Statistics of Two-point Correlation and Network Topology for Lyman Alpha Emitters at $z approx 2.67$. (arXiv:1811.10631v1 [astro-ph.CO])
<a href="http://arxiv.org/find/astro-ph/1/au:+Hong_S/0/1/0/all/0/1">Sungryong Hong</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dey_A/0/1/0/all/0/1">Arjun Dey</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lee_K/0/1/0/all/0/1">Kyung-Soo Lee</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Orsi_A/0/1/0/all/0/1">Álvaro A. Orsi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gebhardt_K/0/1/0/all/0/1">Karl Gebhardt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vogelsberger_M/0/1/0/all/0/1">Mark Vogelsberger</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hernquist_L/0/1/0/all/0/1">Lars Hernquist</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Xue_R/0/1/0/all/0/1">Rui Xue</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jung_I/0/1/0/all/0/1">Intae Jung</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Finklestein_S/0/1/0/all/0/1">Steven L. Finklestein</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tuttle_S/0/1/0/all/0/1">Sarah Tuttle</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Boylan_Kolchin_M/0/1/0/all/0/1">Michael Boylan-Kolchin</a>
We investigate the spatial distribution of Lyman alpha emitting galaxies
(LAEs) at $z approx 2.67$, selected from the NOAO Deep Wide-Field Survey
(NDWFS), using two-point statistics and topological diagnostics adopted from
network science. We measure the clustering length, $r_0 approx 4 h^{-1}$ Mpc,
and the bias, $b_{LAE} = 2.2^{+0.2}_{-0.1}$. Fitting the clustering with halo
occupation distribution (HOD) models results in two disparate possibilities:
(1) where the fraction of central galaxies is $<$1% in halos of mass
$>10^{12}$$M_odot$; and (2) where the fraction is $approx$20%. We refer to
these two scenarios as the `Dusty Core Scenario’ for Model#1 since most of
central galaxies in massive halos are dead in Ly$alpha$ emission, and the
`Pristine Core Scenario’ for Model#2 since the central galaxies are bright in
Ly$alpha$ emission. Traditional two-point statistics cannot distinguish
between these disparate models given the current data sets. To overcome this
degeneracy, we generate mock catalogs for each HOD model using a high
resolution $N$-body simulation and adopt a network statistics approach, which
provides excellent topological diagnostics for galaxy point distributions. We
find three topological anomalies from the spatial distribution of observed
LAEs, which are not reproduced by the HOD mocks. We find that Model#2 matches
better all network statistics than Model#1, suggesting that the central
galaxies in $> 10^{12} h^{-1} M_odot$ halos at $z approx 2.67$ need to be
less dusty to be bright as LAEs, potentially implying some replenishing
channels of pristine gas such as the cold mode accretion.
We investigate the spatial distribution of Lyman alpha emitting galaxies
(LAEs) at $z approx 2.67$, selected from the NOAO Deep Wide-Field Survey
(NDWFS), using two-point statistics and topological diagnostics adopted from
network science. We measure the clustering length, $r_0 approx 4 h^{-1}$ Mpc,
and the bias, $b_{LAE} = 2.2^{+0.2}_{-0.1}$. Fitting the clustering with halo
occupation distribution (HOD) models results in two disparate possibilities:
(1) where the fraction of central galaxies is $<$1% in halos of mass
$>10^{12}$$M_odot$; and (2) where the fraction is $approx$20%. We refer to
these two scenarios as the `Dusty Core Scenario’ for Model#1 since most of
central galaxies in massive halos are dead in Ly$alpha$ emission, and the
`Pristine Core Scenario’ for Model#2 since the central galaxies are bright in
Ly$alpha$ emission. Traditional two-point statistics cannot distinguish
between these disparate models given the current data sets. To overcome this
degeneracy, we generate mock catalogs for each HOD model using a high
resolution $N$-body simulation and adopt a network statistics approach, which
provides excellent topological diagnostics for galaxy point distributions. We
find three topological anomalies from the spatial distribution of observed
LAEs, which are not reproduced by the HOD mocks. We find that Model#2 matches
better all network statistics than Model#1, suggesting that the central
galaxies in $> 10^{12} h^{-1} M_odot$ halos at $z approx 2.67$ need to be
less dusty to be bright as LAEs, potentially implying some replenishing
channels of pristine gas such as the cold mode accretion.
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