3 results
VaTEST III: Validation of eight potential super-earths from TESS data
- Priyashkumar Mistry, Aniket Prasad, Mousam Maity, Kamlesh Pathak, Sarvesh Gharat, Georgios Lekkas, Surendra Bhattarai, Dhruv Kumar, Jack J. Lissauer, Joseph D. Twicken, Abderahmane Soubkiou, Francisco J. Pozuelos, Jon Jenkins, Keith Horne, Steven Giacalone, Khalid Barkaoui, Mathilde Timmermans, Cristilyn N. Watkins, Ramotholo Sefako, Karen A. Collins, David R. Ciardi, Catherine A. Clark, Boris S. Safonov, Avi Shporer, Joshua E. Schlieder, Zouhair Benkhaldoun, Chris Stockdale, Carl Ziegler, Emily A. Gilbert, Jehin Emmanuël, Felipe Murgas, Ian J. M. Crossfield, Martin Paegert, Michael B. Lund, Norio Narita, Richard P. Schwarz, Robert F. Goeke, Sergio B. Fajardo-Acosta, Steve B. Howell, Thiam-Guan Tan, Thomas Barclay, Yugo Kawai
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- Journal:
- Publications of the Astronomical Society of Australia / Volume 41 / 2024
- Published online by Cambridge University Press:
- 11 April 2024, e030
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NASA’s all-sky survey mission, the Transiting Exoplanet Survey Satellite (TESS), is specifically engineered to detect exoplanets that transit bright stars. Thus far, TESS has successfully identified approximately 400 transiting exoplanets, in addition to roughly 6 000 candidate exoplanets pending confirmation. In this study, we present the results of our ongoing project, the Validation of Transiting Exoplanets using Statistical Tools (VaTEST). Our dedicated effort is focused on the confirmation and characterisation of new exoplanets through the application of statistical validation tools. Through a combination of ground-based telescope data, high-resolution imaging, and the utilisation of the statistical validation tool known as TRICERATOPS, we have successfully discovered eight potential super-Earths. These planets bear the designations: TOI-238b (1.61$^{+0.09} _{-0.10}$ R$_\oplus$), TOI-771b (1.42$^{+0.11} _{-0.09}$ R$_\oplus$), TOI-871b (1.66$^{+0.11} _{-0.11}$ R$_\oplus$), TOI-1467b (1.83$^{+0.16} _{-0.15}$ R$_\oplus$), TOI-1739b (1.69$^{+0.10} _{-0.08}$ R$_\oplus$), TOI-2068b (1.82$^{+0.16} _{-0.15}$ R$_\oplus$), TOI-4559b (1.42$^{+0.13} _{-0.11}$ R$_\oplus$), and TOI-5799b (1.62$^{+0.19} _{-0.13}$ R$_\oplus$). Among all these planets, six of them fall within the region known as ‘keystone planets’, which makes them particularly interesting for study. Based on the location of TOI-771b and TOI-4559b below the radius valley we characterised them as likely super-Earths, though radial velocity mass measurements for these planets will provide more details about their characterisation. It is noteworthy that planets within the size range investigated herein are absent from our own solar system, making their study crucial for gaining insights into the evolutionary stages between Earth and Neptune.
The Indian Pulsar Timing Array: First data release
- Pratik Tarafdar, K Nobleson, Prerna Rana, Jaikhomba Singha, M. A. Krishnakumar, Bhal Chandra Joshi, Avinash Kumar Paladi, Neel Kolhe, Neelam Dhanda Batra, Nikita Agarwal, Adarsh Bathula, Subhajit Dandapat, Shantanu Desai, Lankeswar Dey, Shinnosuke Hisano, Prathamesh Ingale, Ryo Kato, Divyansh Kharbanda, Tomonosuke Kikunaga, Piyush Marmat, B. Arul Pandian, T. Prabu, Aman Srivastava, Mayuresh Surnis, Sai Chaitanya Susarla, Abhimanyu Susobhanan, Keitaro Takahashi, P. Arumugam, Manjari Bagchi, Sarmistha Banik, Kishalay De, Raghav Girgaonkar, A. Gopakumar, Yashwant Gupta, Yogesh Maan, P. K. Manoharan, Arun Naidu, Dhruv Pathak
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- Journal:
- Publications of the Astronomical Society of Australia / Volume 39 / 2022
- Published online by Cambridge University Press:
- 24 October 2022, e053
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We present the pulse arrival times and high-precision dispersion measure estimates for 14 millisecond pulsars observed simultaneously in the 300 $-$ 500 MHz and 1260 $-$ 1460 MHz frequency bands using the upgraded Giant Metrewave Radio Telescope. The data spans over a baseline of 3.5 years (2018-2021), and is the first official data release made available by the Indian Pulsar Timing Array collaboration. This data release presents a unique opportunity for investigating the interstellar medium effects at low radio frequencies and their impact on the timing precision of pulsar timing array experiments. In addition to the dispersion measure time series and pulse arrival times obtained using both narrowband and wideband timing techniques, we also present the dispersion measure structure function analysis for selected pulsars. Our ongoing investigations regarding the frequency dependence of dispersion measures have been discussed. Based on the preliminary analysis for five millisecond pulsars, we do not find any conclusive evidence of chromaticity in dispersion measures. Data from regular simultaneous two-frequency observations are presented for the first time in this work. This distinctive feature leads us to the highest precision dispersion measure estimates obtained so far for a subset of our sample. Simultaneous multi-band upgraded Giant Metrewave Radio Telescope observations in 300 $-$ 500 MHz and 1260 $-$ 1460 MHz are crucial for high-precision dispersion measure estimation and for the prospect of expanding the overall frequency coverage upon the combination of data from the various Pulsar Timing Array consortia in the near future. Parts of the data presented in this work are expected to be incorporated into the upcoming third data release of the International Pulsar Timing Array.
pinta: The uGMRT data processing pipeline for the Indian Pulsar Timing Array
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- Abhimanyu Susobhanan, Yogesh Maan, Bhal Chandra Joshi, T. Prabu, Shantanu Desai, K. Nobleson, Sai Chaitanya Susarla, Raghav Girgaonkar, Lankeswar Dey, Neelam Dhanda Batra, Yashwant Gupta, A. Gopakumar, Manjari Bagchi, Avishek Basu, Suryarao Bethapudi, Arpita Choudhary, Kishalay De, M. A. Krishnakumar, P. K. Manoharan, Arun Kumar Naidu, Dhruv Pathak, Jaikhomba Singha, Mayuresh P. Surnis
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- Journal:
- Publications of the Astronomical Society of Australia / Volume 38 / 2021
- Published online by Cambridge University Press:
- 14 April 2021, e017
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We introduce pinta, a pipeline for reducing the upgraded Giant Metre-wave Radio Telescope (uGMRT) raw pulsar timing data, developed for the Indian Pulsar Timing Array experiment. We provide a detailed description of the workflow and usage of pinta, as well as its computational performance and RFI mitigation characteristics. We also discuss a novel and independent determination of the relative time offsets between the different back-end modes of uGMRT and the interpretation of the uGMRT observation frequency settings and their agreement with results obtained from engineering tests. Further, we demonstrate the capability of pinta to generate data products which can produce high-precision TOAs using PSR J1909 $-$ 3744 as an example. These results are crucial for performing precision pulsar timing with the uGMRT.