deletions | additions
diff --git a/Authors.tex b/Authors.tex
index 6290c3d..c1d56fd 100644
--- a/Authors.tex
+++ b/Authors.tex
...
%\author{All of Us, In Some Order}
\author{S.~A.~Rodney\altaffilmark{\affilref{JHU},\affilref{HubbleFellow},\affilref{USC}}} \author{S.~A.~Rodney\altaffilmark{\affilref{JHU},\affilref{USC}}}
\affilreftxt{JHU}{\JHU}
\affilreftxt{HubbleFellow}{\HubbleFellow}
\affilreftxt{USC}{\USC}
diff --git a/Discussion.tex b/Discussion.tex
index ca6474a..3287e5d 100644
--- a/Discussion.tex
+++ b/Discussion.tex
...
\section{Discussion}\label{sec:Discussion}
We have examined three plausible explanations for the \spock events:
(1)
these transients are due to they were surface explosions from a
single RN that reaches an
extraordinarily high peak luminosity, (2) they
are were separate rapid
outbursts of an LBV star, or (3) they
are were each
the result of caused by the rapidly
changing magnification
of a as two unrelated massive
star crossing stars crossed over
one or
more
lensing caustics.
Our We can not make a definitive choice between these
hypotheses, principally due to the scarcity of observational data and
the uncertainty in the the location of the lensing critical curves.
If there is just a single critical curve for a source at $z=1$ passing
between the two \spock locations then our preferred explanation for
the \spock events is that we have observed two distinct eruptive
episodes from a massive LBV star. The light curve shape is consistent
with rapid LBV eruptions seen in systems such as SN 2009ip and NGC
3432-LBV1. The peak luminosity and recurrence timescale are also
within the bounds of what has been observed from nearby LBVs.
The In this
case, the \spock episodes may have been among the fastest and most
luminous of any rapid LBV events yet observed. However, the rapid
outbursts of LBV stars in the local universe have never yet been
observed with such a high cadence, so the detailed light curve shape
of the \spock events cannot be rigorously compared against other
events. In this scenario, the \spock LBV system would most likely
have exhibited multiple eruptions over the last few years, but most of
them were missed, as they landed within the large gaps of the \HST
Frontier Fields imaging program.
We speculate that the very luminous and very fast \spock transients
may be driven by extreme mass eruption events or an extreme form of
...
events are extreme in several dimensions, and should add a useful
benchmark for this theoretical challenge.
If instead the \macs0416 lens has multiple critical curves that
intersect both \spock locations, then the third proposal of a
microlensing-generated transient would be preferred. Stellar caustic
crossings have not been observed before, but the analysis of a likely
candidate behind the MACSJ1149 cluster suggests that massive cluster
lenses may generate such events more frequently than previously
expected \citep{Kelly:2017}. To resolve the uncertainty of the \spock
classification will require refinement of the lens models to more
fully address systematic biases. High-cadence monitoring of the
\macs0416 field may also be important, as it could catch future LBV
eruptions or microlensing transients at or near these locations.
diff --git a/Introduction.tex b/Introduction.tex
index c710939..43008dd 100644
--- a/Introduction.tex
+++ b/Introduction.tex
...
clusters and associated ``blank sky'' fields observed in parallel
(Methods \ref{sec:Discovery}).
Combining the \HST imaging and lens models of the \MACS0416
gravitational lens leads to three key observables for the \spock
events: (1) they are both more luminous than a classical nova, but
less luminous than almost all supernovae (SNe), reaching a peak
luminosity of roughly $10^{41}$ erg s$^{-1}$ ($M_V=−14$); (2) both
transients exhibited fast light curves, with rise and decline
timescales of $\sim$2--5 days in the rest frame; and (3) it is
likely possible that both events arose from the same physical location but
highly unlikely that they were
not coincident in time---they were probably
separated by 3-5 months in the rest frame. These
peculiar transients thus
present
an intriguing a puzzle: they are broadly consistent with the expected
behavior of stellar explosions (they each exhibit a single isolated
rise and decline in brightness), but they can not be trivially
classified into any
of the common
categories category of explosive
or eruptive astrophysical
transients.
The HFF survey was not designed with the discovery of peculiar
extragalactic transients as a core objective, but it has
diff --git a/Results.tex b/Results.tex
index 5c4d8f0..e526232 100644
--- a/Results.tex
+++ b/Results.tex
...
\section{Results}\label{sec:Results}
Photometry collected from the \HST images (Methods
\ref{sec:Photometry}), reveals that
the the two \spock\ both
\spock events exhibited very
rapid light
curves, as shown in Figure \ref{fig:LightCurves}. curves (Figure \ref{fig:LightCurves}). Both events
reached a peak luminosity of $\sim$0.08 \microjansky, with the entire
observable rise and fall occurring in $<20$ days. The host galaxy for
both the \spock events is at a redshift of $z=1.0054\pm0.0002$ (Methods
\ref{sec:Spectroscopy}). After dividing the observed
timescales by ($1+z$) to correct \ref{sec:Spectroscopy}), so after correcting for cosmic time
dilation, we see that
both dilation
these events lasted $<$10 days in the rest frame.
To interpret the observed light curves and the timing of these two
events, we use seven independently constructed cluster mass models to
...
In Table~\ref{tab:LensModelPredictions} we report model-predicted time
delays relative to the \spockone event, which appeared in January 2014
in host image 11.2. We also report absolute magnification values
between about $\mu=10$ and
$\mu=300$ $\mu=200$ for both events. This wide range
is due primarily to the close proximity of the \spock events to the
lensing critical curve (the region of theoretically infinite
magnification) for sources at $z=1$. The location of the critical
curve
relative to each \spock event varies significantly among the models, and is sensitive to many
parameters that are poorly constrained. We have explored model
variations
(described in Methods (Methods \ref{sec:LensModelVariations}) that
adjust the cluster redshift and the masses of cluster member galaxies,
and that account for the impact of lensing perturbations from galaxies
along the line of sight. Most variations that move a critical curve
closer to the position of \spockone\ would drive the magnification of
that event much higher (toward
$\mu_1\sim300$). $\mu_{\rm NW}\sim200$). This generally also
has the effect of moving the critical curve farther from \spocktwo,
which would necessarily drive its magnification downward (toward
$\mu_2\sim10$). $\mu_{\rm SE}\sim10$). Our model variations also show that it is possible to
make reasonable adjustments to the lens model parameters in order to
ensure that a critical curve intersects both of the \spock locations.
Such lensing configurations can qualitatively reproduce the observed
morphology of the \spock host galaxy, but they are disfavored by a
purely quantitative assessment of the positional strong-lensing
constraints.
Figure~\ref{fig:LightCurves} shows that the observed peak brightnesses
for the two events agree to within $\sim30\%$, which means that if
...
%CATS-A2 & & 491 $^{+197}_{-126}$ & 859 $^{+149}_{-105}$ & 3.2 $^{+0.1}_{-0.1}$ & 4.0 $^{+0.6}_{-0.8}$ & -4.3 $^{+0.1}_{-0.1}$\\[0.5em]
\enddata
\tablecomments{
Each lens model is identified by the name of the modeling
method. method
(described in Methods~\ref{sec:LensingModels}). Time delays give
the predicted delay relative to an appearance in the NW host image,
11.2. Positive (negative) values indicate the NW image is the
leading (trailing) image of the pair.
}
\end{deluxetable}
%\renewcommand{\arraystretch}{1.}
\subsection{Ruling Out Common Astrophysical Transients}
There are several categories of astrophysical transients that cannot
accommodate the light curve characteristics of the \spock transients.
We may first dismiss any of the category of {\it periodic} sources
(e.g. (e.g., Cepheids, RR Lyrae, or Mira variables) that exhibit regular
changes in flux due to pulsations of the stellar
photosphere. These variable stars photosphere and do
not exhibit sharp, isolated transient episodes
that could match like the \spock
light curve
shapes. events. Stellar flares provide another very common source for optical
transient events, transients, but the total energy released by even the most
extreme stellar flare falls far short of the observed energy release
from the \spock transients \citep{Balona:2012,Karoff:2016} .
We can also rule out active galactic nuclei (AGN), in which brief
transient episodes (a few days in duration) may be observed from
X-ray x-ray
to infrared wavelengths
\citep[e.g.][]{Gaskell:2003},
principally due to \citep[e.g.][]{Gaskell:2003}. An AGN explanation is
disfavored by the quiescence of the \spock sources between the two
observed episodes and the absence of any of the broad emission lines
that are often
(though not always) observed in AGN. No x-ray emitting
point source was detected in 7 epochs of imaging from the Swift and
Chandra x-ray space telescopes, collected from 2009 to 2014
(Methods~\ref{sec:Xray}). This includes the Chandra imaging on August
31, 2014 (MJD=56900), which was coeval with the peak of IR emission
from \spocktwo, observed with \HST.
Many types of stellar explosions can generate isolated
transient events, and a useful starting point for classification of
...
interpolation of the observed photometry (Methods
\ref{sec:LightCurves}), with corrections for the luminosity distance
(assuming a standard \LCDM cosmology), and accommodating the range of
viable lensing magnifications
($10<\mu<100$) ($10<\mu<200$) derived from the cluster
lens models. This results in two-dimensional constraints on \Lpk and
the decline timescale \t2 (the time over which the transient declines
by 2 magnitudes). The \spockone and \spocktwo events are largely
diff --git a/figures/peakluminosity_vs_declinetime/peakluminosity_vs_declinetime.pdf b/figures/peakluminosity_vs_declinetime/peakluminosity_vs_declinetime.pdf
index 3e4b6c8..c05c139 100644
Binary files a/figures/peakluminosity_vs_declinetime/peakluminosity_vs_declinetime.pdf and b/figures/peakluminosity_vs_declinetime/peakluminosity_vs_declinetime.pdf differ
diff --git a/figures/peakluminosity_vs_declinetime/peakluminosity_vs_declinetime.png b/figures/peakluminosity_vs_declinetime/peakluminosity_vs_declinetime.png
index a519df4..1ba0876 100644
Binary files a/figures/peakluminosity_vs_declinetime/peakluminosity_vs_declinetime.png and b/figures/peakluminosity_vs_declinetime/peakluminosity_vs_declinetime.png differ
diff --git a/spock_localbuild.pdf b/spock_localbuild.pdf
index 68621be..451d507 100644
Binary files a/spock_localbuild.pdf and b/spock_localbuild.pdf differ