< Radiation astronomy
The blue (X-ray) shows evidence for a growing super massive black hole in the centre of the galaxy. Credit: Left panel: D. Alexander et al. S. Chapman et al. T. Hayashino et al. J. Geach et al. Right Illustration: M. Weiss.

The first X-ray source in Aquarius is unknown. The field of X-ray astronomy is the result of observations and theories about X-ray sources detected in the sky above. The first astronomical X-ray source discovered may have been the Sun. But, X-rays from the Sun do not penetrate far enough into Earth's atmosphere to be detected on the ground. The early use of sounding rockets and balloons to carry detectors high enough may have detected X-rays from the Sun as early as the 1940s.

This is a lesson in map reading, coordinate matching, and researching. It is also a research project in the history of X-ray astronomy looking for the first astronomical X-ray source discovered in the constellation of Aquarius.

Nearly all the background you need to participate and learn by doing you've probably already been introduced to at a secondary level.

Some of the material and information is at the college or university level, and as you progress in finding X-ray sources, you'll run into concepts and experimental tests that are actual research.

To succeed in finding an X-ray source in Aquarius is the first step. Next, you'll need to determine the time stamp of its discovery and compare it with any that have already been found. Over the history of X-ray astronomy a number of sources have been found, many as point sources in the night sky. These points are located on the celestial sphere using coordinate systems. Familiarity with these coordinate systems is not a prerequisite. Here the challenge is geometrical, astrophysical, and historical.

Sources

Def. a natural source usually of radiation in the sky especially at night is called an astronomical source.

A source of astronomical information on older detections of X-ray sources is included in the Science section of the lecture/article X-ray astronomy.

Traveling X-ray source

Many X-ray sources do not remain in a constellation for lengthy periods. Some of these are the Sun and sources apparently in orbit around the Sun. The Sun travels through the 13 constellations along the ecliptic, the 12 of the Zodiac and the constellation Ophiuchus.

Backgrounds

To introduce yourself to some aspects of the challenge may I suggest reading the highlighted links mentioned above, and if you're curious, those listed under the section "See also" below.

X-rays are a form of radiation that is currently part of the electromagnetic radiation intersecting the Earth. More information about radiation is in radiation astronomy.

Aquarius

This is an image of the International Astronomical Union (IAU) sky map of the constellation Aquarius. Credit: IAU and Roger Sinnott & Rick Fienberg, Sky & Telescope magazine.

The Wikipedia article about the constellation Aquarius contains a high school level description. The figure at right shows the sky map of Aquarius. Around the edges of the map are coordinates related to longitude and latitude, but with the Earth rotating on its axis every 24 hours the celestial coordinates must remain fixed. How has this been accomplished?

Also, in the Wikipedia article is a list of stars in Aquarius. What's the difference between a star and an astronomical X-ray source?

From the Wikipedia article on the Zodiac, Aquarius is a zodiacal constellation.

Searching catalogs

In the lecture/article X-ray astronomy in the Science section is a list of older catalogs of X-ray sources. Using the constellation description in the previous section, scan through coordinates for these X-ray sources to see if any may be within Aquarius.

If you find any that are, skip down to the section X-ray source in Aquarius and make an entry. Be sure to check the coordinate era, most B1950 coordinates have changed slightly to the new J2000 set. Try the catalog designation at either SIMBAD website.

X-1 designation

In the lecture/article first astronomical X-ray source, a number of X-ray sources carry a designation containing the notation "X-1". Searching Google scholar or other web browsers listed under External links below, using "X-1", with quotes, and "Aquarius", without quotes, may locate an early source. Adding the notation "X-rays" or "X-ray", either with quotes, may reduce the search options.

One astronomical object located by such a search is NGC 7293.

Testing a source

There are many web sites that may have an X-ray source listed for the constellation Aquarius. Some that you may wish to try are in the External links section near the bottom of this lesson.

Wikipedia sources

A. Constellation article

Under "Notable features" in the Wikipedia article on the constellation Aquarius is the list of stars in Aquarius. Click on this link. In the table of this Wikipedia article is β Aqr. To the right are coordinates:

  1. Right ascension (RA): 21h 31m 33.52s and
  2. Declination (Dec): -05° 34' 16.2".

Find these coordinates on the Aquarius map at the right. Is beta Aquarii really inside the boundaries of the constellation?

To evaluate the star as an X-ray source, skip ahead to section "X-ray source".

B. Wikipedia search

Another way to look for X-ray sources in the constellation is to perform a search on Wikipedia. Try "Aquarius "X-ray"" without the outside quotes. This yields about 25 returns which include EZ Aquarii, NGC 7252, 1RXS J210034.1-044442, AE Aquarii, Beta Aquarii, Supercluster, and Gliese 876.

To evaluate each of these as an X-ray source, skip ahead to section "X-ray source".

SIMBAD sources

Another way to find possible X-ray sources in Aquarius is to use search queries on SIMBAD.

Click on either SIMBAD link under "External links" below, then click on "Criteria query".

In the tan box, type in "region(21 31 33.52 -05 34 16.2, 10m)", without the quotes. This tells the SIMBAD computer you are interested in a circular region of the celestial sphere centered on the coordinates for beta Aquarii, with a radius of 10 arcminutes (m).

Notice on the page over at the right from the tan colored box: "Return". The default is "object count". Click on "submit query". In a few moments a result something like "Number of objects: 4" should appear. Click "Back" to see the tan box again.

Add "otype='X'" to the entry so that it reads: "region(21 31 33.52 -05 34 16.2, 10m) & otype='X'", without the outside quotes. Click on "submit query" again. If the result is "0" number of objects, increase the number of arcminutes, or use "1d" which stands for "one degree".

When you find at least one object, change "Return" to "display" by clicking on the circle to its left, then "submit query".

SAO/NASA Astrophysics Data System

In the naming of sources per constellation, the genitive is in common use. For Aquarius, the genitive is Aquarii.

Click on the SAO/NASA Astrophysics Data System link below in the "External links". Try "Aquarii X-ray" without the quotes, or "alpha aquarii" with quotes, followed by "X-ray" without quotes.

Click on a link below # Bibcode Authors. If the Abstract describes the detection of X-rays from a source in the constellation Aquarius, go to the next section under "SAO/NASA Astrophysics Data System".

If it does not try another bibcode link.

X-rays

There are several ways to evaluate an X-ray source for the constellation Aquarius.

Wikipedia source

Click on the link to the Wikipedia article. After you've enjoyed reading about the source, use the 'find' command of your browser to see if this Wikipedia page mentions anything about "X-ray", or "X-rays". Does the article mention whether or not the source is an X-ray source?

What is the current time stamp for the Wikipedia article on the source? [Hint]: look for something like "This page was last modified on 25 December 2011 at 20:12." very near the bottom of the page. For now this is an adequate time stamp.

From reading the Wikipedia article on the source, if you believe the text demonstrates that the source is not an X-ray source in Aquarius edit the "Non-X-ray source in Aquarius" section near the bottom of the page with an entry similar to "# Alpha Aquarius 25 December 2011 at 20:12 Wikipedia article "Alpha Aquarius".", without the outer quotes, and finish the entry with four "~"s without the quotes after the period. The date included with your designation or username is a time stamp for the entry. The last portion of the entry is the source of your information.

On the other hand, if there are one or more sentences in the article that you believe demonstrates that the source is an X-ray source in Aquarius edit the section below "X-ray source in Aquarius" with a similar entry.

Go to the section entitled, "Challenging an entry".

SIMBAD source

To check any source (even one from Wikipedia) on SIMBAD, click of the "External link" to the "SIMBAD Astronomical Database".

At the lower right side of the SIMBAD Astronomical Database page is a "Basic search" box. There are several ways to try your target:

  1. source name: without the quotes or
  2. source coordinates: without the quotes, for example, "21 31 33.52 -05 34 16.2".

If you are looking at a SIMBAD generated table which lists possible targets, click on one.

On its SIMBAD page read down the left side until you see "Other object types:". To the right of this is a list of other object types that the source is. Look for an X. Is there one in this horizontal list?

If an X is present, skip down to the section, "SIMBAD time stamp". Even if an X is not present, noting that SIMBAD does not consider the source to be an X-ray source is important, so skip down to the "SIMBAD time stamp" section.

If you have already found an X-ray source (or a table of them) using SIMBAD, click on the blue link identifier for the first.

SIMBAD time stamp

Peruse the SIMBAD page for a time stamp or date of last revision. [Hint: it may look something like "2012.01.09CET20:10:02" and be in the upper right.]

If the entry at SIMBAD convinces you that the source is not an X-ray source, edit the "Non-X-ray source in Aquarius" section near the bottom of this page and type in an entry similar to "# Source Name 2012.01.09CET20:10:02 SIMBAD article "SIMBAD source name".", without the first set of quotes, followed by four ~s.

If your SIMBAD analysis convinces you that you have found an X-ray source in Aquarius (did you check the coordinates vs. the map of Aquarius?), make an entry something like the ones in the section "X-ray source in Aquarius".

SAO/NASA Astrophysics Data System source

If the abstract states that an X-ray source in Aquarius is detected or studied, consider entering it in the section "X-ray source in Aquarius" below.

Abstract time stamp

On the abstract page is a Publication Date:. This may serve as a time stamp for establishing that the source is detected as an X-ray source on or before the date of publication. The time stamp followed by four ~s for your verification as determiner in the section "X-ray source in Aquarius" completes your entry.

Challenging an entry

Any entry in either the section "X-ray source in Aquarius" or "Non-X-ray source in Aquarius" can be challenged. The time stamp can be challenged to see if there is an earlier one. The source can be challenged by an earlier source.

Wikipedia challenge

Is Wikipedia a 'primary source', or does the Wikipedia article cite a source?

Even though Wikipedia has an article on the source, is it a good place to stop in testing whether the source has been detected as an astronomical X-ray source?

If the Wikipedia article cites a primary source, skip down to the section on "Primary sources".

SIMBAD challenge

Is SIMBAD a 'primary source'?

SIMBAD is an astronomical database provided by the Centre de Données astronomiques de Strasbourg. It is an authoritative source, but they do occasionally make a mistake.

If you find an X-ray source within the constellation on SIMBAD, the next step is to find the earliest time stamp of discovery.

SAO/NASA Astrophysics Data System challenge

Is the SAO/NASA Astrophysics Data System abstract entry a primary source?

The SAO/NASA Astrophysics Data System is an astronomical database provided by the High Energy Astrophysics Division at the Harvard-Smithsonian Center for Astrophysics of Harvard University. The abstract has been copied from the actual article in a scientific journal or other publication. Mistakes can be made and the article may record within its text exact dates when the observation or detection of X-rays actually occurred. Such a record may provide an earlier time stamp.

Primary sources

Primary sources may be searched for possible additional information perhaps not yet evaluated by SIMBAD or not presented in a Wikipedia article about a source.

Wikipedia test source

For a Wikipedia article that cites a primary source, scroll down to the reference and open the reference. Read through the article looking for where the source mentioned in the Wikipedia article occurs. Some primary source authors may use source designations that are not mentioned in the Wikipedia article. To look for other designations, click on the link to SIMBAD in the "External links" on this page, enter the source name from the Wikipedia article, and see if other names are mentioned in the article.

When none of the names are mentioned, click on the link for "Google Advanced Search" in the list of "External links", enter the source name or designation(s) such as "Gliese 866", with "X-ray" to see if the source has a reference indicating it is an X-ray source. And, look for the earliest one. Compose an entry using the primary source.

SIMBAD test source

Further down the SIMBAD page is a list of "Identifiers". Click on the blue bold portion.

On the page that appears should be a primary source listed after Ref:. Click on the blue link with the oldest year. This yields an earlier time stamp and entry citation like the current one in the section "X-ray source in Aquarius". If you find another source or an earlier time stamp, compose a similar entry and edit the section. Additional information to add into the reference can be found by clicking on "ADS services" from the SIMBAD page.

SAO/NASA Astrophysics Data System source test

Click on either the "Electronic Refereed Journal Article (HTML)" or "Full Refereed Journal Article (PDF/Postscript)", if available.

Depending on the article display, if the abstract is repeated and the article is listed as FREE, click on either the PDF or HTML version.

While scanning or reading the article look for "Observations" (or use the Find function of your browser) and the possible inclusion of dates for these. If more than one X-ray source in Aquarius are detected, which one(s) would you list in the section "X-ray source in Aquarius" below?

An example of an article reference is provided in that section.

Changing an entry

From your analysis of the source so far, is it an X-ray source?

If you have found an earlier time stamp for the source than the one listed in the section below "Non-X-ray source in Aquarius" and the answer to the above question is "no", you can edit the section with your result. Or, you can leave the entries as is and try another star.

If you have found an earlier time stamp for the source than the one listed in the section below "X-ray source in Aquarius", edit the section with your result. Or, if you found another X-ray source with a comparable or earlier time stamp, edit the section with your result.

X-ray source in Aquarius

  1. EZ Aquarii March 1984.[1][2] Marshallsumter 21:06, 12 January 2012 (UTC).
  2. 1RXS J213145.0-055439 1999 SIMBAD article "1RXS J143729.3-791432"[3] Marshallsumter 22:30, 12 January 2012 (UTC).
  3. EZ Aquarii 30 November 2011 at 04:55 Wikipedia article "EZ Aquarii" Marshallsumter 19:41, 12 January 2012 (UTC).
  4. beta Aquarii 28 December 2011 at 20:06 Wikipedia article "Beta Aquarii" Marshallsumter 22:43, 12 January 2012 (UTC).
  5. 1RXS J213145.0-055439 2012.01.12CET23:10:30 SIMBAD article "1RXS J213145.0-055439" Marshallsumter 22:30, 12 January 2012 (UTC).
  6. alpha Aquarii[4] 17 January 2005 for 18.20 ks.[5] Marshallsumter (talk) 06:30, 13 June 2012 (UTC).
  7. NGC 7252, "X-ray emissions were observed in NGC 7252. This suggests the existence of nuclear activity or an intermediate-mass black hole in the galaxy."[6] Wikipedia article on NGC 7252, November 15, 2010, at 02:37. --Marshallsumter (discuss • contribs) 06:05, 10 May 2013 (UTC). Observation with the X-ray satellite ASCA of "a nearby merger remnant NGC 7252 ... detected X-ray emission with the X-ray flux of (1.8 ± 0.3) x 10-13 ergs s-1 cm-2 in the 0.5-10 keV band. ... hard X-ray emission ... may indicate the existence of nuclear activity or an intermediate-mass black hole in NGC 7252."[7] --Marshallsumter (discuss • contribs) 14:43, 10 May 2013 (UTC). Using the preceding article as a source, an earlier X-ray observation has been found. "The ROSAT PSPC observations were obtained in 1992 December and 1993 January and amount to 17 381 s of data centered on NGC 7252."[8] --Marshallsumter (discuss • contribs) 15:30, 10 May 2013 (UTC).
  8. 4U 2305-07[9] from "The fourth Uhuru catalog of X-ray sources" is within the figure for the constellation Aquarius. According to the lecture/article X-ray astronomy, "Sources detected during the final observation period from August 27, 1973, to January 12, 1974, are prefixed with "4U"." --Marshallsumter (discuss • contribs) 16:59, 10 May 2013 (UTC). SIMBAD at 2013.05.10CEST19:00:06 claims 4U 2305-07 is Markarian (Mrk) 926, a Seyfert type 1 galaxy. --Marshallsumter (discuss • contribs) 17:14, 10 May 2013 (UTC). This is the only X-ray source in the 4U catalog within Aquarius. --Marshallsumter (discuss • contribs) 21:57, 10 May 2013 (UTC).
  9. The "X-1" Aquarius "X-rays" search on Google scholar came up with "Some examples are NGC 7293 (Helix) in the Aquarius constellation, NGC 7027, and NGC 7009. ... coming from this collisional process ionizes and heats up the gas and may eventually be converted into radiation, including X-rays."[10] SIMBAD at 2013.05.10CEST20:01:49 lists NGC 7293 as an X-ray source detected by 2E (Einstein Observatory), 2RXP (ROSAT), and 2XMM (XMM Newton). --Marshallsumter (discuss • contribs) 21:13, 10 May 2013 (UTC).
  10. Also, from the "X-1" Aquarius "X-rays" search is "Her X-1, as well as the cataclysmic variables AM-Herculis and AE-Aquarius (Weekes, 1988".[11] SIMBAD at 2013.05.11CEST00:53:50 produces a record when "Aqr X-1", without the quotes, is input for a basic search: "X Aqr X-1 -- Cataclysmic Binary Candidate", but without coordinates or other designations. SIMBAD at 2013.05.11CEST01:00:11 yields using AE Aquarii: "V* AE Aqr -- CV DQ Her type (intermediate polar)" otype='X': (1AXG,1E,2E,1ES,1RXS,2XMM,[BM83],[FS2003]). --Marshallsumter (discuss • contribs) 23:03, 10 May 2013 (UTC).

Non-X-ray source in Aquarius

  1. beta Aquarii 2012.01.12CET23:31:47 SIMBAD article "* bet Aqr".
  2. alpha Aquarii 27 January 2012 at 04:04 Wikipedia article Alpha Aquarii. Marshallsumter (talk) 00:37, 4 March 2012 (UTC)
  3. alpha Aquarii 2012.03.04CET01:36:36 SIMBAD article "NAME SADALMELIK". Marshallsumter (talk) 00:40, 4 March 2012 (UTC)
  4. NGC 7252 2013.05.10CEST07:52:57 SIMBAD article "NGC 7252". --Marshallsumter (discuss • contribs) 06:05, 10 May 2013 (UTC)

Oldest record

4U 2305-07[9] from "The fourth Uhuru catalog of X-ray sources" is within the figure for the constellation Aquarius. The article dates from December 1978. According to the lecture/article X-ray astronomy: "Sources detected during the final observation period from August 27, 1973, to January 12, 1974, are prefixed with "4U"."

SIMBAD annotations

For NGC 7252, the SIMBAD record indicates that it is not an X-ray source yet above at least two refereed journal articles indicate that it is. Use the second SIMBAD External links to directly display the SIMBAD database in France.

Enter "NGC 7252", or the source you have found, without the quotes into the search box. Scroll down to the Annotations :. Look for the link "add an annotation to this object". With access to the literature citations available, click on this link. You may need to register as a user. It's free. Post your annotation containing the literature references.

Aquarius X-1

SIMBAD at 2013.05.11CEST00:53:50 produces a record when "Aqr X-1", without the quotes, is input for a basic search: "X Aqr X-1 -- Cataclysmic Binary Candidate", but without coordinates or other designations.

A Google scholar search using "Aqr X-1", with quotes produces one source. In its Table 3 entitled: "Table of observed number of upward showering muons and expected background from atmospheric neutrinos in a cone of half-angle 3◦ from selected point sources along with 90% c.l. muon and neutrino flux limits for a E−2 neutrino spectrum."[12], is an entry "Aqr X-1".[12] No coordinates, any other designation, or literature reference is given.[12]

In examining the article entitled, "33 second X-ray pulsations in AE Aquarii", there is the designation X-1 referring to their first X-ray observation run using the Einstein Observatory. AE Aqr is at J2000 RA 20h 40m 09.1629s Dec -00° 52' 15.071". This X-1 X-ray run has an X-1A and an X-1B, followed by an X-2 observation run. This may have led to AE Aquarii being thought of as Aquarius X-1. AE Aquarii is a cataclysmic variable with nova-like activity and an orbital period of 9.88 hours.[13] "A K dwarf fills its critical Roche surface and transfers matter to a white dwarf via an accretion disk."[13] AE Aquarii was observed "for a total of 1.3 hours on 1979 April 27 and 28."[13] No earlier X-ray observations were mentioned.[13]

Hypotheses

  1. The first X-ray source in Aquarius was detected by Ariel 5.

See also

References

  1. ↑ H. M. Johnson (March 1984). "Survey for Cataloged Stars within 25 Parsecs of the Sun that were not Targeted in the Einstein Data Bank". Bulletin of the American Astronomical Society 16 (3): 472.
  2. ↑ Ch. Leinert, M. Haas, F. Allard, R. Wehrse, D.W. McCarthy Jr., H. Jahreiß, and Ch. Perrier (September 1990). "The nearby binary Gliese 866 A/B - Orbit, masses, temperature, and composition". Astronomy and Astrophysics 236 (2): 399-408.
  3. ↑ Voges, W.; Aschenbach, B.; Boller, Th.; Bräuninger, H.; Briel, U.; Burkert, W.; Dennerl, K.; Englhauser, J.; Gruber, R.; Haberl, F.; Hartner, G.; Hasinger, G.; Kürster, M.; Pfeffermann, E.; Pietsch, W.; Predehl, P.; Rosso, C.; Schmitt, J. H. M. M.; Trümper, J.; Zimmermann, H. U. (September 1999). "The ROSAT all-sky survey bright source catalogue". Astronomy and Astrophysics 349 (9): 389-405.
  4. ↑ RJHall (March 17, 2012). Alpha Aquarii. San Francisco, California: Wikimedia Foundation, Inc. Retrieved 2012-06-12.
  5. ↑ Thomas R. Ayres, Alexander Brown, and Graham M. Harper (July 1, 2005). "Chandra Observations of Coronal Emission from the Early G Supergiants α and β Aquarii". The Astrophysical Journal 627 (1): L53-6. doi:10.1086/431977. http://iopscience.iop.org/1538-4357/627/1/L53/. Retrieved 2012-06-12.
  6. ↑ Mohamed Osama AlNagdy (November 15, 2010). "NGC 7252". Wikipedia (San Francisco, California: Wikimedia Foundation, Inc). http://en.wikipedia.org/w/index.php?title=NGC_7252&diff=396829826&oldid=396807195. Retrieved 2013-05-09.
  7. ↑ Hisamitsu Awaki, Hironori Matsumoto, and Hiroshi Tomida (March 10, 2002). "X-Ray Emission from a Merger Remnant, NGC 7252 (the "Atoms-for-Peace" Galaxy)". The Astrophysical Journal 567 (2): 892-5. doi:10.1086/338694. http://iopscience.iop.org/0004-637X/567/2/892. Retrieved 2013-05-10.
  8. ↑ J. E. Hibbard, Puragra Guhathakurta, J. H. van Gorkom, and François Schweizer (January 1994). "Cold, Warm, and Hot Gas in the Late-Stage Merger NGC 7252". The Astronomical Journal 107 (1): 67-89. doi:10.1086/116835.
  9. 1 2 Forman W, Jones C, Cominsky L, Julien P, Murray S, Peters G (December 1978). "The fourth Uhuru catalog of X-ray sources". The Astrophysical Journal Supplemental Series 38 (12): 357-412. doi:0.1086/190561.
  10. ↑ Walter J. Maciel (2013). Interstellar Ionized Nebulae, In: Astrophysics of the Interstellar Medium. New York: Springer. pp. 147–81. doi:10.1007/978-1-4614-3767-3_8. ISBN 978-1-4614-3766-6. Retrieved 2013-05-10.
  11. ↑ C. L. Bhat (December 1997). "Ground-based γ-ray astronomy : Present status and future prospects". Bulletin of the Astronomical Society of India 25 (12): 461-84.
  12. 1 2 3 S. Desai and The Super-Kamiokande Collaboration (February 2008). "Study of TeV neutrinos with upward showering muons in Super-Kamiokande". Astroparticle Physics 29 (1): 42–54. http://www.sciencedirect.com/science/article/pii/S0927650507001533. Retrieved 2013-05-10.
  13. 1 2 3 4 Joseph Patterson, David Branch and Guido Chincarini, and Edward L. Robinson (15 September 1980). "33 second X-ray pulsations in AE Aquarii". The Astrophysical Journal 240 (09): L133-6. doi:10.1086/183339. http://adsabs.harvard.edu/abs/1980ApJ...240L.133P. Retrieved 2015-09-18.

Further reading

  • Voges, W.; Aschenbach, B.; Boller, Th.; Bräuninger, H.; Briel, U.; Burkert, W.; Dennerl, K.; Englhauser, J.; Gruber, R.; Haberl, F.; Hartner, G.; Hasinger, G.; Kürster, M.; Pfeffermann, E.; Pietsch, W.; Predehl, P.; Rosso, C.; Schmitt, J. H. M. M.; Trümper, J.; Zimmermann, H. U. (September 1999). "The ROSAT all-sky survey bright source catalogue". Astronomy and Astrophysics 349 (9): 389-405. 

{{Principles of radiation astronomy}}{{Radiation astronomy resources}}

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