Singal from the Center of our Galaxy

"GB" == Greg Balaze writes:

GB Scientists detect a repeating, very strong signal coming from the
GB center of our Galaxy, so far they arent sure what it is.

GB http://www.newscientist.com/article....ine-news_rss20

Whoa!

We detected something from the direction of the center of the Galaxy.
Right now we have no estimate for its distance. It could be at the
center of the Galaxy, but it might be very close as well.

Moreover, "signal" is a bit strong. The source repeats on a 77
min. time scale, but there are other kinds of objects that produce
repeating signals (pulsars being the most notable example). Unlike
the expected signal from an ET transmitter, this source emits over a
fairly wide range of frequencies (at least 3 MHz and probably much
more). At this point, while intriguing, there's no reason to expect
that it is not natural.

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Joseph,

I agree, I hope I didn't give the impression that I believe this
signal to be artificial. I'm not sure what to make of it myself.
The thing that fascinated me was that it didn't fit any type of pulsar
known, except maybe a Magnatar.

Hypothetically speaking, 3 Mhz bandwidth isn't to far out for anyone
sending a signal hoping that the receiving intelligence is looking in
the relative area of the frequency.

Then imagine the broad frequency capabilities 3 mhz or more would give
someone who wanted to get his message through interstellar distances
with limiting the signal to noise ratio.

Oh well, one can dream can't they

"GB" == Greg Balaze writes:

GB Hypothetically speaking, 3 Mhz bandwidth isn't to far out for
GB anyone sending a signal hoping that the receiving intelligence is
GB looking in the relative area of the frequency.

GB Then imagine the broad frequency capabilities 3 mhz or more would
GB give someone who wanted to get his message through interstellar
GB distances with limiting the signal to noise ratio.

It's actually the reverse. In order to make the signal stand out,
you'd want to transmit a narrowband signal. If you have a fixed
amount of power, you don't want to spread that power out over lots of
frequencies.

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Joseph Lazio wrote:
"GB" == Greg Balaze writes:


GB Scientists detect a repeating, very strong signal coming from the
GB center of our Galaxy, so far they arent sure what it is.

GB http://www.newscientist.com/article....ine-news_rss20

Whoa!

We detected something from the direction of the center of the Galaxy.
Right now we have no estimate for its distance. It could be at the
center of the Galaxy, but it might be very close as well.

Moreover, "signal" is a bit strong. The source repeats on a 77
min. time scale, but there are other kinds of objects that produce
repeating signals (pulsars being the most notable example). Unlike
the expected signal from an ET transmitter, this source emits over a
fairly wide range of frequencies (at least 3 MHz and probably much
more). At this point, while intriguing, there's no reason to expect
that it is not natural.


darned interesting though!

but for a pulsar it is very unusual, isn't it?
far from a normal expected pulsar signal I think ...

does the 3MHz+ signal spectrum show any features I wonder? ...

"AAA" == Alfred A Aburto writes:

AAA Joseph Lazio wrote:
"GB" == Greg Balaze writes:
GB Scientists detect a repeating, very strong signal coming from the
GB center of our Galaxy, so far they arent sure what it is.
GB
GB http://www.newscientist.com/article....ine-news_rss20
Whoa! We detected something from the direction of the center of
the Galaxy. Right now we have no estimate for its distance. It
could be at the center of the Galaxy, but it might be very close as
well. Moreover, "signal" is a bit strong. The source repeats on a
77 min. time scale, but there are other kinds of objects that
produce repeating signals (...).
Unlike the expected signal from an ET transmitter, this source
emits over a fairly wide range of frequencies (at least 3 MHz and
probably much more). At this point, while intriguing, there's no
reason to expect that it is not natural.

AAA darned interesting though!

Agreed.

AAA but for a pulsar it is very unusual, isn't it? far from a normal
AAA expected pulsar signal I think ...

Yes.

AAA does the 3MHz+ signal spectrum show any features I wonder? ...

Nope. We looked for that.

Indeed much of the paper involves summarizing known kinds of radio
transients and then showing why this object doesn't seem to fit any of
the known categories.

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In message , Joseph Lazio
writes

Indeed much of the paper involves summarizing known kinds of radio
transients and then showing why this object doesn't seem to fit any of
the known categories.


Interesting that about 15 months ago you posted a message on
sci.astro.seti saying
We have an extremely poor
idea of how the radio sky looks on short time scales. We know that
there are gamma-ray bursts, there are some reported optical
transients, but we know next to nothing about potential radio
transients.
!!
Http://groups.google.co.uk/groups?hl...=right&th=46b3
d023182af33c&seekm=lld6cx1ky0.fsf%40adams.patriot. net#link25
--
Remove spam and invalid from address to reply.

"JS" == Jonathan Silverlight writes:

JS In message , Joseph Lazio
JS writes
Indeed much of the paper involves summarizing known kinds of radio
transients and then showing why this object doesn't seem to fit any
of the known categories.

JS Interesting that about 15 months ago you posted a message on
JS sci.astro.seti saying
We have an extremely poor idea of how the radio sky looks on short
time scales. We know that there are gamma-ray bursts, there are
some reported optical transients, but we know next to nothing about
potential radio transients.

JS !!

Yeah, they do seem contradictory. Part of it is definitions. Are
pulsars considered transients? (Some would say yes, some no.)

My comment is perhaps better stated as, there have been few blind
surveys of the radio sky for transients, particularly for transients
on short time scales. An effective blind survey for fast transients
involves a wide field of view and high time resolution. Radio
telescopes are pushing up against natural limits for time resolution
(e.g., the Arecibo telescope has obtained nanosecond time
resolution). However, radio telescopes have had (more or less)
traditionally small fields of view. That's one of the advantages of
the low-frequency systems on the VLA, they have a wide field of view.
Of course, they don't have much in the way of time resolution, as they
are typically used with 10-second time resolution.

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wrote:
Scientists detect a repeating, very strong signal coming from the
center of our Galaxy, so far they arent sure what it is.


http://www.newscientist.com/article....ine-news_rss20


more on the mysterious radio source:

http://www.cnn.com/2005/TECH/space/0...eut/index.html

Alfred A. Aburto Jr. wrote:
wrote:
Scientists detect a repeating, very strong signal coming from the
center of our Galaxy, so far they arent sure what it is.



http://www.newscientist.com/article....ine-news_rss20


more on the mysterious radio source:

http://www.cnn.com/2005/TECH/space/0...eut/index.html


Here's some more on it:


Radio Pulses Could Signal New Class of Astronomical Object

http://www.sciam.com/article.cfm?cha...0483414B7F0000

"It [GCRT J1745-3009] has not been detected since 2002," Hyman notes,
"nor is it present on earlier images."

and

Discovery points to new class of astronomical objects

http://www.spaceflightnow.com/news/n0503/03object/

"Amazingly, even though the sky is known to be full of transient
objects emitting at X- and gamma-ray wavelengths," NRL astronomer Dr.
Joseph Lazio pointed out, "very little has been done to look for radio
bursts, which are often easier for astronomical objects to produce."

(Your name in lights LT, again


IMO, considering that the galactic center is such a high energy
environment that is polluted with black holes and other massive
objects, and the candidate signal seems to be in the same direction as
an expanding shell of a supernova, perhaps there is some interaction of
the expanding shell with the disk of a super-massive object, like laser
photons reflecting off of a laser disk, perhaps the rotation speed of
the disk material is responsible for the periodicity (although one
cannot discount that line-of-sight toward the galactic center might be
an interesting signal path to look for candidates too.)

O' where o'where has my Ee-ee Teee gone, oh where oh where can she be,
with her signal cut short and the distance quite long, o'where o'where
can she be???? Jason H.

Jason H. wrote:
[snip,snip]

Here's some more on it:


Radio Pulses Could Signal New Class of Astronomical Object

http://www.sciam.com/article.cfm?cha...0483414B7F0000

"It [GCRT J1745-3009] has not been detected since 2002," Hyman notes,
"nor is it present on earlier images."

They have been trying to re-acquire it for 3 years now!!? Oh my, I
thought it was a new find!


and

Discovery points to new class of astronomical objects

http://www.spaceflightnow.com/news/n0503/03object/

"Amazingly, even though the sky is known to be full of transient
objects emitting at X- and gamma-ray wavelengths," NRL astronomer Dr.
Joseph Lazio pointed out, "very little has been done to look for radio
bursts, which are often easier for astronomical objects to produce."

(Your name in lights LT, again

I wonder what the recieved signal level was? Maybe SARA members could
look for it too? (SARA: Society of Amateur Radio Astronomers)


IMO, considering that the galactic center is such a high energy
environment that is polluted with black holes and other massive
objects, and the candidate signal seems to be in the same direction as
an expanding shell of a supernova,

I'm not sure of that ... just looking at the photo caption didn't
indicate that was the direction of the source. I thought it was just a
picture of the galactic center (that expanding shell).

The object coordinates are in the object name: GCRT J1745-3009
J2000: RA = 17:45 (HH:MM) and DEC = -30:09 (DD:MM) ... (I haven't
checked the star charts though) ...

perhaps there is some interaction of
the expanding shell with the disk of a super-massive object, like laser
photons reflecting off of a laser disk, perhaps the rotation speed of
the disk material is responsible for the periodicity (although one
cannot discount that line-of-sight toward the galactic center might be
an interesting signal path to look for candidates too.)

The article mentioned a coherent signal ... possible natural maser?


O' where o'where has my Ee-ee Teee gone, oh where oh where can she be,
with her signal cut short and the distance quite long, o'where o'where
can she be???? Jason H.


:-)