145 citations · 1.3k across the 43 of their papers we have counts for
45 papers
Corona Australis 151: an extremely young protostar
E. Redaelli, S. Spezzano, P. Caselli +9
Context. Prestellar cores are the birthplace of stars and planetary systems, but they are short-lived objects, since the initial stages of dense core evolution, collapse, and the f…
MIAO-ALMA: Shocks and Protostellar Outflows in 70 m-dark clumps with 1 /
Shuting Lin, Siyi Feng, Junzhi Wang +16
To investigate the initial conditions of high-mass star-forming regions, we use SiO (2-1) emission to trace early shock-related kinematics toward sixteen 70 m-dark and massive c…
A tale of two isotopes: Spatial variation in HCN fractionation toward young cores
Sigurd S. Jensen, Silvia Spezzano, Olli Sipilä +3
Context. Isotopic fractionation can serve as a powerful tracer of the chemical evolution during star and planet formation. To accurately interpret observations, it is crucial to id…
High C/C isotopic ratios toward G+0.693-0.027: evidence for gas inflow to the Central Molecular Zone
L. Colzi, O. Sipilä, I. Jiménez-Serra +4
Isotopic ratios are key tracers of Galactic chemical evolution because different isotopes are synthesized through distinct stellar nucleosynthesis processes. While the C/$^{…
Tracing the sulfur depletion in starless and pre-stellar cores
L. Schöller, S. Spezzano, O. Sipilä +4
Sulfur is one of the most abundant elements in the Universe, yet the sulfur budget inferred from the observed sulfur-bearing molecules in dense cores is significantly lower than ex…
Modeling the UV-photon irradiation of CS-bearing ices in the laboratory with the pyRate gas-grain astrochemical code. New insights into the missing sulfur problem
O. Sipilä, R. Martín-Doménech, W. Riedel +4
Observations indicate that the total abundance of S-bearing species in dense clouds is orders of magnitude lower than the cosmic sulfur abundance. Addressing this "missing sulfur p…
Using astrochemical models to simulate reactivity experiments on cold surfaces
Valeriia Sokolova, Basile Husquinet, Stephan Diana +7
The development of molecular complexity during stellar and planetary formation owes much to the interaction of gas and dust. When the first astrochemical models including solid-sta…
Deuterium fractionation and CO depletion in Barnard 5
Igor Petrashkevich, Anna Punanova, Paola Caselli +3
Deuterium fractionation provides a key diagnostic of the physical and chemical evolution of prestellar and protostellar cores, where it is strongly linked to CO depletion in cold,…
High sensitivity molecular line observations towards the L1544 pre-stellar core challenge current models
J. Ferrer Asensio, S. S. Jensen, S. Spezzano +4
The increased sensitivity and spectral resolution of observed spectra towards the pre-stellar core L1544 are challenging the current physical and chemical models. With the aim of f…
Cl+ and HCl+ in Reaction with H2 and Isotopologues: A Glance into H Abstraction and Indirect Exchange at Astrophysical Conditions
Miguel Jiménez-Redondo, Olli Sipilä, Robin Dahl +2
Astrochemical models of interstellar clouds, the sites of stars, and planet formation require information about spin-state chemistry to allow quantitative comparison with spectrosc…
Fractionation in young cores: Direct determinations of nitrogen and carbon fractionation in HCN
S. S. Jensen, S. Spezzano, P. Caselli +4
We aim to determine the N/N and C/C ratios for HCN in six starless and prestellar cores and compare the results between the direct method using radiativ…
Combined model for , , and spin-state chemistry in molecular clouds
O. Sipilä, L. Colzi, E. Roueff +3
We present a new gas-grain chemical model for the combined isotopic fractionation of carbon and nitrogen in molecular clouds, in which the isotope chemistry of carbon and nitrogen…
Modelling Deuterated Isotopologues of Methanol toward the Pre-Stellar Core L1544
W. Riedel, O. Sipilä, E. Redaelli +4
Aims. We aim to improve a previous model for the prediction of column densities and deuterium fractions of non- and singly deuterated methanol. Thereby, we try to identify crucial…
Similar levels of deuteration in the pre-stellar core L1544 and the protostellar core HH211
K. Giers, S. Spezzano, P. Caselli +6
In the centre of pre-stellar cores, deuterium fractionation is enhanced due to the low temperatures and high densities. Therefore, the chemistry of deuterated molecules can be used…
First detection of deuterated methylidyne (CD) in the interstellar medium
Arshia M. Jacob, Karl M. Menten, Friedrich Wyrowski +1
While the abundance of elemental deuterium is relatively low (D/H ~ a few 1E-5), orders of magnitude higher D/H abundance ratios have been found for many interstellar molecules, en…
A large (~1 pc) contracting envelope around the prestellar core L1544
E. Redaelli, A. Chacón-Tanarro, P. Caselli +4
Prestellar cores, the birthplace of Sun-like stars, form from the fragmentation of the filamentary structure that composes molecular clouds, from which they must inherit at least p…
Chemistry and dynamics of the prestellar core L1544
O. Sipilä, P. Caselli, E. Redaelli +1
We aim to quantify the effect of chemistry on the infall velocity in the prestellar core L1544. Previous observational studies have found evidence for double-peaked line profiles f…
A Survey of Deuterated Ammonia in the Cepheus Star-Forming Region L1251
Maria Galloway-Sprietsma, Yancy L. Shirley, James Di Francesco +4
Understanding the chemical processes during starless core and prestellar core evolution is an important step in understanding the initial stages of star and disk formation. This pr…
Deuteration of c-CH towards the pre-stellar core L1544
K. Giers, S. Spezzano, F. Alves +7
Context: In the centre of pre-stellar cores, the deuterium fractionation is enhanced due to the cold temperatures and high densities. Therefore, the chemistry of deuterated molecul…
An Interferometric View of H-MM1. I. Direct Observation of NH3 Depletion
Jaime E. Pineda, Jorma Harju, Paola Caselli +14
Spectral lines of ammonia, NH, are useful probes of the physical conditions in dense molecular cloud cores. In addition to advantages in spectroscopy, ammonia has also been sug…
The Central 1000 au of a Pre-stellar Core Revealed with ALMA. II. Almost Complete Freeze-out
Paola Caselli, Jaime E. Pineda, Olli Sipilä +18
Pre-stellar cores represent the initial conditions in the process of star and planet formation. Their low temperatures (10 K) allow the formation of thick icy dust mantles, whic…
A Revised Description of the Cosmic Ray-Induced Desorption of Interstellar Ices
O. Sipilä, K. Silsbee, P. Caselli
Non-thermal desorption of ices on interstellar grains is required to explain observations of molecules that are not synthesized efficiently in the gas phase in cold dense clouds. P…
The chemical structure of young high-mass star-forming clumps: (II) parsec-scale CO depletion and deuterium fraction of
S. Feng, D. Li, P. Caselli +19
The physical and chemical properties of cold and dense molecular clouds are key to understanding how stars form. Using the IRAM 30 m and NRO 45 m telescopes, we carried out a Multi…
First detection of NHD and ND in the interstellar medium
M. Melosso, L. Bizzocchi, O. Sipilä +7
Deuterium fractionation processes in the interstellar medium (ISM) have been shown to be highly efficient in the family of nitrogen hydrides. To date, observations were limited to…