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This is an old revision of this page, as edited by ClarkoEye (talk | contribs) at 01:56, 4 February 2015 (→‎The size of the galaxy relative to the length of the jet: new section). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

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Good articleMessier 87 has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it.
Article milestones
DateProcessResult
October 18, 2010Good article nomineeNot listed
December 12, 2010Good article nomineeListed
Current status: Good article
WikiProject iconAstronomy: Astronomical objects GA‑class Top‑importance
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The following discussion is an archived debate of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the debate was Move all. —Wknight94 (talk) 23:22, 12 August 2006 (UTC)[reply]

Requested move

Discussion

Please discuss this move at Talk:Globular Cluster M2.

The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

habitable?

because of the heavy amount of x-rays is it possible life can exist there? —The preceding unsigned comment was added by 71.105.29.94 (talk) 05:52, 7 December 2006 (UTC).[reply]

Very unlikley, at least not as we know it. It seems the X Rays are produced by the exceptional ionised particle jet ejection energy. See also update ref signal velocity to make it consistent with the 'Superluminal velocity' page a far better explanation than any other offered so far that also seems to resolve some anomalies.Docjudith (talk) —Preceding undated comment added 11:30, 8 February 2010 (UTC).[reply]

I'm not sure how much can speculate about this. All we can say for certain is that space travel would be subject to higher levels of radiation. But a planet may well provide sufficient shielding against the X-ray radiation for life to have evolved. However, the impact of the jet may be another matter.—RJH (talk) 16:55, 17 January 2011 (UTC)[reply]

Components

The best reference for the mass of the supermassive black hole is still the Macchetto et al. (1997) paper, based on rotation of the gas disk. More recent attempts to obtain the black hole mass from the stellar motions (e.g. Gebhardt & Thomas 209) have gotten discrepant and inconsistent results, probably because the stellar data do not resolve the black hole sphere of influence and do not show any clear sign of its presence. These new results are not widely believed in the astrophysical community and should not be reported here, unless a section is added that critically discusses the modelling issues and the shortcomings of the data.130.183.86.193 (talk) 13:54, 27 June 2010 (UTC)[reply]

That seems reasonable, but could I ask why you removed the following?
However, only a fraction of this mass is in the form of stars, as Messier 87 has an estimated mass to luminosity ratio of 6.3 ± 0.8. That is, about one part in six of the galaxy's mass is in the form of stars that are radiating energy.[1]
This is significant, cited information and it needs a reason for exclusion. If it is to be excluded, something needs to be added to replace it.—RJH (talk) 17:04, 27 June 2010 (UTC)[reply]
How about this? [1] -- Polluks ★ 12:31, 17 January 2011 (UTC)[reply]
Yes, it's based on the Gebhardt et al. (2011) paper, which gives a SMBH mass that is fairly consistent with the current value in the article. However, a small concern is that this paper doesn't appear to have been peer reviewed yet, since it isn't published in an astronomy journal.—RJH (talk) 16:58, 17 January 2011 (UTC)[reply]
The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

GA Review

This review is transcluded from Talk:Messier 87/GA1. The edit link for this section can be used to add comments to the review.

Reviewer: Casliber (talk · contribs) 03:37, 14 September 2010 (UTC)[reply]

Okay, I'll make straightforward copyedits as I go and post queries below. Please revert if I change meaning inadvertently. Casliber (talk · contribs) 03:37, 14 September 2010 (UTC)[reply]

"'This is the largest and brightest galaxy within the northern Virgo Cluster, located about 55 million light years away from Earth - the way it reads, it isn't clear whether M87 or the Virgo Cluster (or both) is what is 55 million light years from earth. "  Done
"Messier 87 galaxy has no distinctive dust lanes... - do we need the "galaxy" here? Not written as such elsewhere.  Done
This identification was confirmed by 1953 - odd wording. You mean "The soruce was confirmed as coming from M87" (?)  Done, reworded.
The only known visual observation of the jet was by Russian-American astronomer Otto Struve using the 254 cm (100 in) Hooker telescope - how/why?
and may indicate that the black hole has been accelerated by the jet - I don't follow - you mean "moved" or "displeced" or ..what?
The Virgo Cluster section could be expanded a little - M87's role in it, closest neighbours etc.

Okay - typing "Messier 87" into the Web of Science search engine yields the following:

1. Title: STRUCTURAL PARAMETERS OF THE MESSIER 87 GLOBULAR CLUSTERS Author(s): Madrid JP, Harris WE, Blakeslee JP, et al. Source: ASTROPHYSICAL JOURNAL Volume: 705 Issue: 1 Pages: 237-244 Published: NOV 1 2009 Times Cited: 4

2. Title: Radio Imaging of the Very-High-Energy gamma-Ray Emission Region in the Central Engine of a Radio Galaxy Author(s): Acciari VA, Aliu E, Arlen T, et al. Source: SCIENCE Volume: 325 Issue: 5939 Pages: 444-448 Published: JUL 24 2009 Times Cited: 19

3. Title: A method for deriving accurate gas-phase abundances for the multiphase interstellar galactic halo Author(s): Howk JC, Sembach KR, Savage BD Source: ASTROPHYSICAL JOURNAL Volume: 637 Issue: 1 Pages: 333-341 Part: Part 1 Published: JAN 20 2006 Times Cited: 11

4. Title: THE MORPHOLOGY OF ELLIPTIC GALAXIES INDIFFERENT ENVIRONMENTS Author(s): DAVOUST E Conference Information: World of Galaxies II Meeting, SEP 05-07, 1994 LYON, FRANCE Source: ASTROPHYSICAL LETTERS & COMMUNICATIONS Volume: 31 Issue: 1-6 Pages: 183-186 Published: 1995 Times Cited: 0

5. Title: HIGH-RESOLUTION OBSERVATION OF THE OPTICAL JET OF THE GALAXY MESSIER 87 Author(s): LELIEVRE G, NIETO JL, WLERICK G, et al. Source: COMPTES RENDUS DE L ACADEMIE DES SCIENCES SERIE II Volume: 296 Issue: 23 Pages: 1779-1786 Published: 1983 Times Cited: 12

6. Title: THE HALO GLOBULAR-CLUSTERS OF THE GIANT ELLIPTICAL GALAXY MESSIER 87 Author(s): STROM SE, FORTE JC, HARRIS WE, et al. Source: ASTROPHYSICAL JOURNAL Volume: 245 Issue: 2 Pages: 416-& Published: 1981 Times Cited: 123

7. Title: PHOTOMETRIC ANALYSIS OF THE JET IN MESSIER-87 Author(s): DEVAUCOULEURS G, NIETO JL Source: ASTROPHYSICAL JOURNAL Volume: 231 Issue: 2 Pages: 364-371 Published: 1979 Times Cited: 48

8. Title: LUMINOSITY DISTRIBUTION IN THE CENTRAL REGIONS OF MESSIER-87 - ISOTHERMAL CORE, POINT SOURCE, OR BLACK-HOLE Author(s): DEVAUCOULEURS G, NIETO JL Source: ASTROPHYSICAL JOURNAL Volume: 230 Issue: 3 Pages: 697-712 Published: 1979 Times Cited: 54

9. Title: ENERGY-DISTRIBUTION OF JET IN MESSIER 87 Author(s): KANEKO N, NISHIMUR.M, TOYAMA K Source: PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN Volume: 25 Issue: 2 Pages: 175-180 Published: 1973 Times Cited: 5

10. Title: PHOTOMETRY OF OUTER CORONA OF MESSIER 87 Author(s): DEVAUCOU.G Source: ASTROPHYSICAL LETTERS Volume: 4 Issue: 1 Pages: 17-& Published: 1969 Times Cited: 22

11. Title: MESSIER-87 - GALAXY OF GREATEST KNOWN MASS Author(s): BRANDT JC, ROOSEN RG Source: ASTROPHYSICAL JOURNAL Volume: 156 Issue: 2P2 Pages: L59-& Published: 1969 Times Cited: 18

12. Title: ON SYNCHROTROIN RADIATION FROM MESSIER-87 Author(s): BURBIDGE GR Source: ASTROPHYSICAL JOURNAL Volume: 124 Issue: 2 Pages: 416-429 Published: 1956 Times Cited: 143

13. Title: POLARIZATION IN THE JET OF MESSIER-87 Author(s): BAADE W Source: ASTROPHYSICAL JOURNAL Volume: 123 Issue: 3 Pages: 550-& Published: 1956 Times Cited: 79

Why on Earth would you run such a search? For a start, the astronomy databases (ADS, SIMBAD, NED) are far more sensible places to look than WoS. Secondly, there are thousands of papers on M87. Here is a straightforward ADS object search, which found 4238 papers. Even restricting the search to only papers with 'M87' or 'Messier 87' in the title (let alone the abstract) leaves 913 papers [2]. Good luck digesting all of those! Modest Genius talk 16:03, 16 September 2010 (UTC)[reply]
(belatedly) I have used WoS for biology articles, my usual area of editing on wikipedia. I am a bit of a neophyte on astronomy articles. But in any case, all of these show some other material worth looking at. Casliber (talk · contribs) 21:55, 16 October 2010 (UTC)[reply]


1. Well written?:

Prose quality: - it's okayish but could do with some tightening
Manual of Style compliance:

2. Factually accurate and verifiable?:

References to sources:
Citations to reliable sources, where required:
No original research:

3. Broad in coverage?:

Major aspects: - I am sure there is a bunch of material for this article which could be added, particularly on components section.
Focused:

4. Reflects a neutral point of view?:

Fair representation without bias:

5. Reasonably stable?

No edit wars, etc. (Vandalism does not count against GA):

6. Illustrated by images, when possible and appropriate?:

Images are copyright tagged, and non-free images have fair use rationales:
Images are provided where possible and appropriate, with suitable captions:

Overall:

Pass or Fail: -I think the best thing is to let this nomination slide for the time being as there is no movement. I am actually interested in doing it myself but can't see that happening for a monht or two, so maybe I will wokr on it and nominate it myself sometime. Casliber (talk · contribs) 22:23, 16 October 2010 (UTC)[reply]
Thanks for the review Casliber. I'm unclear why it was nominated if there was no interest in correcting the issues.—RJH (talk) 18:28, 18 October 2010 (UTC)[reply]

PS: As a postscript, I think the concerns I raised are fixed now. As I haven't done any active editing. I'm happy to take a closer look and review when put up again. I'll try and give it a shove toward FAC if I can and look to think what else might be of help. Casliber (talk · contribs) 20:21, 8 December 2010 (UTC)[reply]

Thank you again Casliber.—RJH (talk) 18:34, 10 December 2010 (UTC)[reply]
The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.


The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

GA Review

GA toolbox
Reviewing
This review is transcluded from Talk:Messier 87/GA2. The edit link for this section can be used to add comments to the review.

Reviewer: Casliber (talk · contribs) 19:21, 10 December 2010 (UTC)[reply]

Okay, it seems a good labour-saving act to continue where we left off last review. The article as noted is much improved. I'll have a last read through again to see if I can see anything else:

  • One thing that strikes me is trying to get a sense of how large or small the galaxy is compared with our milky way. Do any sources have that comparison or discuss the size?
    • I added an estimate of the extended stellar halo for the Milky Way.—RJH (talk)
  • Link or explain the word collaminated.
    • Sorry, that was a typo. I linked it.—RJH (talk)
  • Within the galaxy, silicate grains are expected to survive for no more than 46 million years because of the X-ray emission from the core -I think this would leave a lay-reader wondering why and thirsting for more knowledge. Can we quench that thirst at all?
    • The answer appears to be that they don't know. It is either destroyed by the hostile environment, or ejected from the galaxy. But I added a statement with the original source.—RJH (talk)
  • The combined mass of dust in this galaxy is no more than 70,000 times the mass of the Sun - again, it is hard to visualise this unless there is some comparison - this is a little, right? Maybe a note on the Milky Ways (footnote if you like)
  • Messier 87 may have encountered Messier 84 in the past. - again, curious statement - do we just know this from trajectories or is there other interesting evidence.
    • I tried to clarify and expand upon the text.—RJH (talk)
  • Just reminded me - is this number of globular clusters typical for elliptical galaxies, or is it still unusual?
    • I believe the number of globular clusters is proportionate to the size of the galaxy. M87 is not a typical elliptical galaxy.—RJH (talk)
  • I was just winding up when I saw -"This image shows the eruption of a galactic “super-volcano” in M87" as the image caption. Is there info on this that can be added. Amazing pic it would be good to discuss.
    • I revised the caption to give a straight-forward explanation.—RJH (talk)

Otherwise looking very promising. Casliber (talk · contribs) 20:28, 10 December 2010 (UTC)[reply]

1. Well written?:

Prose quality:
Manual of Style compliance:

2. Factually accurate and verifiable?:

References to sources:
Citations to reliable sources, where required:
No original research:

3. Broad in coverage?:

Major aspects:
Focused:

4. Reflects a neutral point of view?:

Fair representation without bias:

5. Reasonably stable?

No edit wars, etc. (Vandalism does not count against GA):

6. Illustrated by images, when possible and appropriate?:

Images are copyright tagged, and non-free images have fair use rationales:
Images are provided where possible and appropriate, with suitable captions:


Overall:

Pass or Fail: - in summary, I think it meets GA criteria. I'll cross my fingers on some more star population attributes turning up for FAC. Casliber (talk · contribs) 01:21, 12 December 2010 (UTC)[reply]

Other

"The galactic envelope extends out to a radius of about 490 kly, where it has been truncated." in the second paragraph needs a better wording. Truncated by what? A physical phenomenon, some arbitrary definition, or an artefact from observation equipment? 88.112.37.71 (talk) 15:33, 14 October 2011 (UTC)[reply]

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.


Comment on I. Balanowski

I think that "I. Balanowski", who discovered a supernova in M87 in 1922, may be the same person as "Inna Lehmann-Balanowsky" or "Inna Lehman-Balanowskaja" from Pulkovo observatory. But I haven't been able to confirm this yet. "I. Balanowski" is used to publish in Astronomische Nachrichten, but the source is Pulkowo. "Inna Lehmann-Balanowskaja" is used for publications from the Bulletin de l'Observatoire central Poulkovo, although the name also appears in a pair of Astronomische Nachrichten publications. She seems to be well published, but there's no real biographical information. There is 848 Inna, however, which is named after Inna Nikolaevna Leman-Balanovskaya (1881-1945).[3] Unfortunately, it turns out she was the wife of Pulkovo astronomer Innokentij Andreevich Balanovskij, which confuses things further. Regards, RJH (talk) 21:36, 15 November 2011 (UTC)[reply]

It looks like there was a purge of Pulkovo astronomers during 1936-37.[4] I. A. Balanovskii, the chairman of the astrophysics department, was among those arrested by the NKVD on 11/7/1936 and sentenced to ten years by a military tribunal. His wife, I. N. Leman-Balanovskaia, was arrested 9/1937. She died shortly after her sentence was completed in 1945. A tragic tale, all told, but I think now that the "I. Balanowski" was likely the husband. For example, Shklovskii (1980) p. 389 references I. A. Balanovskii, Ein merkwürdiger veränderlicher oder Neuer Stern, originally published by I. Balanowsky.[5] Regards, RJH (talk) 03:20, 21 November 2011 (UTC)[reply]

Ex Cathedra

This article is appalling in its relentless assertions about M87 made without relating how the science was done, without stating how one thing was inferred from another. At the very least, it is a wasted opportunity to achieve excellence for the Wikipedia. Is it a good article that simply could be better? No. This article damages science and scientists. "M87" as written is an example of science as take-it-or-leave-it authoritarianism. The adventure of discovery is missing, the failure to relate how knowledge evolved or where it came from slights the role of M87 itself in the history of astronomy, the use of rational thought to make connections that have validity and consistency is not illustrated, the way in which knowledge now presented ex Cathedra actually grew in certainty, that also is missing. Worst of all, the idea that our understanding is incomplete -- some shred of humility before Nature -- is missing. Yes, this is a good summary of what we know at this time, but I never treated my graduate students this way. IMHO, Wikipedia at its best is not just a snapshot in time of where we are, it is also a hand extended to others to carry on and contribute.
Jerry-va (talk) —Preceding undated comment added 22:10, 26 March 2012 (UTC).[reply]

Well it's unfortunate that you think so, but to me your opinion smells distinctly of flame bait. For that reason I'm not going to pursue this further. Regards, RJH (talk) 22:25, 26 March 2012 (UTC)[reply]
You acknowledge that the article is "a good summary of what we know at this time." I disagree with your view that Wikipedia should aspire to be more than this. It's an encyclopedia, not a collection of treatises. Overly rambling and ambitious articles actually defeat the purpose of giving the reader a concise introduction to a topic. --Yaush (talk) 17:39, 27 March 2012 (UTC)[reply]

Black hole and Ejected Star cluster

I don't normally edit astronomy related articles (beyond copy edits) so I'm not going to immediately add any new information, but I do think that this merits consideration for inclusion in the article. The piece in question was published at earthsky.org and is about the first detection of a star cluster getting ejected from its galaxy. Also, the article mentions that there are two supermassive black holes at the center of the galaxy while the wikipedia article only mentions one. Link: http://earthsky.org/space/entire-star-cluster-thrown-out-of-its-galaxy --MorrisIV (talk) 19:55, 1 May 2014 (UTC)[reply]

LARGE error in jet energy?

The M87 wiki at present says in https://en.wikipedia.org/wiki/Messier_87#Observation_history "The total energy output of these electrons was estimated as 5 × 10^56 eV.[18]"

I looked up that actual old article at http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1956Obs....76..141B&link_type=ARTICLE&db_key=AST and it says "... from relativistic electrons... total energy is about 5.1 x 10^56 ergs..."

ERGS are *much* larger energy units than eV. 5.1e+56 ergs = 5.1e+49 joules = 3.2e+68 eV. https://en.wikipedia.org/wiki/Energy_units

Which is correct? Was there a typo in the 1956 paper?

And by the way, 5.1e+56 ergs is 1.3e+23 times Sol's output per second! So, over what time period is the observed jet energy summed?

regards, YodaWhat (talk) 16:02, 10 June 2014 (UTC)[reply]

The size of the galaxy relative to the length of the jet

To a layman (me) the statement that the jet is about 5,000 light years long seems to be at odds with the apparent size of the galaxy as seen in the photo. Since the Milky Way galaxy is about 100,000 light years across, its diameter would seem to be 200 times the length of the jet. Yet the diameter of the M87 galaxy in the photo 'seems' to be much less than the length of its jet. A word of explanation would be welcome. ClarkoEye (talk) 01:56, 4 February 2015 (UTC)[reply]

  1. ^ Cite error: The named reference apj700_2 was invoked but never defined (see the help page).
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