Sky & Telescope - June 2022 - 15
MASS COMPARISONS: GREGG DINDERMAN / S&T, SOURCE: LIGO-G2000963;
TALLY: LIGO-VIRGO / AARON GELLER / NORTHWESTERN UNIVERSITY
Solar masses
Researchers use advanced statis " There
were no theoretical reatical
techniques to take a step back
from these individual finds and
study the big picture. This population
analysis tells astrophysicists
what they would detect if their
instruments were perfect, explains
LIGO's Zoheyr Doctor (Northwestern).
" What we're after is
what's going on out in the universe,
not just what our detector is
seeing, " he says.
This extrapolation has turned
GW150914
31
solar
masses
= 0.86
36
solar
masses
GW190814
up something unexpected: Black
holes tend to cluster at 10 and 35
solar masses. " We've totally baffled
a lot of the theorists, because our
mass distribution looks nothing
like any mass distribution drawn
before, " says LIGO's Maya Fishbach
(also Northwestern).
Below roughly 10 solar masses, the number of black holes
2.6 solar masses
= 0.11
23 solar masses
Most mergers
involve black
holes of similar
masses,
including the
first detection,
GW150914.
But some,
such as
GW190814,
pair one object
with a second
that's much
larger than it.
sons, " says Feryal Özel (University
of Arizona), who helped bring the
paucity to astronomers' attention.
Small stars are more common than
big ones, she explains, " and if the
evolution does nothing special and
the explosion mechanism does
nothing special, then there should
have been far more low-mass black
holes in the 2- to 5-solar-mass
range than, for example, the 5- to
10-solar-mass range. "
Gravitational waves have turned
up a few objects in the valley,
notably the smaller member of
GW190814. This event involved a
23-solar-mass black hole swallowing
a mystery object of 2.6 solar
masses. Many astrophysicists think
the mystery object was a tiny black
plummets, creating a valley in the plot. This dearth of small
black holes has puzzled astronomers long before the advent
of gravitational-wave science. Neutron stars can only survive
up to maybe 2½ solar masses before they collapse under their
own weight; black holes should appear just above that limit.
Yet observations of compact objects in stellar binaries have
found almost no black holes between 2 and 5 solar masses.
200
LIGO-Virgo-KAGRA black holes
100
50
?
20
10
5
EM black holes
?
2
EM neutron stars
1
THE TALLY SO FAR Scientists have now detected 90 gravitational-wave events (blue and orange), expanding considerably on the compact objects
detected at various wavelengths of light (electromagnetic, or " EM " ). The dots indicate the two masses of the objects that merged and of the object
they created. Almost all of the new discoveries appear to be black holes. Objects that lie just above 2 solar masses are of uncertain nature.
sk yand tele scope .o r g * JUNE 2022 15
LIGO-Virgo-KAGRA
neutron stars
?
hole, although a rapidly spinning neutron star might be able
to withstand collapse at that mass.
Other observations also suggest the low-mass valley isn't
empty. Careful monitoring of tiny flashes created as unseen
objects pass between us and our galaxy's stars, bending and
magnifying the stars' light, have turned up eight objects
that might lie in the valley, Łukasz Wyrzykowski (Warsaw
(continued on page 18)
http://www.skyandtelescope.com
Sky & Telescope - June 2022
Table of Contents for the Digital Edition of Sky & Telescope - June 2022
Contents
Sky & Telescope - June 2022 - Cover1
Sky & Telescope - June 2022 - Cover2
Sky & Telescope - June 2022 - 1
Sky & Telescope - June 2022 - Contents
Sky & Telescope - June 2022 - 3
Sky & Telescope - June 2022 - 4
Sky & Telescope - June 2022 - 5
Sky & Telescope - June 2022 - 6
Sky & Telescope - June 2022 - 7
Sky & Telescope - June 2022 - 8
Sky & Telescope - June 2022 - 9
Sky & Telescope - June 2022 - 10
Sky & Telescope - June 2022 - 11
Sky & Telescope - June 2022 - 12
Sky & Telescope - June 2022 - 13
Sky & Telescope - June 2022 - 14
Sky & Telescope - June 2022 - 15
Sky & Telescope - June 2022 - 16
Sky & Telescope - June 2022 - 17
Sky & Telescope - June 2022 - 18
Sky & Telescope - June 2022 - 19
Sky & Telescope - June 2022 - 20
Sky & Telescope - June 2022 - 21
Sky & Telescope - June 2022 - 22
Sky & Telescope - June 2022 - 23
Sky & Telescope - June 2022 - 24
Sky & Telescope - June 2022 - 25
Sky & Telescope - June 2022 - 26
Sky & Telescope - June 2022 - 27
Sky & Telescope - June 2022 - 28
Sky & Telescope - June 2022 - 29
Sky & Telescope - June 2022 - 30
Sky & Telescope - June 2022 - 31
Sky & Telescope - June 2022 - 32
Sky & Telescope - June 2022 - 33
Sky & Telescope - June 2022 - 34
Sky & Telescope - June 2022 - 35
Sky & Telescope - June 2022 - 36
Sky & Telescope - June 2022 - 37
Sky & Telescope - June 2022 - 38
Sky & Telescope - June 2022 - 39
Sky & Telescope - June 2022 - 40
Sky & Telescope - June 2022 - 41
Sky & Telescope - June 2022 - 42
Sky & Telescope - June 2022 - 43
Sky & Telescope - June 2022 - 44
Sky & Telescope - June 2022 - 45
Sky & Telescope - June 2022 - 46
Sky & Telescope - June 2022 - 47
Sky & Telescope - June 2022 - 48
Sky & Telescope - June 2022 - 49
Sky & Telescope - June 2022 - 50
Sky & Telescope - June 2022 - 51
Sky & Telescope - June 2022 - 52
Sky & Telescope - June 2022 - 53
Sky & Telescope - June 2022 - 54
Sky & Telescope - June 2022 - 55
Sky & Telescope - June 2022 - 56
Sky & Telescope - June 2022 - 57
Sky & Telescope - June 2022 - 58
Sky & Telescope - June 2022 - 59
Sky & Telescope - June 2022 - 60
Sky & Telescope - June 2022 - 61
Sky & Telescope - June 2022 - 62
Sky & Telescope - June 2022 - 63
Sky & Telescope - June 2022 - 64
Sky & Telescope - June 2022 - 65
Sky & Telescope - June 2022 - 66
Sky & Telescope - June 2022 - 67
Sky & Telescope - June 2022 - 68
Sky & Telescope - June 2022 - 69
Sky & Telescope - June 2022 - 70
Sky & Telescope - June 2022 - 71
Sky & Telescope - June 2022 - 72
Sky & Telescope - June 2022 - 73
Sky & Telescope - June 2022 - 74
Sky & Telescope - June 2022 - 75
Sky & Telescope - June 2022 - 76
Sky & Telescope - June 2022 - 77
Sky & Telescope - June 2022 - 78
Sky & Telescope - June 2022 - 79
Sky & Telescope - June 2022 - 80
Sky & Telescope - June 2022 - 81
Sky & Telescope - June 2022 - 82
Sky & Telescope - June 2022 - 83
Sky & Telescope - June 2022 - 84
Sky & Telescope - June 2022 - Cover3
Sky & Telescope - June 2022 - Cover4
https://www.nxtbook.com/nxtbooks/aas/st_202411
https://www.nxtbook.com/nxtbooks/aas/st_202410
https://www.nxtbook.com/nxtbooks/aas/st_202409
https://www.nxtbook.com/nxtbooks/aas/st_202408
https://www.nxtbook.com/nxtbooks/aas/st_202407
https://www.nxtbook.com/nxtbooks/aas/st_202406
https://www.nxtbook.com/nxtbooks/aas/st_202405
https://www.nxtbook.com/nxtbooks/aas/st_202404_qr
https://www.nxtbook.com/nxtbooks/aas/st_202404
https://www.nxtbook.com/nxtbooks/aas/st_202403
https://www.nxtbook.com/nxtbooks/aas/st_202402
https://www.nxtbook.com/nxtbooks/aas/st_202401_aus
https://www.nxtbook.com/nxtbooks/aas/st_202401
https://www.nxtbook.com/nxtbooks/aas/st_202312_aus
https://www.nxtbook.com/nxtbooks/aas/st_202312
https://www.nxtbook.com/nxtbooks/aas/st_202311
https://www.nxtbook.com/nxtbooks/aas/st_202310
https://www.nxtbook.com/nxtbooks/aas/st_202309
https://www.nxtbook.com/nxtbooks/aas/st_202308
https://www.nxtbook.com/nxtbooks/aas/st_202307
https://www.nxtbook.com/nxtbooks/aas/st_202306
https://www.nxtbook.com/nxtbooks/aas/st_202305
https://www.nxtbook.com/nxtbooks/aas/st_202304
https://www.nxtbook.com/nxtbooks/aas/st_202304_qr
https://www.nxtbook.com/nxtbooks/aas/st_202303
https://www.nxtbook.com/nxtbooks/aas/st_202302
https://www.nxtbook.com/nxtbooks/aas/st_202301
https://www.nxtbook.com/nxtbooks/aas/st_202212
https://www.nxtbook.com/nxtbooks/aas/st_202211
https://www.nxtbook.com/nxtbooks/aas/st_202210
https://www.nxtbook.com/nxtbooks/aas/st_202209
https://www.nxtbook.com/nxtbooks/aas/st_202208
https://www.nxtbook.com/nxtbooks/aas/st_202207
https://www.nxtbook.com/nxtbooks/aas/st_202206
https://www.nxtbook.com/nxtbooks/aas/st_202205
https://www.nxtbook.com/nxtbooks/aas/st_202204
https://www.nxtbook.com/nxtbooks/aas/st_202203
https://www.nxtbook.com/nxtbooks/aas/st_202202
https://www.nxtbook.com/nxtbooks/aas/st_202201
https://www.nxtbook.com/nxtbooks/aas/st_202112
https://www.nxtbook.com/nxtbooks/aas/st_202111
https://www.nxtbook.com/nxtbooks/aas/st_202110
https://www.nxtbook.com/nxtbooks/aas/st_202109
https://www.nxtbook.com/nxtbooks/aas/st_202108
https://www.nxtbook.com/nxtbooks/aas/st_202107
https://www.nxtbook.com/nxtbooks/aas/st_202106
https://www.nxtbook.com/nxtbooks/aas/st_202105
https://www.nxtbook.com/nxtbooks/aas/st_202104
https://www.nxtbook.com/nxtbooks/aas/st_202103
https://www.nxtbook.com/nxtbooks/aas/st_202102
https://www.nxtbook.com/nxtbooks/aas/st_202101
https://www.nxtbook.com/nxtbooks/aas/skywatch_2021
https://www.nxtbook.com/nxtbooks/aas/st_202012
https://www.nxtbook.com/nxtbooks/aas/st_202011
https://www.nxtbook.com/nxtbooks/aas/st_202010
https://www.nxtbook.com/nxtbooks/aas/st_202009
https://www.nxtbook.com/nxtbooks/aas/st_202008
https://www.nxtbook.com/nxtbooks/aas/st_202007
https://www.nxtbook.com/nxtbooks/aas/st_202006
https://www.nxtbook.com/nxtbooks/aas/st_202005
https://www.nxtbook.com/nxtbooks/aas/st_202004
https://www.nxtbook.com/nxtbooks/aas/st_202003
https://www.nxtbook.com/nxtbooks/aas/st_202002
https://www.nxtbook.com/nxtbooks/aas/st_202001
https://www.nxtbook.com/nxtbooks/aas/st_201912
https://www.nxtbook.com/nxtbooks/aas/st_201911
https://www.nxtbook.com/nxtbooks/aas/st_201910
https://www.nxtbook.com/nxtbooks/aas/st_201909
https://www.nxtbook.com/nxtbooks/aas/st_201908
https://www.nxtbook.com/nxtbooks/aas/st_201907
https://www.nxtbook.com/nxtbooks/aas/st_201906
https://www.nxtbook.com/nxtbooks/aas/st_201905
https://www.nxtbook.com/nxtbooks/aas/st_201904
https://www.nxtbook.com/nxtbooks/aas/st_201903
https://www.nxtbook.com/nxtbooks/aas/st_201902
https://www.nxtbook.com/nxtbooks/aas/st_201901
https://www.nxtbook.com/nxtbooks/aas/st_201812
https://www.nxtbook.com/nxtbooks/aas/st_201811
https://www.nxtbook.com/nxtbooks/aas/st_201810
https://www.nxtbook.com/nxtbooks/aas/st_201809
https://www.nxtbook.com/nxtbooks/aas/st_201808
https://www.nxtbook.com/nxtbooks/aas/st_201807
https://www.nxtbook.com/nxtbooks/aas/st_201806
https://www.nxtbook.com/nxtbooks/aas/st_201805
https://www.nxtbook.com/nxtbooks/aas/st_201804
https://www.nxtbook.com/nxtbooks/aas/st_201803
https://www.nxtbook.com/nxtbooks/aas/st_201802
https://www.nxtbook.com/nxtbooks/aas/st_201801
https://www.nxtbook.com/nxtbooks/aas/st_201712
https://www.nxtbook.com/nxtbooks/aas/st_201711
https://www.nxtbook.com/nxtbooks/aas/st_201710
https://www.nxtbook.com/nxtbooks/aas/st_201709
https://www.nxtbook.com/nxtbooks/aas/st_201708
https://www.nxtbook.com/nxtbooks/aas/st_201707
https://www.nxtbook.com/nxtbooks/aas/st_201706
https://www.nxtbook.com/nxtbooks/aas/st_201705
https://www.nxtbook.com/nxtbooks/aas/st_201704
https://www.nxtbook.com/nxtbooks/aas/st_201703
https://www.nxtbook.com/nxtbooks/aas/st_201702
https://www.nxtbook.com/nxtbooks/aas/st_201701
https://www.nxtbook.com/nxtbooks/aas/st_201612
https://www.nxtbook.com/nxtbooks/aas/st_201611
https://www.nxtbook.com/nxtbooks/aas/st_201610
https://www.nxtbook.com/nxtbooks/aas/st_201609
https://www.nxtbook.com/nxtbooks/aas/st_201608
https://www.nxtbook.com/nxtbooks/aas/st_201607
https://www.nxtbook.com/nxtbooks/aas/st_201606
https://www.nxtbook.com/nxtbooks/aas/st_201605
https://www.nxtbook.com/nxtbooks/aas/st_201604
https://www.nxtbook.com/nxtbooks/aas/st_201603
https://www.nxtbook.com/nxtbooks/aas/st_201602
https://www.nxtbook.com/nxtbooks/aas/st_201601
https://www.nxtbook.com/nxtbooks/aas/st_201512
https://www.nxtbook.com/nxtbooks/aas/st_201511
https://www.nxtbook.com/nxtbooks/aas/st_201510
https://www.nxtbook.com/nxtbooks/aas/st_201509
https://www.nxtbook.com/nxtbooks/aas/st_201508
https://www.nxtbook.com/nxtbooks/aas/st_201507
https://www.nxtbook.com/nxtbooks/aas/st_201506
https://www.nxtbook.com/nxtbooks/aas/st_201505
https://www.nxtbook.com/nxtbooks/aas/st_201504
https://www.nxtbook.com/nxtbooks/aas/st_201503
https://www.nxtbook.com/nxtbooks/aas/st_201502
https://www.nxtbook.com/nxtbooks/aas/st_201501
https://www.nxtbook.com/nxtbooks/aas/st_201412
https://www.nxtbook.com/nxtbooks/aas/st_201411
https://www.nxtbook.com/nxtbooks/aas/st_201410
https://www.nxtbook.com/nxtbooks/aas/st_201409
https://www.nxtbook.com/nxtbooks/aas/st_201408
https://www.nxtbook.com/nxtbooks/aas/st_201407
https://www.nxtbook.com/nxtbooks/aas/st_201406
https://www.nxtbook.com/nxtbooks/aas/st_mars
https://www.nxtbook.com/nxtbooks/aas/st_201405
https://www.nxtbook.com/nxtbooks/aas/st_201404
https://www.nxtbook.com/nxtbooks/aas/st_201403
https://www.nxtbook.com/nxtbooks/aas/st_201402
https://www.nxtbook.com/nxtbooks/aas/st_201401
https://www.nxtbook.com/nxtbooks/aas/st_201312
https://www.nxtbook.com/nxtbooks/aas/st_201311
https://www.nxtbook.com/nxtbooks/aas/st_201310
https://www.nxtbook.com/nxtbooks/aas/st_201309
https://www.nxtbook.com/nxtbooks/aas/st_201308
https://www.nxtbook.com/nxtbooks/aas/st_201307
https://www.nxtbook.com/nxtbooks/aas/st_201306
https://www.nxtbook.com/nxtbooks/aas/st_201305
https://www.nxtbook.com/nxtbooks/aas/st_201304
https://www.nxtbook.com/nxtbooks/aas/st_201303
https://www.nxtbook.com/nxtbooks/aas/st_201302
https://www.nxtbook.com/nxtbooks/aas/st_201301
https://www.nxtbook.com/nxtbooks/aas/st_201212
https://www.nxtbook.com/nxtbooks/aas/st_201211
https://www.nxtbook.com/nxtbooks/aas/st_201210
https://www.nxtbook.com/nxtbooks/aas/st_201209
https://www.nxtbook.com/nxtbooks/aas/st_201208
https://www.nxtbook.com/nxtbooks/aas/st_201207
https://www.nxtbook.com/nxtbooks/aas/st_201206
https://www.nxtbook.com/nxtbooks/aas/st_201205
https://www.nxtbook.com/nxtbooks/aas/st_201204
https://www.nxtbook.com/nxtbooks/aas/st_201203
https://www.nxtbook.com/nxtbooks/aas/st_201202
https://www.nxtbook.com/nxtbooks/aas/st_201201
https://www.nxtbook.com/nxtbooks/aas/st_201112
https://www.nxtbook.com/nxtbooks/aas/st_201111
https://www.nxtbook.com/nxtbooks/aas/st_201110
https://www.nxtbook.com/nxtbooks/aas/st_201109
https://www.nxtbook.com/nxtbooks/aas/st_201108
https://www.nxtbook.com/nxtbooks/aas/st_201107
https://www.nxtbook.com/nxtbooks/aas/st_201106
https://www.nxtbook.com/nxtbooks/aas/st_201105
https://www.nxtbook.com/nxtbooks/aas/st_201104
https://www.nxtbook.com/nxtbooks/aas/st_201103
https://www.nxtbook.com/nxtbooks/aas/st_201102
https://www.nxtbook.com/nxtbooks/aas/st_201101
https://www.nxtbook.com/nxtbooks/aas/st_201012
https://www.nxtbook.com/nxtbooks/aas/st_201011
https://www.nxtbook.com/nxtbooks/aas/st_201010
https://www.nxtbook.com/nxtbooks/aas/st_201009
https://www.nxtbook.com/nxtbooks/aas/st_201008
https://www.nxtbook.com/nxtbooks/aas/st_201007
https://www.nxtbook.com/nxtbooks/aas/st_201006
https://www.nxtbook.com/nxtbooks/aas/st_201005
https://www.nxtbook.com/nxtbooks/aas/st_201004
https://www.nxtbook.com/nxtbooks/aas/st_201003
https://www.nxtbook.com/nxtbooks/aas/st_201002
https://www.nxtbook.com/nxtbooks/aas/st_201001
https://www.nxtbookmedia.com