J/AJ/167/10 Technosignature Search of 97 Nearby Galaxies (Choza+, 2024)
The Breakthrough Listen Search for Intelligent Life: Technosignature Search of
97 Nearby Galaxies.
Choza C., Bautista D., Croft S., Siemion A.P.V., Brzycki B., Bhattaram K.,
Czech D., de Pater I., Gajjar V., Isaacson H., Lacker K., Lacki B.,
Lebofsky M., MacMahon D.H.E., Price D., Schoultz S., Sheikh S.,
Varghese S.S., Morgan L., Drew J., Worden S.P.
<Astron. J., 167, 10 (2024)>
=2024AJ....167...10C 2024AJ....167...10C
ADC_Keywords: Galaxies; Spectra, radio; Spectra, millimetric/submm
Keywords: Technosignatures ; Search for extraterrestrial intelligence ;
Astrobiology ; Radio astronomy ; Galaxies
Abstract:
The Breakthrough Listen search for intelligent life is, to date, the
most extensive technosignature search of nearby celestial objects. We
present a radio technosignature search of the centers of 97 nearby
galaxies, observed by Breakthrough Listen at the Robert C. Byrd Green
Bank Telescope. We performed a narrowband Doppler drift search using
the turboSETI pipeline with a minimum signal-to-noise parameter
threshold of 10, across a drift rate range of ±4Hz/s, with a
spectral resolution of 3Hz and a time resolution of 18.25s. We removed
radio frequency interference (RFI) by using an on-source/off-source
cadence pattern of six observations and discarding signals with
Doppler drift rates of 0. We assess factors affecting the sensitivity
of the Breakthrough Listen data reduction and search pipeline using
signal injection and recovery techniques and apply new methods for the
investigation of the RFI environment. We present results in four
frequency bands covering 1-11GHz, and place constraints on the
presence of transmitters with equivalent isotropic radiated power on
the order of 1026W, corresponding to the theoretical power consumption
of Kardashev Type II civilizations.
Description:
We searched for technosignatures originating from 97 nearby galaxies
from the Isaacson+ (2017, J/PASP/129/E4501) sample, using four of the
the Robert C. Byrd Green Bank Telescope (GBT) receivers covering
1.10-2.7GHz and 4.0-11.2GHz.
The sample spans 5 years from early 2018 to late 2022, totaling 229h
of observation time. See Section 2.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table5.dat 74 97 Properties of the galaxy sample analyzed in
this work
--------------------------------------------------------------------------------
See also:
J/ApJ/767/94 : 1.1-1.9GHz SETI survey of KOIs. I. (Siemion+, 2013)
J/ApJ/795/158 : The MASSIVE survey ; 116 candidate galaxies (Ma+, 2014)
J/MNRAS/498/5720 : ExtendedBreakthrough Listen sample (Wlodarczyk-Sroka+, 2020)
J/AJ/161/55 : Observation of 31 G-stars at 1.5GHz with GBT (Margot+, 2021)
J/AJ/165/61 : 12 transiting Kepler exoplanet properties (Sheikh+, 2023)
J/AJ/165/114 : SpecMatch-Emp isochrone analysis 45 stars (Zuckerman+, 2023)
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Galaxy Galaxy identifier
12- 16 F5.2 Mpc Dist [0.06/29.2] Distance
18- 21 F4.1 mag Kmag [0.9/14] Apparent K band magnitude
23- 38 A16 --- Type Galaxy morphology type
40- 47 E8.2 --- L-band [29600/527000000000] Number of stars captured
in L-band
49- 56 E8.2 --- S-band [12800/527000000000] Number of stars captured in
S-band
58- 65 E8.2 --- C-band [5360/527000000000] Number of stars captured
in C-band
67- 74 E8.2 --- X-band [5470/430000000000] Number of stars captured
in X-band
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 19-Apr-2024