Overview of KP GT proposals
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SCIENCE CATEGORY: Solar system (1)
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Proposal ID: KPGT_pharto01_1
Title:
"Water and Related Chemistry in the Solar System"
Principal Investigator:
Paul Hartogh (Max Planck Institute for Solar System Research)
Category:
KPGT
Summary:
Water is ubiquitous in the Solar System, being present in gaseous form in
all planetary and cometary atmospheres, as ice on the surface and subsurface
of Mars, comets, most planetary satellites and distant bodies, and in the
liquid phase on Earth. Water plays an important or dominant role in the
chemistry of planetary and cometary atmospheres. Comets are sources of water
for planets through episodic collisions and continuous production of ice-dust
grains. This proposal addresses the broad topic of water and its isotopologues
in planetary and cometary atmospheres. The nature of cometary activity and the
thermodynamics of cometary comae will be investigated by studying water
excitation in a sample of comets. The D/H ratio, the key for constraining the
origin and evolution of Solar System species, will be measured for the first
time in a Jupiter- family comet. A comparison with existing and new
measurements of D/H in Oort-cloud comets will constrain the composition of
pre-solar cometary grains and possibly the dynamics of the protosolar nebula.
New measurements of D/H in Giant Planets, similarly constraining the
composition of proto-planetary ices, will be obtained. The D/H and other
isotopic ratios, diagnostic of Mars' atmosphere evolution, will be accurately
measured in H2O and CO. The role of water vapor in Mars' atmospheric chemistry
will be studied by monitoring vertical profiles of H2O and HDO and by
searching for several other species. A detailed study of the source of water
in the upper atmosphere of the Giant Planets and Titan will be performed. By
monitoring the water abundance, vertical profile, and input fluxes in the
various objects, and when possible with the help of mapping observations, we
will discriminate between the possible sources of water in the outer planets
(interplanetary dust particles, cometary impacts, and local sources). In
addition to these inter-connected objectives, serendipitous searches will
enhance our knowledge of the composition of planetary and cometary
atmospheres.
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SCIENCE CATEGORY: ISM/Star formation (10)
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Proposal ID: KPGT_aabergel_1
Title:
"Evolution of interstellar dust"
Principal Investigator:
Alain Abergel (Institut d'Astrophysique Spatiale (IAS)
Category
KPGT
Summary
The scientific motivation for this proposal is to trace the evolution of
dust grains in relation to changes of the physical, dynamical and chemical
properties of the interstellar medium. This program will provide an
unprecedented view of the structure of the ISM at far-infrared and
submillimeter wavelengths and will enable us to investigate the impact of
dust grains on the ISM physical and chemical state. The program will take
full advantage of four unique characteristics of SPIRE and PACS: brightness
sensitivity, wavelength coverage, angular resolution, and mapping efficiency.
The brightness sensitivity is essential to measure the faint infrared
emission from the diffuse regions. The spectrometers will provide the
necessary information to derive the physical properties of the atomic and
molecular gas and completely characterize dust evolution. The angular
resolution is critical for tracing the dominant processes in grain evolution
which takes place on all scales down to a few arcseconds. The data statistics
will allow us to probe the impact of extreme physical conditions, e.g., high
densities, intense vortices or illumination, on the dust evolution. Our goal
is to build with Herschel a coherent database on interstellar dust emission
extending to much smaller angular scales than the IRAS and DIRBE surveys and
covering a wide range of ISM physical conditions, from diffuse clouds to the
sites of star formation and protostars. The program is supported by
state-of-art modelling of the dust emission and physical processes acting on
dust as well as by on-going laboratory measurements of the grains properties
at far-infrared and submillimeter wavelengths. The Herschel observations will
benefit from ground-based ancillary data (HI and CO) and from Spitzer programs
yielding a full description of the spectral energy distribution of
interstellar dust from the near-infrared to the submillimeter.
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Proposal ID: KPGT_cceccare_1
Title:
"HIFI Spectral Surveys of Star Forming Regions"
Principal Investigator:
Cecilia Ceccarelli (Laboratoire d'Astrophysique de Grenoble)
Category:
KPGT
Summary:
Study of the molecular content of regions far beyond our Solar System has
advanced enormously during the last few decades, from the first detections
of diatomic molecules to the discovery of polyatomic, complex organic
molecules. Nowadays, one major goal of Astrochemistry is to have the most
accurate census of the molecular content (and complexity) in Star Forming
Regions (SFRs). In the era of the molecular content census, unbiased spectral
surveys in the radio to Infrared of SFRs have become a fundamental and
necessary tool in modern astrochemistry research. In this context, the
frequency range covered by HSO-HIFI, 500-2000 GHz, is of particular
importance. It is in this frequency range that light molecules have their
ground and low energy transitions, whereas heavier molecules have higher
energy transitions. The latter are excited in the warm gas, whereas the
former probe the gas at low temperatures as well. It is therefore in the
HIFI frequency range that the major gas coolants (notably H$_2$O) and some
key components of the chemical composition of SFRs emit. We propose to
obtain Spectral Surveys in the HSO-HIFI range of a representative sample of
SFRs. To have a meaningful coverage of the different evolutionary stages and
different masses requires a large amount of time, about 300 hrs. The proposed
observations will provide a large dataset of uttermost interest for the
entire astronomical community, and, particularly for the study of star
formation processes and of the influence of chemistry on star and planet
formation. These two basic aspects, a large requested observing time and an
output of high archival value, make the present proposal suitable for a HSO
Key Program.
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proposal ID: KPGT_ebergin_1
Title:
"HEXOS: Herschel Observations of EXtra-Ordinary Sources: The Orion and Sgr B2 Star-Forming Regions"
Principal Investigator:
Edwin Bergin (University of Michigan)
Category:
KPGT
Summary:
As a GT Key Program we propose to perform full HIFI and PACS line surveys of
5 sources in the giant molecular clouds Orion and Sagittarius B2. These
extraordinary star-forming regions contain the best studied examples of
physical and chemical processes prevalent in the interstellar medium,
including gravitational compression, thermal and turbulent pressure support,
photodissociation, gas and grain chemistry in dense and diffuse quiescent gas,
and shocks. With high excitation, rich chemistry, and large molecular column
they give the highest chance for new detections in a sensitive search for new
molecules. Line surveys of sources (Orion KL, Orion S, Orion Bar, Sgr B2 N+M)
defined by these phenomena form the backbone of this proposed program.
Herschel offers unprecedented sensitivity and relative calibration accuracy,
as well as continuous spectral coverage across the gaps imposed by the
atmosphere, opening up a largely unexplored wavelength regime to high
resolution spectroscopy. These data will take line surveys to a new level
and we will use them to comprehensively characterize the physics (density,
thermal balance, kinematics, radiation field) and chemistry (chemical assay,
ionization, deuterium fractionation, water ortho/para ratio) of star-forming
molecular gas in a manner not previously possible. The opening of this
spectral range is also an opportunity to detect the bending transitions of
carbon chains and polycyclic aromatic hydrocarbons, along with the rotational
transitions of complex organics. Given that these sources have the richest
emission spectra seen for star-forming regions in the Galaxy, we anticipate
that the proposed observations will define the sub-millimeter/far infrared
region of the spectrum and that these data will form a lasting Herschel
legacy.
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Proposal ID: KPGT_evandish_1
Title:
"Water in Star-forming regions with Herschel (WISH)"
Principal Investigator:
Ewine van Dishoeck (Sterrewacht Leiden)
Category:
KPGT
Summary:
Water is a key molecule for determining the physical and chemical structure
of star-forming regions because of its large abundance variations --both in
the gas and in the ice-- between warm and cold regions. In this HIFI-led Key
Program, we propose a comprehensive set of water observations toward a large
sample of well-characterized protostars, covering a wide range of masses and
luminosities -- from the lowest to the highest mass protostars -- and a large
range of evolutionary stages -- from the first stages represented by the
pre-stellar cores to the last stages represented by the pre-main sequence
stars surrounded only by their protostellar disks. Lines of H2O, H218O,
H217O and chemically related hydrides will be observed. In addition, selected
high-frequency lines of CO isotopes, [O I] as well as dust continuum maps
will be obtained with HIFI and PACS, and will be complemented by ground-based
HDO, CO and continuum maps to ensure a self-consistent data set for analysis.
Limited mapping information on arcmin scale provides information on local
variations due to outflows and clustered star formation. Together, the data
will elucidate the physical processes responsible for the warm gas, probe
dynamical processes associated with forming stars and planets, reveal the
chemical evolution of water and the oxygen-reservoir, and test basic gas-grain
chemical interactions. They will form an unique legacy for the community as
a complement to future ground-based programs and for planning future space
missions.
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Proposal ID: KPGT_fmotte_1
Title:
"HOBYS: the Herschel imaging survey of OB Young Stellar objects"
Principal Investigator:
Frédérique Motte (SAp/CEA Saclay)
Category
KPGT
Summary:
With its unprecedented spatial resolution in the critical 75-500 microns
wavelength range, Herschel will provide a unique opportunity to determine,
for the first time, the fundamental properties of the precursors of OB stars
at distances out to a few kpc. The imaging speed of SPIRE and PACS in the
parallel mode will enable us to map the entire extent of massive cloud
complexes and detect the massive young stellar objects which have been
overlooked by IRAS and Spitzer, i.e. the high-mass infrared-quiet protostars
and pre-stellar cores. We propose to use SPIRE and PACS to image essentially
all of the regions forming OB-type stars at distances 3 kpc from the Sun
(total area of 22~deg^2). To complement this imaging survey, we propose to
take smaller photometric and spectroscopic maps with PACS toward a handful
of isolated regions that display triggered star formation. The 75/110/170
micronsPACS and 250/350/500 microns SPIRE images of this project will provide
an unbiased census of both massive pre-stellar cores and massive Class~0-like
protostars, and will trace the large-scale emission of the surrounding clouds.
This survey will yield for the first time accurate far-infrared photometry,
and thus good luminosity and mass estimates, for a comprehensive, homogeneous
sample of OB-type young stellar objects at all evolutionary stages. The
multi-wavelength imaging will also reveal spatial variations of the cloud
temperature close to HII regions and OB associations. These data, along with
the detailed photometric and spectroscopic study of a few prototypical regions
of induced star formation, will allow us to determine the importance of
external triggers for high-mass star formation in the nearest massive
molecular cloud complexes. This Herschel Key Programme is crucially needed
to better understand the formation of OB-type stars and will provide the basis
for many follow-up studies. In addition, the data will provide templates for
galactic studies of star formation, both in our Galaxy and others.
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Proposal ID: KPGT_golofs01_1
Title:
"Stellar Disk Evolution"
Principal Investigator:
Göran Olofsson (Stockholm Observatory)
Category:
KPGT
Summary:
In a collaboration between the HSC, P. Harvey (Mission Scientist) and the
three instrument consortia we propose to apply the full power of Herschel
to investigate the properties of circum-stellar disks. The versatility of
Herschel allows us to address several key questions: How do the disks evolve
with time? Planets clearly form out of circum-stellar disks and there is
growing evidence that the time scale is short, 1 - 10 Myr, for the main
accretion phase. During this time period, the stellar radiation and stellar
winds clean the disks from most of their dust and gas, eventually making them
transparent. However, collisions and evaporation from comet- like bodies will
continue to produce dust and gas. This activity declines with time, and we
will pursue this scenario by observing a sample of IR excess stars of known
age, ranging from a few million years to the age of the sun. Are there
analogues to our Kuiper belt around nearby stars? The Kuiper belt is a dust
belt surrounding the Sun, located outside the orbit of Neptune, which has a
key role in stabilizing orbits of the KE-objects and this dynamical aspect
makes it particularly interesting to search for stars that may host KE-belt
analogues. Herschel offers a unique sensitivity beyond 100 µm and we propose
an extensive survey of nearby stars seeking cold dust emission. What will a
closer IR look at the "Fabulous Four" (and some other resolved disks) reveal?
Several nearby MS stars with IR excesses have circumstellar dust structures
that can be resolved by Herschel. Imaging these structures in the six
PACS+SPIRE bands will enable us to explore the dust properties, notably the
size distribution and albedo.. What is the composition of young disks? We
propose a detailed spectroscopic investigation of four bright disks, including
a full spectral scan with PACS, an FTS scan at full resolution and HIFI
observations of selected frequencies. The aim is to constrain the properties
of both the dust and gas components.
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Proposal ID: KPGT_mgerin_1
Title:
"PRISMAS: PRobing InterStellar Molecules with Absorption line Studies"
Principal Investigator:
Maryvonne Gerin (Observatoire de Paris and École Normale Supérieure)
Category:
KPGT
Summary:
We will carry out a comprehensive spectroscopic study of key molecular line
carriers, probing interstellar hydrides and carbon chains. Our investigation
will entail high-resolution HIFI spectroscopy of some 25 molecules towards 8
sources, and full spectral scans with PACS. The target hydrides contain the
elements H, D, C, N, O, F and Cl. We will take advantage of the strong dust
emission from massive star forming regions to detect multiple absorption
components from foreground clouds of diverse properties that are known to
intersect the selected sight-lines, along with emission and absorption
intrinsic to the background sources. Our investigation will provide a wealth of
new information about interstellar hydrides -- addressing key puzzles posed by
previous observations from the ground since the 1940's, and recently with ISO,
SWAS, and ODIN -- and leaving an important Herschel legacy to astrochemistry
and ISM science. We will address the role of high temperature chemical
reactions in the formation of interstellar molecules, and the question of how
such reactions might be driven. We will also investigate the role of grain
surface reactions in interstellar chemistry, and the growth of carbon
molecules, bridging the gap between molecules and aggregates, as unique
spectroscopic signatures of carbon chains and rings, are accessible in the
FIR. Many of the lines that are detectable with Herschel in the local Universe
become accessible to ground-based observatories for redshifted sources. Our
programme will provide an unique benchmark for the studies of molecular gas at
high redshift with ALMA.
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Proposal ID: KPGT_okrause_1
Title:
"The earliest phases of star formation: From low- to high-mass objects"
Principal Investigator:
Oliver Krause (Max Planck Institut fuer Astronomie)
Category:
KPGT
Summary:
Present-day star formation starts in the coldest and densest cores of
molecular clouds. Still, our knowledge about the very early stages of
star formation is limited. Objects at these stages emit most of their
luminosity at FIR wavelengths, which is not observable from the ground.
Hence, our view in this wavelength range to date remains fuzzy at best,
since all available information from the FIR is generally obtained from
small aperture satellites severely lacking spatial resolution. Therefore,
data are strongly affected by source blending, especially within
protoclusters, where the density of potential protostars is very high. This
limits the derivation of core masses and density profiles which is a major
drawback for detailed studies of young low-mass cores. In addition, it has
severely hampered progress in characterising young and cold high-mass cores
which are, on average, far more distant. Nevertheless, detailed knowledge
about these pre- and protostellar stages is indispensable for answering
fundamental questions about the physics of the early collapse phase, the
core fragmentation and the general ways to finally form stars of all masses.
With Herschel we have the unique opportunity to deeply scrutinise such cold
cradles of stars with unprecedented sensitivity and angular resolution in the
FIR. We therefore propose to use the PACS and SPIRE instruments to perform
deep and directed FIR mapping of confined regions. We have compiled a unique
sample of low and high-mass targets that we identified based on careful
preparatory studies (including ISO and Spitzer observations) as very
promising sources for the study of initial conditions of star formation.
The Herschel data will allow us to reconstruct the (3D) density and
temperature structure and assess the energy budget of the cores. Furthermore,
Herschel will for the first time enable us to perform an advanced modelling
of such cold cores that is not affected by simplifications and parameter
ambiguities.
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Proposal ID: KPGT_pandre_1
Title:
"Probing the origin of the stellar initial mass function: A wide-field Herschel photometric survey of nearby star-forming cloud complexes"
Principal Investigator:
Philippe Andre (SAp/CEA Saclay)
Category:
KPGT
Summary:
Herschel provides a unique opportunity to study the earliest stages of star
formation. What is the origin of the stellar initial mass function (IMF)?
This issue is central in local star formation research and for understanding
whether the IMF is truly universal or is likely to depend on metallicity,
pressure, or temperature. As prestellar cores and young (Class 0) protostars
emit the bulk of their luminosity at ~80-400 microns, the Herschel imaging
instruments SPIRE and PACS are ideal for taking a census of such objects down
to ~0.01-0.1 Msun in the nearby (0.5 kpc) molecular cloud complexes. We
propose an extensive imaging survey of the densest portions of the Gould
Belt with SPIRE at 250-500 and PACS at 110-170 microns down to a 5-sigma
column sensitivity NH2~10^21 cm^-2 or Av~1. Our goal is to make a complete,
homogeneous mapping of the Av>3 regions with SPIRE and of the Av>6 regions
with PACS, and representative areas at Av~1-3 levels with both instruments.
The survey sensitivity is well matched to the expected cirrus confusion limit,
so we should detect structures throughout the maps. The target clouds span a
range of physical conditions, from active, cluster-forming complexes to
quiescent regions with lower star formation activity. We should detect
hundreds Class 0 protostars and thousands prestellar condensations in the
entire ~145 deg^2 SPIRE survey, i.e. ~10 times more cold objects than already
identified from the ground. These numbers should allow us to derive an
accurate prestellar core mass function. The temperature and density
structures of the nearest ( 0.2 kpc) cores will be resolved, revealing the
initial conditions for individual protostellar collapse. The large spatial
dynamic range of the proposed survey will probe the link between diffuse
cirrus-like structures and compact self-gravitating cores. Our main
scientific goal is to elucidate the physical mechanisms for the formation
of prestellar cores out of the diffuse medium, crucial for understanding the
origin of stellar masses.
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Proposal ID: KPGT_vossenko_1
Title:
"The warm and dense ISM"
Principal Investigator:
Volker Ossenkopf (KOSMA, Universitaet zu Koeln)
Category:
KPGT
Summary:
We propose to perform FIR spectroscopy of the warm and dense ISM (WADI)
using the unique observational opportunities of Herschel to improve our
understanding of the physical and chemical processes controlling the
interaction between stars and their environment. The program will focus on
four core topics, energy balance of photon-dominated regions (PDRs),
photo-induced chemistry, PDR dynamics and kinematics, shock structures.
Both radiative (FUV) and dynamical (shocks) processes will be probed, as
key factors in the evolution of the ISM. They regulate star formation and
may even govern galaxy evolution on large scales. Most of the energy input
in star-forming regions is released as FIR radiation, either as dust
continuum or as gas cooling lines. The bright cooling lines from these
regions are natural tracers of star formation activity throughout the
history of the cosmos; detailed understanding of their origin thus provides
the basis for proper interpretation of the observations both of the Milky
Way, as well as of nearby and distant galaxies. Herschel's unprecedented
spectral coverage at high spatial resolution combined with the spectral
resolution of the HIFI instrument allows a detailed study of many key
tracers of PDRs and shocks. This allows to deeply probe the interaction of
stars with their surrounding through radiation (PDRs) and shocks (SNRs).
Observing a proper selection of prototype sources and key lines, will give
insight into the details of the physical and chemical processes controlling
each of the four core topics above, and will thus allow to model the FIR
emission of star forming regions.
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SCIENCE CATEGORY: Stars (2)
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Proposal ID: KPGT_mgroen01_1
Title:
"The circumstellar environment in post-main-sequence objects"
Principal Investigator:
Martin Groenewegen (University of Leuven)
Category:
KPGT
Summary:
Mass loss is one of the most fundamental properties of post-main sequence
evolution. The mass-loss process leads to the formation of circumstellar
shells containing dust and molecules. Although the mass-loss phenomenon has
been studied since the 1960s, and important results have been obtained with
the IRAS, ISO and Spitzer space missions, the details of the mass-loss
process and the formation and evolution of the circumstellar shells are
still not well understood. With its improved spatial resolution compared
to ISO and Spitzer, better sensitivity, the extension to longer and
unexplored wavelength regions, and medium resolution spectrometers, the
combination of PACS and SPIRE observations will lead to a significant
improvement in our understanding of the phenomena of mass loss and dust
formation. The main aims of this programme are three-fold: (1) to study the
time dependence of the mass loss process, via a search for shells and
multiple shells around a wide range of evolved objects, in order to
quantify the total amounts of mass lost at the various evolutionary stages
of low to high-mass stars, (2) to study the dust and gas chemistry as a
function of progenitor mass, and (3) to study the properties and asymmetries
of evolved star envelopes. To this end, a sample of 103 Asymptotic Giant
Branch and Red Super Giants, post-AGB and Planetary Nebulae, Luminous Blue
Variables and Wolf-Rayet stars, and 5 Supernovae remnants will be imaged
with PACS at 70+170 micron, and a sub-set of 32 stars will be imaged at all
3 wavelengths with SPIRE. In spectroscopy, a sample of 55 stars will be
observed over the full wavelength range of PACS and, 23 stars will be
observed with the SPIRE FTS. The sample of AGB stars has been selected to
cover all chemical types (M-, S-, C-stars), variability types (irregular,
semi-regular, Miras) and periods, and mass-loss rates. Stars have been
selected to have high IRAS fluxes and low background levels. The
spectroscopic targets are typically the brightest of the mapping targets.
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Proposal ID: KPGT_vbujarra_1
Title:
"HIFISTARS: The physical and chemical properties of circumstellar environments around evolved stars"
Principal Investigator:
Valentin Bujarrabal (Observatorio Astronomico Nacional)
Category:
KPGT
Summary:
We propose to carry out a comprehensive study of circumstellar envelopes
(CSEs) around evolved stars, as a HIFI GTKP. The main scientific aims are
to gain deeper insight into the structure, thermodynamics, kinematics and
chemistry of CSEs and into the mass-loss history of evolved stars, thereby
advancing our understanding on the final stages of stellar evolution of the
majority of stars and their resultant impact on the interstellar medium and
the cosmic cycle. We will use the unique capabilities of HIFI to probe the
inner regions of CSEs, by means of spectrally-resolved observations of the
principal cooling transitions: thermal transitions of H2O, and high-excitation
rotational transitions of CO and HCN. Such observations provide unique
information about the shells where the gas temperatures are 100 - 2000 K
and the material is being accelerated. We propose to observe a set of 38
objects, chosen to sample the parameter space of relevance for evolved stars
and their circumstellar material. For every star, 3 lines of both 12CO and
13CO will be observed to unravel the mass-loss history. To further unveil
the inner structure in the CSEs, observations of different H2O lines are
crucial, since H2O is a key molecule to understand the chemistry, the
thermodynamics and the dynamics of the inner CSE. We propose to observe a
carefully-selected list of H2O transitions covering different excitation
degrees, including para- and ortho-H2O lines and a few isotopic lines. The
high spectral resolution observations will allow us to determine the velocity
field in the warm acceleration regions. With HCN being a major coolant in
C-rich CSEs, 2 high-excitation lines will be observed in C-rich AGBs to probe
the temperature structure. To further study the oxygen chemistry, we will
obtain OH and [OI] lines from PACS GT data. Finally, we will address the
puzzling question of the origin of water vapor observed previously in the
extreme carbon star IRC+10216, and survey 9 additional C-rich stars for
evidence of water.
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SCIENCE CATEGORY: Galaxies/AGNs (5)
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Proposal ID: KPGT_cwilso01_1
Title:
"Physical Processes in the Interstellar Medium of Very Nearby Galaxies"
Principal Investigator:
Christine Wilson (McMaster University)
Category
KPGT
Summary
We propose to use the SPIRE and PACS instruments on Herschel to measure the
emission spectrum from dust as well as important cooling lines from the
gaseous interstellar medium in sample of 13 very nearby galaxies (M51, M81,
NGC2403, NGC891, M83, M82, Arp220, NGC4038/39, NGC1068, NGC4151, CenA,
NGC4125, and NGC205). These galaxies have been chosen to probe as wide a
region in galaxy parameter space as possible while maximizing the achievable
spatial resolution and are already well-studied from X-ray and optical
through to radio wavelengths. The far-infrared and submillimeter wavelengths
probed by Herschel are absolutely crucial for understanding the physical
processes and properties of the interstellar medium,the interplay between
star formation and the interstellar medium in galaxies, and how they may
depend on the wider galaxian environment.
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Proposal ID: KPGT_smadde01_1
Title:
"The ISM in Low Metallicity Environments: Bridging the Gap Between
Local Universe and Primordial Galaxies"
Principal Investigator:
Suzanne Madden (CEA Saclay
Category
KPGT
Summary
While much of what we have gleaned of the details of dust and gas properties
and the processes of dust recycling and heating and cooling in galaxies has
been limited to Galactic studies, with Herschel we will be able to explore
these issues in low metallicity dwarf galaxies which are known by now to
exhibit dust and gas properties different from more metal-rich galaxies.
Because these objects are relatively nearby, it is possible to relate the
observed variations in the SEDs to the actual physical phenomena occuring
within the ISM of the galaxy, allowing the construction of a rich
interpretative framework for unresolved, more distant galaxies in the early
universe. Using the SPIRE and PACS instruments on Herschel, we propose to map
the dust and gas in a 51 dwarf galaxies, sampling a broad metallicity range
of 1/50 to 1/3 solar. These data, in conjunction with other ancillary data,
will be used to construct the emission spectrum of the dust plus that of the
gas in the most important cooling lines. The combination of these instruments
onboard Herschel will provide the first opportunity to study the dust and gas
in extremely low metallicity environments that have not yet experienced
repeated recycling through the ISM. The interpretation of this data will
open the door to comprehending primordial ISM conditions and star formation
in the young universe.
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Proposal ID: KPGT_rguesten_1
Title:
"The HEXGAL (Herschel EXtraGALactic) Key Project: Physical and Chemical
Conditions of the ISM in Galactic Nuclei"
Principal Investigator: Rolf Güsten (Max Planck Institut fuer Radioastronomie)
Category:
KPGT
Summary:
Herschel/HIFI?s unique spectroscopic capabilities will allow us to make a
representative velocity-resolved inventory of important cooling lines in
nearby galaxies, AGN and starburst nuclei. Such observations explore the
physical conditions within regions of active star formation in low and high
metallicity environments, shedding light on the physics of large scale star
formation in the contemporary and, by extension, the early universe.
Multi-line data combined with numerical radiative transfer and chemical
network models quantitatively constrain the various phases of the
interstellar medium (ISM). Key lines in Herschel/HIFI?s spectral range
include the bright fine-structure lines of neutral and ionized atomic carbon,
nitrogen and oxygen, a unique set of water lines, and the high-excitation CO
transitions. The far-infrared spectra of many galaxies reflect the gas energy
balance through atomic and molecular cooling lines from photo-dissociation
regions (PDRs) and forbidden fine-structure lines from HII-regions. Within
the beam of an extragalactic observation, any of the ISM components (dense
warm PDRs on the surfaces of UV-exposed molecular clouds, low-density warm
atomic clouds will contribute to the brightness of the molecular or
fine-structure lines. Our high spectral resolution studies will unravel the
structure of the ISM by analysis of their main cooling lines. Velocity
information provides sub-beam spatial resolution and ties HIFI observations
of different species to complementary PACS line integrated intensity maps on
larger scales. In addition, water is a key molecule for our understanding of
the chemistry and energy balance in the denser ISM. Herschel/HIFI will
measure the brightness of the ground-state transitions to determine the gas
temperature of the ISM via line ratios.
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Proposal ID: KPGT_esturm_1
Title:
"Star formation and activity in infrared bright galaxies at 0<z<1"
Principal Investigator:
Eckhard Sturm (Max Planck Institut fuer E. Physik)
Category:
KPGT
Summary:
We will perform a comprehensive far-infrared spectroscopic and photometric
survey of infrared bright galaxies at local and intermediate redshifts. Our
goal is to use the superior sensitivity, spatial and spectral resolution of
Herschel to study these galaxies with minimal extinction effects. We aim to
obtain a comprehensive view of the physical processes at work in the
interstellar medium of local galaxies ranging from objects with moderately
enhanced star formation to the most dense, energetic, and obscured
environments in ultra-luminous infrared galaxies (ULIRGs) and around AGN.
The objects cover a wide parameter range in luminosity, activity level, and
metal enrichment, and will be complemented by a few objects at intermediate
redshifts, i.e. at a more active epoch of star formation. In particular we
plan to - study the obscuration and physical conditions of the central
regions of infrared galaxies by obtaining full PACS and SPIRE spectra of
five template starbursts, AGN and ULIRGs. - characterise for a larger local
sample the state of the ionised medium and of photo-dissociation and X-ray
dominated regions through PACS observations of key diagnostic fine-structure
and molecular lines. The densest and warmest region near AGN will also be
probed for highly excited CO emission, - determine the role of metallicity
in star formation processes of low metallicity galaxies from the nearby
LMC/SMC to more distant galaxies, - search for evolution from the
intermediate redshift population close to the peak of cosmic star formation
till the present time, - study the triggering mechanisms and temporal
evolution of infrared activity by photometric mapping of a large sample of
interacting galaxies, - determine the structure of a few local templates by
spectroscopic mapping along characteristic axes. These PACS line maps will
establish the physical conditions of nuclear region, spiral arms/disk, and
wind regions.
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Proposal ID: KPGT_seales01_1
Title:
"The Herschel Reference Survey"
Principal Investigator:
Stephen Eales (Cardiff University)
Category:
KPGT
Summary:
Despite IRAS, ISO and Spitzer, there is still much we do know about dust in
galaxies, partly because of sensitivity limitations and partly because
previous telescopes were insensitive to dust colder than about 15 K. Our
knowledge is especially poor for ellipticals which have barely been detected
by previous telescopes. As part of the SPIRE GT programme, we propose to
obtain images at 250, 350 and 520 microns of a sample of 323 galaxies
selected to be useful both for studying the dust in individual galaxies and
for drawing statistical conclusions about the role of dust in galaxies in
general. The Herschel Reference Survey will be the first survey sensitive
to all the dust in galaxies and which will detect dust in galaxies of all
Hubble types. Apart from its legacy value, we intend to use the survey for
the following projects:
1) We will make a comprehensive study of dust along the Hubble sequence,
investigating how the dust mass varies with Hubble type: mass of stars,
current star formation rate, past star formation rate, and the masses of
molecular and atomic gas.
2) We will investigate within individual galaxies the connections between
the star formation rate and the different phases of the ISM, from the nucleus
to the HI outside the optical disk. 3) We will investigate how the mass and
distribution of dust depend on a galaxy's environment. 4) We will investigate
whether there is an intergalactic dust cycle by looking for dusty halos,
dusty superwinds and tidally-stripped dust around galaxies. 5) We will
investigate the origin of dust in ellipticals, and the evolution of the
galaxies themselves, by looking for dust disks and dust shells and by
looking for correlations between the mass and distribution of the dust and
the other properties of the galaxy. 6) We will measure the local luminosity
and dust-mass functions, which will be necessary to interpret the results
of the deep surveys, another part of the proposed GT programme. The total
time required for the survey is 112.6 hours.
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SCIENCE CATEGORY: Cosmology (3)
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Proposal ID: KPGT_soliver_1
Title:
"The Herschel Multi-tiered Extragalactic Survey (HerMES):
Measuring the Infrared Galaxy Formation History of the Universe"
Principal Investigator: Seb Oliver (University of Sussex)
Category:
KPGT
Summary:
A central challenge in astrophysics today is to understand the complex
processes of galaxy formation: the development of galactic structure, the
conversion of gas into stars, and the growth of supermassive black holes.
The far-infrared / submillimetre waveband is of particular importance for
studying these processes because roughly half of the cosmic energy density
produced by galaxies arises from optical/UV starlight that has been absorbed
by dust and reradiated at these wavelengths. Existing surveys are already
presenting a serious challenge for theorists, revealing many more luminous,
massive galaxies at high redshifts than are predicted by simple prescriptions
within the hierarchical merging paradigm. Submillimetre surveys however have
been extremely limited but have already provided tantalizing clues to a
strongly evolving population of infrared-luminous galaxies. We propose
HerMES, the Herschel Multi-tiered Extragalactic Survey, to chart the
formation and evolution of infrared galaxies throughout cosmic history.
HerMES consists of a nested set of fields that will bring unprecedented
depth and breadth to the study of infrared galaxies. We will use HerMES
to measure the bolometric emission of infrared galaxies, study the evolution
of the luminosity function, measure their clustering properties, and probe
populations of galaxies below the confusion limit through lensing and
statistical techniques. HerMES is closely coordinated with the PACS
Evolutionary Probe survey. We will make maximum use of ancillary surveys
from radio to X-ray wavelengths to facilitate redshift determination,
rapidly identify unusual objects, and understand the relationships between
thermal dust emission and other emission mechanisms. HerMES will provide a
rich data set legacy for the greater astronomical community to mine for
years to come.
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Proposal ID: KPGT_kmeisenh_1
Title:
"The Dusty Young Universe: Photometry and Spectroscopy of Quasars at z>2"
Principal Investigator:
Klaus Meisenheimer (Max-Planck-Institut für Astronomie)
Category:
KPGT
Summary:
The detection of a significant fraction of the highest redshift quasars
(z > 5) in the (sub-)mm wavelength range indicates that a substantial
amount of dust has been synthesized already during the first billion year
since the Big Bang. Recent 24 micron observations with Spitzer have shown
that very hot dust is present close to the QSO core in most z >5 quasars.
However, both the (sub-)mm and MIR observations can only catch tails of the
dust emission spectrum, at lambda_rest > 200 µm, and at lambda_rest 5 µm,
respectively. Measuring the peak of the dust emission, expected to reach
10 ... 30 mJy around lambda_rest ~ 50 µm (120µm lambda_obs 700µm), has been
beyond the capabilities of FIR satellites or ground-based sub-mm telescopes.
Thus, critical properties, such as FIR luminosity, dust temperatures and
mass, remain unconstrained. To improve on this situation, we propose a
Herschel Guaranteed Time Key Programme (GT KP) to collect far-infrared and
sub-millimeter photometry of more than 100 high redshift quasars using the
PACS and SPIRE instruments. We plan to determine the SEDs of three samples
of QSOs: (i) all z > 5 quasars known to date, (ii) a dozen radio loud quasars
and galaxies at the highest redshifts, and (iii) 29 Broad Absorption Line
(BAL) quasars together with a comparison sample of 17 non-BAL QSOs at
matching redshifts. In addition, we plan to obtain PACS spectroscopy of
four very dust-rich and lensed high-redshift QSOs and galaxies for spectral
line diagnostics, which will help to disentangle the contributions of AGN-
and starburst-heated dust and thus complement the SED-based study. We will
spend in total 165 hours of PACS GT in this key programme, 115 hours for the
photometry with PACS and SPIRE, and 50 hours for the FIR spectroscopy. )
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Proposal ID: KPGT_dlutz_1
Title:
"PACS Evolutionary Probe - A guaranteed time key programme survey of the extragalactic sky"
Principal Investigator:
Dieter Lutz (Max Planck Institut fuer E. Physik)
Category:
KPGT
Summary:
We describe a key programme using the unprecedented sensitivity and spatial
resolution of Herschel for a comprehensive far-infrared photometric survey
of the extragalactic sky. Blank field surveys using PACS at 170, 110 and
75 micron are supplemented with targeted observations of massive z~1 clusters
and lensing clusters. We will resolve the bulk of the Cosmic Infrared
Background, determine the nature of its constituent sources and trace the
evolution of dust-obscured star formation. Our survey will study the
evolution of galaxies and AGN over a wide range of redshifts and in
environments of different density, and provide the crucial far-infrared
measurements lacking for a full understanding of intermediate and high
redshift galaxy populations previously identified at other wavelengths. We
have chosen fields with excellent multi-wavelength coverage enabling both
rapid science results and a lasting legacy value. This survey is coordinated
with Herschel/SPIRE observations of the same fields in a Key programme
submitted by the SPIRE SAG 1.
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