, Nicola P. Gentile, Ashley, R. P., Bours, Madelon C. P., Cunningham, Tim, Dyer, Martin J., Gänsicke, Boris T., Izquierdo, Paula, Pala, Anna F., Pattama, Chuangwit, Outmani, Sabrina, Sahman, David I., Sukaum, Boonchoo, Wild, James, Green, Matthew J., Marsh, Thomas R., Carter, Philip J., Steeghs, Danny, Breedt, Elmé, Dhillon, V. S., Littlefair, S. P., Parsons, Steven G., Kerry, Paul, Fusillo, Nicola P. Gentile, Ashley, R. P., Bours, Madelon C. P., Cunningham, Tim, Dyer, Martin J., Gänsicke, Boris T., Izquierdo, Paula, Pala, Anna F., Pattama, Chuangwit, Outmani, Sabrina, Sahman, David I., Sukaum, Boonchoo, and Wild, James

Abstract

Ultracompact accreting binary systems each consist of a stellar remnant accreting helium-enriched material from a compact donor star. Such binaries include two related sub-classes, AM CVn-type binaries and helium cataclysmic variables, in both of which the central star is a white dwarf. We present a spectroscopic and photometric study of six accreting binaries with orbital periods in the range of 40--70 min, including phase-resolved VLT spectroscopy and high-speed ULTRACAM photometry. Four of these are AM CVn systems and two are helium cataclysmic variables. For four of these binaries we are able to identify orbital periods (of which three are spectroscopic). SDSS J1505+0659 has an orbital period of 67.8 min, significantly longer than previously believed, and longer than any other known AM CVn binary. We identify a WISE infrared excess in SDSS J1505+0659 that we believe to be the first direct detection of an AM CVn donor star in a non-direct impacting binary. The mass ratio of SDSS J1505+0659 is consistent with a white dwarf donor. CRTS J1028-0819 has an orbital period of 52.1 min, the shortest period of any helium cataclysmic variable. MOA 2010-BLG-087 is co-aligned with a K-class star that dominates its spectrum. ASASSN-14ei and ASASSN-14mv both show a remarkable number of echo outbursts following superoutbursts (13 and 10 echo outbursts respectively). ASASSN-14ei shows an increased outburst rate over the years following its superoutburst, perhaps resulting from an increased accretion rate., Comment: 22 pages, 21 figures. Accepted for publication by MNRAS

Published
2020
Full Text
View/download PDF

14. A pulsating white dwarf in an eclipsing binary

Author

Parsons, Steven G., Brown, Alexander J., Littlefair, Stuart P., Dhillon, Vikram S., Marsh, Thomas R., Hermes, J. J., Istrate, Alina G., Breedt, Elmé, Dyer, Martin J., Green, Matthew J., Sahman, David I., Parsons, Steven G., Brown, Alexander J., Littlefair, Stuart P., Dhillon, Vikram S., Marsh, Thomas R., Hermes, J. J., Istrate, Alina G., Breedt, Elmé, Dyer, Martin J., Green, Matthew J., and Sahman, David I.

Abstract

White dwarfs are the burnt out cores of Sun-like stars and are the final fate of 97% of all stars in our Galaxy. The internal structure and composition of white dwarfs are hidden by their high gravities, which causes all elements, apart from the lightest ones, to settle out of their atmospheres. The most direct method to probe the inner structure of stars and white dwarfs in detail is via asteroseismology. Here we present the first known pulsating white dwarf in an eclipsing binary system, enabling us to place extremely precise constraints on the mass and radius of the white dwarf from the light curve, independent of the pulsations. This 0.325M$_\odot$ white dwarf --- one member of SDSS J115219.99+024814.4 --- will serve as a powerful benchmark to constrain empirically the core composition of low-mass stellar remnants and investigate the effects of close binary evolution on the internal structure of white dwarfs., Comment: Accepted for publication in Nature Astronomy

Published
2020
Full Text
View/download PDF

15. A search for optical bursts from the repeating fast radio burst FRB 121102

Author

Hardy, Liam K, Dhillon, Vik S, Spitler, Laura G, Littlefair, Stuart P, Ashley, Richard P, De Cia, Annalisa, Green, Matthew J, Jaroenjittichai, Phrudth, Keane, Evan F, Kerry, Paul, Kramer, Michael, Malesani, Daniele, Marsh, Tom R, Parsons, Steven G, Possenti, Andrea, Rattanasoon, Somsawat, Sahman, David I, Hardy, Liam K, Dhillon, Vik S, Spitler, Laura G, Littlefair, Stuart P, Ashley, Richard P, De Cia, Annalisa, Green, Matthew J, Jaroenjittichai, Phrudth, Keane, Evan F, Kerry, Paul, Kramer, Michael, Malesani, Daniele, Marsh, Tom R, Parsons, Steven G, Possenti, Andrea, Rattanasoon, Somsawat, and Sahman, David I

Abstract

We present a search for optical bursts from the repeating fast radio burst FRB 121102 using simultaneous observations with the high-speed optical camera ULTRASPEC on the 2.4-m Thai National Telescope and radio observations with the 100-m Effelsberg Radio Telescope. A total of 13 radio bursts were detected, but we found no evidence for corresponding optical bursts in our 70.7-ms frames. The 5-sigma upper limit to the optical flux density during our observations is 0.33 mJy at 767nm. This gives an upper limit for the optical burst fluence of 0.046 Jy ms, which constrains the broadband spectral index of the burst emission to alpha < -0.2. Two of the radio pulses are separated by just 34 ms, which may represent an upper limit on a possible underlying periodicity (a rotation period typical of pulsars), or these pulses may have come from a single emission window that is a small fraction of a possible period., Comment: 8 pages, 4 figures, accepted for publication in MNRAS

Published
2017
Full Text
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16. A search for optical bursts from the repeating fast radio burst FRB 121102

Author

Hardy, Liam K, Dhillon, Vik S, Spitler, Laura G, Littlefair, Stuart P, Ashley, Richard P, De Cia, Annalisa, Green, Matthew J, Jaroenjittichai, Phrudth, Keane, Evan F, Kerry, Paul, Kramer, Michael, Malesani, Daniele, Marsh, Tom R, Parsons, Steven G, Possenti, Andrea, Rattanasoon, Somsawat, Sahman, David I, Hardy, Liam K, Dhillon, Vik S, Spitler, Laura G, Littlefair, Stuart P, Ashley, Richard P, De Cia, Annalisa, Green, Matthew J, Jaroenjittichai, Phrudth, Keane, Evan F, Kerry, Paul, Kramer, Michael, Malesani, Daniele, Marsh, Tom R, Parsons, Steven G, Possenti, Andrea, Rattanasoon, Somsawat, and Sahman, David I

Abstract

We present a search for optical bursts from the repeating fast radio burst FRB 121102 using simultaneous observations with the high-speed optical camera ULTRASPEC on the 2.4-m Thai National Telescope and radio observations with the 100-m Effelsberg Radio Telescope. A total of 13 radio bursts were detected, but we found no evidence for corresponding optical bursts in our 70.7-ms frames. The 5-sigma upper limit to the optical flux density during our observations is 0.33 mJy at 767nm. This gives an upper limit for the optical burst fluence of 0.046 Jy ms, which constrains the broadband spectral index of the burst emission to alpha < -0.2. Two of the radio pulses are separated by just 34 ms, which may represent an upper limit on a possible underlying periodicity (a rotation period typical of pulsars), or these pulses may have come from a single emission window that is a small fraction of a possible period., Comment: 8 pages, 4 figures, accepted for publication in MNRAS

Published
2017
Full Text
View/download PDF

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