topic


OJ 287 퀘이사에서 2022년에 예상되었던 대형 플레어가 관측되지 않은 것은 이론적 오류가 아니라, 지구 기반 망원경으로는 여름 동안 OJ 287을 관측할 수 없었기 때문이며, 실제 플레어는 예상보다 10일 일찍 발생하여 관측 가능한 범위를 벗어났다.


coremsg

No missing flare in OJ 287
Mauri J. Valtonen
FINCA, University of Turku, FI-20014 Turku, Finland
Tuorla Observatory, Department of Physics and Astronomy,
University of Turku, FI-20014 Turku, Finland and
Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK a†
(Dated: November 5, 2024)
The quasar OJ 287 has shown large flares since 1888, following a pattern that arises in a super-
massive black hole binary when the secondary hits the accretion disk of the primary, and releases
a hot bubble of gas at every disk crossing. A complete mathematical solution of the flare sequence
produced a list of future flares, the latest happening in the summer of 2022. Here I look into the
origin of the idea that the lack of seeing the 2022 flare is a theoretical problem. During the summer
OJ 287 cannot be observed by ground-based optical telescopes. In a paper published in 2021, ahead
of the 2022 observing campaign, this was clearly stated. The often repeated claim that there is
a ”missing flare problem”, is a misunderstanding, as no detection was possible with the current
instrumentation.
To appear in RNAAS.:
keywords: Blazars; Active Galactic Nuclei; BL Lacertae objects: individual (OJ 287):
I.
INTRODUCTION
OJ 287 is a blazar/quasar at the redshift 0.306. It is one of the brightest quasars and its images can be found in old
photographic plates since 1888. More recently, it has been intensively observed due its periodic properties. A recent
description of the light curve and its explanation using a binary black hole model is found in Valtonen et al. [1].
The binary model assumes an unequal mass black hole binary with an accretion disk. Every impact of the secondary
produces a bubble of high temperature gas on both sides of the disk. The bubble initially radiates as a synchrotron
source of flat spectral index, due to recent shock acceleration of relativistic electrons. With subsequent expansion it
is seen as a large bremstrahlung flare when the bubble becomes optically thin.
Since the discovery of the periodic nature of OJ 287 in 1982, large flares fitting this description have been observed
in 1983, 1984, 1994, 1995, 2005, 2007, 2015 and 2019. It should be noted that the large flares come in doubles and in
occasional triples. The first triple was observed in 1957, 1959 and 1964, while the next triple is 2015, 2019 and 2022.
Using the timings of ten bright flares one finds a unique mathematical orbit solution with nine parameters. The
model uses Post-Newtonian General Relativity to the order of 4.5, a theory of expanding shock-heated bubbles, disk
level calculations at the times of impacts, and spin-orbit coupling. The model is over-determined since it also explains
the timing of eight other flares. There are no free parameters that could be used to improve the model.
II.
THE 2022 FLARE
The 2022 flare was expected to start at 2022.548. Because there was an inevitable gap in observations from 2022.52
to 2022.66, Valtonen et al. [2] conclude that ”The first big flare during 2022 is not expected to be visible from any
Earth-based facility”.
We know when the secondary crosses the average mid-plane of the accretion disk. However, until the position of
the actual disk plane is calculated, we don’t know the time of the impact. For impacts prior to 2022 the disk levels
were calculated in Valtonen [3]. However, back in 2007, the year 2022 seemed so far away that I did not include it.
The range of disk levels is from -75 AU to 265 AU, with the positive sign meaning that the secondary pulls the disk
toward itself. In order that 2022 flare would be seen, the disk has to be below -500 AU, meaning that the approaching
secondary would push away the disk.
This calculation was reported in the second draft of Valtonen et al. [4] (posted as Valtonen et al. [5] in arXiv), but
it was removed from the next draft and the final paper, since by then the disk level calculation was done. The disk
was found at its mean level, and the impact point a little closer to the center than in 2005. This made the bubble
a visitor
† mvaltonen2001@yahoo.com
arXiv:2411.00908v1  [astro-ph.HE]  1 Nov 2024

2
2005.0
2005.2
2005.4
2005.6
2005.8
2006.0
Year (2005 flare)
4
6
8
10
12
14
V-band flux (mJy)
Model lines
Observed points
2021.805
2022.005
2022.205
2022.405
2022.605
2022.805
Year (2022 predicted flare)
FIG. 1. The optical light curve of OJ 287 during 2005 in V-band mJy units, in averaged data points. The dashed-line curve
gives the general outline. If the disk levels and the impact distances were the same in 2005 and in 2022, one can draw an upper
scale for the expected light curve in 2022 [2].
expansion also faster. Combining this new theoretical knowledge with the detection of the early synchrotron flare
in March 2022 (reported in the first draft in June 2022) it became clear that the big flare had happened 10 days
earlier than was initially expected. Even the tail end of the flare was out of reach of the ground-based observations.
Theoretically, there was no chance of seeing any trace of the big flare, and observations agreed.
In Figure 1 we outline the 2005 flux evolution by dashed lines. The timescale for the expected flux evolution in
2022 is displayed in the upper scale, assuming that the 2022 and 2005 disk levels and light curves were the same.
This graph was drawn before the 2022 disk level calculation: we have to slide the upper x-axis forward by 0.027 units
to make the flare happen 10 days earlier. Now the summer gap in observations covers rather exactly the part of the
2005 light curve which is marked by the dashed line on the right hand side of the figure. Disregarding this section,
the 2005 and 2022 light curves match well.
So what was missing then? Initially, I recommended observers carry out the campaign past the end of summer,
since the disk level had not yet been calculated. This was misunderstood as a suggestion that the big flare should
happen after the summer, and this showed up in the second draft [5]. The last sentence of the abstract, ’Observing the
next impact flare of OJ 287 in October 2022 will substantiate the theory of disk impacts in binary black hole systems’,
was so poorly formulated, that it caused some people to expect something special in October. It was contrary to the
main text which made clear that a flare in October would have required an unreasonable and previously unseen disk
level. This sentence was meant to refer to the theory of disk impacts, not to their timing. The latter would have been
awkward, and with later knowledge, contrary to the theory, if the flare had happened in October. The next draft,
soon thereafter, corrected these misunderstandings.
Komossa et al. [6] quote [5], rather than the next draft with corrections. Other authors, e.g. de la Parra et al. [7]
have followed the practice and so the misunderstandings have snowballed.

3
ACKNOWLEDGMENTS
This work has been supported by the Finnish Society of Sciences and Letters as well as the Institute of Astronomy
at University of Cambridge.
[1] Valtonen, M.J., Zola, S., Gupta, A.C., Kishore, S., Gopakumar, A., Jorstad, S.G., Wiita, P., Gu, M., Nilsson, K., Marscher,
A.P. et al., apjl 2024, 968, L17
[2] Valtonen, M. J., Dey, L.; Gopakumar, A., Zola, S.; Komossa, S., Pursimo, T., Gomez, J. L., Hudec, R., Jermak, H. &
Berdyugin, A. V., Galaxies 2021, 10, 1
[3] Valtonen, M.J., ApJ 2007, 659, 1074-1081
[4] Valtonen, M. J., Zola, S., Gopakumar, A., L¨ahteenm¨aki, Tornikoski, M., Dey, L., Gupta, A. C., Pursimo, T., Knudstrup,
E., Gomez, J. L. et al., MNRAS 2023, 521, 6143
[5] Valtonen, M. J., Zola, S., Gopakumar, A., McCall, C., Jermak, H., Dey, L., Komossa, S.H., Pursimo, T., Knudstrup, E.,
Grupe, D. et al., eprint arXiv 2022, 2209.08360
[6] Komossa S., Grupe D., Kraus, A., Gonzalez, A., Gallo, L.C., Valtonen, M.J., Laine, S., Krichbaum, T.P., Gurwell, M.A.,
G´omez, J.L. et al., MNRAS 2022a, 513, 3165
[7] de la Parra, P. V., Kiehlmann, S., Mroz, P., Readhead, A. C. S., Synani, A., Begelman, M. C., Blandford, R. D., Ding, Y.,
Harrison, F., Liodakis, I., Max-Moerbeck, W. et al., eprint arXiv 2024, 2408.02645



No missing flare in OJ~287

### title_rewrite
OJ 287에서 예상되었던 플레어는 누락되지 않았다

### category
천문학

### topic
OJ 287 퀘이사 관측

### coremsg
OJ 287 퀘이사에서 2022년에 예상되었던 대형 플레어가 관측되지 않은 것은 이론적 오류가 아니라, 지구 기반 망원경으로는 여름 동안 OJ 287을 관측할 수 없었기 때문이며, 실제 플레어는 예상보다 10일 일찍 발생하여 관측 가능한 범위를 벗어났다.

### note
## OJ 287 퀘이사 관측에 대한 연구 논문 요약

**참고 문헌:** Valtonen, M.J. (2024). No missing flare in OJ~287. *RNAAS*.

**연구 목적:** 2022년 여름 OJ 287 퀘이사에서 예상된 대형 플레어가 관측되지 않은 이유를 규명하고, 이것이 기존 이론과 모순되는지 여부를 밝히는 것을 목표로 한다.

**연구 방법:** OJ 287 퀘이사의 플레어 발생 패턴을 설명하는 기존 이론과 2022년 관측 캠페인 당시의 상황을 분석하고, 플레어 미관측 원인에 대한 다양한 주장을 비판적으로 검토한다.

**주요 결과:** 2022년 여름 OJ 287 퀘이사의 플레어 미관측은 이론적 오류가 아니라, 지구 기반 망원경으로는 여름 동안 OJ 287을 관측할 수 없었기 때문임을 밝혔다. 또한, 초기 예상보다 10일 일찍 플레어가 발생하여 관측 가능한 범위를 벗어났음을 확인했다.

**주요 결론:** OJ 287 퀘이사의 플레어 발생 메커니즘을 설명하는 기존 이론은 여전히 유효하며, 2022년 플레어 미관측은 관측 한계로 인한 것임을 명확히 하였다. 

**의의:** 본 연구는 OJ 287 퀘이사의 플레어 발생 메커니즘에 대한 이해를 높이고, 향후 더 정확한 플레어 예측을 위한 연구의 필요성을 제시한다.

**제한점 및 향후 연구 방향:** 2022년 플레어를 직접 관측하지 못했기 때문에 플레어의 강도와 지속 시간에 대한 정보는 얻을 수 없었다. 향후 우주 기반 망원경을 활용한 상시 관측 시스템 구축을 통해 플레어 발생 과정을 실시간으로 포착하고 분석하는 연구가 필요하다.

### data_sheet
- OJ 287 퀘이사의 플레어는 1888년부터 관측되었으며, 이는 초대질량 블랙홀 쌍성계에서 발생하는 현상으로 설명된다.
- 2022년 플레어는 2022.548에 시작될 것으로 예상되었으나, 2022.52부터 2022.66까지 지구 기반 관측이 불가능했다.
- 실제 플레어는 예상보다 10일 일찍 발생했으며, 이는 2005년 플레어와 비교 분석한 결과 확인되었다.

### quotes
- "The first big flare during 2022 is not expected to be visible from any Earth-based facility" (Valtonen et al., 2021).
- "Observing the next impact flare of OJ 287 in October 2022 will substantiate the theory of disk impacts in binary black hole systems" (Valtonen et al., 2022, withdrawn).

### further_questions
- 만약 2022년 플레어를 우주 기반 망원경으로 관측했다면, 기존 이론을 뛰어넘는 새로운 사실을 발견할 수 있었을까?
- 일부 과학자들은 OJ 287의 플레어 주기가 점차 변하고 있다고 주장하는데, 이는 블랙홀 쌍성계의 진화와 어떤 관련이 있을까?
- OJ 287과 같은 퀘이사 연구는 인류가 우주를 이해하는 데 어떤 의미를 지니는가? 


OJ 287 퀘이사 관측

oj-287에서-예상되었던-플레어는-누락되지-않았다

note



"The first big flare during 2022 is not expected to be visible from any Earth-based facility" (Valtonen et al., 2021).
"Observing the next impact flare of OJ 287 in October 2022 will substantiate the theory of disk impacts in binary black hole systems" (Valtonen et al., 2022, withdrawn).


quotes



OJ 287 퀘이사의 플레어는 1888년부터 관측되었으며, 이는 초대질량 블랙홀 쌍성계에서 발생하는 현상으로 설명된다.
2022년 플레어는 2022.548에 시작될 것으로 예상되었으나, 2022.52부터 2022.66까지 지구 기반 관측이 불가능했다.
실제 플레어는 예상보다 10일 일찍 발생했으며, 이는 2005년 플레어와 비교 분석한 결과 확인되었다.


data_sheet


OJ 287에서 예상되었던 플레어는 누락되지 않았다


OJ 287에서 예상되었던 플레어는 누락되지 않았다

OJ 287 퀘이사 관측에 대한 연구 논문 요약

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No missing flare in OJ~287

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