GWPAW 2017...rad,obs,BATband L rad,obs,UVOTband L rad,obs,low L rad,obs,high EXPECTED NUMBER OF...
Transcript of GWPAW 2017...rad,obs,BATband L rad,obs,UVOTband L rad,obs,low L rad,obs,high EXPECTED NUMBER OF...
Constraining BNS merger rates and X-ray counterpart models with existing data
02/06/2017
S.Vinciguerra, M.Branchesi, I.Mandel, R.Ciolfi, A.Tiengo, R.Salvaterra, A.Belfiore, A.De Luca,
D.Salvietti, M.Marelli and G.Stratta.
GWPAW
Rodrigo Fernández and Brian D. Metzger Ann. Rev. Nuc. Part. Sci. 2016. 66:1–24
most popular emissions in BNS mergers
Time since triggerAfterglow
Typical afterglow
Flare
Jet break
log(
Flux
)
Initial “PROMPT” emission of γ-
rays (≤30s)
Eventual collapse to a black hole?
X-ray AFTERGLOW emission
EMISSION PLATEAUX (≤several hundreds s)
Short gamma-ray bursts
supra-massive NS stable NS (magnetar)
Time since triggerAfterglow
Typical afterglow
Flare
Jet break
log(
Flux
)
Initial “PROMPT” emission of γ-
rays (≤30s)
Eventual collapse to a black hole?
X-ray AFTERGLOW emission
EMISSION PLATEAUX (≤several hundreds s)
Rowlinson et al. MNRAS Vol. 430, 2,
1061-1087
~50%SGRBs have a plateaux phase
Short gamma-ray bursts
supra-massive NS stable NS (magnetar)
ADDITIONAL EMISSIONS
long-lived NS likely• From observations maximum NS
mass is about 2 MSun; ✤ higher mass up to 2.4 MSun
for uniform rotation support
• NS masses in binary peaks at ~ 1.3-1.4 MSun, which leads to typical remnant masses of 2.3-2.4 MSun after the merger;
ZOO OF EMISSIONS now predicted for
NS-NS mergers
Binary neutron star mergers
Can archived data already tell us something about BNS emission?
OUTPUTSPREDICTIONS
OBSERVATIONS
CONSTRAINS ON THE EMISSION MODELS OR BNS MERGER RATES
S.Vinciguerra, M.Branchesi, I.Mandel, R.Ciolfi, & G.Stratta.
saprEMoPREDICTIONS
simplified algorithm
for predicting EM observation
�2 0 2 4 6
log t [s]
38
40
42
44
46
48
50
52
logLrad[erg
s�1]
Lrad,tot
Lsd
Lrad,obs,XRTband
Lrad,obs,BATband
Lrad,obs,UVOTband
Lrad,obs,low
Lrad,obs,high
EXPECTED NUMBER OF DETECTABLE EVENTS IN THE SURVEY AS A FUNCTION OF REDSHIFT AND FLUX
A. Read (University of Leicester) & ESA.
from SGRB data
BNS population models
LIGHT CURVES
Instrument and survey properties
main code of our
REDSHIFT DISTRIBUTION OF
BNS MERGER RATES
fraction of BNS emitting a specific model
L
t
observation period
counting both the contributions of “PEAKS” & “TAILS"
from observations SGRBs
Time
observation time
Na
tot
⇡ fNS
· nobs
FOV
Areasky
"T eq
obs
Zz
max
0
RV
(z)
1 + z
dV c
dzdz +
Z +1
�1
Zz
t
(L(t))
0
RV
(z)
(1 + z)2dV c
dzdz dt
#PEAKS TAILS
effective
PEAKS & TAILS(depends on the
light curve)
Time
observation time
Na
tot
⇡ fNS
· nobs
FOV
Areasky
"T eq
obs
Zz
max
0
RV
(z)
1 + z
dV c
dzdz +
Z +1
�1
Zz
t
(L(t))
0
RV
(z)
(1 + z)2dV c
dzdz dt
#PEAKS TAILS
effective
PEAKS & TAILS(depends on the
light curve)
without the TAILS
is not the same
CODE STRENGHTS
Fixing the BNS merger rate model, we can constrain the emission model;
Fixing the emission model, we can constrain the BNS merger rate model;
Versatile in topic: BNS mergers motivated the development of the code,
nevertheless other EM source can be used as well;
can be applied also for future instrument: • to predict observations as well as • for defining an observational strategy
Versatile in EM windows: can be applied in different EM bands;
OUR FIRST CASE STUDY: X-ray
ADVANTAGES DISVANTAGES• Many X-ray emission
models have been recently proposed;
• most of them are very bright and substantially isotropic;
• very few contaminants for the soft band (0.2-10 keV) (in comparison with the other EM bands);
• characterised by lower absorption than the optical band.
• Satellites with small (arcmin) FoV.
X-ray model luminosities & SGRBs
FoV ~ 1/4 deg2 SLEW DATA POINTED OBSERVATIONS
SENSITIVITY ~10-12 erg s-1 cm-2 ~10-15 erg s-1 cm-2
COVERED AREA ~80% ~3.3%AVERAGE TIME OF
OBSERVATION ~10s ~21 ks
XMM Newton (0.2-12) keV
X-ray model luminosities & SGRBs
Slew data
Pointed Obs.
FoV ~ 1/4 deg2 SLEW DATA POINTED OBSERVATIONS
SENSITIVITY ~10-12 erg s-1 cm-2 ~10-15 erg s-1 cm-2
COVERED AREA ~80% ~3.3%AVERAGE TIME OF
OBSERVATION ~10s ~21 ks
XMM Newton (0.2-12) keV
X-ray model - Siegel & Ciolfi (2016)• ISOTROPIC• VERY BRIGHT• SPECIFIC SPECTRUM MODEL
Stable NS
SMNS
First preliminary results
Dominick et al.(2013) -high-
http://www.syntheticuniverse.org
RATES FOR BNS MERGERS
from synthetic universe
EMITTED LIGHT CURVE
from Siegel & Ciolfi
2015
First preliminary results
Stable NS SMNS
Slew data: N~ 5
Pointed Obs.: N~3
Slew data: N~4
Pointed Obs.: N~2
First results - code optimisation
Galactic absorption model
for specific observations
Light curve at different energies L
t
E
more precise account for light curve shifts in redshift and
sensitivity
position of observations compared to the galactic plane
NH
0 < NH < 2 1022 cm−2, logarithmic scale
R. Willingale et al. 2010 eq(5-6)
Wisconsin (Morrison and McCammon; ApJ 270, 119)
CROSS SECTION
P. M. W. Kalberla et al 2005
molecular
First results - code optimisation
Galactic absorption model
for specific observations
Light curve at different energies L
t
E
more precise account for light curve shifts in redshift and
sensitivity
position of observations compared to the galactic plane
NH
0 < NH < 2 1022 cm−2, logarithmic scale
R. Willingale et al. 2010 eq(5-6)
Wisconsin (Morrison and McCammon; ApJ 270, 119)
CROSS SECTION
P. M. W. Kalberla et al 2005
molecular
z
First results - code optimisation
Galactic absorption model
for specific observations
Light curve at different energies L
t
E
more precise account for light curve shifts in redshift and
sensitivity
position of observations compared to the galactic plane
NH
0 < NH < 2 1022 cm−2, logarithmic scale
R. Willingale et al. 2010 eq(5-6)
Wisconsin (Morrison and McCammon; ApJ 270, 119)
CROSS SECTION
P. M. W. Kalberla et al 2005
molecular
z
First results - code optimisation
Galactic absorption model
for specific observations
Light curve at different energies L
t
E
more precise account for light curve shifts in redshift and
sensitivity
position of observations compared to the galactic plane
NH
0 < NH < 2 1022 cm−2, logarithmic scale
R. Willingale et al. 2010 eq(5-6)
Wisconsin (Morrison and McCammon; ApJ 270, 119)
CROSS SECTION
P. M. W. Kalberla et al 2005
molecular
ABSORPTION ~1 event less in slew
ABSORPTION ~1 event less in pointed observations
z
S.Vinciguerra, M.Branchesi, I.Mandel, R.Ciolfi, A.Tiengo, R.Salvaterra, A.Belfiore, A.De Luca,
D.Salvietti, M.Marelli and G.Stratta.
OBSERVATIONS
DATA ANALYSIS - status & plan
1. sanity checks on data 2. discarding extended sources 3. discarding observations inconsistent
with the proposed emissions 4. selecting unknown objects by cross-
matches with catalogues: • setting correct match-radio
5. selecting characteristic consistent with the emissions
Within all the data we need to find the “right” ones!
- KEY-QUESTIONS -
We need to apply filters consistently to the algorithm dedicated in predicting the number of events in the data
Is it a transient?
Is it consistent with the model?
On going/future investigations
BNS MERGER RATE MODELS
LIGHT CURVES models
distributionsDIFFERENT
INSTRUMENTSENVIRONMENT
CODE DEVELOPING (detection criteria)
more informative outputsDATA
ANALYSYS
Summary
!ank y"
• constrains on models
helping organising new observing strategies
many years of observations are already available in archive data
many new emission models have been
proposed to be associated to BNS
mergers
saprEMo + data analysis
• predictions for new instruments
-Extra
slides-
Stab
le N
S sp
ectr
a z =
0
SMN
S sp
ectr
a z =
0Stable NS vs SMNS
Binary neutron star mergers
Binary neutron star mergers
ADDITIONAL EMISSIONS
long-lived NS likely• From observations maximum NS
mass is about 2 MSun; ✤ higher mass up to 2.4 MSun
for uniform rotation support
• NS masses in binary peaks at ~ 1.3-1.4 MSun, which leads to typical remnant masses of 2.3-2.4 MSun after the merger;
Binary neutron star mergers
ZOO OF EMISSIONS now predicted for
NS-NS mergers
Binary neutron star mergers