Photoionization Analysis and Abundance Determination of Classical Nova V6567 Sgr

Year 2025, Volume: 6 Issue: Special Issue: UAK2024 Proc., 159 - 166, 01.07.2025

Hasan H. Esenoğlu , Gamal M. Hamed

https://doi.org/10.55064/tjaa.1592027

Abstract

In this study, we present the results of a photoionization analysis and abundance determination of the optical spectrum of the classical nova V6567 Sgr, using the Cloudy code. This nova was discovered on June 1, 2020, and reached peak brightness on June 17, 2020. The spectrum was obtained on June 30, 2020, with the TUG-RTT150 telescope. When classical novae are observed in the nebular phase, this modeling approach offers insights into abundance analysis, the characteristics of the underlying white dwarf, the outburst mechanism, and the physical conditions of the system prior to the explosion. Thirteen days after V6567 Sgr reached its maximum brightness, its shell was modeled in this way, and the model outputs were compared with observational data. Using the Cloudy code in this model, we solved the thermal and statistical equilibrium equations for the nova shell, calculating the electron temperature, number density, emission spectrum, and ionization levels. The discrepancies between the modeled and observed spectra for V6567 Sgr, along with certain spectral features, suggest that the nova has not yet entered the nebular phase. The results of the photoionization analysis and abundance determination indicate that V6567 Sgr is not in the nebular phase. This suggests that the nebular phase of the nova likely occurred sometime after the 13th day following the outburst. The findings from three different novae were compared at distinct stages: day 13 (pre-cloud phase), day 265 (cloud phase), and day 515 (late cloud phase) after maximum brightness.

Keywords

nova , cataclysmic variable , V6567 Sgr , spectroscopy

Klasik Nova V6567 Sgr’un Fotoiyonizasyon Analizi ve Bolluk Tayini

Abstract

Bu araştırma, 2020-06-01 tarihinde keşfedildiği ve 2020-06-17 tarihinde patlama olayının en büyük parlaklığa ulaştığı klasik nova V6567 Sgr'un 2020-06-30’da TUG-RTT150 teleskopundan alınan optik tayfının Cloudy kodu kullanılarak fotoinizasyon analizi ve bolluk tayini sonuçlarını sunuyoruz. Klasik novalar eğer bulutsu evrede bulunursa bu model, bolluk analizi, içteki beyaz cüce, patlamanın mekanizması ve patlamadan önceki sistemin fiziksel koşulları hakkında bilgi verir. Maksimum parlaklığından sonraki 13. gününde V6567 Sgr'un kabuğu bu şekilde modellenmiştir ve çıktıları gözlemle karşılaştırılmıştır. Modelde kullanılan Cloudy kodu ile, bu nova kabuğunun termal ve istatistiksel denge denklemleri çözülmüş ve bu yolla elektron sıcaklığı ve sayı yoğunluğu ile salma tayfı ve iyonlaşma hesaplanmıştır. V6567 Sgr için uygulanan model ve gözlem tayflarının uyuşmaması ve gözlenen tayfsal özellikler nedeniyle novanın bulutsu evreye henüz girmediği görülmüştür. Fotoiyonizasyon analizinin ve bolluk tayininin sonuçları bulutsu evreye ait olmadığı yönündedir. Bu durumda, novanın bulutsu evresi, patlamanın 13. günden sonraki zamanlarda gerçekleşmiş olmalıdır. Maksimum ışıktan 13. (bulut öncesi evre), 265. (bulut evresi) ve 515. (geç bulut evresi) günlerde üç farklı novanın tüm bulguları da karşılaştırılmıştır.

Keywords

nova , cataclysmic variable , V6567 Sgr , spectroscopy

References

• Andreä, J., Drechsel, H., Starrfield, S., AA 191 (1994) 869–889
• Astropy Collaboration, AA 558 (2013) A33
• Astropy Collaboration, AA 156 (2018) 123–132
• Austin, S.J., Wagner, R.M., Starrfield, S., Shore, S.N., Sonneborn, G., Bertram, R., AJ 111 (1996) 869–898
• Balman, S., Yilmaz, A., Retter, A., Saygac, T., Esenoglu, H., MNRAS 356 (2005) 773–777
• Banerjee, D.P.K and Ashok, N.M., BASI 40 (2012) 243–265
• Banerjee, D.P.K., Woodward, C.E., Evans, A., Bus, S.J., Starrfield, S., Wagner, R.M., ATel 13888 (2020)
• Cayrel, R. The Impact of Very High S/N Spectroscopy on Stellar Physics (Eds. G. Cayrel de Strobel, M. Spite), IAUS 132 (1988) 345–353
• Craig, M. et al. Astropy/ccdproc: v1.3.0.post1 (2017)
• De, K., Hankins, M.J., Kasliwal, M.M., Moore, A.M., Ofek, E.O., Adams, S.M., Ashley, M.C.B., Babul, A.N., Bagdasaryan, A., Burdge, K.B., Burnham, J., Dekany, R.G., Declacroix, A., Galla, A., Greffe, T., Hale, D., Jencson, J.E., Lau, R.M., Mahabal, A., McKenna, D., Sharma, M., Shopbell, P.L., Smith, R.M., Soon, J., Sokoloski, J., Soria, R., Travouillon, T., PASP 132 (2020a) 025001
• De, K., Hankins, M., Kasliwal, M.M., Sokoloski, J., Ashley, M., Babul, A., Karambelkar, V., Lau, R.M., Moore, A., Ofek, E.O.,
• Sharma, M., Soon, J., Soria, R., Travouillon, T., ATel 13790 (2020b)
• Della Valle, M., Bianchini, A., Livio, M., Orio, M., AA 266 (1992) 232–236
• Ferland, G.J., Chatzikos, M., Guzmán, F., Lykins, M.L., van Hoof, P.A. M., Williams, R.J.R., Abel, N.P., Badnell, N.R., Keenan, F.P., Porter, R.L., Stancil, P.C., RMxAA 53 (2017) 385–438
• Fitzpatrick, E.L., Massa, D., Gordon, K.D., Bohlin, R., Clayton, G.C., AJ 886 (2019) 108–132
• González-Riestra, R., Krautter, J., Ultraviolet Astrophysics Beyond the IUE Final Archive (Eds. W. Wamsteker, R. González Riestra, B. Harris) ESA Special Publication 413 (1998)
• Hamed, G.M., Esenoglu, H.H., TJAA 4 (2023) 397–400
• Hamed G.M., Esenoglu, H.H, Galeev, A.I., New Astronomy 113 (2024) 102273
• Iijima, T., Esenoglu, H.H., AA 404 (2003) 997–1009 José, J. Stellar Explosions: Hydrodynamics and Nucleosynthesis, (2016) ISBN: 978-1-4398-5306-1
• Joshi, V., Banerjee, D.P.K., Srivastava, M., ApJ 851 (2017) L30
• Kalberla, P.M.W., Burton, W.B., Hartmann, D., Arnal, E.M., Bajaja, E., Morras, R., Pöppel, W.G.L., AA 440 (2005) 775–782
• Khamitov, I.M., Bikmaev, I.F., Burenin, R.A., Glushkov, M.V., Melnikov, S.S., Lyapin, A.R., Astron Lett 46 (2020) 1–11
• Kramida, A., Ralchenko, Y., Reader, J., NIST ASD Team NIST atomic spectra database (ver. 5.8) (2020) https://physics.nist.gov/asd
• Lenz, D.D., Ayres, T.R., PASP 104 (1992) 1104–1106
• Luridiana, V., Morisset, C., Shaw, R.A., AA 573 (2015) A42
• Masci, F.J., Laher, R.R., Rusholme, B., Shupe, D.L., Groom, S., Surace, J., Jackson, E., Monkewitz, S., Beck, R., Flynn, D., Terek, S., Landry, W., Hacopians, E., Desai, V., Howell, J., Brooke, T., Imel, D., Wachter, S., Ye, Q.Z., Lin, H.W., Cenko, S.B., Cunningham, V., Rebbapragada, U., Bue, B., Miller, A.A., Mahabal, A., Bellm, E.C., Patterson, M.T., Jurić, M., Golkhou, V.Z., Ofek, E.O., Walters, R., Graham, M., Kasliwal, M.M., Dekany, R.G., Kupfer, T., Burdge, K., Cannella, C.B., Barlow, T., Van Sistine, A., Giomi, M., Fremling, C., Blagorodnova, N., Levitan, D., Riddle, R., Smith, R.M., Helou, G., Prince, T.A., Kulkarni, S.R., PASP 131 (2020) 018003
• McCully, C., Crawford, S., Kovacs, G., Tollerud, E., Betts, E., Bradley, L., Craig, M., Turner, J., Streicher, O., Sipocz, B., Robitaille, T., Deil, C., Astropy/astroscrappy: v1.0.5 zenodo release (2018) https://zenodo.org/records/1482019
• Munari, U., Ochner, P., Vagnozzi, A., Moretti, S., Valisa, P., Maitan, A., Dallaporta, S., ATel 13807 (2020)
• Oke, J.B., AJ 99 (1990) 1621–1631
• Sokolovsky, K., Korotkiy, S., Lebedev, A., Stella Novae: Past and Future Decades (Eds. P.A.Woudt and V.A.R.M. Ribeiro) ASPC 197 (2014) 395–400
• Rayner, J.T., Toomey, D.W., Onaka, P.M., Denault, A.J.,
• Stahlberger, W.E., Vacca, W.D., Cushing, M.C., Wang, S., PASP 115 (2003) 362–382
• Saizar, P., Starrfield, S., Ferland, G.J., Wagner, R.M., Truran, J.W., Kenyon, S.J., Sparks, W.M., Williams, R.E., Stryker, L.L., ApJ 367 (1991) 310–320
• Shappee, B.J., Prieto, J.L., Grupe, D., Kochanek, C.S., Stanek, K.Z., De Rosa, G., Mathur, S., Zu, Y., Peterson, B.M., Pogge, R.W., Komossa, S., Im, M., Jencson, J., Holoien, T.W.S., Basu, U., Beacom, J.F., Szczygieł, D.M., Brimacombe, J., Adams, S., Campillay, A., Choi, C., Contreras, C., Dietrich, M., Dubberley, M., Elphick, M., Foale, S., Giustini, M., Gonzalez, C., Hawkins, E., Howell, D.A., Hsiao, E.Y., Koss, M., Leighly, K.M., Morrell, N., Mudd, D., Mullins, D., Nugent, J.M., Parrent, J., Phillips, M.M., Pojmanski, G., Rosing, W., Ross, R., Sand, D., Terndrup, D.M., Valenti, S., Walker, Z., Yoon, Y., ApJ 788 (2014) 48–61
• Sokolovsky K.V., Aydi E., Chomiuk, L., Kawash, A., Strader, J., Mukai, K., Hambsch, F.J., Vanmunster, T., Korotkiy, S., Beloushkin, A., ATel 13804 (2020)
• Stickland, D.J., Penn, C.J., Seaton, M.J., Snijders, M.A.J., Storey, P.J., MNRAS 197 (1981) 107003
• van den Bergh, S., Younger, P.F., AASuppl 70 (1987) 125–140
• Tody, D. Astronomical Data Analysis Software and Systems II (Eds. R.J. Hanisch, R.J.V. Brissenden, J. Barnes), AASuppl 52 (1993) 173–183
• van Dokkum, P.G., PASP 113 (2001) 1420–1427
• Yaron, O., Prialnik, D., Shara, M.M., Kovetz, A., ApJ 623 (2005) 398–410
• Warner B., Cataclysmic Variable Stars
• Woodward, C.E., Banerjee, D.P.K., Evans, A., Starrfield, S., Wagner, R.M., ATel 13801 (2020a)
• Woodward, C.E., Banerjee, D.P.K., Evans, A., Starrfield, S., Wagner, R.M., ATel 13852 (2020b)
• Woodward, C.E., Banerjee, D.P.K., Evans, A., ATel 14034 (2020c)