P2.1:
- TESS mission
P2.2:
- Extragalatic Transients
- Supernovae
- Thermonuclear, Type Ia: standardizable candle
- Core-collapse, Ib, Ic and II: Massive stars
- Superluminous
- Gamma-ray bursts (GRB)
- Active Galactic Nuclei (AGN)
- TDE
- FRB
Introduction:
Type Ia supernovae (SNe), also known as thermonuclear supernovae, are an important type of transient event, representing the explosive death of a white dwarf star, whose mass is often less than eight solar masses, in a binary system. Just like other Type I SNe, their spectra do not show hydrogen lines; in contrast, they usually occur when two white dwarfs merge and explode, in the most common scenarios, or when the mass of the white dwarf exceeds a critical threshold, after the dwarf has accreted enough mass from its companion star. What makes Type Ia SNe invaluable in astronomy research is that they can be used as “standard candles” to measure cosmic distances, playing a crucial role in understanding the expanding universe and the nature of dark energy.
Polish my writing below, an introduction for course project in observational astronomy, about spectroscopy/photometry on a transient, especially about observing a transient like Type Ia supernovae. To be detailed, please:
- show me the revised version
- show me some specific suggestions about improving this paragraph I wrote
Please note that:
- make sure that the revised version is tailored to the writing style of academic journals, like recent astronomy articles on the arXiv: https://arxiv.org/archive/astro-ph . For example, refer to the introduction in these papers: https://arxiv.org/pdf/1902.03261, https://arxiv.org/pdf/astro-ph/0701904
- Styles for short essay, report, post are not welcomed. Please make sure the revised one follows the styles of academic journals/papers. To be more specific, it should follow the styles of introduction in academic papers.
- in addition to changes made in writing style, you should also be very faithful about scientific facts and logic mentioned in my text. Add some terminologies, explanations (searching the web or textbook and adding the reference) if needed.
Okay, I can help you polish your introduction to match the style of academic journals in observational astronomy. Here's the revised version and some suggestions for improvement:
Revised Introduction:
Type Ia supernovae (SNe Ia), resulting from the thermonuclear runaway of a white dwarf (WD) in a binary system, represent a crucial class of transient phenomena in astrophysics (e.g., Filippenko, 1997). These events, which do not exhibit hydrogen lines in their spectra (Branch et al., 1993), are primarily understood to arise either from the merger of two WDs or through the accretion of material onto a WD from a companion star, eventually leading it to exceed the Chandrasekhar mass limit (∼1.4M⊙) (Hoyle & Fowler, 1960; Nomoto et al., 1984). Notably, SNe Ia serve as invaluable "standardizable candles" for extragalactic distance measurements, playing a pivotal role in the discovery of the accelerating expansion of the Universe and the subsequent investigation of dark energy (Riess et al., 1998; Perlmutter et al., 1999). The spectroscopic and photometric study of these transients provides critical insights into their explosion mechanisms, progenitor systems, and their utility in cosmology.
References:
- Branch, D., Livio, M., Yungelson, L. R., Boffi, F. R., & Baron, E. (1993). Type Ia supernovae as standard candles. Publications of the Astronomical Society of the Pacific, 105(691), 903.
- Filippenko, A. V. (1997). Optical spectra of supernovae. Annual Review of Astronomy and Astrophysics, 35(1), 309-355.
- Hoyle, F., & Fowler, W. A. (1960). Nucleosynthesis in massive stars and supernovae. The Astrophysical Journal, 132, 565.
- Nomoto, K., Thielemann, F. K., & Yokoi, K. (1984). Thermonuclear runaway on accreting white dwarfs and type I supernovae. III—Carbon deflagration models. The Astrophysical Journal, 286, 644-658.
- Perlmutter, S., Aldering, G., Della Valle, M., Deustua, S., Ellis, R. S., Fabbro, S., ... & Walton, N. A. (1999).Measurements of Ω and Λ from 42 high-redshift supernovae. The Astrophysical Journal, 517(2), 565.
- Riess, A. G., Filippenko, A. V., Challis, P., Hogan, C., Kirshner, R. P., Leibundgut, B., ... & Suntzeff, N. B. (1998). Observational evidence from supernovae for an accelerating universe and a cosmological constant. The Astronomical Journal, 116(3), 1009.
Specific Suggestions for Improving Your Original Paragraph:
- More Formal and Precise Language:
- Replace "explosive death" with a more scientific term like "thermonuclear runaway" or "terminal explosion."
- Instead of "whose mass is often less than eight solar masses," which refers to the progenitor system in general, be more specific about the white dwarf mass, mentioning the Chandrasekhar limit.
- "Just like other Type I SNe, their spectra do not show hydrogen lines" is correct but could be integrated more smoothly and referenced.
- "in the most common scenarios" is informal. Use more precise terminology like "primarily understood to arise either from..."
- Include Key Terminology and Explanations:
- Explicitly mention the Chandrasekhar mass limit as the critical threshold for explosion in the accretion scenario.
- Use the standard abbreviation SNe Ia for Type Ia supernovae.
- Briefly explain the significance of the lack of hydrogen lines in the spectra as a defining characteristic of Type I supernovae.
- Enhance Scientific Accuracy and Detail:
- While the mass of the progenitor system can vary, the key factor for a Type Ia supernova is the white dwarf reaching a critical mass (around the Chandrasekhar limit). The "less than eight solar masses" typically refers to the initial mass of the star that eventually becomes a white dwarf. Focus on the white dwarf itself.
- The merger scenario is increasingly recognized as a significant pathway to SNe Ia. Acknowledge both scenarios more explicitly.
- Connect to Spectroscopy and Photometry:
- Since your project focuses on spectroscopy and photometry, it's crucial to mention this in the introduction. Briefly state that these observational techniques are essential for studying SNe Ia and understanding their properties.
- Adopt the Style of Academic Introductions:
- Start with a broader statement about the importance of the phenomenon.
- Introduce the specific topic (Type Ia supernovae).
- Highlight the key aspects and significance (standardizable candles, cosmology).
- Briefly mention the observational methods relevant to your project (spectroscopy and photometry).
- Include references to established works in the field to support your statements and demonstrate your understanding of the literature.
By incorporating these suggestions, the revised introduction aligns more closely with the style and content expected in academic astronomy journals. Remember to always cite your sources appropriately in your project.