SGR 0418+5729 - How does a Young Neutron Star Spin Down to a 9 s Period with a Dipole Field less than 10^13 G?

M.A. Alpar; S. Caliskan; U. Ertan

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SGR 0418+5729 - How does a Young Neutron Star Spin Down to a 9 s Period with a Dipole Field less than 10^13 G?

M.A. Alpar, U. Ertan, S. Caliskan

High Energy Astrophysical Phenomena · Submitted 7 Feb 2011

abstract compiled · 2026-09-23 · no language-model review

The authors' main claim A fallback disk will spin down a neutron star with surface dipole magnetic field in the 10^{12} G range and initial rotation period P_0 ~ 100 ms to the 9.1 s period of SGR 0418+5729 in a few 10^4 to ~10^5 years.

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arXiv ID1102.1336 (version 2)

Pith IDXAMWOQL3, Pith's permanent record of this paper and its review

CitationM.A. Alpar, S. Caliskan, U. Ertan. "SGR 0418+5729 - How does a Young Neutron Star Spin Down to a 9 s Period with a Dipole Field less than 10^13 G?." arXiv:1102.1336 (2011). https://pith.science/paper/XAMWOQL3

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The compiled record

The paper's own sentences, arranged. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.

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Compiled by classifier-1.13-20260917 via OpenRouter, question bank abstract-p1-20260923, 2026-09-23: 1 request, 4,614 input tokens, $0.0002 reported.

What the abstract itself states, as probabilities: claims first 0.03 · states limitation 0.29 · human participants 0.01 · controlled comparison 0.09 · randomized assignment 0.01 · states quantitative result 0.96 · compares with prior results 0.84 · mentions code or data availability 0.02.

The abstract, sentence by sentence

arXiv listing abstract v2. Results and the main claim are underlined; show every role.

The period derivative bound for SGR 0418+5729 (Rea et al. 2010) establishes the magnetic dipole moment to be distinctly lower than the magnetar range, placing the source beyond the regime of isolated pulsar activity in the P - dP/dt diagram and giving a characteristic age > 2 \times 10^{7} years, much older than the 10^5 year age range of SGRs and AXPs. So the spindown must be produced by a mechanism other than dipole radiation in vacuum. A fallback disk will spin down a neutron star with surface dipole magnetic field in the 10^{12} G range and initial rotation period P_0 ~ 100 ms to the 9.1 s period of SGR 0418+5729 in a few 10^4 to ~10^5 years. The current upper limit to the period derivative gives a lower limit of \sim 10^5 years to the age that is not sensitive to the neutron star's initial conditions. The total magnetic field on the surface of SGR 0418+5729 could be significantly larger than its 10^{12} G dipole component.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#	sentence	role	the authors' own work	states the main conclusion	strength
s0	The period derivative bound for SGR 0418+5729 (Rea et al. 2010) establishes the magnetic dipole moment to be distinctly lower than the magnetar range, placing the source beyond the regime of isolated pulsar activity in the P - dP/dt diagram and giving a characteristic age > 2 \times 10^{7} years, much older than the 10^5 year age range of SGRs and AXPs.	background 0.48	0.09	0.17	asserted 1.00
s1	So the spindown must be produced by a mechanism other than dipole radiation in vacuum.	interpretation 0.99	0.32	0.33	asserted 1.00
s2	A fallback disk will spin down a neutron star with surface dipole magnetic field in the 10^{12} G range and initial rotation period P_0 ~ 100 ms to the 9.1 s period of SGR 0418+5729 in a few 10^4 to ~10^5 years.	result 0.47	0.45	0.51	asserted 0.93
s3	The current upper limit to the period derivative gives a lower limit of \sim 10^5 years to the age that is not sensitive to the neutron star's initial conditions.	result 0.90	0.39	0.12	asserted 0.98
s4	The total magnetic field on the surface of SGR 0418+5729 could be significantly larger than its 10^{12} G dipole component.	interpretation 0.93	0.26	0.13	hedged possibility 1.00

What kind of paper the classifier reports this is: theoretical result 0.54 · evidence from analysis of existing data 0.50.

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arXiv listing abstract v2

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full text
figures and tables
references and citing sentences
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Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

The paper

Original abstract

The period derivative bound for SGR 0418+5729 (Rea et al. 2010) establishes the magnetic dipole moment to be distinctly lower than the magnetar range, placing the source beyond the regime of isolated pulsar activity in the P - dP/dt diagram and giving a characteristic age > 2 \times 10^{7} years, much older than the 10^5 year age range of SGRs and AXPs. So the spindown must be produced by a mechanism other than dipole radiation in vacuum. A fallback disk will spin down a neutron star with surface dipole magnetic field in the 10^{12} G range and initial rotation period P_0 ~ 100 ms to the 9.1 s period of SGR 0418+5729 in a few 10^4 to ~10^5 years. The current upper limit to the period derivative gives a lower limit of \sim 10^5 years to the age that is not sensitive to the neutron star's initial conditions. The total magnetic field on the surface of SGR 0418+5729 could be significantly larger than its 10^{12} G dipole component.

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