Large Latin American Millimeter Array

Large Latin American Millimeter Array
	The site for the LLAMA telescope
Alternative names	LLAMA
Location(s)	Puna de Atacama, San Antonio de los Cobres, Salta, Argentina
Coordinates	24°11′31″S 66°28′29″W / 24.19206°S 66.47483°W
Organization	Argentine Institute of Radio Astronomy; University of São Paulo
Altitude	4,820 m (15,810 ft)
Wavelength	35, 1,000 GHz (8.57, 0.30 mm)
Built	July 2014–
Telescope style	Cassegrain reflector; radio telescope
Diameter	12 m (39 ft 4 in)
Focal length	4.8 m (15 ft 9 in)
Mounting	altazimuth mount
Website	www.llamaobservatory.org
	Location of Large Latin American Millimeter Array
	Related media on Commons
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The Large Latin American Millimeter Array (LLAMA) is a single-dish 12 m

Very Large Base Line Interferometry

or to work in standalone mode. Financial support is provided by the Argentinian and Brazilian governments. The total cost of construction, around US$20 million, and operation as well as the telescope time use will be shared equally by the two countries. Construction planning started in July 2014 after the formal signature of an agreement between the main institutions involved.

Overview

LLAMA is a joint project between Argentinian and Brazilian Astronomers to build and operate a radio telescope at submillimeter wavelengths, that can work in stand alone mode or join a

cryogenic

receivers with very high sensitivity in order to observe very faint sources, and filters to observe the Sun.

History

The history of the instrument can be traced back to 2007, during the XII Latin American Regional IAU Meeting (LARIM)

Universidade de São Paulo (USP), was signed in June 2014, and on July 9, it was formally presented to the public.^[7]

Measurements of the electrical characteristics of the site were carried out in late 2016, and construction of the road to the summit began in December 2016.[8] Assembly of the antenna is planned to take place in 2022, with testing beginning in 2023.^[9]

Origin of the name

The observatory acronym comes from the Quechuan word llama that designates the South American camelid that lives in the region where the telescope is being installed. There is some confusion with the word array, since LLAMA will consist of a single dish antenna, but the instrument will have VLBI technology and can therefore be part of an antenna array with telescopes of other observatories. Moreover, the LLAMA observatory can be expanded in the future by installing other antennas in different sites.

In different official documents the acronym LLAMA may be found expanded as Long Latin American Millimeter Array rather than Large. It is also possible to read Millimetric instead of Millimeter. After some debate, the LLAMA Executive Committee stated that Large Latin American Millimeter Array is the right expansion for the LLAMA acronym.^[10]

The observatory logo has as symbols the

which?

] page is the official logo since August 2014.

Science

LLAMA is a multipurpose instrument, with the capacity to both observe bright sources like the Sun, and very weak sources very far from Earth. The following is a list of different subjects that will be addressed with LLAMA observations.

The Sun

In the unperturbed solar atmosphere, the shorter the wavelength the deeper the observation. Frequencies near the submillimeter range are produced in the lower

Solar Flares at high frequencies with a high sensitive instrument will give clues about the acceleration of the high energetic particles in the Sun, complementing results obtained with the Solar Submillimeter Telescope. In particular the still unexplained spectral inversion above ≈ 100 GHz.^[13]

A possible experiment would be to make VLBI solar observations. For example, in a joint observation between LLAMA and some of the ALMA antennas, a spatial resolution of 0.001" would be achieved for λ ≈ 1 mm, corresponding to a distance of 700 m on the solar surface.

Planets

Extra-solar planetary systems around stars near the Sun.
Proto-planetary disks in star located in the Solar neighborhood.
Near-Earth objects.

Stellar objects

Star forming regions, young stellar objects, and mechanisms of the star formation.
Non-thermal processes in stellar magnetospheres.
Interaction of stars and remnants of supernova with the interstellar medium.

Astrophysical jets and maser emission

Astrophysical jets.
Maser phenomena of the recombination lines of the hydrogen atom.
Maser emission in star-forming regions.
Maser emission in late stars stellar envelopes.

Galactic and Intergalactic interstellar medium

Continuum radiation from extragalactic cold dust.
Molecular material in the direction of different stellar objects.
Intergalactic Medium using the detection of molecular absorption lines in the direction of quasars.
Cosmic background radiation.

Galaxies

Search for CO in galaxies with high redshift.
Molecular abundance.
Active Galactic Nuclei (AGN).
Variation of the fundamental constants by the observation of gravitational lensing.
High redshifts of regions with very high rate of star formation.
Proto-clusters of galaxies.
Space-time distortion produced by massive black holes.

High energies

Optics, Receivers

The Nasmyth optics will allow the installation of up to as six different

heterodyne receivers. There is a consensus for these receivers to use the same spectral bands as ALMA.^[14]

With this scheme the Nasmyth cabins will allocate receivers for the bands

#	Frequency Band [GHz]	Wavelength Band [mm]
1	35 - 50	8.6 - 6.0
3	84 - 116	3.6 - 2.6
5	162 - 211	1.9 - 1.4
6	211 - 275	1.4 - 1.1
7	275 - 373	1.1 - 0.8
9	602 - 720	0.5 - 0.4

It is intended to install a

heterodyne

array.

References

^ 12th LARIM, 2007
^ Mirabel, I.F, Arnal, M.E., Morras, R., Romero, G, Proyecto Latinoamericano de Astronomía en Argentina, 2008, presented during the Annual Meeting of the Astronomical Argentinian Association
^ Arnal,E.M, Morras, R., García Lambas, D.G., Recabarren P., ¿Dónde instalamos el telescopio?, Revista Ciencia Hoy, 19, 110, Abril-Mayo, 2009
^ Bareilles, F., Opacidad al cénit a 210 GHz (tipper)
^ XVII IAU GA, Rio de Janeiro, 3-14 Aug 2009
^ Mirabel, I.F, Arnal, E.M., Morras, R., Romero, G., Lepine, J.R.D., Abraham, Z., de Gouveia Dal Pino, E., Long Latin American Millimeter Array,pdf Archived 2014-08-19 at the Wayback Machine)
^ Jesús Rodríguez, Diario Clarín, Buenos Aires, 9 July 2014, accessed on 15 August 2014
^ LLAMA site at Alto Chorrillos. LLAMA News #2, Feb. 2017. https://www.llamaobservatory.org/LLAMA_newsletter_n_2.pdf. Retrieved 24 September 2018.
^ LLAMA Overview. LLAMA News #3, June 2021. https://www.llamaobservatory.org/sobre/LLAMA_news_en_3_2021.pdf. Retrieved 6 March 2022. "LLAMA News #2" (PDF). 2022-03-06. Archived (PDF) from the original on 2022-03-06. Retrieved 2022-03-06.
^ LLAMA Executive Committee Meeting, May 2014, La Plata (personal communication)
^ De la Luz, V, Lara, A., Raulin, J.-P., Synthetic spectra of radio, millimeter, sub-millimeter, and infrared regimes with non-local thermodynamic equilibrium approximation, Astrophys. J., 737, 1 (2011)
^ Silva, A. V. et al., Diffuse Component Spectra of Solar Active Regions at Submillimeter Wavelengths, Solar Phys., 227,261 (2005)
^ Kaufmann, P et al. , A new solar burst spectral component emitting only in the Terahertz range, Astrophys. J. 603, L121 (2004)
^ ALMA frequency bands

[1] 12th LARIM, 2007

[2] Mirabel, I.F, Arnal, M.E., Morras, R., Romero, G, Proyecto Latinoamericano de Astronomía en Argentina, 2008, presented during the Annual Meeting of the Astronomical Argentinian Association

[3] Arnal,E.M, Morras, R., García Lambas, D.G., Recabarren P., ¿Dónde instalamos el telescopio?, Revista Ciencia Hoy, 19, 110, Abril-Mayo, 2009

[4] Bareilles, F., Opacidad al cénit a 210 GHz (tipper)

[5] XVII IAU GA, Rio de Janeiro, 3-14 Aug 2009

[6] Mirabel, I.F, Arnal, E.M., Morras, R., Romero, G., Lepine, J.R.D., Abraham, Z., de Gouveia Dal Pino, E., Long Latin American Millimeter Array,pdf Archived 2014-08-19 at the Wayback Machine)

[7] Jesús Rodríguez, Diario Clarín, Buenos Aires, 9 July 2014, accessed on 15 August 2014

[8] LLAMA site at Alto Chorrillos. LLAMA News #2, Feb. 2017. https://www.llamaobservatory.org/LLAMA_newsletter_n_2.pdf. Retrieved 24 September 2018.

[9] LLAMA Overview. LLAMA News #3, June 2021. https://www.llamaobservatory.org/sobre/LLAMA_news_en_3_2021.pdf. Retrieved 6 March 2022. "LLAMA News #2" (PDF). 2022-03-06. Archived (PDF) from the original on 2022-03-06. Retrieved 2022-03-06.

[10] LLAMA Executive Committee Meeting, May 2014, La Plata (personal communication)

[11] De la Luz, V, Lara, A., Raulin, J.-P., Synthetic spectra of radio, millimeter, sub-millimeter, and infrared regimes with non-local thermodynamic equilibrium approximation, Astrophys. J., 737, 1 (2011)

[12] Silva, A. V. et al., Diffuse Component Spectra of Solar Active Regions at Submillimeter Wavelengths, Solar Phys., 227,261 (2005)

[13] Kaufmann, P et al. , A new solar burst spectral component emitting only in the Terahertz range, Astrophys. J. 603, L121 (2004)

[14] ALMA frequency bands

[7]

[9]

[10]

[13]

[14]