Solar system (1)

TNOs are Cool: A Survey of the Transneptunian Region

Proposal ID: KPOT_thmuelle_1

Principal Investigator: Thomas Mueller

Time: 372.7 h Priority 1

Category: Kuiper Belt bodies


Over one thousand objects have been discovered orbiting beyond Neptune. These trans-Neptunian objects (TNOs) represent the primitive remnants of the planetesimal disk from which the outer planets formed, and is an analog for unseen dust parent-bodies in debris disks observed around other main-sequence stars. The dynamical and physical properties of these bodies provide unique and important constraints on formation and evolution models of the outer Solar System. While the dynamical architecture in this region (also known as the Kuiper Belt) is becoming relatively clear, the physical properties of the objects are only beginning to be revealed. In particular, fundamental parameters such as size, albedo, density and thermal properties are difficult to measure. Measurements of their thermal emission, which peaks at far-IR wavelengths, offer the best means available to determine those physical properties. While Spitzer has provided the first results, notably revealing a large albedo diversity in this population, the increased sensitivity of Herschel and its wavelength coverage will permit profound advances in the field. We propose to perform radiometric measurements of 141 objects, including 25 known multiple systems. This large sample will permit: (i) A determination of the size distribution of the large (> 200 km) objects, thought to have remained unchanged from the accretion phase. (ii) Systematic searches for correlations between size, albedo, and other physical and orbital parameters, diagnostic of formation and evolution processes. (iii) Determination of mass-density for at least 20 binary TNOs, diagnostic of nebular chemistry and interior structure. (iv) The first study of their thermophysical properties, including thermal inertia and surface emissivity. When combined with measurements of the dust population beyond Neptune (e.g. from the New Horizons mission to Pluto and beyond), our results will provide a benchmark for understanding the solar system debris disk, and extra-solar ones as well.

ISM/Star formation (10)

Gas in Protoplanetary Systems. (GASPS)

Proposal ID: KPOT_bdent_1

Principal Investigator: Bill Dent

Time: 400.0 h Priority 1

Category: Circumstellar/Debris disks


We propose the first extensive, systematic survey of gas in circumstellar disks over the critical transition from gas-rich protoplanetary through to gas-poor debris system. The brightest spectral lines from disks lie in the far-infrared and arise from radii ~10-500 AU, where giant planets are expected to form. Herschel is uniquely able to observe this wavelength regime with the sensitivity to allow a large scale survey. We will carry out a 2-phase PACS study, surveying the fine structure lines of [CII]157um and [OI]63um in 274 objects, and following up the brightest sources with observations of H2O and [OI]145um. The gas mass sensitivity, a few 1e-5 Msun, will be more than an order of magnitude lower than achieved by ISO and Spitzer and expected for SOFIA. We will also measure the dust continuum to an equivalent mass sensitivity. Team members include experts in the modeling of disk structure, chemistry, and radiative transfer necessary to interpret these data. We will observe nearby clusters in the age range 1-30Myr, encompassing disk masses 1e-2 - 1e-5 Msun, and stellar luminosity 1-100 Lsun. This covers the dominant epoch of planet formation and the mass from protoplanetary through to young debris disk. Furthermore our sample is chosen to include a wide range of X-ray & UV flux, and SED shape, from classical SED Class II, through "transition" disks with inner dust holes, to disks with small IR excesses. With this extensive dataset, our program will: - Trace gas and dust in the planet formation region across an extensive multivariate parameter space - Provide the first definitive measurement of the gas dissipation timescale in disks - Study the evolutionary link between protoplanetary and debris disks - Investigate the extent and evolution of warm H2O in the planet-forming regions of disks, with implications for the volatile content of developing planets - Provide an extensive database of disk observations and models with long-lasting legacy value for followup observations

DEBRIS: Disc Emission via a Bias-free Reconnaissance in the Infrared/Sub-millimetre

Proposal ID: KPOT_bmatthew_1

Principal Investigator: Brenda Matthews

Time: 140.0 h Priority 1

Category: Circumstellar/Debris disks


Debris discs are belts of dust particles created from collisions of planetesimals (comets and asteroids) in extrasolar planetary systems. The prototype disc around Vega was discovered ~25 years ago by IRAS, and ~20 discs have been imaged to date, primarily by HST, SCUBA and Spitzer. Despite the relatively low numbers, debris discs are seen to be extraordinarily diverse in character, including systems with vast populations of comets or with perturbations by planets at tens of AU from the host star. Due to this low number, however, our knowledge of debris discs is incomplete; there has been no unbiased survey specifically designed to image a large number of discs. Spitzer greatly improved our understanding of the disc-rich A stars but the number of detections is still low for solar-analogue FGK stars and especially the numerous M stars. For Herschel, we therefore propose the DEBRIS (``Disc Emission via a Bias-free Reconnaissance in the Infrared/Submillimetre") Key Project which will probe 450 nearby A-M stellar systems for debris and measure Solar System dust levels in debris discs for the first time. The large sample is statistically robust and without bias, providing a rich legacy for debris disc and exo-planet science. This deep, flux-limited survey will obtain PACS 100/160 images of all 450 systems (472 fields due to wide binaries), and it will be possible to resolve discs toward each one with the PACS' high resolution. DEBRIS includes SPIRE imaging in systems where debris is detected with PACS (a rate of 50% is expected). The key science questions are: (a) which kinds of stars have debris and why? (b) what are the sizes, temperatures and masses of the debris discs? (c) what is the relation of resolved disc structures to the exo-planets? and (d) is our Kuiper Belt common or unusual? The Herschel DEBRIS Key Project will answer these questions using Herschel's high sensitivity, spectral coverage and resolution. Our team includes world experts in debris discs and exo-planet science from 8 countries.

Cold Disks around Nearby Stars. A Search for Edgeworth-Kuiper Belt analogues (DUNES: DUst disks around NEarby Stars)

Proposal ID: KPOT_ceiroa_1

Principal Investigator: Carlos Eiroa

Time: 140.0 h Priority 1

Category: Circumstellar/Debris disks


We plan to use the unique photometric capabilities provided by Herschel to perform a deep and systematic survey for faint, cold debris disks. We propose a sensitivity-limited Herschel Key Programme that aims at finding and characterizing faint exo-solar analogues to the Edgeworth-Kuiper Belt in a statistical sample of 283 nearby main-sequence stars. Our sample is volume-limited (distances < 25 pc) and covers a decade in stellar mass from 0.2 to 2 solar masses (M- to A-type stars). This will provide an unprecedented lower limit to the fractional abundance of planetesimal systems, and act as a proxy to assess the presence of giant planets resembling the roles played by Neptune and Jupiter in the solar system. We will perform PACS and SPIRE photometric observations covering the wavelength range from 70 to 500 micron. PACS observations at 100 micron have been designed to detect the stellar photospheres down to the confusion noise with a signal to noise ratio at least 5. Observations in the other Herschel bands will allow us to characterize, model, and constrain the disks. As a result, it will be possible for us to reach fractional luminosities L(dust)/L(star) a few times 10^(-7), close to the EKB level in our solar system. The extensive and unique data set will allow us to address some fundamental questions related to exo-EKBs: - Dependence of planetesimal formation on stellar mass. - Collisional and dynamical evolution. - Correlation with planets. - Dust properties and size distribution. Herschel is the first and the only facility for the foreseeable future which is providing the observational capability required to successfully addressing the scientific case we are proposing. The outcome of this project has high science legacy and outreach values that will impact on studies related to planet formation and planetary systems.

HIGGS: The Herschel Inner Galaxy Gas Survey

Proposal ID: KPOT_cmarti01_1

Principal Investigator: Christopher Martin

Time: 125.0 h Priority 1

Category: Galactic Structure


We will investigate the inflow of matter in the bulge of the Milky Way using the HIFI and PACS instruments on Herschel to observe [C II], [N II], [O I], [O III], and high-J CO emission lines to determine the relationship between central black holes and their host galactic bulges and thus the causes and mechanisms of starbursts. As Binney et al. (1991) have suggested, the gas in closed orbits in the bar of the Milky Way provides a means to study in detail the accretion processes leading to starbursts and active galactic nuclei. Shocks effectively transfer some fraction of the clouds' orbital kinetic energy into heat which escapes through dust continuum and line emission. By measuring this emission and characterizing the star formation that occurs under these unusual conditions, we can estimate the amount of orbital energy that has been dissipated and constrain estimates of the mass inflow from the decaying orbits. For this purpose high velocity resolution observations of interstellar cooling lines are required. In the following proposal we discuss how HIFI and PACS observations of [C II], [N II], [O I], [O III], and high-J CO lines can be combined with existing radio emission line surveys and far-infrared continuum surveys to identify and estimate the energy loss and resulting infall motions from clumps in the inner galaxy. Using existing submillimeter-wave spectral line surveys, we are able to identify those regions lying between 2 kpc and 200 pc of the Galactic center that are emitting significant terahertz line radiation, and we can therefore accomplish a comprehensive characterization of gas in the inner galaxy using pointed Herschel observations. As ALMA comes online, we will be able to use the understanding produced by this study to understand the gas dynamics of other galaxies and properly place them in context.

Galactic Cold Cores: A Herschel survey of the source populations revealed by Planck

Proposal ID: KPOT_mjuvela_1

Principal Investigator: Mika Juvela

Time: 150.9 h Priority 1

Category: Star Formation/Young Stellar Objects


In this programme we propose to study starless cores and the initial conditions of star formation using the Herschel satellite and the combined power of its PACS and SPIRE instruments. As the starting point we have the Planck survey that will provide the first all-sky survey of Galactic cold and compact dust clouds. We will concentrate our study on mid- and high Galactic latitudes. Our program complements the accepted GT and proposed OT programs which target the most prominent regions already in the phase of active star formation. The main objective is to build a coherent observational database representing the entire cold core population in the Galaxy.

Dust, Ice, and Gas In Time (DIGIT)

Proposal ID: KPOT_nevans_1

Principal Investigator: Neal Evans

Time: 250.0 h Priority 1

Category: Circumstellar/Debris disks


Dust, ice, and gas evolve as they move from envelopes of forming stars into circumstellar disks where they can become the main building blocks of planets. Herschel-PACS is uniquely suited to trace this evolution through broadband emission from dust, through specific features of solids which reveal elemental composition and water content, and through spectral bands of the main icy components. Both atomic and molecular lines, in particular the [O I], H2O and OH lines, will be used to follow the gas, study the interchange between gas and ice, and trace the oxygen budget. The gas and dust spectral features are at the same time excellent probes of macroscopic parameters, such as temperature, UV and X-ray fields, density and thermal structures of envelopes and disks, and dynamical mixing processes. Our sample covers sources with a range in evolutionary state from embedded objects with massive envelopes to weak-line T Tauri stars with dissipating disks, and with a range in luminosity, spectral type, and dust characteristics. Both our high S/N PACS full spectral range scans (complemented by Spitzer mid-IR spectral scans) and our targeted, deep gas-phase line measurements will have lasting archival value.

Herschel Oxygen Project

Proposal ID: KPOT_pgolds01_1

Principal Investigator: Paul Goldsmith

Time: 140.0 h Priority 1

Category: Interstellar Medium/HII regions


Oxygen is the third most abundant element in the Universe and as such it plays a decisive role in the chemistry and physics of molecular clouds. Chemical models have long predicted that some of the simplest molecules would be the primary reservoirs of oxygen in space: CO, H2O, and O2, and under these conditions would be major cloud coolants influencing the evolution of the cloud and the process of star formation. Molecular oxygen has remained elusive, with results from SWAS and Odin missions indicating abundances approximately two orders of magnitude below those predicted by standard gas phase chemistry models. The favored explanation is that oxygen atoms are tied up as water ice on grain surfaces in the cold, extended regions of clouds probed with the relatively large beams of previous space observatories. We propose to use Herschel HIFI to carry out a survey of regions in which the O2 abundance is predicted to be large due to reestablishment of standard gas phase chemistry. We will observe a selected group of sources including regions of heated gas surrounding embedded young stars, photon dominated regions, X-ray dominated regions, and shock-heated regions, in the 487 and 774 GHz lines of O2, and a subset of these in the 1121 GHz line. We expect that these sources will be of small angular size, and can be observed using beam switching in mini line survey mode, to enable sideband deconvolution and minimize interference from confusing lines of other species. The greatly improved sensitivity of HIFI receivers and the far smaller Herschel beam relative to SWAS and Odin allow us to probe these regions to levels below those predicted by sophisticated astrochemical models. By measuring the O2 abundance, we can verify important aspects of models of these regions, put constraints on key gas-grain interaction parameters, and probe critical chemistry and physics in regions that are tracers of recent and prospective star formation.

Hi-GAL: the Herschel infrared Galactic Plane Survey

Proposal ID: KPOT_smolinar_1

Principal Investigator: Sergio Molinari

Time: 344.3 h Priority 1

Category: Star Formation/Young Stellar Objects


We propose to use SPIRE and PACS in parallel mode to carry out a 720 sq.deg. unbiased imaging survey of the entire Galactic Plane of the Milky Way, uniformly sampling a 2°-wide strip centered on the warped midplane in the 70, 170, 250, 350 and 500um photometric bands. The Herschel infrared Galactic Plane Survey (Hi-GAL) embodies the optimum combination of Herschel wavelength coverage, sensitivity, mapping strategy and speed to deliver, in a single and homogeneous dataset of the highest statistical significance, the ultimate census and characterisation (temperature, luminosity, mass and Spectral Energy Distribution) of star forming regions and cold ISM structures in all the environments of the Galactic ecosystem, at unprecedented resolutions, and at all scales from massive objects in protoclusters to the full spiral arm. This will enable decisive steps toward the formulation of a global predictive model of the ISM/star formation cyclic transformation process which is the engine responsible for most of the energy budget in normal star-forming galaxies. It will be a cornerstone to unveil the evolution of galaxies through redshift back to their formation. Hi-GAL will also deliver a dataset of extraordinary legacy value for decades to come, with a strong potential of systematic and serendipitous science in a wide range of astronomical fields, and enabling the optimum use of future major facilities such as ALMA. In addition to a suite of enhanced products, including mosaiced images and source catalogues in all bands, we will create an immediate legacy value by waiving the totality of our proprietary time. The complete 60-600um view of the Milky Way at 10-35" resolution will be unique to Herschel, as it is beyond the capabilities of all of the future planned ground-based and space-borne facilities either for highest resolution (ALMA, SPIRIT, FIRI and SPECS interferometers) or for highest sensitivity (SPICA and SAFIR actively cooled single-dishes).

The Herschel Orion Protostar Survey (HOPS)

Proposal ID: KPOT_tmegeath_2

Principal Investigator: Tom Megeath

Time: 200.0 h Priority 1

Category: Star Formation/Young Stellar Objects


Understanding protostellar evolution is a necessary step toward characterizing the factors which ultimately determine the properties of emerging stars and their planetary systems. We propose PACS imaging and spectroscopy of protostars identified in Spitzer surveys of the Orion molecular cloud complex. This is the richest known sample of protostars at a common distance within 450 pc of the Sun. Deep PACS 70 and 160 micron imaging will be obtained for 283 protostars ranging in luminosity from 0.1 to 1000 Lsun and spanning the Class 0, Class I and flat spectrum evolutionary phases. The high sensitivity and angular resolution will enable us to measure bolometric luminosities in crowded fields, removing potentially significant contributions from external heating. In concert with existing near-IR and Spitzer mid-IR images and spectra, the deep PACS imaging will be used to determine the fundamental properties of the protostellar envelopes and disks (properties such as envelope structure, density and angular momentum, disk luminosity). PACS spectroscopy of 37 protostars will be used to measure water vapor, OH and O lines arising in the envelope, in the accretion shock onto the central protostellar disk, and in outflows. These data will provide an unparalleled view of the flow of material from the envelope onto the disk, through the disk to the star, and away from the star in outflows. The Orion molecular cloud complex contains an exceptionally wide range of parental gas conditions (i.e. initial conditions) and environments (from dense clusters to relatively isolated protostars). By comparing the properties of protostars in different regions of Orion clouds; we will assess the roles of initial conditions, environment and feedback from outflows in guiding protostellar evolution. These observations will produce a unique legacy dataset for guiding and testing a theory of protostellar evolution.

State of the Diffuse ISM: Galactic Observations of the Terahertz CII Line (GOT CPlus)

Proposal ID: KPOT_wlanger_1

Principal Investigator: William Langer

Time: 223.0 h Priority 1

Category: Interstellar Medium/HII regions


Star formation activity throughout the Galactic disk depends on the thermal and dynamical state of the interstellar gas, which in turn depends on heating and cooling rates, modulated by the gravitational potential and shock and turbulent pressures. Molecular cloud formation, and thus the star formation, may be regulated by pressures in the interstellar medium (ISM). To understand these processes we need information about the properties of the diffuse atomic and diffuse molecular gas clouds, and Photon Dominated Regions (PDR). An important tracer of these regions is the CII line at 158 microns (1900.5 GHz). We propose a "pencil-beam" survey of CII with HIFI band 7b, based on deep integrations and systematic sparse sampling of the Galactic disk plus selected targets, totaling over 900 lines of sight. We will detect both emission and, against the bright inner Galaxy and selected continuum sources, absorption lines. These spectra will provide the astronomical community with a large rich statistical database of the diffuse cloud properties throughout the Galaxy for understanding the Milky Way ISM and, by extension, other galaxies. It will be extremely valuable for determining the properties of the atomic gas, the role of barometric pressure and turbulence in cloud evolution, and the properties of the interface between the atomic and molecular clouds. The CII line is one of the major ISM cooling lines and is present throughout the Galactic plane. It is the strongest far-IR emission line in the Galaxy, with a total luminosity about a 1000 times that of the CO J=1-0 line. Combined with other data, it can be used to determine density, pressure, and radiation environment in gas clouds, and PDRs, and their dynamics via velocity fields. HSO is the best opportunity over the next several years to probe the ISM in this tracer and will provide a template for large-scale surveys with dedicated small telescopes and future surveys of other important ISM tracers.

Galaxies/AGNs (8)

Constraining the cold gas and dust in Cluster Cooling Flows

Proposal ID: KPOT_aedge_1

Principal Investigator: Alastair Edge

Time: 140.5 h Priority 1

Category: Galaxy clusters/Lensing clusters


A major cosmological event is the formation of first massive galaxies, which evolve to the luminous elliptical galaxies of today. Star formation in these galaxies was regulated and ultimately stifled by energetic AGN feedback processes, according to simulations. However, the nature of these processes is open to speculation because at these enormous distances, observations provide few constraints. Similar processes occur in some low redshift galaxy clusters where star formation and cold gas is detected in and around the brightest cluster galaxies. These modern-day analogs provide us with the opportunity to understand the heating, cooling, and star formation that occur on a grand scale at high redshift. In this Herschel Key Project, we will determine the location and mass of cooled gas, along with its temperature, ionization state, density and cooling rate. These new data, only possible with Herschel, are supplemented by radio, X-ray, and optical studies of the stars, hot gas, and AGN activity. To accomplish our goals, we will use PACS to measure the line strengths of [OI], [OIII], [NII], [CII] and [SiI], major coolants at low temperatures that also reflect the ionization state of the gas. The requested PACS and SPIRE photometry will determine the distribution of dust temperatures and masses, including the detection of the coolest gas clouds. These datasets will reveal the pathway from the hot ambient medium to cool gas to star formation, a process that was widespread when the universe was young.

Herschel M33 extended survey (HERMES): star-formation interplay with the ISM

Proposal ID: KPOT_ckrame01_1

Principal Investigator: Carsten Kramer

Time: 191.9 h Priority 1

Category: Local Group galaxies


In the local universe, most of the observable matter is contained in stellar objects shaping the morphology and dynamics of their "parent" galaxy. In view of the dominance of stellar mass, a better understanding of star formation and its consequences is mandatory and forms a central topic of contemporary astrophysical research. There exist a large number of high linear resolution studies related to individual star forming regions of the Galaxy as well as of low linear resolution studies of external galaxies. For a complete view onto the physical and chemical processes driving star formation and galactic evolution it is, however, essential to combine local conditions affecting individual star formation with properties only becoming apparent on global scales. The optimal target providing such a complete view is a galaxy that is actively forming stars, that is not seen edge-on (like our Galaxy), that has been studied at radio, optical and X-ray wavelengths, and that is sufficiently nearby to also permit studies on small scales. For our carefully chosen template galaxy, we plan to use HIFI to obtain fully-sampled large-scale [CII] (and H2O) maps. PACS will add important interstellar cooling lines, [OI], [NII], [NIII]. And SPIRE & PACS will be used to map the dust spectral energy distribution over the entire galaxy. Observing a deep, extended strip along the major axis of our template galaxy M33, will allow us to study the ionized, atomic, and molecular phases of the interstellar medium, its life cycle and thermal balance, tracing the formation of molecular clouds and of stars. Aside of insights related to the local processes in the galaxy itself, the mapped source will set a standard, providing a basis for the interpretation of phenomena encountered in other targets of the Local Group and in more distant galaxies.

The Herschel Lensing Survey

Proposal ID: KPOT_eegami_1

Principal Investigator: Eiichi Egami

Time: 292.3 h Priority 1

Category: Galaxy clusters/Lensing clusters


For deep imaging longward of 100 um, confusion noise sets the fundamental sensitivity limits achievable with Herschel, and these limits cannot be improved by integrating longer. As a result, Herschel PACS/SPIRE images will not quite reach the depth of Spitzer 24 um, not to mention that of ALMA. This means that with the raw sensitivities of PACS and SPIRE, it will be difficult to reach the population of infrared-luminous galaxies at z>2. To penetrate through the Herschel confusion limits with the lensing power of massive galaxy clusters and to reach z>2 infrared-luminous galaxies, we propose here a deep PACS/SPIRE imaging survey of 40 lensing clusters, which have carefully been selected from the past and on-going HST/Spitzer surveys. Although both the PACS and SPIRE GT teams will conduct similar surveys, its small sample size of 10 clusters is not enough to fully achieve the great potential of such a survey since highly magnified (e.g., >5-10x) lensed galaxies are rare. By expanding the sample size by a factor of four, and by pre-selecting most spectacular sources from our on-going Spitzer 24um survey of ~100 X-ray-luminous (i.e., massive) clusters, we will detect a significant number of highly magnified infrared-luminous galaxies at z>2 with PACS and SPIRE, which will enable us to (1) resolve a large fraction of the far-infrared/submillimeter background in the PACS/SPIRE bands and (2) map out the full spectral energy distributions (SEDs) of detected galaxies from mid-infrared to submillimter. Such an extensive survey of lensing clusters will be a great legacy of Herschel, providing a large number of interesting high-redshift targets for ALMA follow-up in the future. Because of the large sample size and strong lensing power of the targeted clusters, this survey also offers a great potential for breakthrough discoveries such as the first detection of a star-forming (i.e., non-AGN) galaxy at z>>4 in the far-infrared/submillimeter.

LoCuSS: A Legacy Survey of Galaxy Clusters at z=0.2

Proposal ID: KPOT_gsmith01_1

Principal Investigator: Graham Smith

Time: 145.0 h Priority 1

Category: Galaxy clusters/Lensing clusters


We propose a definitive census of obscured star formation in intermediate redshift clusters and its relationship with the recent mass assembly and thermodynamic histories of the clusters. Specifically, we propose to use Herschel/PACS observations at 100 and 160um in conjunction with our Spitzer 24um data to characterize the dust-obscured galaxy populations (star formation rate, AGN contamination, bolometric IR luminosity, dust temperature) in a large unbiased sample of galaxy clusters at 0.15

Herschel Virgo Cluster Survey (HeViCS)

Proposal ID: KPOT_jdavie01_1

Principal Investigator: Jonathan Davies

Time: 286.0 h Priority 1

Category: Nearby galaxies


We are proposing to make a fully sampled map of about 60 sq deg of the nearby Virgo galaxy cluster using both PACS and SPIRE (PMODE). This will provide a wavelength coverage in five bands from about 100 to 600 microns. We estimate that we will detect about 400 galaxies at 250 micron. Our science interests include: a) The detection of dust in the intra-cluster medium, b) Extended cold dust around galaxies. c) FIR-submm luminosity functions, d) The UV to sub-mm spectral energy distribution of galaxies of various morphological types, e) The detection of dust in dwarf and giant elliptical galaxies.

HERschel Inventory of The Agents of Galaxy Evolution (HERITAGE) in the Magellanic Clouds

Proposal ID: KPOT_mmeixner_1

Principal Investigator: Margaret Meixner

Time: 238.0 h Priority 1

Category: Local Group galaxies


We propose a uniform survey of the Large Magellanic Cloud (LMC, 8x8.5 degrees), Small Magellanic Cloud (SMC, 5x5 degrees), and the Magellanic bridge (4x3 degrees) in SPIRE 250, 350, 500 um and PACS 100 and 160 um bands, and PACS spectroscopy of key neutral gas regions in order to produce a HERschel Inventory of The Agents of Galaxy Evolution (HERITAGE), the interstellar medium (ISM) and massive stars. Herschel images will provide key insights into the life cycle of galaxies because the far-infrared and submm emission from dust grains is an effective tracer of the coldest ISM dust, the most deeply embedded young stellar objects (YSOs), and the dust ejected over the lifetime of massive stars. The ISM dust map will directly measure dust on a scale size of individual regions (~10pc, ~5-20 K) with column densities >0.85x10^{21} and >6x10^{21} H-atoms cm^{-2} for the LMC and SMC, respectively. Dust emission per beam will be detected for regions with >0.1 Msun at ~25 K, >5 Msun of 10 K. The [CII] 158, [OI] 63, 146 and [NII] 122 um lines in combination with the total far-infrared emission will 1) probe the physical conditions in the warm neutral medium and photodissociation regions, 2) clarify the origin of [CII] emission in low-metallicity galaxies and 3) constrain the physical conditions of the ISM gas required for star formation. HERITAGE will complete 1) the census of massive YSOs down to >4 Msun Class 0 sources and 2) the inventory of dust injected into the ISM by massive evolved stars and supernova remnants (SNRs). The variation in dust properties discerned from the dust maps and the measurements of the main cooling lines of the SNR shocks will quantify their effect on the interstellar grain size distribution. HERITAGE will create an archival data set that promises a lasting legacy to match current LMC and SMC surveys at other wavelengths. HERITAGE will bridge the gap between Herschel studies of the Milky Way and those of nearby galaxies and provide a template for high red shift galaxies.

A Herschel survey of molecular lines in (U)LIRGs: physical conditions, the nature of the power source, and a benchmark for high-z observations

Proposal ID: KPOT_pvanderw_1

Principal Investigator: Paul van der Werf

Time: 100.0 h Priority 1

Category: Active galaxies/ULGs/QSOs


The key diagnostic of the warm star-forming molecular clouds in galaxies is provided by their cooling radiation: [CII] and [OI] lines, but also lines of CO, the main tracer of molecular gas. While in our Galaxy cooling by CO lines is unimportant, this situation is totally different in local ULIRGs, where the CO is an important coolant, and the thermal balance is totally different from that in our Galaxy. These results demonstrate the enormous, as yet almost unexplored, diagnostic power of these lines for probing physical conditions. Since these lines are very luminous, they can be used to probe galaxies out to very high redshifts. Here we propose a systematic study with the SPIRE-FTS and PACS of the principal neutral gas cooling lines ([CII], [OI] and the CO ladder from 5-4 to 13-12) in a 60 micron flux-limited sample of 32 galaxies: 24 LIRGs and 8 ULIRGs. Aims of this key project are: - analysis of the neutral gas cooling budget, in particular the relative importance of CO and [CII] emission; - analysis of the CO rotational ladder to derive the mass of molecular gas as a function of temperature and density; - modeling of the data using advanced PDR/XDR models with the goal of separating UV-excited (starburst) and X-ray excited (AGN) components; - analysis of the implications for molecular mass measurements based on CO lines, both at low and high redshift; - achieving statistical robustness, so that inferences can be made on the infrared galaxy population in general, and trends with other galaxy characteristics (IR luminosity, type of power source,...) can be traced. Only Herschel can provide the necessary high-J CO and cooling line data. Combined with our extensive ground-based data (low-J CO, HCN lines) this dataset will elucidate the energy source and physical conditions in local ULIRGs, and establish the critical link necessary for the interpretation of observations of high-z galaxies in mid-J CO lines and other luminous lines, which will become routine in the ALMA era.

Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel (KINGFISH)

Proposal ID: KPOT_rkennicu_1

Principal Investigator: Robert Kennicutt

Time: 536.6 h Priority 1

Category: Nearby galaxies


We propose the KINGFISH project (Key Insights on Nearby Galaxies: a Far-Infrared Survey with Herschel) of nearby (D<30 Mpc) galaxies mostly drawn from the SINGS sample, which span a large range of star forming (SF) environments found in the nearby Universe. KINGFISH will provide for the first time (1) imaging across the peak of the dust SED at a spatial resolution that matches individual SF complexes, and (2) spectroscopic maps of key diagnostic lines to constrain the cooling and heating processes of the warm neutral medium and the obscured ionized ISM. The PACS and SPIRE imaging from 75 to 500 microns will produce the first comprehensive census of dust in different galactic environments on a spatially resolved basis. KINGFISH's spectral line mapping will sample the full range of SF environments in regions that have already been targeted by SINGS IRS mapping. Leveraging the synergy between imaging and spectroscopy, KINGFISH will provide robust measures of the bolometric luminosity and star formation rates, the mass and spatial distribution of cold dust and the relevance of different heating mechanisms in the energy balance of the dust in distinctly different environments. Measurements of [CII]158 micron, [OI]63 micron, [OIII]88 micron, and [NII]122, 205 micron, will finally provide the diagnostics needed to understand two crucial, but so far ill-understood, components of the star formation and feedback matter cycle: the warm neutral medium and the obscured ionized medium. The analysis and modeling of KINGFISH's imaging and spectroscopy will draw on the unique expertise from the Spitzer SINGS survey at shorter wavelengths. The resulting dataset will be of immense astrophysical power and enormous long-term legacy value, bringing us a crucial step closer to understanding star formation and energy feedback on scales of galaxies. It will also provide an invaluable foundation for interpreting observations of more distant galaxies with Herschel, ALMA, and other facilities.

Cosmology (2)

The Great Observatories Origins Deep Survey : far-infrared imaging with Herschel

Proposal ID: KPOT_delbaz_1

Principal Investigator: David Elbaz

Time: 362.6 h Priority 1

Category: Cosmology/Extra-galactic surveys


The bolometric energy emerging from dusty star formation and active galactic nuclei (AGN) peaks at far-infrared wavelengths, which current deep surveys have barely been able to touch. Prior to Herschel, the best observations have been made at wavelengths that are either too long (submm) or too short (mid-IR) to detect the bulk of this emission. While planned Herschel surveys will advance the study of the most luminous objects, they will not be sensitive enough to explore the typical star forming galaxies from z=1 to 4 as well as to identify obscured AGN. We propose ultra-deep PACS imaging, complemented with SPIRE observations, to push the imaging potential of Herschel to its limits in the GOODS fields where the deepest probes at all other wavelengths are also (and will be) located. The 100 micron capability of PACS is uniquely matched to the needs of observing at or near the peak of redshifted emission from star formation and AGN activity, while avoiding the worst effects of confusion. With the proposed survey we will: (1) resolve most of the cosmic star formation rate density up to z~4 ; (2) determine definitively star formation rates in both IR and UV selected galaxies down to the level where both SFR agree, up to z<1.5 and potentially up to z~4 ; (3) identify the Compton-thick AGN responsible for the missing part of the cosmic X-ray background that remains unresolved in current surveys. Observing two widely separated fields will offset the effects of cosmic variance. The proposed observations will be fully 3 times deeper than the planned GT GOODS-South survey, reaching 0.6 mJy (5 sigma) at 100 micron over 1/3 of each GOODS field. We additionally propose modest PACS and SPIRE imaging to bring the coverage of the complete GOODS-N up to the level of the GT GOODS-S survey. By conducting the proposed survey in the GOODS fields, the resulting dataset will have lasting legacy and archival value.

The Herschel Thousand Degree Survey

Proposal ID: KPOT_seales01_2

Principal Investigator: Stephen Eales

Time: 600.0 h Priority 1

Category: Cosmology/Extra-galactic surveys


We still know little about dust in the nearby universe, because IRAS was only sensitive to the 10% of dust warm enough to radiate in the far-IR, and submm surveys have not covered enough area to sample a representative volume of the local universe. We propose to use Herschel to survery 1000 square degrees in five bands. The survey will detect ~100,000 galaxies at z <0.3, and we will use the results in six key projects: (1) By using the the SDSS and 2dFGRS redshifts that will exist for half the galaxies, we will carry out an unprecedented study of dust and dust-obscured star formation in the nearby universe, determining for example how these depend on Hubble type, metallicity and environment. We will also measure the submm luminosity function, a key benchmark for galaxy evolution models, and test 'down-sizing'models by investigating the cosmic evolution that is known to have occurred over the last 3 billion years. (2) We will detemine the relative contributions of the SZ effect and dusty galaxies in Planck sources, which will make it possible to measure the number-density and bulk flows of clusters in the high-z universe - two fundamental tests of the cosmological paradigm. (3) Using the largest ever sample of gravitational lenses (~1000), we will investigate the evolution of the mass profiles of galaxies, another key test of cosmological models. (4) We will investigate the relationship between the formation of the black holes and stars in quasars by observing the 20,000 SDSS quasars in our fields. (5) By measuring the structure of the submm sky up to a scale of 1000 Mpc, we will estimate the masses of the dark-matter halos containing the far-IR/submm sources. (6) We will carry out the first census of dust and protostars at high galactic latitudes. Our fields are the best-studied large fields in the sky and will be the targets of future surveys with VISTA, VST, UKIRT, SPT and the SKA-precusor telescopes, KAT, ASKAP and LOFAR, and so the survey will be of immense legacy value.