Single- DISH mode

In the single dish mode Millimetron will be aimed mainly at the investigation of the cold matter which is involved in the formation of stars and planets in our and other galaxies, and also at the investigation of numerous atomic and molecular spectral lines.

The formation and evolution of galaxies, stars and planetary systems.

  • The search for the hidden Hydrogen

  • Structure and kinematics of the dense interstellar clouds and star-forming filaments

  • Mechanisms of massive star formation

  • General properties of the interstellar medium in galaxies

  • Photometry and spectroscopic observations of galactic and extragalactic star-forming regions, protostars

  • Determination of parameters of the protoplanetary disks, the search for water

  • Direct observation of cold (T < 30K) exoplanets

  • Photometry of cold white dwarfs

  • Accretion disks in close binary systems

  • Space infrared background and surveys of distant galaxies (z > 1)

Radiation of molecules and atoms in the sub-millimeter range occurs at much lower temperatures than in the optical and infrared ranges. It provides an ability to explore the cold interstellar medium, and in particular, examine the contents of the "hidden hydrogen", practically not radiating directly and detected only by related elements and molecules. The most important spectral lines are transitions HD 112 microns, CII 158 microns, HeH+ 149 microns, series of rotational transitions of CO.

Star formation is associated with the appearance of large amounts of dust emitting in the sub-millimeter range. Modern data obtained using the Herschel Space Telescope shows that star formation occurs in thin (less than 0.1 pc) filaments of gas and dust. The parameters of these filaments are not fully defined, in particular, the role of the magnetic field in their formation is not clarified. To answer this question, we need a higher angular resolution, sensitivity better than Herschel's, and the ability to measure polarization. Options of “Millimetron” meet these criteria. In addition, “Millimetron” contribution to the study of star formation and evolution is associated with the observation of a more distant star-forming regions (including extragalactic), which will bring an opportunity to investigate the initial mass function of stars in a wider range.

During the formation of planetary systems in protoplanetary disks, sub-millimeter observations also provide important information: radiation of HD molecules at wavelengths of 112 and 56 microns, OI at a wavelength of 63 microns presumably will provide an ability to determine the mass of the gas in the protoplanetary disk. Extremely interesting is to determine the position of the "ice line" – the boundary of the water ice in the disk. This requires observation of water lines, for which the Earth's atmosphere is opaque.

27 filaments in which the star formation currently occures in the IC 5146 cloud, based on the images taken by Herschel space observatory. Source: D. Arzoumanian et al., A&A 529, L6 (2011)

Because the star formation process generates dust, galaxies with active star formation are of great luminosity in the sub-millimeter range. This will give an opportunity to “Millimetron” with its high sensitivity to detect galaxies throughout the whole era when they exist, and obtain a complete picture of the evolution of galaxies. To accomplish this goal it is necessary to observe as a continuum (spectral energy distribution), as well as in the spectral lines (CO, CII, OI, etc.). The key parameter here is also the angular resolution. The amount of galaxies with active star formation in the sky is so large that they merge together if the resolution is insufficient. For “Millimetron” which has the main mirror of 10 meters in diameter, this effect is much weaker than for the Herschel and Spica with a mirror diameter of 3.5 m. Preliminary estimation say that “Millimetron” can obtain spectra of not less than 100 000 galaxies, and make observations in the continuum for tens of millions of galaxies. Thus, it will be possible to receive 3 orders of magnitude more scientific information about the evolution of galaxies than it was done by Herschel.

Physics and evolution of solid objects in the Solar system, our own and other galaxies, the manifestations of life and mind.

  • Dust in nearby galaxies

  • Production of dust in star-forming regions

  • Sub-millimeter observations of asteroids and comets of the solar system

  • Search for Dyson sphere candidates

Observations with Herschel observatory and other sub-millimeter and infrared telescopes has shown that there is dust even in the places where its presence had not been expected: in the elliptical galaxies, where it supposed to be destroyed, in the periphery of galactic disks far away from star-forming regions. These findings raised new questions about the mechanism of dust formation and spreading. To answer these questions the new high-sensitivity observations are required, as for weak dust on the galaxies periphery, as well as for protostellar and protoplanetary objects. The main research method is the obtaining of the spectral energy distributions over images of galaxies and nearby objects; the key requirement is the high accuracy of the calibration, which provides small systematic errors.

“Millimetron” opportunities should be sufficient for the detection of radiation from dust clouds of 1 mass of the Sun at a distance of 1 Mpc (at a cloud temperature of 20K), or 10-8 solar masses at a distance of 100 pc.

The submillimeter observatory in space will give valuable information about the properties of the Solar system bodies, chiefly about atmospheres of the planets, the distribution of water and the transneptunian objects.

The formation and evolution of supermassive black holes, dark matter and dark energy.

  • Sunyaev-Zeldovich effect for clusters of galaxies

  • Small-scale anisotropy of the cosmic microwave background (CMB) radiation

  • Parameters of active sub-millimeter galactic nuclei

  • Large-scale structure of the Universe at z> 2

  • Gravitational lensing of distant galaxies

  • Jet physics

The study of clusters of galaxies using thermal and kinetic Sunyaev-Zeldovich effect will provide constraints on the parameters of the cosmological model, including the parameters that characterize the evolution of the dark energy. Also by observing the polarization of the Sunyaev-Zeldovich effect it is planned to measure the quadruple component of the CMB anisotropy from the point of view of an observer located in the cluster, i.e., from different places of the Universe. This will finally solve the "problem of the quadruple" of modern measurements of the CMB anisotropy.

The mechanism of formation of supermassive black holes in the centers of galaxies is still not determined. According to modern observations, objects with mass of a billion masses of Sun already existed less than one billion years after the Big Bang, and only 300-500 million years later than the formation of the first stars. Sub-millimeter observations of spectral lines allow us to study black holes in the accretion process – active galactic nuclei (AGN). Moreover, in contrast to the optical and near-infrared range, in which the study of AGN can significantly (or even completely) absorbed, the sub-millimeter range can get an accurate estimate of the black hole energy. “Millimetron” can study co-evolution of black holes and galaxies. Unlike its predecessors, only for “Millimetron” will be available typical (not only outstandingly bright) objects for almost of the entire epoch of the evolution of galaxies.

Obtaining spectra of a large number of galaxies for the first time will help building three-dimensional catalogs of galaxies at redshifts z > 2 and investigate the evolution of large-scale distribution of dark matter in the epoch when the Universe was less than three billion years old. “Millimetron” can fill the gap in information on this subject between the epoch of recombination (300,000 years) and existing three-dimensional directories (3-13 billion years).

Besides the interferometer mode, important information about the immediate vicinity of black holes can be obtained by another method – by observing extreme Faraday rotation generated by strong magnetic field near the black hole. Such observations do not require high angular resolution and can be carried out in single dish mode, but it requires a very high sensitivity (to allocate a very small fraction of the polarized signal).

The first objects in the Universe, the first stars and galaxies, primordial black holes, wormholes and Multiverse.

  • Spectroscopic observations of the most distant galaxies, search for the first galaxies containing Population III stars

  • Search for afterglows of gamma -ray bursts and determination of their energy

  • Search for the possible manifestations of primordial black holes, wormholes

First stars (Population III) and galaxies were formed from substance which is not enriched in heavy elements. Observations of such objects are not only important for testing of star formation theories, but also is a key for answering the question about the origin of supermassive black holes. Sub-millimeter spectral line observations of carbon monoxide, oxygen and other elements measure the abundance of heavy elements in galaxies, so observations of distant galaxies in future optical and infrared telescopes such as JWST and WISH must be accompanied by sub-millimeter observations with very high sensitivity. In this case, the lack of detection in the sub-millimeter range would mean the discovery of potentially primordial object. The main advantage of “Millimetron” for this task is the high sensitivity and absence of atmosphere that will allow observing all possible spectral lines.

Possible detection of the HeH+ ion emission line in the spectrum of a distant quasar with redshift z=6.42. Source: I. Zinchenko, V. Dubrovich, C. Henkel “A search for HeH+ and CH in a high-redshift QSO”, MNRAS 415, L78-L80 (2011).

The gamma-ray bursts (GRBs) are studied much less than the supernovae. Particularly, it is difficult to investigate GRBs at high redshift (z > 5), due to the fact that optical radiation may undergo strong absorption on its way to the observer. But at the same time, distant objects are also the most interesting, since they can be associated with hypothetical explosions of the first stars. Sub-millimeter observations of gamma-ray bursts afterglows provide the possibility to avoid absorption and to define the energy of the explosion better, as well as to determine the exact coordinates on the sky for guidance of powerful optical telescopes. Currently, more than 50 similar observations were conducted on ground-based submillimeter observatories. High sensitivity of “Millimetron” will give an opportunity to observe weaker and therefore more frequent or more distant afterglows.

Study of the structure of the magnetic field in the vicinity of black holes using Faraday rotation will test the effects predicted by the theory of wormholes and verify the existence of these objects.