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36 results on '"Sadler, E.M."'

1. The FLASH pilot survey: An H i absorption search against MRC 1-Jy radio sources

Author

Aditya, J.N.H.S., Yoon, H., Allison, J.R., An, T., Chhetri, Rajan, Curran, S.J., Darling, J., Emig, K.L., Glowacki, Marcin, Kerrison, E., Koribalski, B.S., Mahony, E.K., Moss, V.A., Morgan, John, Sadler, E.M., Soria, R., Su, R., Weng, S., Whiting, M., Aditya, J.N.H.S., Yoon, H., Allison, J.R., An, T., Chhetri, Rajan, Curran, S.J., Darling, J., Emig, K.L., Glowacki, Marcin, Kerrison, E., Koribalski, B.S., Mahony, E.K., Moss, V.A., Morgan, John, Sadler, E.M., Soria, R., Su, R., Weng, S., and Whiting, M.

Abstract

We report an ASKAP search for associated H i 21-cm absorption against bright radio sources from the Molonglo Reference Catalogue (MRC) 1-Jy sample. The search uses pilot survey data from the ASKAP First Large Absorption Survey in H i (FLASH) covering the redshift range 0.42 < z < 1.00. From a sample of 62 MRC 1-Jy radio galaxies and quasars, we report three new detections of associated H i 21-cm absorption, yielding an overall detection fraction of. The detected systems comprise two radio galaxies (MRC 2216-281 at z = 0.657 and MRC 0531-237 at z = 0.851) and one quasar (MRC 2156-245 at z = 0.862). The MRC 0531-237 absorption system is the strongest found to date, with a velocity integrated optical depth of. All three objects with detected H i 21-cm absorption are peaked-spectrum or compact steep-spectrum (CSS) radio sources. Two of them show strong interplanetary scintillation at 162 MHz, implying that the radio continuum source is smaller than 1 arcsec in size even at low frequencies. Among the class of peaked-spectrum and compact steep-spectrum radio sources, the H i detection fraction is. All three detections have a high 1.4 GHz radio luminosity, with MRC 0531-237 and MRC 2216-281 having the highest values in the sample,. The preponderance of extended radio sources in our sample could partially explain the overall low detection fraction, while the effects of a redshift evolution in gas properties and AGN UV luminosity on the neutral gas absorption still need to be investigated.

Published
2024

2. Illuminating gravitational waves : A concordant picture of photons from a neutron star merger

Author

Kasliwal, M. M., Nakar, E., Singer, L. P., Kaplan, D. L., Cook, D. O., Van Sistine, A., Lau, R. M., Fremling, C., Gottlieb, O., Jencson, J. E., Adams, S. M., Feindt, U., Hotokezaka, K., Ghosh, S., Perley, D. A., Yu, P.-C., Piran, T., Allison, J. R., Anupama, G. C., Balasubramanian, A., Bannister, K. W, Bally, J., Barnes, J., Barway, S., Bellm, E., Bhalerao, V., Bhattacharya, D., Blagorodnova, N., Bloom, J. S., Brady, P. R., Cannella, C., Chatterjee, D., Cenko, S. B., Cobb, B. E., Copperwheat, C., Corsi, A., De, K., Dobie, D., Emery, S. W. K., Evans, P. A., Fox, O. D., Frail, D. A., Frohmaier, C., Goobar, A., Hallinan, G., Harrison, F., Helou, G., Hinderer, T., Ho, A. Y. Q., Horesh, A., Ip, W.-H., Itoh, R., Kasen, D., Kim, H., Kuin, N. P. M., Kupfer, T., Lynch, C., Madsen, K., Mazzali, P. A., Miller, A. A., Mooley, K., Murphy, T., Ngeow, C.-C., Nichols, D., Nissanke, S., Nugent, P., Ofek, E. O., Qi, H., Quimby, R. M., Rosswog, S., Rusu, F., Sadler, E.M., Schmidt, P., Sollerman, J., Steele, I., Williamson, A. R., Xu, Y., Yan, L., Yatsu, Y., Zhang, C., and Zhao, W.

Published
2017

3. The host galaxy of FRB 20171020A revisited

Author

Lee-Waddell, Karen, James, Clancy, Ryder, S.D., Mahony, E.K., Bahramian, Arash, Koribalski, B.S., Kumar, P., Marnoch, L., North-Hickey, F.O., Sadler, E.M., Shannon, R., Tejos, N., Thorne, J.E., Wang, J., Wayth, Randall, Lee-Waddell, Karen, James, Clancy, Ryder, S.D., Mahony, E.K., Bahramian, Arash, Koribalski, B.S., Kumar, P., Marnoch, L., North-Hickey, F.O., Sadler, E.M., Shannon, R., Tejos, N., Thorne, J.E., Wang, J., and Wayth, Randall

Abstract

The putative host galaxy of FRB 20171020A was first identified as ESO 601-G036 in 2018, but as no repeat bursts have been detected, direct confirmation of the host remains elusive. In light of recent developments in the field, we re-examine this host and determine a new association confidence level of 98%. At 37 Mpc, this makes ESO 601-G036 the third closest FRB host galaxy to be identified to date and the closest to host an apparently non-repeating FRB (with an estimated repetition rate limit of

Published
2023

4. The Demographics, Stellar Populations, and Star Formation Histories of Fast Radio Burst Host Galaxies: Implications for the Progenitors

Author

Gordon, A.C., Fong, W.F., Kilpatrick, C.D., Eftekhari, T., Leja, J., Prochaska, J.X., Nugent, A.E., Bhandari, S., Blanchard, P.K., Caleb, M., Day, C.K., Deller, A.T., Dong, Y., Glowacki, Marcin, Gourdji, K., Mannings, A.G., Mahoney, E.K., Marnoch, L., Miller, A.A., Paterson, K., Rastinejad, J.C., Ryder, S.D., Sadler, E.M., Scott, D.R., Sears, H., Shannon, R.M., Simha, S., Stappers, B.W., Tejos, N., Gordon, A.C., Fong, W.F., Kilpatrick, C.D., Eftekhari, T., Leja, J., Prochaska, J.X., Nugent, A.E., Bhandari, S., Blanchard, P.K., Caleb, M., Day, C.K., Deller, A.T., Dong, Y., Glowacki, Marcin, Gourdji, K., Mannings, A.G., Mahoney, E.K., Marnoch, L., Miller, A.A., Paterson, K., Rastinejad, J.C., Ryder, S.D., Sadler, E.M., Scott, D.R., Sears, H., Shannon, R.M., Simha, S., Stappers, B.W., and Tejos, N.

Abstract

We present a comprehensive catalog of observations and stellar population properties for 23 highly secure host galaxies of fast radio bursts (FRBs). Our sample comprises 6 repeating FRBs and 17 apparent nonrepeaters. We present 82 new photometric and 8 new spectroscopic observations of these hosts. Using stellar population synthesis modeling and employing nonparametric star formation histories (SFHs), we find that FRB hosts have a median stellar mass of ≈109.9 M ⊙, mass-weighted age ≈5.1 Gyr, and ongoing star formation rate ≈1.3 M ⊙ yr-1 but span wide ranges in all properties. Classifying the hosts by degree of star formation, we find that 87% (20 of 23 hosts) are star-forming, two are transitioning, and one is quiescent. The majority trace the star-forming main sequence of galaxies, but at least three FRBs in our sample originate in less-active environments (two nonrepeaters and one repeater). Across all modeled properties, we find no statistically significant distinction between the hosts of repeaters and nonrepeaters. However, the hosts of repeating FRBs generally extend to lower stellar masses, and the hosts of nonrepeaters arise in more optically luminous galaxies. While four of the galaxies with the clearest and most prolonged rises in their SFHs all host repeating FRBs, demonstrating heightened star formation activity in the last 2100 Myr, one nonrepeating host shows this SFH as well. Our results support progenitor models with short delay channels (i.e., magnetars formed via core-collapse supernova) for most FRBs, but the presence of some FRBs in less-active environments suggests a fraction form through more delayed channels.

Published
2023

5. The First Large Absorption Survey in H i (FLASH): I. Science goals and survey design

Author

Allison, J.R., Sadler, E.M., Amaral, A.D., An, T., Curran, S.J., Darling, J., Edge, A.C., Ellison, S.L., Emig, K.L., Gaensler, B.M., Garratt-Smithson, L., Glowacki, Marcin, Grasha, K., Koribalski, B.S., Lagos, C.D.P., Lah, P., Mahony, E.K., Mao, S.A., Morganti, R., Moss, V.A., Pettini, M., Pimbblet, K.A., Power, C., Salas, P., Staveley-Smith, L., Whiting, M.T., Wong, O.I., Yoon, H., Zheng, Z., Zwaan, M.A., Allison, J.R., Sadler, E.M., Amaral, A.D., An, T., Curran, S.J., Darling, J., Edge, A.C., Ellison, S.L., Emig, K.L., Gaensler, B.M., Garratt-Smithson, L., Glowacki, Marcin, Grasha, K., Koribalski, B.S., Lagos, C.D.P., Lah, P., Mahony, E.K., Mao, S.A., Morganti, R., Moss, V.A., Pettini, M., Pimbblet, K.A., Power, C., Salas, P., Staveley-Smith, L., Whiting, M.T., Wong, O.I., Yoon, H., Zheng, Z., and Zwaan, M.A.

Abstract

We describe the scientific goals and survey design of the First Large Absorption Survey in H i (FLASH), a wide field survey for 21-cm line absorption in neutral atomic hydrogen (H i) at intermediate cosmological redshifts. FLASH will be carried out with the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope and is planned to cover the sky south of at frequencies between 711.5 and 999.5 MHz. At redshifts between and (look-back times of 4-8 Gyr), the H i content of the Universe has been poorly explored due to the difficulty of carrying out radio surveys for faint 21-cm line emission and, at ultra-violet wavelengths, space-borne searches for Damped Lyman-absorption in quasar spectra. The ASKAP wide field of view and large spectral bandwidth, in combination with a radio-quiet site, will enable a search for absorption lines in the radio spectra of bright continuum sources over 80% of the sky. This survey is expected to detect at least several hundred intervening 21-cm absorbers and will produce an H i-absorption-selected catalogue of galaxies rich in cool, star-forming gas, some of which may be concealed from optical surveys. Likewise, at least several hundred associated 21-cm absorbers are expected to be detected within the host galaxies of radio sources at

Published
2022

6. A search for supernova-like optical counterparts to ASKAP-localised fast radio bursts

Author

Marnoch, L., Ryder, S.D., Bannister, K.W., Bhandari, S., Day, C.K., Deller, A.T., Macquart, Jean-Pierre, McDermid, R.M., Xavier Prochaska, J., Qiu, H., Sadler, E.M., Shannon, Ryan, Tejos, N., Marnoch, L., Ryder, S.D., Bannister, K.W., Bhandari, S., Day, C.K., Deller, A.T., Macquart, Jean-Pierre, McDermid, R.M., Xavier Prochaska, J., Qiu, H., Sadler, E.M., Shannon, Ryan, and Tejos, N.

Abstract

Fast radio bursts (FRBs) are millisecond-scale radio pulses, which originate in distant galaxies and are produced by unknown sources. The mystery remains partially because of the typical difficulty in localising FRBs to host galaxies. Accurate localisations delivered by the Commensal Real-time ASKAP Fast Transients (CRAFT) survey now provide an opportunity to study the host galaxies and potential transient counterparts of FRBs at a large range of wavelengths. In this work, we investigate whether the first three FRBs accurately localised by CRAFT have supernova-like transient counterparts. We obtained two sets of imaging epochs with the Very Large Telescope for three host galaxies, one soon after the burst detection and one several months later. After subtracting these images no optical counterparts were identified in the associated FRB host galaxies, so we instead place limits on the brightness of any potential optical transients. A Monte Carlo approach, in which supernova light curves were modelled and their base properties randomised, was used to estimate the probability of a supernova associated with each FRB going undetected. We conclude that Type Ia and IIn supernovae are unlikely to accompany every apparently non-repeating FRB.

Published
2020

7. The Host Galaxies and Progenitors of Fast Radio Bursts Localized with the Australian Square Kilometre Array Pathfinder

Author

Bhandari, S., Sadler, E.M., Prochaska, J.X., Simha, S., Ryder, S.D., Marnoch, L., Bannister, K.W., Macquart, Jean-Pierre, Flynn, C., Shannon, Ryan, Tejos, N., Corro-Guerra, F., Day, C.K., Deller, A.T., Ekers, Ron, Lopez, S., Mahony, E.K., Nuñez, C., Phillips, C., Bhandari, S., Sadler, E.M., Prochaska, J.X., Simha, S., Ryder, S.D., Marnoch, L., Bannister, K.W., Macquart, Jean-Pierre, Flynn, C., Shannon, Ryan, Tejos, N., Corro-Guerra, F., Day, C.K., Deller, A.T., Ekers, Ron, Lopez, S., Mahony, E.K., Nuñez, C., and Phillips, C.

Abstract

The Australian SKA Pathfinder (ASKAP) telescope has started to localize fast radio bursts (FRBs) to arcsecond accuracy from the detection of a single pulse, allowing their host galaxies to be reliably identified. We discuss the global properties of the host galaxies of the first four FRBs localized by ASKAP, which lie in the redshift range 0.11 < z < 0.48. All four are massive galaxies (log(M ∗/Mo&dot;) ∼ 9.4-10.4) with modest star formation rates of up to 2 M o&dot; yr-1 - very different to the host galaxy of the first repeating FRB 121102, which is a dwarf galaxy with a high specific star formation rate. The FRBs localized by ASKAP typically lie in the outskirts of their host galaxies, which appears to rule out FRB progenitor models that invoke active galactic nuclei or free-floating cosmic strings. The stellar population seen in these host galaxies also disfavors models in which all FRBs arise from young magnetars produced by superluminous supernovae, as proposed for the progenitor of FRB 121102. A range of other progenitor models (including compact-object mergers and magnetars arising from normal core-collapse supernovae) remain plausible.

Published
2020

8. Host Galaxy Properties and Offset Distributions of Fast Radio Bursts: Implications for Their Progenitors

Author

Heintz, K.E., Prochaska, J.X., Simha, S., Platts, E., Fong, W.F., Tejos, N., Ryder, S.D., Aggerwal, K., Bhandari, S., Day, C.K., Deller, A.T., Kilpatrick, C.D., Law, C.J., Macquart, Jean-Pierre, Mannings, A., Marnoch, L.J., Sadler, E.M., Shannon, Ryan, Heintz, K.E., Prochaska, J.X., Simha, S., Platts, E., Fong, W.F., Tejos, N., Ryder, S.D., Aggerwal, K., Bhandari, S., Day, C.K., Deller, A.T., Kilpatrick, C.D., Law, C.J., Macquart, Jean-Pierre, Mannings, A., Marnoch, L.J., Sadler, E.M., and Shannon, Ryan

Abstract

We present observations and detailed characterizations of five new host galaxies of fast radio bursts (FRBs) discovered with the Australian Square Kilometre Array Pathfinder (ASKAP) and localized to ≲1″. Combining these galaxies with FRB hosts from the literature, we introduce criteria based on the probability of chance coincidence to define a subsample of 10 highly confident associations (at z = 0.03-0.52), 3 of which correspond to known repeating FRBs. Overall, the FRB-host galaxies exhibit a broad, continuous range of color (M u - M r = 0.9-2.0), stellar mass (M ∗ = 108 - 6 × 1010 M o˙), and star formation rate (SFR = 0.05-10 M o˙ yr-1) spanning the full parameter space occupied by z < 0.5 galaxies. However, they do not track the color-magnitude, SFR-M ∗, nor BPT diagrams of field galaxies surveyed at similar redshifts. There is an excess of "green valley"galaxies and an excess of emission-line ratios indicative of a harder radiation field than that generated by star formation alone. From the observed stellar mass distribution, we rule out the hypothesis that FRBs strictly track stellar mass in galaxies (>99% c.l.). We measure a median offset of 3.3 kpc from the FRB to the estimated center of the host galaxies and compare the host-burst offset distribution and other properties with the distributions of long- and short-duration gamma-ray bursts (LGRBs and SGRBs), core-collapse supernovae (CC-SNe), and SNe Ia. This analysis rules out galaxies hosting LGRBs (faint, star-forming galaxies) as common hosts for FRBs (>95% c.l.). Other transient channels (SGRBs, CC-, and SNe Ia) have host-galaxy properties and offsets consistent with the FRB distributions. All of the data and derived quantities are made publicly available on a dedicated website and repository.

Published
2020

11. Radio emission from the unusual supernova 1998bw and its association with the gamma-ray burst of 25 April 1998

Author

Kulkarni, S.R., Frail, D.A., Wieringa, M.H., Ekers, R.d., Sadler, E.M., Wark, R.M., Higdon, J.L., Phinney, E.S., and Bloom, J.S.

Subjects
Supernovae -- Observations, Gamma rays -- Observations, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Gamma-ray bursts (GRBs) are only just beginning to be understood, and at least one GRB is known to be of extragalactic origin. Supernovae are similar explosive events, but are more numerous. Radio observation of the supernova SN1998bw, which exploded at around the same time and direction as the gamma-ray burst GRB980425, suggest a link between some GRBs and supernovae. It may mean that GRB980425 is a new type of GRB with different optical and radio properties.

Published
1998

13. A single fast radio burst localized to a massive galaxy at cosmological distance

Author

Bannister, K.W., Deller, A.T., Phillips, C., Macquart, Jean-Pierre, Prochaska, J.X., Tejos, N., Ryder, S.D., Sadler, E.M., Shannon, Ryan, Simha, S., Day, C.K., McQuinn, M., North-Hickey, F.O., Bhandari, S., Arcus, W.R., Bennert, V.N., Burchett, J., Bouwhuis, M., Dodson, R., Ekers, Ronald, Farah, W., Flynn, C., James, Clancy, Kerr, M., Lenc, E., Mahony, E.K., O'Meara, J., Osłowski, S., Qiu, H., Treu, T., U, V., Bateman, T.J., Bock, D.C.J., Bolton, R.J., Brown, A., Bunton, J.D., Chippendale, A.P., Cooray, F.R., Cornwell, T., Gupta, N., Hayman, D.B., Kesteven, M., Koribalski, B.S., MacLeod, A., McClure-Griffiths, N.M., Neuhold, S., Norris, R.P., Pilawa, M.A., Qiao, R.Y., Reynolds, J., Roxby, D.N., Shimwell, T.W., Voronkov, M.A., Wilson, C.D., Bannister, K.W., Deller, A.T., Phillips, C., Macquart, Jean-Pierre, Prochaska, J.X., Tejos, N., Ryder, S.D., Sadler, E.M., Shannon, Ryan, Simha, S., Day, C.K., McQuinn, M., North-Hickey, F.O., Bhandari, S., Arcus, W.R., Bennert, V.N., Burchett, J., Bouwhuis, M., Dodson, R., Ekers, Ronald, Farah, W., Flynn, C., James, Clancy, Kerr, M., Lenc, E., Mahony, E.K., O'Meara, J., Osłowski, S., Qiu, H., Treu, T., U, V., Bateman, T.J., Bock, D.C.J., Bolton, R.J., Brown, A., Bunton, J.D., Chippendale, A.P., Cooray, F.R., Cornwell, T., Gupta, N., Hayman, D.B., Kesteven, M., Koribalski, B.S., MacLeod, A., McClure-Griffiths, N.M., Neuhold, S., Norris, R.P., Pilawa, M.A., Qiao, R.Y., Reynolds, J., Roxby, D.N., Shimwell, T.W., Voronkov, M.A., and Wilson, C.D.

Abstract

Fast radio bursts (FRBs) are brief radio emissions from distant astronomical sources. Some are known to repeat, but most are single bursts. Nonrepeating FRB observations have had insufficient positional accuracy to localize them to an individual host galaxy. We report the interferometric localization of the single-pulse FRB 180924 to a position 4 kiloparsecs from the center of a luminous galaxy at redshift 0.3214. The burst has not been observed to repeat. The properties of the burst and its host are markedly different from those of the only other accurately localized FRB source. The integrated electron column density along the line of sight closely matches models of the intergalactic medium, indicating that some FRBs are clean probes of the baryonic component of the cosmic web.

Published
2019

14. Tidal disruptions of the Magellanic Clouds by the Milky Way

Author

Putman, M.E., Gibson, B.K., Staveley-Smith, L., Banks, G., Barnes, D.G., Bhatal, R., Disney, M.J., Ekers, R.D., Freeman, K.C., Koribalski, B., Knezek, P., Malin, D.F., Mould, J.R., Oosterloo, T., Price, R.M., Ryder, S.D., Sadler, E.M., Stewart, I., Stootman, F., Vaile, R.A., Webster, R.L., Wright, A.E., Haynes, R.F., Henning, P., Jerjen, H., and Kilborn, V.

Subjects
Galaxies -- Observations, Magellanic Clouds -- Observations, Milky Way -- Observations, Astronomical research -- Observations, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

An important consideration when determining the morphologies of the galaxies is their interaction over time. The interaction between the Milky Way and the neighbouring Large and Small Magellanic Clouds is one example. A new atomic-hydrogen survey of the southern skies reveal a new stream of gas moving around the Milky Way in the opposite direction to the trailing Magellan Stream, leading the motion of the clouds. It is probable that these leading and trailing streams have been torn from the Magellanic Clouds by gravitational tidal interaction.

Published
1998

16. A radio counterpart to a neutron star merger

Author

Hallinan, G., Corsi, A., Mooley, K.P., Hotokezaka, K., Nakar, E., Kasliwal, M.M., Nissanke, S., Sadler, E.M., Singer, L.P., Hallinan, G., Corsi, A., Mooley, K.P., Hotokezaka, K., Nakar, E., Kasliwal, M.M., Nissanke, S., Sadler, E.M., and Singer, L.P.

Abstract

Contains fulltext : 181160.pdf (publisher's version ) (Closed access) Contains fulltext : 181160-1.pdf (preprint version ) (Closed access)

Published
2017

17. The Challenges of Low-Frequency Radio Polarimetry: Lessons from the Murchison Widefield Array

Author

Lenc, E., Anderson, C.S, Barry, N., Bowman, J.D., Cairns, I.H., Farnes, J.S., Gaensler, B.M., Heald, G., Johnston-Hollitt, M., Kaplan, D.L., Lynch, C.R., McCauley, P.I., Mitchell, D.A., Morgan, J., Morales, M.F., Murphy, T., Offringa, A.R., Ord, S.M., Pindor, B., Riseley, C., Sadler, E.M., Sobey, C, Sokolowski, M., Sullivan, I.S., O’Sullivan, S.P., Sun, X.H., Tremblay, S.E., Trott, C.M., Wayth, R.B., Lenc, E., Anderson, C.S, Barry, N., Bowman, J.D., Cairns, I.H., Farnes, J.S., Gaensler, B.M., Heald, G., Johnston-Hollitt, M., Kaplan, D.L., Lynch, C.R., McCauley, P.I., Mitchell, D.A., Morgan, J., Morales, M.F., Murphy, T., Offringa, A.R., Ord, S.M., Pindor, B., Riseley, C., Sadler, E.M., Sobey, C, Sokolowski, M., Sullivan, I.S., O’Sullivan, S.P., Sun, X.H., Tremblay, S.E., Trott, C.M., and Wayth, R.B.

Abstract

Contains fulltext : 178478.pdf (publisher's version ) (Closed access) Contains fulltext : 178478.pdf (preprint version ) (Open Access)

Published
2017

18. Galaxy And Mass Assembly (GAMA): end of survey report and data release 2

Author

Liske, J., Baldry, I.K., Driver, S.P., Tuffs, R.J., Alpaslan, M., Andrae, E., Brough, S., Cluver, M.E., Grootes, M.W., Gunawardhana, M.L.P., Kelvin, L.S., Loveday, J., Robotham, A.S.G., Taylor, E.N., Bamford, S.P., Bland-Hawthorn, J., Brown, M.J.I., Drinkwater, M.J., Hopkins, A.M., Meyer, M.J., Norberg, P., Peacock, J.A., Agius, N.K., Andrews, S.K., Bauer, A.E., Ching, J.H.Y., Colless, M., Conselice, Christopher J., Croom, S.M., Davies, L.J.M., De Propris, R., Dunne, L., Eardley, E.M., Ellis, S., Foster, C., Frenk, C.S., Holwerda, B.W., Howlett, C., Ibarra, H., Jarvis, M.J., Jones, D.H., Kafle, P.R., Lacey, C.G., Lange, R., Lara-Lopez, M.A., Lopez-Sanchez, A.R., Maddox, S., Madore, B.F., McNaught-Roberts, T., Moffett, A.J., Nichol, R.C., Owers, M.S., Palamara, D., Penny, S.J., Phillipps, S., Pimbblet, K.A., Popescu, C.C., Prescott, M., Proctor, R., Sadler, E.M., Sansom, A.E., Seibert, M., Sharp, R., Sutherland, W., Vazquez-Mata, J.A., van Kampen, E., Wilkins, S.M., Williams, R., and Wright, A.H.

Subjects
surveys – galaxies: distances and redshifts, galaxies: fundamental parameters, galaxies: general, galaxies: photometry, galaxies: statistics
Abstract

The Galaxy And Mass Assembly (GAMA) survey is one of the largest contemporary spectroscopic surveys of low redshift galaxies. Covering an area of∼286 deg2 (split among five survey regions) down to a limiting magnitude of r < 19.8 mag, we have collected spectra and reliable redshifts for 238 000 objects using the AAOmega spectrograph on the Anglo-Australian Telescope. In addition, we have assembled imaging data from a number of independent surveys in order to generate photometry spanning the wavelength range 1 nm–1 m. Here, we report on the recently completed spectroscopic survey and present a series of diagnostics to assess its final state and the quality of the redshift data. We also describe a number of survey aspects and procedures, or updates thereof, including changes to the input catalogue, redshifting and re-redshifting, and the derivation of ultraviolet, optical and near-infrared photometry. Finally, we present the second public release of GAMA data. In this release, we provide input catalogue and targeting information, spectra, redshifts, ultraviolet, optical and near-infrared photometry, single-component Sersic fits, stellar masses, Hα-derived star formation rates, environment information, and group properties for all galaxies with r < 19.0 mag in two of our survey regions, and for all galaxies with r < 19.4 mag in a third region (72 225 objects in total). The data base serving these data is available at http://www.gama-survey.org/.

Published
2015

20. Galaxy And Mass Assembly (GAMA): Galaxy environments and star formation rate variations

Author

Wijesinghe, D.B., Hopkins, A.M., Brough, S., Taylor, E.N., Norberg, P., Bauer, A., Brown, M.J.I., Cameron, E., Conselice, C.J., Croom, S., Driver, S., Grootes, M.W., Jones, D.H., Kelvin, L., Loveday, J., Pimbblet, K.A., Popescu, C.C., Prescott, M., Sharp, R., Baldry, I., Sadler, E.M., Liske, J., Robotham, A.S.G., Bamford, S., Bland-Hawthorn, J., Gunawardhana, M., Meyer, M., Parkinson, H., Drinkwater, M.J., Peacock, J., and Tuffs, R.

Subjects
Galaxies: general, Galaxies: star formation, evolution, Galaxies: formation, Galaxies: star formation [Galaxies], Galaxies: evolution, general [Galaxies], Astrophysics::Cosmology and Extragalactic Astrophysics, evolution [Galaxies], star formation. [Galaxies], formation [Galaxies], Astrophysics::Galaxy Astrophysics
Abstract

Monthly Notices of the Royal Astronomical Society, 423 (4), ISSN:0035-8711, ISSN:1365-2966, ISSN:1365-8711

Published
2012
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21. GAMA/H-ATLAS: the ultraviolet spectral slope and obscuration in galaxies

Author

Wijesinghe, D.B., Da Cunha, E., Hopkins, A.M., Dunne, L., Sharp, R., Gunawardhana, M., Brough, S., Sadler, E.M., Driver, S., Baldry, I., Bamford, S., Liske, J., Loveday, J., Norberg, P., Peacock, J., Popescu, C.C., Tuffs, R., Andrae, E., Auld, R., Baes, M., Bland-Hawthorn, J., Buttiglione, S., Cava, A., Cameron, E., Conselice, C.J., Cooray, A., Croom, S., Dariush, A., DeZotti, G., Dye, S., Eales, S., Frenk, C., Fritz, J., Hill, D., Hopwood, R., Ibar, E., Ivison, R., Jarvis, M., Jones, D.H., Kampen, E. van, Kelvin, L., Kuijken, K.H., Maddox, S.J., Madore, B., Michalowski, M.J., Nichol, B., Parkinson, H., Pascale, E., Pimbblet, K.A., Pohlen, M., Prescott, M., Rhodighiero, G., Robotham, A.S.G., Rigby, E.E., Seibert, M., Sergeant, S., Smith, D.J.B., Temi, P., Sutherland, W., Taylor, E., Thomas, D., and Werf, P.P. van der

Subjects
Galaxies: evolution, Galaxies: formation, Galaxies: general, Astronomy and Astrophysics, Space and Planetary Science, Cosmology and Gravitation, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics, QB, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We use multiwavelength data from the Galaxy And Mass Assembly (GAMA) and Herschel ATLAS (H-ATLAS) surveys to compare the relationship between various dust obscuration measures in galaxies. We explore the connections between the ultraviolet (UV) spectral slope, $\beta$, the Balmer decrement, and the far infrared (IR) to $150\,$nm far ultraviolet (FUV) luminosity ratio. We explore trends with galaxy mass, star formation rate (SFR) and redshift in order to identify possible systematics in these various measures. We reiterate the finding of other authors that there is a large scatter between the Balmer decrement and the $\beta$ parameter, and that $\beta$ may be poorly constrained when derived from only two broad passbands in the UV. We also emphasise that FUV derived SFRs, corrected for dust obscuration using $\beta$, will be overestimated unless a modified relation between $\beta$ and the attenuation factor is used. Even in the optimum case, the resulting SFRs have a significant scatter, well over an order of magnitude. While there is a stronger correlation between the IR to FUV luminosity ratio and $\beta$ parameter than with the Balmer decrement, neither of these correlations are particularly tight, and dust corrections based on $\beta$ for high redshift galaxy SFRs must be treated with caution. We conclude with a description of the extent to which the different obscuration measures are consistent with each other as well as the effects of including other galactic properties on these correlations., Comment: Accepted by MNRAS, 12 pages, 8 figures

Published
2011

22. Galaxy and mass assembly (GAMA): dust obscuration in galaxies and their recent star formation histories

Author

Wijesinghe, D.B., Hopkins, A.M., Sharp, R., Gunawardhana, M., Brough, S., Sadler, E.M., Driver, S., Baldry, I., Bamford, S., Liske, J., Loveday, J., Norberg, P., Peacock, J., Popescu, C.C., Tuffs, R.J., Bland-Hawthorn, J., Cameron, E., Croom, S., Frenk, C., Hill, D., Jones, D.H., Kampen, E. van, Kelvin, L., Kuijken, K.H., Madore, B., Nichol, B., Parkinson, H., Pimbblet, K.A., Prescott, M., Robotham, A.S.G., Seibert, M., Simmat, E., Sutherland, W., Taylor, E., and Thomas, D.

Subjects
Galaxies: general, Galaxies: fundamental parameters, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Galaxies: luminosity function, mass function, FOS: Physical sciences, Galaxies: evolution, evolution, Galaxies: formation, Galaxies: luminosity function, mass function [Galaxies], Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

Monthly Notices of the Royal Astronomical Society, 410 (4), ISSN:0035-8711, ISSN:1365-2966, ISSN:1365-8711

Published
2011

25. Division VIII: Galaxies and the Universe

Author

Bertola, Francesco, primary, Birkinshaw, M., additional, Combes, F., additional, Lilly, S., additional, Okamura, S., additional, Peacock, J., additional, Sadler, E.M., additional, Trimble, V., additional, and Webster, R., additional

Published
2005
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28. The 2QZ BL Lac survey.

Author

Londish, D., Croom, S.M., Boyle, B.J., Shanks, T., Outram, P.J., Sadler, E.M., Loaring, N.S., Smith, R.J., Miller, L., and Maxted, P.F.L.

Subjects
FIELD theory (Physics), QUASARS, REDSHIFT
Abstract

We have optically identified a sample of 56 featureless continuum objects without significant proper motion from the 2dF quasi-stellar object (QSO) redshift survey (2QZ). The steep number–magnitude relation of the sample, n(b[sub J]) ∝ 10[sup 0.7b[sub J]], is similar to that derived for QSOs in the 2QZ and inconsistent with any population of Galactic objects. Follow-up high-resolution, high signal-to-noise spectroscopy of five randomly selected objects confirms the featureless nature of these sources. Assuming the objects in the sample to be largely featureless active galactic nuclei (AGN), and using the QSO evolution model derived for the 2QZ, we predict the median redshift of the sample to be z= 1.1. This model also reproduces the observed number–magnitude relation of the sample using a renormalization of the QSO luminosity function, O[sup *]=O[sup *][sub QSO]/66 ≃ 1.65 x 10[sup –10] mag[sup –1] MPC[sup –3]. Only ∼20 per cent of the objects have a radio flux density of S[sub 1.4] > 3 mJy, and further Very Large Array observations at 8.4 GHz place a 5σ limit of S[sub 8.4] < 0.2 mJy on the bulk of the sample. We postulate that these objects could form a population of radio-weak AGN with weak or absent emission lines, whose optical spectra are indistinguishable from those of BL Lac objects. [ABSTRACT FROM AUTHOR]

Published
2002
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29. Radio sources in the 2dF Galaxy Redshift Survey – II. Local radio luminosity functions for AGN and star-forming galaxies at 1.4 GHz.

Author

Sadler, E.M., Jackson, C.A., Cannon, R.D., McIntyre, V.J., Murphy, T., Bland-Hawthorn, J., Bridges, T., Cole, S., Colless, M., Collins, C., Couch, W., Dalton, G., de Propris, R., Driver, S.P., Efstathiou, G., Ellis, R.S., Frenk, C.S., Glazebrook, K., Lahav, O., and Lewis, I.

Subjects
*COSMIC magnetic fields, *VERY large array telescopes, *GALAXIES
Abstract

We have cross-matched the 1.4-GHz NRAO VLA Sky Survey (NVSS) with the first 210 fields observed in the 2dF Galaxy Redshift Survey (2dFGRS), covering an effective area of 325 deg[sup 2] (about 20 per cent of the final 2dFGRS area). This yields a set of optical spectra of 912 candidate NVSS counterparts, of which we identify 757 as genuine radio identifications – the largest and most homogeneous set of radio source spectra ever obtained. The 2dFGRS radio sources span the redshift range z=0.005 to 0.438, and are a mixture of active galaxies (60 per cent) and star-forming galaxies (40 per cent). About 25 per cent of the 2dFGRS radio sources are spatially resolved by NVSS, and the sample includes three giant radio galaxies with projected linear size greater than 1 Mpc. The high quality of the 2dF spectra means we can usually distinguish unambiguously between AGN and star-forming galaxies. We make a new determination of the local radio luminosity function at 1.4 GHz for both active and star-forming galaxies, and derive a local star formation density of 0.022±0.004 M[sub ⊙] yr[sup -1] Mpc[sup -3] (H[sub 0]=50 km s[sup -1] Mpc[sup -1]). [ABSTRACT FROM AUTHOR]

Published
2002
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30. Spectral evolution of the peculiar Ic Supernova 1998bw.

Author

Stathakis, R.A., Boyle, B.J., Jones, D.H., Bessell, M.S., Galama, T.J., Germany, L.M., Hartley, M., James, D.M., Kouveliotou, C., Lewis, I.J., Parker, Q.A., Russell, K.S., Sadler, E.M., Tinney, C.G., van Paradijs, J., and Vreeswijk, P.M.

Subjects
SUPERNOVAE spectra, SPEED
Abstract

Supernova 1998bw holds the record for the most energetic Type Ic explosion, one of the brightest radio supernovae and probably the first supernova associated with a γ-ray burst. In this paper we present spectral observations of SN 1998bw observed in a cooperative monitoring campaign using the Anglo-Australian Telescope, the UK Schmidt Telescope and the Siding Springs Observatories 2.3-m telescope. We investigate the evolution of the spectrum between 7 and 94 d after V-band maximum in comparison with well-studied examples of Type Ic SNe in order to quantify the unusual properties of this supernova event. Though the early spectra differ greatly from observations of classical Ic supernovae (SNe), we find that the evolution from the photospheric to nebular phases is slow but otherwise typical. The spectra differ predominantly in the extensive line blending and blanketing which has been attributed to the high velocity of the ejecta. We find that by day 19, the absorption line minima blueshifts are 10–50 per cent higher than other SNe and on day 94 emission lines are 45 per cent broader, as expected if the progenitor had a massive envelope. However, it is difficult to explain the extent of line blanketing entirely by line broadening, and we argue that an additional contribution from other species is present, indicating unusual relative abundances or physical conditions in the envelope. [ABSTRACT FROM AUTHOR]

Published
2000
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31. Galaxy destruction and diffuse light in clusters.

Author

Calcáneo-Roldán, C., Moore, B., Bland-Hawthorn, J., Malin, D., and Sadler, E.M.

Subjects
CENTAURUS (Constellation), GALAXY clusters
Abstract

Deep images of the Centaurus and Coma clusters reveal two spectacular arcs of diffuse light that stretch for over 100 kpc, yet are just a few kiloparsecs wide. At a surface brightness of m[sub b]∼27–28 mag arcsec[sup -2], the Centaurus arc is the most striking example known of structure in the diffuse light component of a rich galaxy cluster. We use numerical simulations to show that the Centaurus feature can be reproduced by the tidal debris of a spiral galaxy that has been tidally disrupted by the gravitational potential of NGC 4709. The surface brightness and narrow dimensions of the diffuse light suggest that the disc was corotating with its orbital path past pericentre. Features this prominent in clusters will be relatively rare, although at fainter surface brightness levels the diffuse light will reveal a wealth of structure. Deeper imaging surveys may be able to trace this feature for several times its presently observed extent, and somewhere along the tidal debris, a fraction of the original stellar component of the disc will remain bound, but transformed into a faint spheroidal galaxy. It should be possible to confirm the galactic origin of the Centaurus arc by observing planetary nebulae along its length with redshifts close to that of NGC 4709. [ABSTRACT FROM AUTHOR]

Published
2000
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33. Follow up of GW170817 and its electromagnetic counterpart by Australian-led observing programmes

Author

Andreoni, I., Ackley, K., Cooke, J., Acharyya, A., Allison, J.R., Anderson, G.E., Ashley, M.C.B., Baade, D., Bailes, M., Bannister, K., Beardsley, A., Bessell, M.S., Bian, F., Bland, P.A., Boer, M., Booler, T., Brandeker, A., Brown, I.S., Buckley, D.A.H., Chang, S.-W., Coward, D.M., Crawford, S., Crisp, H., Crosse, B., Cucchiara, A., Cupák, M., de Gois, J.S., Deller, A., Devillepoix, H.A.R., Dobie, D., Elmer, E., Emrich, D., Farah, W., Farrell, T.J., Franzen, T., Gaensler, B.M., Galloway, D.K., Gendre, B., Giblin, T., Goobar, A., Green, J., Hancock, P.J., Hartig, B.A.D., Howell, E.J., Horsley, L., Hotan, A., Howie, R.M., Hu, L., Hu, Y., James, C.W., Johnston, S., Johnston-Hollitt, M., Kaplan, D.L., Kasliwal, M., Keane, E.F., Kenney, D., Klotz, A., Lau, R., Laugier, R., Lenc, E., Li, X., Liang, E., Lidman, C., Luvaul, L.C., Lynch, C., Ma, B., Macpherson, D., Mao, J., McClelland, D.E., McCully, C., Möller, A., Morales, M.F., Morris, D., Murphy, T., Noysena, K., Onken, C.A., Orange, N.B., Osłowski, S., Pallot, D., Paxman, J., Potter, S.B., Pritchard, T., Raja, W., Ridden-Harper, R., Romero-Colmenero, E., Sadler, E.M., Sansom, E.K., Scalzo, R.A., Schmidt, B.P., Scott, S.M., Seghouani, N., Shang, Z., Shannon, R.M., Shao, L., Shara, M.M., Sharp, R., Sokolowski, M., Sollerman, J., Staff, J., Steele, K., Sun, T., Suntzeff, N.B., Tao, C., Tingay, S., Towner, M.C., Thierry, P., Trott, C., Tucker, B.E., Väisänen, P., Krishnan, V. Venkatraman, Walker, M., Wang, L., Wang, X., Wayth, R., Whiting, M., Williams, A., Williams, T., Wolf, C., Wu, C., Wu, X., Yang, J., Yuan, X., Zhang, H., Zhou, J., Zovaro, H., Andreoni, I., Ackley, K., Cooke, J., Acharyya, A., Allison, J.R., Anderson, G.E., Ashley, M.C.B., Baade, D., Bailes, M., Bannister, K., Beardsley, A., Bessell, M.S., Bian, F., Bland, P.A., Boer, M., Booler, T., Brandeker, A., Brown, I.S., Buckley, D.A.H., Chang, S.-W., Coward, D.M., Crawford, S., Crisp, H., Crosse, B., Cucchiara, A., Cupák, M., de Gois, J.S., Deller, A., Devillepoix, H.A.R., Dobie, D., Elmer, E., Emrich, D., Farah, W., Farrell, T.J., Franzen, T., Gaensler, B.M., Galloway, D.K., Gendre, B., Giblin, T., Goobar, A., Green, J., Hancock, P.J., Hartig, B.A.D., Howell, E.J., Horsley, L., Hotan, A., Howie, R.M., Hu, L., Hu, Y., James, C.W., Johnston, S., Johnston-Hollitt, M., Kaplan, D.L., Kasliwal, M., Keane, E.F., Kenney, D., Klotz, A., Lau, R., Laugier, R., Lenc, E., Li, X., Liang, E., Lidman, C., Luvaul, L.C., Lynch, C., Ma, B., Macpherson, D., Mao, J., McClelland, D.E., McCully, C., Möller, A., Morales, M.F., Morris, D., Murphy, T., Noysena, K., Onken, C.A., Orange, N.B., Osłowski, S., Pallot, D., Paxman, J., Potter, S.B., Pritchard, T., Raja, W., Ridden-Harper, R., Romero-Colmenero, E., Sadler, E.M., Sansom, E.K., Scalzo, R.A., Schmidt, B.P., Scott, S.M., Seghouani, N., Shang, Z., Shannon, R.M., Shao, L., Shara, M.M., Sharp, R., Sokolowski, M., Sollerman, J., Staff, J., Steele, K., Sun, T., Suntzeff, N.B., Tao, C., Tingay, S., Towner, M.C., Thierry, P., Trott, C., Tucker, B.E., Väisänen, P., Krishnan, V. Venkatraman, Walker, M., Wang, L., Wang, X., Wayth, R., Whiting, M., Williams, A., Williams, T., Wolf, C., Wu, C., Wu, X., Yang, J., Yuan, X., Zhang, H., Zhou, J., and Zovaro, H.

Abstract

The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.

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34. Follow up of GW170817 and its electromagnetic counterpart by Australian-led observing programmes

Author

Andreoni, I., Ackley, K., Cooke, J., Acharyya, A., Allison, J.R., Anderson, G.E., Ashley, M.C.B., Baade, D., Bailes, M., Bannister, K., Beardsley, A., Bessell, M.S., Bian, F., Bland, P.A., Boer, M., Booler, T., Brandeker, A., Brown, I.S., Buckley, D.A.H., Chang, S.-W., Coward, D.M., Crawford, S., Crisp, H., Crosse, B., Cucchiara, A., Cupák, M., de Gois, J.S., Deller, A., Devillepoix, H.A.R., Dobie, D., Elmer, E., Emrich, D., Farah, W., Farrell, T.J., Franzen, T., Gaensler, B.M., Galloway, D.K., Gendre, B., Giblin, T., Goobar, A., Green, J., Hancock, P.J., Hartig, B.A.D., Howell, E.J., Horsley, L., Hotan, A., Howie, R.M., Hu, L., Hu, Y., James, C.W., Johnston, S., Johnston-Hollitt, M., Kaplan, D.L., Kasliwal, M., Keane, E.F., Kenney, D., Klotz, A., Lau, R., Laugier, R., Lenc, E., Li, X., Liang, E., Lidman, C., Luvaul, L.C., Lynch, C., Ma, B., Macpherson, D., Mao, J., McClelland, D.E., McCully, C., Möller, A., Morales, M.F., Morris, D., Murphy, T., Noysena, K., Onken, C.A., Orange, N.B., Osłowski, S., Pallot, D., Paxman, J., Potter, S.B., Pritchard, T., Raja, W., Ridden-Harper, R., Romero-Colmenero, E., Sadler, E.M., Sansom, E.K., Scalzo, R.A., Schmidt, B.P., Scott, S.M., Seghouani, N., Shang, Z., Shannon, R.M., Shao, L., Shara, M.M., Sharp, R., Sokolowski, M., Sollerman, J., Staff, J., Steele, K., Sun, T., Suntzeff, N.B., Tao, C., Tingay, S., Towner, M.C., Thierry, P., Trott, C., Tucker, B.E., Väisänen, P., Krishnan, V. Venkatraman, Walker, M., Wang, L., Wang, X., Wayth, R., Whiting, M., Williams, A., Williams, T., Wolf, C., Wu, C., Wu, X., Yang, J., Yuan, X., Zhang, H., Zhou, J., Zovaro, H., Andreoni, I., Ackley, K., Cooke, J., Acharyya, A., Allison, J.R., Anderson, G.E., Ashley, M.C.B., Baade, D., Bailes, M., Bannister, K., Beardsley, A., Bessell, M.S., Bian, F., Bland, P.A., Boer, M., Booler, T., Brandeker, A., Brown, I.S., Buckley, D.A.H., Chang, S.-W., Coward, D.M., Crawford, S., Crisp, H., Crosse, B., Cucchiara, A., Cupák, M., de Gois, J.S., Deller, A., Devillepoix, H.A.R., Dobie, D., Elmer, E., Emrich, D., Farah, W., Farrell, T.J., Franzen, T., Gaensler, B.M., Galloway, D.K., Gendre, B., Giblin, T., Goobar, A., Green, J., Hancock, P.J., Hartig, B.A.D., Howell, E.J., Horsley, L., Hotan, A., Howie, R.M., Hu, L., Hu, Y., James, C.W., Johnston, S., Johnston-Hollitt, M., Kaplan, D.L., Kasliwal, M., Keane, E.F., Kenney, D., Klotz, A., Lau, R., Laugier, R., Lenc, E., Li, X., Liang, E., Lidman, C., Luvaul, L.C., Lynch, C., Ma, B., Macpherson, D., Mao, J., McClelland, D.E., McCully, C., Möller, A., Morales, M.F., Morris, D., Murphy, T., Noysena, K., Onken, C.A., Orange, N.B., Osłowski, S., Pallot, D., Paxman, J., Potter, S.B., Pritchard, T., Raja, W., Ridden-Harper, R., Romero-Colmenero, E., Sadler, E.M., Sansom, E.K., Scalzo, R.A., Schmidt, B.P., Scott, S.M., Seghouani, N., Shang, Z., Shannon, R.M., Shao, L., Shara, M.M., Sharp, R., Sokolowski, M., Sollerman, J., Staff, J., Steele, K., Sun, T., Suntzeff, N.B., Tao, C., Tingay, S., Towner, M.C., Thierry, P., Trott, C., Tucker, B.E., Väisänen, P., Krishnan, V. Venkatraman, Walker, M., Wang, L., Wang, X., Wayth, R., Whiting, M., Williams, A., Williams, T., Wolf, C., Wu, C., Wu, X., Yang, J., Yuan, X., Zhang, H., Zhou, J., and Zovaro, H.

Abstract

The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.

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35. Follow up of GW170817 and its electromagnetic counterpart by Australian-led observing programmes

Author

Andreoni, I., Ackley, K., Cooke, J., Acharyya, A., Allison, J.R., Anderson, G.E., Ashley, M.C.B., Baade, D., Bailes, M., Bannister, K., Beardsley, A., Bessell, M.S., Bian, F., Bland, P.A., Boer, M., Booler, T., Brandeker, A., Brown, I.S., Buckley, D.A.H., Chang, S.-W., Coward, D.M., Crawford, S., Crisp, H., Crosse, B., Cucchiara, A., Cupák, M., de Gois, J.S., Deller, A., Devillepoix, H.A.R., Dobie, D., Elmer, E., Emrich, D., Farah, W., Farrell, T.J., Franzen, T., Gaensler, B.M., Galloway, D.K., Gendre, B., Giblin, T., Goobar, A., Green, J., Hancock, P.J., Hartig, B.A.D., Howell, E.J., Horsley, L., Hotan, A., Howie, R.M., Hu, L., Hu, Y., James, C.W., Johnston, S., Johnston-Hollitt, M., Kaplan, D.L., Kasliwal, M., Keane, E.F., Kenney, D., Klotz, A., Lau, R., Laugier, R., Lenc, E., Li, X., Liang, E., Lidman, C., Luvaul, L.C., Lynch, C., Ma, B., Macpherson, D., Mao, J., McClelland, D.E., McCully, C., Möller, A., Morales, M.F., Morris, D., Murphy, T., Noysena, K., Onken, C.A., Orange, N.B., Osłowski, S., Pallot, D., Paxman, J., Potter, S.B., Pritchard, T., Raja, W., Ridden-Harper, R., Romero-Colmenero, E., Sadler, E.M., Sansom, E.K., Scalzo, R.A., Schmidt, B.P., Scott, S.M., Seghouani, N., Shang, Z., Shannon, R.M., Shao, L., Shara, M.M., Sharp, R., Sokolowski, M., Sollerman, J., Staff, J., Steele, K., Sun, T., Suntzeff, N.B., Tao, C., Tingay, S., Towner, M.C., Thierry, P., Trott, C., Tucker, B.E., Väisänen, P., Krishnan, V. Venkatraman, Walker, M., Wang, L., Wang, X., Wayth, R., Whiting, M., Williams, A., Williams, T., Wolf, C., Wu, C., Wu, X., Yang, J., Yuan, X., Zhang, H., Zhou, J., Zovaro, H., Andreoni, I., Ackley, K., Cooke, J., Acharyya, A., Allison, J.R., Anderson, G.E., Ashley, M.C.B., Baade, D., Bailes, M., Bannister, K., Beardsley, A., Bessell, M.S., Bian, F., Bland, P.A., Boer, M., Booler, T., Brandeker, A., Brown, I.S., Buckley, D.A.H., Chang, S.-W., Coward, D.M., Crawford, S., Crisp, H., Crosse, B., Cucchiara, A., Cupák, M., de Gois, J.S., Deller, A., Devillepoix, H.A.R., Dobie, D., Elmer, E., Emrich, D., Farah, W., Farrell, T.J., Franzen, T., Gaensler, B.M., Galloway, D.K., Gendre, B., Giblin, T., Goobar, A., Green, J., Hancock, P.J., Hartig, B.A.D., Howell, E.J., Horsley, L., Hotan, A., Howie, R.M., Hu, L., Hu, Y., James, C.W., Johnston, S., Johnston-Hollitt, M., Kaplan, D.L., Kasliwal, M., Keane, E.F., Kenney, D., Klotz, A., Lau, R., Laugier, R., Lenc, E., Li, X., Liang, E., Lidman, C., Luvaul, L.C., Lynch, C., Ma, B., Macpherson, D., Mao, J., McClelland, D.E., McCully, C., Möller, A., Morales, M.F., Morris, D., Murphy, T., Noysena, K., Onken, C.A., Orange, N.B., Osłowski, S., Pallot, D., Paxman, J., Potter, S.B., Pritchard, T., Raja, W., Ridden-Harper, R., Romero-Colmenero, E., Sadler, E.M., Sansom, E.K., Scalzo, R.A., Schmidt, B.P., Scott, S.M., Seghouani, N., Shang, Z., Shannon, R.M., Shao, L., Shara, M.M., Sharp, R., Sokolowski, M., Sollerman, J., Staff, J., Steele, K., Sun, T., Suntzeff, N.B., Tao, C., Tingay, S., Towner, M.C., Thierry, P., Trott, C., Tucker, B.E., Väisänen, P., Krishnan, V. Venkatraman, Walker, M., Wang, L., Wang, X., Wayth, R., Whiting, M., Williams, A., Williams, T., Wolf, C., Wu, C., Wu, X., Yang, J., Yuan, X., Zhang, H., Zhou, J., and Zovaro, H.

Abstract

The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.

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36. Follow up of GW170817 and its electromagnetic counterpart by Australian-led observing programmes

Author

Andreoni, I., Ackley, K., Cooke, J., Acharyya, A., Allison, J.R., Anderson, G.E., Ashley, M.C.B., Baade, D., Bailes, M., Bannister, K., Beardsley, A., Bessell, M.S., Bian, F., Bland, P.A., Boer, M., Booler, T., Brandeker, A., Brown, I.S., Buckley, D.A.H., Chang, S.-W., Coward, D.M., Crawford, S., Crisp, H., Crosse, B., Cucchiara, A., Cupák, M., de Gois, J.S., Deller, A., Devillepoix, H.A.R., Dobie, D., Elmer, E., Emrich, D., Farah, W., Farrell, T.J., Franzen, T., Gaensler, B.M., Galloway, D.K., Gendre, B., Giblin, T., Goobar, A., Green, J., Hancock, P.J., Hartig, B.A.D., Howell, E.J., Horsley, L., Hotan, A., Howie, R.M., Hu, L., Hu, Y., James, C.W., Johnston, S., Johnston-Hollitt, M., Kaplan, D.L., Kasliwal, M., Keane, E.F., Kenney, D., Klotz, A., Lau, R., Laugier, R., Lenc, E., Li, X., Liang, E., Lidman, C., Luvaul, L.C., Lynch, C., Ma, B., Macpherson, D., Mao, J., McClelland, D.E., McCully, C., Möller, A., Morales, M.F., Morris, D., Murphy, T., Noysena, K., Onken, C.A., Orange, N.B., Osłowski, S., Pallot, D., Paxman, J., Potter, S.B., Pritchard, T., Raja, W., Ridden-Harper, R., Romero-Colmenero, E., Sadler, E.M., Sansom, E.K., Scalzo, R.A., Schmidt, B.P., Scott, S.M., Seghouani, N., Shang, Z., Shannon, R.M., Shao, L., Shara, M.M., Sharp, R., Sokolowski, M., Sollerman, J., Staff, J., Steele, K., Sun, T., Suntzeff, N.B., Tao, C., Tingay, S., Towner, M.C., Thierry, P., Trott, C., Tucker, B.E., Väisänen, P., Krishnan, V. Venkatraman, Walker, M., Wang, L., Wang, X., Wayth, R., Whiting, M., Williams, A., Williams, T., Wolf, C., Wu, C., Wu, X., Yang, J., Yuan, X., Zhang, H., Zhou, J., Zovaro, H., Andreoni, I., Ackley, K., Cooke, J., Acharyya, A., Allison, J.R., Anderson, G.E., Ashley, M.C.B., Baade, D., Bailes, M., Bannister, K., Beardsley, A., Bessell, M.S., Bian, F., Bland, P.A., Boer, M., Booler, T., Brandeker, A., Brown, I.S., Buckley, D.A.H., Chang, S.-W., Coward, D.M., Crawford, S., Crisp, H., Crosse, B., Cucchiara, A., Cupák, M., de Gois, J.S., Deller, A., Devillepoix, H.A.R., Dobie, D., Elmer, E., Emrich, D., Farah, W., Farrell, T.J., Franzen, T., Gaensler, B.M., Galloway, D.K., Gendre, B., Giblin, T., Goobar, A., Green, J., Hancock, P.J., Hartig, B.A.D., Howell, E.J., Horsley, L., Hotan, A., Howie, R.M., Hu, L., Hu, Y., James, C.W., Johnston, S., Johnston-Hollitt, M., Kaplan, D.L., Kasliwal, M., Keane, E.F., Kenney, D., Klotz, A., Lau, R., Laugier, R., Lenc, E., Li, X., Liang, E., Lidman, C., Luvaul, L.C., Lynch, C., Ma, B., Macpherson, D., Mao, J., McClelland, D.E., McCully, C., Möller, A., Morales, M.F., Morris, D., Murphy, T., Noysena, K., Onken, C.A., Orange, N.B., Osłowski, S., Pallot, D., Paxman, J., Potter, S.B., Pritchard, T., Raja, W., Ridden-Harper, R., Romero-Colmenero, E., Sadler, E.M., Sansom, E.K., Scalzo, R.A., Schmidt, B.P., Scott, S.M., Seghouani, N., Shang, Z., Shannon, R.M., Shao, L., Shara, M.M., Sharp, R., Sokolowski, M., Sollerman, J., Staff, J., Steele, K., Sun, T., Suntzeff, N.B., Tao, C., Tingay, S., Towner, M.C., Thierry, P., Trott, C., Tucker, B.E., Väisänen, P., Krishnan, V. Venkatraman, Walker, M., Wang, L., Wang, X., Wayth, R., Whiting, M., Williams, A., Williams, T., Wolf, C., Wu, C., Wu, X., Yang, J., Yuan, X., Zhang, H., Zhou, J., and Zovaro, H.

Abstract

The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.

Full Text
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