Ralf Klessen
(Heidelberg University, Center for Astronomy)
22/08/2016, 09:45
Stars and star clusters are the fundamental visible building blocks of galaxies at
present days as well as in the early universe. They form by gravitational collapse in
regions of high density in the complex multi-phase interstellar medium (ISM). The
process of stellar birth is controlled by the intricate interplay between the
self-gravity of the star-forming gas and various opposing...
Steve Longmore
(Liverpool John Moore University)
22/08/2016, 11:15
The formation environment of stars in massive, dense stellar
clusters is similar to the environment of stars forming in
galaxies at a redshift of 1 - 3, at the peak star formation
rate density of the Universe. As massive clusters are still
forming at the present day at a fraction of the distance to
high-redshift galaxies they offer an opportunity to
understand the processes controlling...
Alex Hygate
(Max Planck Institute of Astronomy (MPIA)/Astronomisches Rechen-Institut, University of Heidelberg (ARI/ZAH), Heidelberg, Germany)
22/08/2016, 12:00
In this contribution, I will discuss a new method of observationally measuring the
key quantities describing the cloud-scale physics of star formation and feedback,
such as the cloud lifetime, feedback timescale, star formation efficiency, mass
loading factor, etc. (Kruijssen & Longmore, 2014). This method for the first time
allows us to probe these physics over a large galaxy sample and...
Paul Clark
(Cardiff University)
22/08/2016, 12:20
The timescale over which GMCs form and disperse sets the timescale for star
formation. Until recently, most observational studies of GMCs have focused on the
molecular tracers, which are good probe of the cool interiors of the clouds, but have a
limited ability to trace the dynamics of the transition to the warm neutral medium
(WNM). In this study, we assess the ability of [CII]...
Daniel Haydon
(Astronomisches Rechen-Institut, University of Heidelberg (ARI/ZAH), Germany)
22/08/2016, 12:40
A major problem in star/cluster formation and feedback is to constrain the
cloud-scale physics across galactic environment and cosmic time. A promising solution
has been put forward by Kruijssen & Longmore (2014), who present a statistical method
for measuring ill-constrained cloud-scale quantities such as the cloud lifetime, star
formation / feedback time-scales, star formation...
Diederik Kruijssen
(Heidelberg University (ARI/ZAH))
22/08/2016, 14:30
Stellar clusters are a fundamental (by)product of the
galactic-scale star formation process. I will discuss how
recent theoretical insights in cluster formation and
evolution have led to a unified understanding of stellar
clustering across cosmic time, from local open clusters and
associations to old globular cluster populations. I will
conclude by discussing our recent work on the...
Kathryn Grasha
(University of Massachusetts)
22/08/2016, 15:35
A turbulent interstellar medium will drive the hierarchical nature of star formation, resulting in a
smoothly varying distribution of substructure, where bound star clusters occupy the smallest,
densest regions. We use young stellar clusters to trace the unbound hierarchical star-forming
structures for several nearby galaxies drawn from the Legacy ExtraGalactic UV Survey (LEGUS).
We...
Matteo Messa
(Stockholm University)
22/08/2016, 16:25
While star formation has been long studied on the
single-star scale and on the galaxy scale, the link between
these two widely separated scales still needs to be firmly
established. We use the new high-resolution NUV and U band
HST observations from LEGUS (Legacy Extra Galactic UV
Survey) to study the nearby interacting spiral galaxy M51 at
the intermediate scale of the star cluster...
Jay Gallagher
(Dept of Astronomy, University of Wisconsin-Madison)
22/08/2016, 16:45
This talk will briefly review patterns of star formation in
NGC 1275, the brightest galaxy in the Perseus cluster. NGC
1275 is of special interest as it contains examples of
unusual modes of star formation in a complex environment.
Young massive star clusters detected via HST UV imaging are
associated with gaseous filaments that
are arrayed over 10s of kpc around the center of the...
Amanda Heiderman
(University of Virginia)
23/08/2016, 09:00
Oscar Agertz
(University of Surrey)
23/08/2016, 09:45
I will review recent advances in sub-galactic scale modelling of star formation, with a
particular emphasize on the interplay between star formation and stellar feedback and
how this impacts galaxy formation and evolution over cosmic time.
Andreas Schruba
(Max-Planck-Institut für extraterrestrische Physik)
23/08/2016, 11:00
State-of-the-art instrumentation is currently revolutionizing our view on the gas-star
cycle in nearby galaxies by resolving individual star-forming clouds and their young
stellar population. I will highlight recent results from several concerted legacy-type
surveys targeting galaxies in the Local Group and Local Universe. This includes (a)
the structure of the atomic and molecular gas...
Nimisha Kumari
(Institute of Astronomy, Cambridge, United Kingdom)
23/08/2016, 11:20
The Kennicutt-Schmidt law relating the surface densities of the star-formation rate
(SFR) and gas (atomic and molecular) is a widely-accepted star-formation law.
However, it is a disk-averaged law smoothing over local variations, and hence may not
provide an explanation for the local relationship between SFR and gas density at the
sub-galactic scale. To further probe this, various groups...
Sarah Ragan
(University of Leeds)
23/08/2016, 11:40
In the era of multi-wavelength surveys of the Milky Way, we are well-equipped to
observationally characterise the conditions necessary for star formation on parsec
size-scales. With this wealth of information, we can now not only ask the question of
what these conditions are, but also why they arise where they do. I employ the
Herschel Galactic Plane survey (Hi-GAL) to study the connection...
Camilo Penaloza
(Cardiff University)
23/08/2016, 12:00
Over the past decade, there has been a move to better connect observations with
numerical simulations. In this work we focus on mimicking the CO emission for
simulated Giant Molecular Clouds (GMCs). We performed a set of smooth particle
hydrodynamics (SPH) simulations with time-dependent chemistry, in which environmental
conditions such as mass, density, size, metallicity and Interstellar...
Francoise Combes
(Observatoire de Paris, LERMA)
23/08/2016, 14:30
Beyond the observed proportionality between surface densities of molecular gas and
star formation, the efficiency of star formation varies significantly with
environment. I will review the situations where the star formation is triggered by
dynamical processes, such as bars or spirals, tidal interactions, ram-pressure
due to AGN feedback or in groups and clusters.
Alessandro Romeo
(Chalmers University of Technology)
23/08/2016, 15:15
Gravitational instabilities play a primary role in shaping the structure and powering the
star formation activity of disc galaxies. We review the effort made by theorists to
provide the astronomical community with reliable disc stability diagnostics. The most
well-known diagnostic is Toomre's Q parameter, but there are newer and more powerful
tools for detecting gravitational...
Jose Utreras
(Universidad de Chile)
23/08/2016, 15:45
Knowing how efficiently stars are formed in galaxies is fundamental to understand the
evolution of our universe. Unfortunately, several physical processes governing star
formation are dynamically coupled in the non-linear regime, complicating the study of
their independent effects. Here we use numerical experiments to study the effects of
galactic rotation, employing the Adaptive Mesh...
Anne Jaskot
(Smith College)
24/08/2016, 09:00
Although few in number, massive stars play an outsize role
in reshaping their local and global environments. Using
observations of starburst regions in low-redshift galaxies,
I will highlight the importance of Wolf-Rayet stellar winds,
binary stellar populations, supernovae, and geometry in
clearing out neutral gas from star-forming environments.
This feedback from sub-galactic scales...
Chang-Goo Kim
(Princeton University)
24/08/2016, 09:45
Supernova (SN) explosions inject a prodigious amount of energy into the interstellar
medium (ISM). This powerful feedback implies that SNe are a major driver of
turbulence and galactic winds, and may be the dominant regulator of star formation
(SF) in disk galaxies. Our understanding of the interaction of SN(e) with the ISM
have gradually improved over many decades. However, a complete and...
Ben Keller
(McMaster University)
24/08/2016, 10:30
M* galaxies, with halo masses ~10^12 Msun, live in an interesting part of parameter space. Not only are they
the "turnover" in the galaxy mass Schecter function, they also have the highest stellar mass (and baryon)
fraction, very low bulge-to-disk ratios, and dominate the star formation of the epoch they live in. In this talk I will
present the results of a sample of 18 cosmological M*...
Arjan Bik
(Stockholm University)
24/08/2016, 11:20
The feedback of massive stars and star clusters has a dramatic effect on the
surrounding interstellar matter (ISM), affecting the shape and fate of galaxies as a
whole. The molecular ISM in which the stars are formed is transformed to a warm
ionized medium by means of the Lyman continuum output as well as the stellar wind
and supernovae of the massive stars in the galaxy. The large...
Katherine HOLLYHEAD
(Astrophysics Research Institute)
24/08/2016, 11:40
The initial stages of star cluster formation (the first 10 Myr) are
still not entirely clear, though this age is highly important for
understanding their subsequent evolution and that of the galaxy itself.
We have studied a sample of young massive clusters (<10 Myr, >5000 solar
masses) in nearby spiral galaxy M83, using archival HST WFC3 data
available on the HST Legacy Archive. By...
Peter Creasey
(University of California at Riverside (UCR))
24/08/2016, 12:00
The mechanisms of feedback in which Milky-Way and smaller galaxies are regulated by
events on scales of parsecs and below is still poorly understood. In this talk I will
look at hydrodynamical simulations on cosmological and interstellar medium scales and
tease out some of the dynamical and chemical indicators at small and large (galaxy
population) scales that can be used to identify the...
Robbert Verbeke
(Ghent University)
24/08/2016, 12:20
Dwarf galaxies occupy the faint end of the galaxy mass function and their properties are often regarded as
strong tests for cosmological and galaxy evolution models. Indeed, their shallow gravitational potential makes
them very susceptible to both external and internal processes, such as ram-pressure stripping and supernova
feedback. Using computer simulations, the effects of such...
Evangelia Ntormousi
(CEA/Saclay)
24/08/2016, 12:40
The large-scale shocks formed by the clustered feedback of
young stars are considered an important source of mechanical
energy for the interstellar medium and a trigger of
molecular cloud formation. Their interaction sites are
locations where kinetic energy and magnetic field are
redistributed between ISM phases. In this work we study the
role of turbulence and magnetic fields in the...
Wako Ishibashi
(ETH Zurich)
24/08/2016, 13:00
Black hole feedback is often invoked to suppress star formation in galaxies by
driving galaxy-scale outflows. However, radiative feedback from the central black
hole may actually trigger star formation within those galactic outflows. In our
picture, new stars are formed at increasingly larger radii in the outflowing shell,
with young stellar populations gradually populating the outer...
Amelie Saintonge
(University College London)
25/08/2016, 09:00
Over the past 5 years, it has become possible to assemble measurements of molecular
gas in large samples of normal star-forming galaxies up to z=2. These observations
have been key in establishing the currently favoured model for galaxy evolution,
which is centered around the cycling of gas in and out of galaxies and the efficiency
of the star formation process. While star formation is a...
Abdurrouf Abdurrouf
(Astronomical Institute, Tohoku University)
25/08/2016, 10:05
According to Lambda CDM paradigm of hierarchical galaxy formation, galactic disks
were form gradually from inside to outside (“inside-out” scenario of galaxy
formation). In spite of this being a long-known prediction, but very few
observational evidences have been brought forward to support it. In order to sought
the indication of this “inside-out” scenario in the local universe and also...
Quentin SALOME
(LERMA, Observatoire de Paris)
25/08/2016, 10:25
Recent studies suggest that AGN can regulate the gas accretion and thus slow
down star formation (negative feedback). However, evidence of AGN positive
feedback is also invoked in a few radio galaxies (eg. Centaurus A, Minkowski's
Object, 3C 285, ...).
I will present a multi-wavelength study of the northern filaments of Centaurus A.
These filaments of gas and young stars extend...
Isadora Chaves Bicalho
(Observatoire de Paris)
25/08/2016, 11:15
The spatially resolved star formation law has been studied
in great detail in galaxies in recent years. At high surface
density, when most of the gas is molecular, the
Kennicutt-Schmidt relation is almost linear providing a
constant gas consumption time-scale of about 3Gyr (e.g
Bigiel et al. 2011, Saintonge et al 2011). However the star
formation efficiency (SFE) falls very quickly when...
Rodrigo Herrera-Camus
(Max Planck Institute for Extraterrestrial Physics)
25/08/2016, 11:35
The [CII] 158 um and [NII] 122 and 205 um far-infrared
transitions are powerful tracers of the neutral and ionized
gas in the interstellar medium of local and high-z galaxies.
In this talk I will discuss the ability of these lines to
trace the star formation activity in a wide range of
environments that include low metallicity, normal,
star-forming galaxies, AGN, LIRGS and high-z...
Martin Roth
(Leibniz Institute for Astrophysics Potsdam (AIP))
25/08/2016, 11:55
We present first results from a study of resolved stellar
populations in the 2 Mpc distant sculptor group disk galaxy
NGC300 using integral field spectroscopy with MUSE. From
data cubes obtained under conditions of excellent seeing we
are able to extract on the order of 1500 stellar spectra per
pointing of 1.5 hours observing time, using the PampelMuse
code that has already...
Karen Knierman
(Arizona State University)
25/08/2016, 12:25
While major mergers and their tidal debris are well studied, equal mass galaxy
mergers are relatively rare compared to minor mergers (mass ratio <0.3).
Minor mergers are less energetic than major mergers, but more common in the
observable universe, and thus likely played a pivotal role in the formation of most
large galaxies. Tidal debris regions have large amounts of neutral gas but a...
Alton Padraig
(Durham University)
25/08/2016, 12:45
Massive elliptical galaxies are thought to form in two stages - first, the formation
of a central core via fast dissipative processes by z~2, followed by the accumulation
of mass through (mostly minor) dry mergers. A combination of evidence from
spectroscopy, lensing, and stellar dynamics appears to suggest that in the most
massive central cores stars form according to a 'bottom-heavy' IMF...
Janice Lee
(Space Telescope Science Institute)
25/08/2016, 14:30
Since the discovery of "isolated extragalactic H II regions"
by Sargent & Searle in 1970, low mass dwarf galaxies
experiencing intense bursts of star formation have
periodically become the subject of frenetic research because
of their unusual and discordant properties. Today, the
study of massive star formation and its impact on the
interstellar medium seems to be at a major crossroad,...
Stijn Wuyts
(University of Bath)
25/08/2016, 15:15
For many years, far-infrared and optical/near-infrared astronomers focused on largely
disjoint samples of high-redshift galaxies. While the far-infrared community
primarily studied luminous and dusty starbursting monsters, detailed spectroscopic
analyses in the (rest-)optical preferentially targeted less obscured systems. With
the increased sensitivity offered by Herschel, PdBI-NOEMA and...
Dawn Erb
(University of Wisconsin Milwaukee)
25/08/2016, 16:30
Low mass, low metallicity galaxies are the most likely source of the photons that
reionized the universe, but the relationships between low metallicity star formation,
galactic outflows, and the escape of ionizing radiation at high redshifts are still
unclear. Using rest-frame UV and optical spectra of lensed and unlensed low
metallicity galaxies at z~2, I will discuss constraints on the...
Andrew Battisti
(UMass Amherst)
26/08/2016, 09:00
The presence of dust in galaxies can significantly alter their observed spectral
energy distribution. If not properly accounted for, this effect can lead to incorrect
values of derived physical quantities such as the star formation rate, stellar mass,
and photometric redshift. Virtually all studies of star forming galaxies, both local
and distant, make use the attenuation curve derived...
Anna Cibinel
(Astronomy Centre, U. of Sussex)
26/08/2016, 09:20
Key aspects of galaxy evolution including bulge formation and quenching may be
regulated by the dynamics of large star forming clumps which are almost ubiquitous in
the gas-rich ISM medium of normal high redshift galaxies. The impact of clump-driven
dynamical processes on the evolution of galaxies depends crucially on whether these
giant clumps are transient phenomena or not. Clump...
Lea Hagen
(Penn State University)
26/08/2016, 09:40
The Swift Ultraviolet/Optical Telescope (UVOT) is uniquely suited to study star
formation and dust extinction in nearby galaxies. I will discuss results from the
Small Magellanic Cloud (SMC) and M33, for which we have unprecedented
observations in three near-UV bands from 1700-3000 A at 2.5" resolution. We
combine our UV imaging with archival optical and infrared data to model the...
Matthew Hayes
(Stockholm University)
26/08/2016, 10:00
I will present the first image of an individual extragalactic object in which the
coronal gas phase (T ~300,000 K) is both isolated and spatially resolved, by
targeting the O VI doublet at 1032,1037 Å in emission. The combination of HST UV
imaging and spectroscopy provides unique new insights into the mass, cooling,
kinematics, and ultimately the fate of gas that has been heated by...
Jennifer Schober
(Nordita)
26/08/2016, 11:00
Magnetic fields are omnipresent in local galaxies and can affect the star formation
process crucially. Observational evidence between the coupling of the magnetic field
and the star formation rate (SFR) comes from the far-infrared(FIR)-radio correlation
which holds over more than six orders of magnitude. While the FIR radiation is a
tracer of the SFR, radio emission is typically...
Polychronis Papaderos
(Instituto de Astrofísica e Ciências do Espaço, Centro de Astrofísica da Universidade do Porto)
26/08/2016, 11:20
Despite significant progress over the past decades, all
state-of-the-art population spectral synthesis (pss) codes
suffer from two major conceptual deficiencies that limit
their potential of gaining sharp insights into the star
formation history (SFH) of star-forming (SF) galaxies and
potentially introduce substantial biases in studies of their
physical properties (e.g., stellar mass and...
Daniela Calzetti
(UMASS)
26/08/2016, 13:30
Using recent 1.1 mm maps of the dust continuum of
NGC4449 obtained with the Large Millimiter Telescope (LMT),
we derive a high-angular resolution map of the gas in this
nearby dwarf starburst galaxy. We combine the gas map with
star formation rate tracers at optical and infrared wavelengths,
and investigate the SFR-gas relation at ~250 parsec resolution.
Thøger Emil Rivera-Thorsen
(Stockholm University)
26/08/2016, 13:50
The ISM of starburst galaxies is well known to contain a wide variety of physical
conditions and be kinematically complex. Yet, when describing it spectroscopically,
a single number is often relied on to characterize each physical property, derived
from data integrated over the entire slit. Here, we present a highly detailed spatial
and kinematic decomposition of 2D spectra of three...
Johannes Puschnig
(Stockholm University)
26/08/2016, 14:10
Carbon Monoxide has proven to be a well-calibrated tracer of
the total molecular gas content in galaxies at low and high
redshift. However, CO observations in galaxies of subsolar
metallicity remain challenging, even in the local universe.
For that reason, the dust mass is often used to infer the
molecular gas in low metallicity systems. I will present
first results of CO and dust...
Robert Kennicutt
(University of Cambridge)
26/08/2016, 14:30
